You just have to find a comparable turbo with the same specs. A 7875 china is ( almost) same as a precision, garret or whatever and use their map. It will be closer than you think
I like the way that you made it so simple like you are an elementary school teacher. I was thought compressor maps in the uni in a much more complicated way. I think that it's going to help a lot of people.
Compressor maps are very cool, its a very useful way to do comparisons and compressors have improved very substantially from the humble garret T04. It would helpful if turbos had maps for the exhaust turbine section also, because that also affects the ability to drive the compressor.
This is starting to be more common…we need more info on regulating boost through the intake pipe using a DBW TB and speed sensor would love too see a demo on that
Thank you! Thank you! Thank you! I've always been baffled by these compressor maps. Your Super Richie cheat code really helped me to see at a glance what that turbo efficiency map means in layman's terms. Keep up the great work Richard, I always enjoy your videos and content.
Great Stuff!! I wish more turbo manufacturers would provide maps. Very informative session! Thanks for the content! The tips and tricks make it easier to look at the maps.
From my experience, it's a bit of trial and error. You have to run the turbo and measure the exhaust manifold pressure to see if the turbine AR ratio is too small. You really don't want more than double your boost pressure. 15psi intake, 30psi exhaust is getting really restrictive. Gotta increase the AR.
You handed me an epiphany, The vertical numbers reflect manifold absolute pressure in Barre`s where 1 is sea-level atmospheric pressure. Now I understand some what better. Great video!
Great video, Richard! I've looked at compressor maps before, so I already had a fair understanding of them, but I was still able to learn from your video. I really like the 10 hp per lb/min of airflow rule of thumb. In my opinion, that's an excellent way to have a better understanding of a map without having to do a lot of math. One question that I have though is, in your example with the engine that was way too small for the size of turbo, wouldn't it have trouble getting the turbo to even spool to the boost levels needed? Id think throttle response would be enough of a reason to stay away from oversizing a compressor like that. I suppose a lot of turbo response depends on the turbine (hot) side of the turbo, which I don't understand near as well. In the future do you think you could do a similar type of video talking about sizing a hot side for a turbo (size, A/R, etc)?
@@richardholdener1727 in relation to what he mentioned about the a/r , what gives most people a headache is to decide between a bigger turbine wheel and smaller a/r or smaller turbine wheel and bigger a/r . I am talking for exactly the same compressor.
@user-vw1vf5cw7d I think that's been a longstanding question because, as we've been seeing lately, it depends on the given turbo/combo. Some turbos, like the Xona with the UHF turbine wheels, are really liking a smaller than usual AR and still at surprisingly low backpressure even when maxing out the compressor wheel in some cases. It's been eye opening how much real world difference there has been with turbines/housings designed around each other and just well designed stuff in general and blade/housing spacing etc. There are still rules of thumb to get a good idea and real world results from others to hone in further, but even if a test was done on one combination (which would be cool as hell to see) where it is apples to apples, it still probably wouldn't apply across the board.
@@mattmorrison6958 I would ask for something pretty standard that many people can relate too. So what is most typical. I would say the standard Garrett GT series with the cast compressor which have been to the market for many years now and many people are familiar with, so they can have a point of reference. Then someone can make his comparisons with other turbochargers of Garrett or others, having this test as a point reference. Of course between turbochargers they are real differences that they affect performance. Mitsubishi is something similar with what you just mentioned, with their 12/11 Blade turbines (instead of 9 blades) and generally smaller a/r they would have a similar top end with an equivalent GT series Garrett.
You're doing petrol head God's work Richard! You should be proud of what you are providing this community! You're my fav watch before sleep over here in cold Swe. (67 Camaro with turbo LS2 in the works) :-)
And in one video you've inadvertently explained the exact situation that drives the need for compound boost! Low N/A airflow relative to target airflow. Staging the turbos keeps you down inside the compressor map.
Well worded. You use a small turbo in its range to amplify the motors total flow... Which then makes it acceptable to run a bigger turbo on the, already turbo'd combination.
This works for superchargers as well. I spent some time a couple months back plotting this for the Vortech choices I was looking at for my Ford 363. Respectively, plotting desired hp and psi relative to rpm. The best efficiency range for the plotted line, the Supercharger essentially chose itself. Keeping the unit as small as possible for response, but as big as possible for the desired power goals.
If you don't have a compressor map you can always measure Pressure and temp before/after the comp, and calculate the compressor efficiency, to better understand if you work it in a good running point.
Pressure Ratio Calculation Gauge Pressure+Atmoshperic Pressure/Atmospheric Pressure (minus 1psi if using air filter) Example would be at Sea Level running 20psi 20psi+14.7psi/13.7psi = 2.53 for pressure ratio...
Have you also noticed that peak efficiency is usually also peak torque? That's what I've seen. Not always true but usually is for a good NA motor with a flat torque curve in the power band. I like to take the NA dyno numbers every 1,000rpm, put those points on the bottom of the map, double them, put them on the 2.0 line, then draw lines between the dots, and continue the line to the top of the map. Really nice and easy to read. Looks kind of like your fingers spread out.
