DYNO RUN: C4 GRAND SPORT ... did GM criminally underrate these motors? (yes)
Vložit
- čas přidán 22. 05. 2024
- There are a lot of rumors online that GM underrated the 1996 LT4 motor so it wouldn't embarrass the new LS1 that came in 1997. Add this dyno session to the pile of evidence. Test was done at a local shop Shogun Speed in Colorado Springs, CO (6200'). Corrected for sea level, it produced ~317 RWHP (~250 RWHP at test conditions). I talk a bit about dyno testing, expectations, and how to interpret the results to the best of my ability. I've never done a dyno session before and am NOT AN EXPERT. All comments and thoughts are welcome. Cheers!
Links:
LT4 testing data: www.corvetteactioncenter.com/...
LT4 dyno results from other owners: www.grandsportregistry.com/dy...
LT4 vs. LT1 website: www.grandsportregistry.com/lt...
LT4 vs. LT1 video: • Viewer Requested: 1996...
Timestamps:
00:00 Intro and why I'm doing this
01:35 Expectations
03:00 About LT4 motor
05:36 Getting to the shop
06:09 Run #1
07:56 Run #2
09:04 Run #3
09:48 Results on screen
10:05 Running rich?
11:21 Conclusions
14:54 New parts
#chevy #c4 #corvette #grandsport #c4grandsport #LT4 #corvettegrandsport #grandsportcorvette #dyno #dynotest #WOT #morepowahbaby
TBH, the C4's have been neglected since C5, C6, C7. They have started to get some love again with the release of the C8.
This is well said. The late C4's are arguably super cars; however, the C5 stole the show (understandably).
I love the look, style of the c4s.. especially the ‘96 Gs.. my era of rides!
Man i miss the 90's like crazy. When this stuff was latest and greatest! Stuff nowdays has WAY too much electronics and unnecessary bs. I love my 20+ year-old vehicles
@@Ballen1182 yeah, I had a ‘91 Iroc run mid-low 12s back then.. I have my late uncles stock ‘87 grand national (he purchased new) with 57.xxx on the dash, I’ve had since the late 90’s.
@@scarface9617 nice! I had a 91 rs with the 305 and 5spd. White with red interior. Hard top and no options. Miss that car a lot 😔 it was totalled in a rearending back in 2005. Then got a 95 z28, then a 98 trans am m6 with ttops which i severely regret selling now lol
@@Ballen1182 I liked the 305 5spd.. that’s weird, I also have my (late brothers) blk. ‘02 ram air, ws6, tops, 6spd. factory short-throw shifter with 34,xxx on the dash, it and the ‘87 gn are 1 owner cars purchased new by family!
@@scarface9617 very cool!! Cherish both! I'm sure you do. I'm now pretty content with my '00 z28 with ls6 intake and 6spd. Was damn glad to have one 4th gen again after 7 years! Mint cond for $13k, not too bad. And sorry for your loss bro
Nice , cool to see a C4 getting some love. I own a 1990 ZR-1 , after hearing all the negative crap about C4s over the years , I have come to my own conclusion about these cars. They are well engineered machines that are light years ahead of the C3s. Every car ever built has a particular issue, maybe even a few. The C4 had growing pains for sure but by say 86-88 the C4 was well sorted. I really enjoy driving my C4 and drive her I do , I have put 7k miles on my Z since 2020. No mechanical issues at all , fun cars to drive and you rarely see C4s on the road.
Enjoyed your video , very nice example you have , will be watching your progress. Subbed.👍👍🏁🏁
have you ever run it down the 1/4et?
I had an 87 with 34,000 on the clock when I got it. Never had a problem with it. I sold it at 125+k miles. Loved it. It had full bolt ons and it eventually ran 14.0 quarter mile.
My 6speed 1997 z28 was rated at 285hp and I dynoed it stock, and it put down 281hp. The lt1s were definitely under rated.
Thanks for your video man. I’m currently in the middle of modifying my LT4 love your GrandSport man wish I had one!