These maps are often representing motor/crank hp correct? so inflating the intersection point for both axis a bit (10-15%) will give you a better idea for whp when picking a turbo. I was just explaining compressor maps to a friend last month as his turbo size for his power goal and engine size is perfect right now but he wants a new goal that pushes it well beyond the efficiency islands. He wasnt too happy. Had to tell him he can still make the power but the air is going to be getting heated even more
yesssir! I just shared this video with a customer lol, I was trying to explain to him that on a twin turbo set up on his 5th gen its ok to go with 55mm to 67 mm turbos from percision. If the flow on the turbos are there it will make the power he wants 800 hp lol Thanks again richard!!!
Hello again! What about in a compound setup? Will the bigger turbo see the engine and the small high pressure turbo as one unit? Let's an engine make 150hp na, when receiving 1 bar from the small turbo the big turbo will see it like a 300hp na engine? I was asking that to myself on not necessarly a big high horsepower engine but maybe on a setup to reduce turbo lag to minimum Thanks in advance
Love the video Richard! Very easy to get a rough estimate this way. I do have some questions! I'm currently looking for turbos for my NA ka24de that I mainly use for drifting. Im looking for a turbo that would be a bit more future proof as i plan to run just about 14.7psi at first to get around the 300-310hp (crank) mark. Then later down the line when i rebuild the engine with stronger internals I'll want to be able to go to around 500hp max. So it would be nice to find a turbo that works inbetween those guide lines. So I was currently comparing the gtx3067r, gtx3071r gen2, g25-660 and g30-660. (I will probably go for a Pulsar equivalent, although it might not be everyones first choice) But what i noticed was that most compressor maps are for just one turbine housing AR ratio, but they have another very simple looking map with 3 lines representing the different AR ratios you can get. How do you use those? Say you look at the gtx3067r AR60 map, it would be too small for my needs, but the AR82 might be better suited? Im just not sure how to combine those maps! If you think you know what turbo to use for my particular setup, feel free to chip in! For the higher hp I might also get cams and other supporting mods, which would lower the amount of boosg needed to achieve the same goals, right?
I would like a follow up video showing the math/logic/whatever on the airflow to horsepower relationship and converting from one to the other, ending with why its "about 10:1"
A major thing I consider when going through compressor maps is trying to run the engine without an intercooler. If I can get the combination to be happy without an intercooler, what it really means is my combination will be really resistant to heat-soak once I finally do get an intercooler set up figured out.
@@richardholdener1727 I approximate things like idling and burnouts as running without an intercooler. It's my way of trying to keep temperatures down. If I'm in the middle of the map, then it's that much easier for the intercooler to get the temps down.
I've been doing a lot of reading on turbo sizing lately. Everyone seems to focus on compressor maps but I feel like turbine sizing and ar has a lot to do with the general performance of the turbo and where it makes power. At least intuitively anyways. I would think a smaller turbine and AR would spool the turbo quicker (i.e. get it flowing more air sooner) but choke the power output up top as the turbine can only flow so much exhaust. I know people talk about peak hp numbers but for my setup (atlas 4200 + ar5) im looking for something that would make for a fun driver. I'm more interested in a big usable torque curve vs. big hp numbers, and have yet to find a video that caters towards that kind of build.
Yes you are right, turbomatching was part of my profession for many years at a OEM. We spent alot of time on the turbine side, its very important since thats where you get all the drive energy from. And turbines can be very different in their characteristics, so you need something that suits your flow and pulsation characteristics for your engine and torque curve demands. Sadly turbine maps and detailed data is never shared for after market stuff, but its not always easy to evaluate either without some decent simulation tools.
can you run some tests on how much timing efficiency is lost to heat? maybe put some heaters on the heads. I ask because many OEM cars loose allot of power in warm weather and i feel the aftermarket underrates this..i do see tuners remove timing in hot engines but how much is enough? i feel more than 2deg is needed?
Ok I somewhat understand compressor maps now but I’ll have to speak with someone to better understand fully but I get the idea, I’ll like to have some insights on my set up and if my turbo is out of efficiency at the boost level at the moment I have a 2.0 motor that’s fully built with 280/288 cams,10.5.1 compression, 2600cc injectors, running a 10569 xona and I made 700hp on a mustang dyno at 36psi but I want to push this turbo to 50psi so would that put the turbo outside of the efficiency level ? Or how efficient is it running at the moment ?
Let's say I have a 400hp na motor and I want 1000 hp. I also want the 78 percent efficient but that seems like it would be a way over sized turbo. Is efficiency range not as important as final hp numbers. What are the benefits to being more efficient and where does that intersect with turbo performance/turbo lag?
Richard - Let me throw a variable at you regarding this. Say instead of a single turbo you want to run twins(c'mon you know 2 is always better than 1 and in the spirit of Richie Rich's "is always way more fun") and to keep it simple lets say they are going on a V8 that makes 450HP total NA and your end goal is to make 1500hp. So in order to get you there you have to take the NA horsepower and divide it by 2 so that would mean each half of the engine should in theory make 225HP, correct? and the number you should calculate the NA horsepower required to get to the right sized turbos needed for the combined total horsepower you're trying to achieve at the best possible efficiency on the map, correct? So concluding the end goal is 1500HP that would be 750hp per side or per turbo @225HP per side NA on a gt45 compressor map x2 (twin turbos) or 7.5#/min of corrected air flow at a pressure ratio of 2.25 has me dead center line and at the lower third of the 78% efficiency band. I dont think that tracks my Motor HP NA = 450hp/2(2 banks on a V8)=225hp So 750hp per turbo / 225hp from each bank of the motor gives me a PR Vale of 3.333 / 2 turbo's= 1.6667PR), correct or am i missing something?(i think i'm messing up the PR value by dividing it a second time by 2 because i added a second turbo to the mix). Let me know where i am screwing up the equation Thanks! Rick
Don't divide the pressure ratio by two because you have twins. They are running in parallel and pumping into a manifold at the same pressure. Flow is divided by two, not pressure.
Richard holdener So please tell me if I understand this If I had a 500 horsepower motor and I wanted 850 On this compressor map that would put me at 1.7 boost ratio and 85 on the pounds per hour putting me well outside of the map However, if I was only moving 42.5 lb at 1.7, that would put me very close to the 78% Does that mean I would need two of these? Turbos to divide the pounds of 85
I guess the better question is, how do you figure out the size turbo, if you're going to run twin turbos instead of a single turbo. And you want them to both live as much time as you can in the efficiency area
This is why people need to build their tuning around mass airflow, there's a reason every OE EFI system uses one. Speed density is a trap unless you know exactly what you're looking at. So many aftermarket ECUs push speed density because it's "easy" it's a real disservice to their customers.
A maf is another part to fail which does fail, it’s another restriction point and most maf systems will max out at low boost unless you enlarge the tube, then when you enlarge the tube, you lose accuracy and it just pits you right back where you were in speed density and it adds to the chasing your tail. The only thing you might add is fuel mileage. Maybe. I haven’t seen difference either way tho. I tried using the maf to get better fuel mileage and it didn’t do any different. I ditched the maf years ago on boosted vehicles and never looked back.
The OEMs use MAF because it is better at adapting to wear/tear of the engine (and thus, VE) over 100s of thousands of miles - something which is less important to tuner cars with built engines. In exchange, MAP/speed density gives us less inlet restriction and easier intake plumbing. Last, not all OEMs use MAF. Chrysler, for example rarely uses MAF. I've tuned a lot of MAP EFI systems - it works great and never once have I thought "gee, I wish this were MAF"...
What really confuses me is how some engines are WAAAY past the surge line, like the guys who run S480s on 4G63s and make well above 1,000 horsepower on an engine that would only make 130-150ish horsepower N/A, but as far as I know they aren't blowing up turbos. What am I missing?
@@richardholdener1727 Still kinda going over my head, is it not a problem because the hot side is so big that they don't create boost low enough to cause surge?
If the turbo is only 78% efficient at its highest eff. island. How is it doubling the NA hp at 1 bar? Wouldn't it have to be 100% efficient to double the power at 1 bar? Even with a 10% eff gain from intercooling (which usually isn't seen) you'd still be shy of doubling the factory NA hp. Yet we see in many dyno's that the motor sometimes makes more than double the NA power per bar? It all seems very contradicting.
you are confusing correlation to causal relationships. The efficiency of the impeller design does not mean it will increase the power level by the same amount. The flow rate does that
How can this relate when looking at supercharger maps given that are mechanically driven. Are the RPM lines on the map not as relevant? Example I have a Vortech Si, making 10.5psi @7000rpm, 622hp at the wheels on a Dart 363. When I use this method I'm at around 40,000 rpm on the map, but I'm actually running my impeller at 48,000 Where do I factor this in?
@@richardholdener1727 It’s directly on their site. I post a link and it keeps getting taken down. Just google Vortech SI compressor map and it’ll come up first hit.
Please help Hey Richard, I have a LQ9 turbo LS with cheap eBay hyp pistons, what RPM is “peak torque” so I quit blasting rings and lands apart ? Trickflow trackmax .595 lift 238/242 Wondering what area on the Holley timing table to pull timing and when to add it back with only a butt dyno and being too broke to pay for any tuning Thanks
I watched a lot of the 6liter cam test videos and the torque curve is so flat with that big comp cam you’ve done a bunch of testing with I assume mine is similar and basically the torque never drops off more then 50ft lbs until 6k rpm
Is removing timing around peak torque actually say higher timing number under 4500 rpm then is dips until 6000 ? Trying to get a grasp of “removing timing around peak torque”
@@richardholdener1727 e85 now , treadstone? It’s a decent air to air intercooler, knocked a couple pistons apart on pump gas 10psi and 18-19 degrees timing , car normally runs pump 91-93 octane not the E85 that’s in it now. Twin mirror image vs racing 67/62’s journal bearing turbos, 3400 yank stall, 3.50 gear , 29inch tall tire, snake eater 1000 injectors, fuel pressure been good on a single 450 pump, I know I need to install a 2nd one for running e85 and any real amount of boost like 15psi or more. Just don’t want to hurt the pistons again . DA is normally 5000 to 7000 I’m at 4000ft elevation. Heavy car, it’s a 70 Chevelle , 9” rear, 4l80 trans . Just learning to tune terminator x myself doing street pulls.
1000hp turbo on too small of motor not only that the turbo won’t spool Even if you did the turbine would have to be too small and not flowing enough you won’t make any power cause you never get into the compressor efficiency island. This is because you can’t get the exhaust out of the cylinders
@@richardholdener1727 hi, what’s the closest to the RS3 turbo charger spec? From what it seems, loom like a borg Warner spec turbo, but I can’t say for certain
That's a hard ask. I couldn't find anything in the Garrett catalog that meets that requirement. Something like the old GT2252 or GT2860RS are sized appropriately for that power range, but aren't rated for that high of a pressure ratio. You're at least on the map for a GTX2860R GEN II, but are well outside the efficiency island, and approaching the surge line. Unless you can live with one or the other of the above situations, you'll want to either drop your HP expectations, or modify the engine to make more NA horsepower to begin with. By the way, what engine are you working with that only has 65 HP NA? (240 HP/3.7 PR) A motorcycle or a kei car?