Thank you! I actually just sold it this weekend. I have a few videos in the can I need to upload so feel free to subscribe. I can't promise frequent uploads like the "real channels" but I forsee another LT4 in my future... maybe one I'll feel comfortable modifying like you! What are you working on?
I’m having Callies build me an ultra light forged 383 stroker crank rods and pistons. The configuration I’m going with is really hard to find so I’m having Callies build it from scratch. It’s not cheap but it’s the only way to get it. Bump stick is just a GM hot cam. Going with AFR heads full C&C porting. Stainless full length headers and all titanium pipes and muffler to the back. No cats. And dropping rear end gears down to next ratio. My wife is probably going to leave me😂
Beautiful car and great video! Lots of and good information… I have learned a few things myself! I own a 96 LT4 which I rescued. I have a long list of performance parts that I will be installing. I have two episodes on this car in my CZcams channel and I plan on doing more episodes soon.
The c4 is so under appreciated. I have a 95 ZR-1 and my dad has a 96 GS. Both extremely fun to drive and just the right amount of performance for the street. The styling has aged well and climbing down into the jet fighter cockpit never gets old. The GS is so eye catching and the ZR-1 is sound perfection all the way up to the 7200 RPM red line. Growing up in the 90's the C4 was a dream car for me and to this day it's my favorite generation Vette.
agreed! I will likely get another C4 in the future. GS left the garage a few months ago but the itch never leaves... lol
This time maybe try a ZR-1. They just feel extra special and have a more exotic sound with the 4 cams. They pull like a freight train in the higher RPM where the LT4 starts gasping for breath. My buddy has a 03 Z06 and from a 50 roll my 95 ZR-1 stayed right along side him. Both cars are stock. I was pretty surprised by that. Also the LT5 responds really well to mods and lots of the owners mod them so it doesn't hurt the value. It hurts the wallet though as the go fast parts/labor can get pretty pricey.
@@MrNeon2002 Best track times will be shifting just above 6k...7k its doing nothing but creating heat. Had one also
Great looking car for sure. Would love too have one so clean! Can't wait to follow along with this build 🚀
Awesome! I clicked the link you provided to see the details of the improvements/differences of engine components in the LT4 vs the LT1.........very impressive. Gorgeous car!!!
Biggest difference between secind generation LT-4 and LT-1 is in the heads intake and cam. Hte intake runners are raised in the casting and shorter straight shot for better high RPM flow, along with the LT-4 hotcam....
I have a 1985 Corvette rated for 230hp and 330 ft lbs, with things like EGR/Air pump deleted, with a stock cam/ stock headers/ stock intake, it put down 262 HP and 368 Ft lbs of torque at the rear wheels. Definitely underrated
I'veeeeeee been WAITING for this for a long long time!!
Here we go🤟🏾. You’ve just gained a follower buddy. I’m looking for a 96 c4 manual as I write. Was looking between lt1 and lt4. Obviously lt4 has more power but was curious with possibly same bolt ons what would be the outcome. Like if it was 420 vs 450 hp would it matter that much to get lt4 car. Anyway I’m definitely gonna be watching you buddy. Also when you do povs on the highway please let us know what rpm your cruising at in 5 and 6 gear for us guys that do a lot of highway miles. Appreciate you buddy.
closest race I ever had was a stock 2018 335i with 2 people in it. The lt4 was always a factory freak.
Always loved those GS great numbers. with 12:8 to 13:1 A/F Ratio it will gain some good power too.
I own a 96 GS too and suspect you’re right… GM really underrated the LT4 to avoid any disappointment when releasing the LS1.
I did a few simple mods to mine: Corsa exhaust, SLP blackwing cold air intake, and a throttle body flow booster air foil. Kept all the original parts but I sure enjoy the improved sound. I suspect there’s more power there now but haven’t had it on the dyno to confirm.
Thanks for sharing your work and results!!
Cool video man. Mine made 342whp after some bolt on mods with a mustang dyno. You can see my page for a little acceleration run. Glad you did this test! Fun car !
I had a 2001 Camaro SS with just a catback that made 3 runs on dyno 330ish RWHP. We could not believe it. I knew it ran great.