@Joel_E g10 suzuki came in chevy sprint and geo metro in the USA. Rest of the world got the suzuki cultus. With a cam head porting and intake work makes 68 wheel hp
@@freyja4954 oh, okay. I've driven a vehicle with a Suzuki G10, and can certainly see why you'd want some more power. Keep in mind when you're looking at airflow and horsepower that the compressor maps are based on flywheel, not whp. The turbo doesn't know anything about driveline loss, since it only flows air. If you're looking for 240 WHP, you need to be looking at closer to 28 lb/hr (280 flywheel HP) on the compressor map, and the GTX2860R Gen II starts to become a more reasonable choice.
if you feel hard to understand,just make the explanation backwards..... just think you have a spesific turbo,and open the compressor map...just think what engine is suitable for my turbo 😂 just look at efficiency range,and look the horsepower you want,and boost you want,and than choose your engine based on that,you will understand what you need
It's cool info but in the real world it's not very helpful sadly. Because many manufacturers dont publish maps and most people don't know the airflow capability of their engine anyway. Also it ALL ignores the arguably more important (in the real world) conversation of the turbine wheel. Much more effective approach is to just observe results of very similar combos which is easy these days due to channels like this one👍
It is very helpful to the customer, however many people even if they know how to read the basics of a compressor map they struggle to understand how it translates as performance differences in their cars. The usual stories of guys that paid a lot of money to swap their GT and GTXs for GTXg2 and Gs only to find out that the gains were marginal at best and sometimes even worse.
But wait my Chinese turbo doesn't even have a compressor map.
Yet it works just fine...
lolololol
🤡🔫 hand over the maps and nobody gets hurt, Procharger
Neither does Precision ))
You just have to find a comparable turbo with the same specs. A 7875 china is ( almost) same as a precision, garret or whatever and use their map. It will be closer than you think
I like the way that you made it so simple like you are an elementary school teacher. I was thought compressor maps in the uni in a much more complicated way. I think that it's going to help a lot of people.
I was actually trying to learn about compressor maps the other day so this video couldn’t be better timed. Long live the turbo!
love the Suzuki motor reference. I'm actually watching this trying to decide for a small turbo for my geo metro. lol
Match Bot is fun to play with. The turbine side is where the magic happens though.
Good stuff
Compressor maps are very cool, its a very useful way to do comparisons and compressors have improved very substantially from the humble garret T04. It would helpful if turbos had maps for the exhaust turbine section also, because that also affects the ability to drive the compressor.
I have heard a lot of explanations of how to read a compressor map, but it never clicked until now, thank you.
This is starting to be more common…we need more info on regulating boost through the intake pipe using a DBW TB and speed sensor
would love too see a demo on that
Thank you. You are the first person that I have ever seen that has simplified the map to be understandable to someone like me,lol
Wow I feel like all adventures into boosting to engine should start with this
Thank you! Thank you! Thank you! I've always been baffled by these compressor maps. Your Super Richie cheat code really helped me to see at a glance what that turbo efficiency map means in layman's terms. Keep up the great work Richard, I always enjoy your videos and content.
Great Stuff!! I wish more turbo manufacturers would provide maps. Very informative session! Thanks for the content! The tips and tricks make it easier to look at the maps.
Garrett turbo has a tool on their website
Very good simple explanation, now a video on turbine sizing and turbine AR would be very helpful. Thanks
From my experience, it's a bit of trial and error. You have to run the turbo and measure the exhaust manifold pressure to see if the turbine AR ratio is too small.
You really don't want more than double your boost pressure. 15psi intake, 30psi exhaust is getting really restrictive. Gotta increase the AR.
Yes, but the AR and turbine sizing can be calculated
You the man Richard! By far the most useful gearhead channel. Now if we can just get a video on converting a carb to blow through hint hint 😂
IKR
Great way to get a grasp on compressor maps and immediately put them to use. Really wish this info was around back in the day! Great stuff
You handed me an epiphany, The vertical numbers reflect manifold absolute pressure in Barre`s where 1 is sea-level atmospheric pressure. Now I understand some what better. Great video!
Great video, Richard! I've looked at compressor maps before, so I already had a fair understanding of them, but I was still able to learn from your video. I really like the 10 hp per lb/min of airflow rule of thumb. In my opinion, that's an excellent way to have a better understanding of a map without having to do a lot of math.
One question that I have though is, in your example with the engine that was way too small for the size of turbo, wouldn't it have trouble getting the turbo to even spool to the boost levels needed? Id think throttle response would be enough of a reason to stay away from oversizing a compressor like that.
I suppose a lot of turbo response depends on the turbine (hot) side of the turbo, which I don't understand near as well. In the future do you think you could do a similar type of video talking about sizing a hot side for a turbo (size, A/R, etc)?
the 100-hp would also never spool this turbo-it was just an extreme example to make a point about surge
@@richardholdener1727 in relation to what he mentioned about the a/r , what gives most people a headache is to decide between a bigger turbine wheel and smaller a/r or smaller turbine wheel and bigger a/r . I am talking for exactly the same compressor.
@user-vw1vf5cw7d I think that's been a longstanding question because, as we've been seeing lately, it depends on the given turbo/combo. Some turbos, like the Xona with the UHF turbine wheels, are really liking a smaller than usual AR and still at surprisingly low backpressure even when maxing out the compressor wheel in some cases. It's been eye opening how much real world difference there has been with turbines/housings designed around each other and just well designed stuff in general and blade/housing spacing etc. There are still rules of thumb to get a good idea and real world results from others to hone in further, but even if a test was done on one combination (which would be cool as hell to see) where it is apples to apples, it still probably wouldn't apply across the board.
@@mattmorrison6958 I would ask for something pretty standard that many people can relate too. So what is most typical. I would say the standard Garrett GT series with the cast compressor which have been to the market for many years now and many people are familiar with, so they can have a point of reference. Then someone can make his comparisons with other turbochargers of Garrett or others, having this test as a point reference. Of course between turbochargers they are real differences that they affect performance. Mitsubishi is something similar with what you just mentioned, with their 12/11 Blade turbines (instead of 9 blades) and generally smaller a/r they would have a similar top end with an equivalent GT series Garrett.
Thanks again Richard. I really loved this master class on compressor maps.
Super educational richard! Thanks as always
Thanks for a great explanation and solid examples!
Great video!! Thanks! Totally helped me!
Excellent guidance 🙏🏼🙏🏼🙏🏼 easiest one I've seen 👌🏼👌🏼👌🏼👌🏼
Brilliant, thought i was the only person that did this. i kinda picked it up sizing pumps for bulk water pipelines .
That's great info thanks.makes it easier to shop for a turbo
I wish i saw this video yesterday. Got lucky and bought a decently sized turbo just guessing lol
You're doing petrol head God's work Richard! You should be proud of what you are providing this community! You're my fav watch before sleep over here in cold Swe. (67 Camaro with turbo LS2 in the works) :-)
Great explain i think 3 or 4 years looking for this
Great video. Thank you.
Thanks for this, Richard
And in one video you've inadvertently explained the exact situation that drives the need for compound boost! Low N/A airflow relative to target airflow. Staging the turbos keeps you down inside the compressor map.
Well worded. You use a small turbo in its range to amplify the motors total flow...
Which then makes it acceptable to run a bigger turbo on the, already turbo'd combination.
Bro, what a nice explanation 👏
Nice that you mentioned match bot. That thing works pretty good.
Thank you!
This works for superchargers as well. I spent some time a couple months back plotting this for the Vortech choices I was looking at for my Ford 363.
Respectively, plotting desired hp and psi relative to rpm. The best efficiency range for the plotted line, the Supercharger essentially chose itself. Keeping the unit as small as possible for response, but as big as possible for the desired power goals.
Very informative 👍
Really helpful but, as mentioned in another comment, EBay turbos typically don't provide this information. Thanks, Richard. Well done.
If you don't have a compressor map you can always measure Pressure and temp before/after the comp, and calculate the compressor efficiency, to better understand if you work it in a good running point.
Great video. How would the flow/HP scale work out for diesel?
makes so much sence.
Damn, it all makes sense now
Excellent
Pressure Ratio Calculation
Gauge Pressure+Atmoshperic Pressure/Atmospheric Pressure (minus 1psi if using air filter)
Example would be at Sea Level running 20psi
20psi+14.7psi/13.7psi = 2.53 for pressure ratio...
I'd love a video on more of the maths behind all of this :)
Part two exhaust flow choose the proper exhaust housing
So , how do you plot the map for a twin turbo setup? I am planning to use a pair of Holeset H1Cs on my Vortec 350 with a blow through carb.
Have you also noticed that peak efficiency is usually also peak torque? That's what I've seen. Not always true but usually is for a good NA motor with a flat torque curve in the power band.
I like to take the NA dyno numbers every 1,000rpm, put those points on the bottom of the map, double them, put them on the 2.0 line, then draw lines between the dots, and continue the line to the top of the map. Really nice and easy to read. Looks kind of like your fingers spread out.
there is no rpm reference on the compressor map
@@richardholdener1727 I'm saying plot the engines HP output every 1,000 rpm. I wish I could show what I mean.
These maps are often representing motor/crank hp correct? so inflating the intersection point for both axis a bit (10-15%) will give you a better idea for whp when picking a turbo. I was just explaining compressor maps to a friend last month as his turbo size for his power goal and engine size is perfect right now but he wants a new goal that pushes it well beyond the efficiency islands. He wasnt too happy. Had to tell him he can still make the power but the air is going to be getting heated even more
yesssir! I just shared this video with a customer lol, I was trying to explain to him that on a twin turbo set up on his 5th gen its ok to go with 55mm to 67 mm turbos from percision. If the flow on the turbos are there it will make the power he wants 800 hp lol Thanks again richard!!!
Camaro?
Hello again!
What about in a compound setup? Will the bigger turbo see the engine and the small high pressure turbo as one unit? Let's an engine make 150hp na, when receiving 1 bar from the small turbo the big turbo will see it like a 300hp na engine? I was asking that to myself on not necessarly a big high horsepower engine but maybe on a setup to reduce turbo lag to minimum
Thanks in advance
Very helpful breaking it down like that. Now only if all the crap i can afford actually had maps. 😮
Love the video Richard! Very easy to get a rough estimate this way. I do have some questions!
I'm currently looking for turbos for my NA ka24de that I mainly use for drifting. Im looking for a turbo that would be a bit more future proof as i plan to run just about 14.7psi at first to get around the 300-310hp (crank) mark.
Then later down the line when i rebuild the engine with stronger internals I'll want to be able to go to around 500hp max. So it would be nice to find a turbo that works inbetween those guide lines.
So I was currently comparing the gtx3067r, gtx3071r gen2, g25-660 and g30-660. (I will probably go for a Pulsar equivalent, although it might not be everyones first choice)
But what i noticed was that most compressor maps are for just one turbine housing AR ratio, but they have another very simple looking map with 3 lines representing the different AR ratios you can get. How do you use those?
Say you look at the gtx3067r AR60 map, it would be too small for my needs, but the AR82 might be better suited? Im just not sure how to combine those maps!
If you think you know what turbo to use for my particular setup, feel free to chip in! For the higher hp I might also get cams and other supporting mods, which would lower the amount of boosg needed to achieve the same goals, right?
a GT3076 (the cheap ones) will do what you want
I would like a follow up video showing the math/logic/whatever on the airflow to horsepower relationship and converting from one to the other, ending with why its "about 10:1"
Big bang turbo! Let's see what happens if you surge it😂
How do you spec out twin turbos? Do you half the horsepower/flow and then look at Compressor maps for 1/2 the total power/flow?
So I’m assuming if you wanted to run twins you would divide your numbers in half?
Is it fair to say that surge is the limit to compressor back pressure?
Thanks!!! Great shortcuts....can you speak to boost lag and what side of the map will be a better responding turbo?
smaller turbo and hot side will be more responsive
A major thing I consider when going through compressor maps is trying to run the engine without an intercooler. If I can get the combination to be happy without an intercooler, what it really means is my combination will be really resistant to heat-soak once I finally do get an intercooler set up figured out.
an intercooler will always help and a compressor map has no effect on heat soak
@@richardholdener1727 I approximate things like idling and burnouts as running without an intercooler. It's my way of trying to keep temperatures down. If I'm in the middle of the map, then it's that much easier for the intercooler to get the temps down.
I've been doing a lot of reading on turbo sizing lately. Everyone seems to focus on compressor maps but I feel like turbine sizing and ar has a lot to do with the general performance of the turbo and where it makes power. At least intuitively anyways. I would think a smaller turbine and AR would spool the turbo quicker (i.e. get it flowing more air sooner) but choke the power output up top as the turbine can only flow so much exhaust.
I know people talk about peak hp numbers but for my setup (atlas 4200 + ar5) im looking for something that would make for a fun driver. I'm more interested in a big usable torque curve vs. big hp numbers, and have yet to find a video that caters towards that kind of build.
Check out the borg match calculator. Works really well for dialing in the right ar for your application.
Yes you are right, turbomatching was part of my profession for many years at a OEM. We spent alot of time on the turbine side, its very important since thats where you get all the drive energy from. And turbines can be very different in their characteristics, so you need something that suits your flow and pulsation characteristics for your engine and torque curve demands. Sadly turbine maps and detailed data is never shared for after market stuff, but its not always easy to evaluate either without some decent simulation tools.
Can convert m3/s to lbs/m have Mitsubishi compressor map in m3/sec.
can you run some tests on how much timing efficiency is lost to heat? maybe put some heaters on the heads. I ask because many OEM cars loose allot of power in warm weather and i feel the aftermarket underrates this..i do see tuners remove timing in hot engines but how much is enough?
i feel more than 2deg is needed?
timing lost to heat?
How vnt affect map? How to optimize vane control?
Tell us about calculation for twin turbo,biturbo and two-stage turbo.And I am from Serbia,so can you use metric units,as well?Thank you.
easier for you to tell me the desired power output
Ok I somewhat understand compressor maps now but I’ll have to speak with someone to better understand fully but I get the idea, I’ll like to have some insights on my set up and if my turbo is out of efficiency at the boost level at the moment I have a 2.0 motor that’s fully built with 280/288 cams,10.5.1 compression, 2600cc injectors, running a 10569 xona and I made 700hp on a mustang dyno at 36psi but I want to push this turbo to 50psi so would that put the turbo outside of the efficiency level ? Or how efficient is it running at the moment ?
do you have a map of that turbo and is it still on the map at that pressure ratio?
Let's say I have a 400hp na motor and I want 1000 hp. I also want the 78 percent efficient but that seems like it would be a way over sized turbo. Is efficiency range not as important as final hp numbers. What are the benefits to being more efficient and where does that intersect with turbo performance/turbo lag?
just get a 1000+ hp turbo (don't worry about the 78%)
Richard rocks harder that Rammstein.
Richard - Let me throw a variable at you regarding this. Say instead of a single turbo you want to run twins(c'mon you know 2 is always better than 1 and in the spirit of Richie Rich's "is always way more fun") and to keep it simple lets say they are going on a V8 that makes 450HP total NA and your end goal is to make 1500hp. So in order to get you there you have to take the NA horsepower and divide it by 2 so that would mean each half of the engine should in theory make 225HP, correct? and the number you should calculate the NA horsepower required to get to the right sized turbos needed for the combined total horsepower you're trying to achieve at the best possible efficiency on the map, correct? So concluding the end goal is 1500HP that would be 750hp per side or per turbo @225HP per side NA on a gt45 compressor map x2 (twin turbos) or 7.5#/min of corrected air flow at a pressure ratio of 2.25 has me dead center line and at the lower third of the 78% efficiency band. I dont think that tracks my Motor HP NA = 450hp/2(2 banks on a V8)=225hp So 750hp per turbo / 225hp from each bank of the motor gives me a PR Vale of 3.333 / 2 turbo's= 1.6667PR), correct or am i missing something?(i think i'm messing up the PR value by dividing it a second time by 2 because i added a second turbo to the mix). Let me know where i am screwing up the equation Thanks! Rick
Don't divide the pressure ratio by two because you have twins. They are running in parallel and pumping into a manifold at the same pressure. Flow is divided by two, not pressure.
Andy is correct-don't divide the PR
Richard holdener
So please tell me if I understand this
If I had a 500 horsepower motor and I wanted 850
On this compressor map that would put me at 1.7 boost ratio and 85 on the pounds per hour putting me well outside of the map
However, if I was only moving 42.5 lb at 1.7, that would put me very close to the 78%
Does that mean I would need two of these? Turbos to divide the pounds of 85
this turbo would be fine at 800 hp starting with 500 hp-it's just a low position on the compressor map (But I have run that)
I guess the better question is, how do you figure out the size turbo, if you're going to run twin turbos instead of a single turbo. And you want them to both live as much time as you can in the efficiency area
Doesefficiency change the compressor charge temp?
yes-to a minor extent-not nearly as much as changes in boost pressure
Are compressor Mabs then useless if you want to pick out twin turbos or how was that done?
works the same way
Have you a video on how to calculate exhaust housing A/r?
THE AR IS USUALLY PROVIDED BY THE TURBO MANUFACTURER
@@richardholdener1727 I mean how to choose one?
What’s a vs 7875 flow like 100 lbs?
the Gen 2 should be near that
This is why people need to build their tuning around mass airflow, there's a reason every OE EFI system uses one. Speed density is a trap unless you know exactly what you're looking at. So many aftermarket ECUs push speed density because it's "easy" it's a real disservice to their customers.
Speed density plus air temp equals mass flow. OEMs like redundancy and accuracy that's why they have both
A maf is another part to fail which does fail, it’s another restriction point and most maf systems will max out at low boost unless you enlarge the tube, then when you enlarge the tube, you lose accuracy and it just pits you right back where you were in speed density and it adds to the chasing your tail. The only thing you might add is fuel mileage. Maybe. I haven’t seen difference either way tho. I tried using the maf to get better fuel mileage and it didn’t do any different. I ditched the maf years ago on boosted vehicles and never looked back.
The OEMs use MAF because it is better at adapting to wear/tear of the engine (and thus, VE) over 100s of thousands of miles - something which is less important to tuner cars with built engines. In exchange, MAP/speed density gives us less inlet restriction and easier intake plumbing. Last, not all OEMs use MAF. Chrysler, for example rarely uses MAF. I've tuned a lot of MAP EFI systems - it works great and never once have I thought "gee, I wish this were MAF"...
@@GroovesAndLands truth.
Has anyone made a map for the gt35 and gt45 turbos
How is the equation affected/changed when using a twin set up?
2 500-hp turbos make 1000 hp
There's 2 liter engines making 2000 hp. IDK how many of those use a compound setup
Your face at 16:14 😂
What really confuses me is how some engines are WAAAY past the surge line, like the guys who run S480s on 4G63s and make well above 1,000 horsepower on an engine that would only make 130-150ish horsepower N/A, but as far as I know they aren't blowing up turbos. What am I missing?
the concern for surge line would be during spool up
@@richardholdener1727 Still kinda going over my head, is it not a problem because the hot side is so big that they don't create boost low enough to cause surge?
So the more efficient the faster the spool time?
no, efficiency has little to do with spool time
If the turbo is only 78% efficient at its highest eff. island. How is it doubling the NA hp at 1 bar? Wouldn't it have to be 100% efficient to double the power at 1 bar? Even with a 10% eff gain from intercooling (which usually isn't seen) you'd still be shy of doubling the factory NA hp. Yet we see in many dyno's that the motor sometimes makes more than double the NA power per bar? It all seems very contradicting.
you are confusing correlation to causal relationships. The efficiency of the impeller design does not mean it will increase the power level by the same amount. The flow rate does that
Thank you verry muuch. Now can you do it with twins ahahahha
Twins are exactly the same. You just doubled the Inducer area and you can use a single turbo map or a TwinTurbo map will be exactly. the same.
2 500-hp turbos makes 1000 hp (very simple)
How can this relate when looking at supercharger maps given that are mechanically driven. Are the RPM lines on the map not as relevant? Example I have a Vortech Si, making 10.5psi @7000rpm, 622hp at the wheels on a Dart 363. When I use this method I'm at around 40,000 rpm on the map, but I'm actually running my impeller at 48,000 Where do I factor this in?
do you have a Vortech compressor map?
@@richardholdener1727 It’s directly on their site. I post a link and it keeps getting taken down. Just google Vortech SI compressor map and it’ll come up first hit.
So then would twin s475 be a bad idea on a 520 bb due to under 3k rpm it’s all in surge???
twin s475s are 2000 hp worth of turbo-do you want that and what is the starting na power?
@@richardholdener1727 400 na power and only 1500whp for now was thinking of giving my self room to grow
Please help
Hey Richard, I have a LQ9 turbo LS with cheap eBay hyp pistons, what RPM is “peak torque” so I quit blasting rings and lands apart ?
Trickflow trackmax
.595 lift 238/242
Wondering what area on the Holley timing table to pull timing and when to add it back with only a butt dyno and being too broke to pay for any tuning
Thanks
I watched a lot of the 6liter cam test videos and the torque curve is so flat with that big comp cam you’ve done a bunch of testing with I assume mine is similar and basically the torque never drops off more then 50ft lbs until 6k rpm
Is removing timing around peak torque actually say higher timing number under 4500 rpm then is dips until 6000 ? Trying to get a grasp of “removing timing around peak torque”
let's start with how much timing you have at WOT, how much boost? and what fuel? is it intercooled?
@@richardholdener1727 e85 now , treadstone? It’s a decent air to air intercooler, knocked a couple pistons apart on pump gas 10psi and 18-19 degrees timing , car normally runs pump 91-93 octane not the E85 that’s in it now. Twin mirror image vs racing 67/62’s journal bearing turbos, 3400 yank stall, 3.50 gear , 29inch tall tire, snake eater 1000 injectors, fuel pressure been good on a single 450 pump, I know I need to install a 2nd one for running e85 and any real amount of boost like 15psi or more. Just don’t want to hurt the pistons again . DA is normally 5000 to 7000 I’m at 4000ft elevation. Heavy car, it’s a 70 Chevelle , 9” rear, 4l80 trans . Just learning to tune terminator x myself doing street pulls.
1000hp turbo on too small of motor not only that the turbo won’t spool Even if you did the turbine would have to be too small and not flowing enough you won’t make any power cause you never get into the compressor efficiency island. This is because you can’t get the exhaust out of the cylinders
What about a turbo replacement (for a factory turbo engine)...?😅
if it has a map, we can then read it
@@richardholdener1727 I don't know...😅
It's the EJ257 in my 2018 WRX STI !
How does having twins vs a single effect this? Half the flow for each turbo?
2 500-hp turbos make 1000 hp
@@richardholdener1727 so half the flow of the total power per turbo, makes sense. Thanks!
@@richardholdener1727 no change to the pressure ratio side? (Y axis)
I have search the internet and can find the compressor map for the audi rs3 2.5T charger, could u perhaps assist.
there may not be one avail
@@richardholdener1727 hi, what’s the closest to the RS3 turbo charger spec? From what it seems, loom like a borg Warner spec turbo, but I can’t say for certain
couldn't pressure ratio be expressed as [(14.7*ratio) - 14.7] therefore at a boost ratio of 2.0, that's 14.7psi on youer boost gauge.
👍💪
May the boost be with you!
Eat the squirrels!
RIP Justin Sane
Turns bc up to 24.7
171702 compressor map
Wouldn't 1.0 be 14.7 if its 1 atmosphere? 2.0 would be 29.4 because thats 14.7 x 2.0?
1.0 on the map is 14.7 psi above atmospheric pressure
@@richardholdener1727 oh I see now. Do you have to tune the ecm first then put on a turbo? Or put on a turbo, data log then do ecm tune? If you know.
lbs/m is a heinous units lol, why not kg/s SI units lol
Now if i could only find a magic turbo that is most eficant aroud 24 lb/min at a 3.7 presure ratio lol
Garrett might have that
That's a hard ask. I couldn't find anything in the Garrett catalog that meets that requirement. Something like the old GT2252 or GT2860RS are sized appropriately for that power range, but aren't rated for that high of a pressure ratio. You're at least on the map for a GTX2860R GEN II, but are well outside the efficiency island, and approaching the surge line. Unless you can live with one or the other of the above situations, you'll want to either drop your HP expectations, or modify the engine to make more NA horsepower to begin with.
By the way, what engine are you working with that only has 65 HP NA? (240 HP/3.7 PR) A motorcycle or a kei car?
@Joel_E g10 suzuki came in chevy sprint and geo metro in the USA. Rest of the world got the suzuki cultus. With a cam head porting and intake work makes 68 wheel hp
@@freyja4954 oh, okay. I've driven a vehicle with a Suzuki G10, and can certainly see why you'd want some more power.
Keep in mind when you're looking at airflow and horsepower that the compressor maps are based on flywheel, not whp. The turbo doesn't know anything about driveline loss, since it only flows air. If you're looking for 240 WHP, you need to be looking at closer to 28 lb/hr (280 flywheel HP) on the compressor map, and the GTX2860R Gen II starts to become a more reasonable choice.
Low horsepower = 1 GT45
High horsepower = 2 GT45s
if you feel hard to understand,just make the explanation backwards.....
just think you have a spesific turbo,and open the compressor map...just think what engine is suitable for my turbo 😂 just look at efficiency range,and look the horsepower you want,and boost you want,and than choose your engine based on that,you will understand what you need
It's cool info but in the real world it's not very helpful sadly. Because many manufacturers dont publish maps and most people don't know the airflow capability of their engine anyway. Also it ALL ignores the arguably more important (in the real world) conversation of the turbine wheel. Much more effective approach is to just observe results of very similar combos which is easy these days due to channels like this one👍
It is very helpful to the customer, however many people even if they know how to read the basics of a compressor map they struggle to understand how it translates as performance differences in their cars. The usual stories of guys that paid a lot of money to swap their GT and GTXs for GTXg2 and Gs only to find out that the gains were marginal at best and sometimes even worse.