Awsome vid!
Great video. I have a 96 LT4 base coupe myself. I did the hotcam, headers and tune among a few other things. Car definitely pulls hard with hotcam. Noticeable more mid-range and top end power.
Love to hear it. I actually just listed this GS for sale yesterday, and see myself getting a base LT4 in the future that either has the hot cam already, or is a worthy donor. I even see GS's with the hot cam for sale here and there and they actually go for LESS MONEY which is hilarious. Maybe I'll find me one of those. Cheers and thanks for the details!
Nice man I'm trying to build a lt4
Beautiful car man ive had ten c4s qnd just finally Got the 90 ZR1
Makes sense now. In the early 2000’s I had an 03 mustang GT with some mods. Probably a little over 300 hp. I remember the first time I drove my dad’s C4 six speed thinking they should be “ about the same” (330hp?) lol…yeah… not even in the same galaxy of horsepower. I was like… this thing is much closer to 430. WAY faster than my mustang.
A chassis dyno test typically includes approximately 15% losses due to drivetrain friction. With the numbers you are reporting this would translate to about 365 on a good properly calibrated engine dyno. Of course this assumes the chassis dyno calibration has been checked recently to be correct and good accurate numbers for temperature, humidity and elevation above sea level was entered for the correction factor value into the dyno to report accurate corrected horsepower and torque numbers for the test location and weather conditions for that day.
11.x afr on na is great!! Rich afr is safe! Awesome car, and red interior😎. Love the car. I plan on the exact same mods for my 96 lt4 ce as well. Hotcam and longtubes. Already has a corsa with no resonator.
Thanks, after some looking around I have to agree. I bet a that hot cam really changes the personality of the car! Do you recall what it took to get that installed, or did the car come with it?
@@HoffmansHoopties Haven't done those mods yet. I was just saying I want that cam and longtubes.
That C4 Grand Sport on the dyno sounds like the Battlestar Galactica entering warp speed.
Sell the exhaust clip to an EV engineer, so they can at least "sound" like a sports car. I've ridden in a Plaid only once; if I heard that while doing warp speed, it would of sounded mean and added to the whole "experience".
BTW, my daily driver is an '04 C5. It's modified too, BTR cam, Kooks headers, other engine upgrades, parts, gaskets, seals, etc. I don't care about messing with the resale value. Not a garage queen with 412hp; this Vette will "hit a lick" upon the unsuspecting who care to.
Thanks for uploading the vid, the GS is special.
Put the muffler eliminator kit on then got the rest straight piped on my c4 LT1. It sounds great. Sounds like what a Corvette should. Actually no drone and very quiet when cruising
Yep I’ve been dragging ass on uploading but I installed the same kit last month and it’s absolutely perfect
@@HoffmansHoopties I am not a fan of attracting attention. Quiet is nice. If car is not cammed then it sounds like somebody took the mufflers off a stock car.... Too bad GM didn't install the "Hot cam" from the factory. It would've made more power than the great ZR-1... and they knew it lol...
@@tommyteeth5874 Stock cars that are loud are comical.
Better to be stealthy about things no unwanted attention
Catbacks dont do much anyways.
Cool video. We have an LT4 we paid $2750 for. My 16yo daughter wanted to try drifting at our local track so we bought this car which was sitting outside with a leaky rear hatch seal. It was disgusting with the mold and mildew. She removed the entire interior and cleaned. Even threw away the seats. She is replacing all the weatherstripping. We have decided not to trash it and make a drift car. She learned stick on it and has been driving it a few times a week. From about a 40 roll it pulled out on a newer SRT-8 Jeep (non S/C). Gotta love the high revving motor... great bang for the buck.
That's awesome!
They aren’t Slow!
The C4 is a good project car but not a good drift car just look at the E-brake it’s all tucked away not ideal for drifting, entry level drift cars would be Miata’s, 350z’s, and E36 BMW’s.
It's a 350hp engine, stock. I was not surprised 🤷♂️ just like the fbody ls1, throw on some headers and wide exhaust, and it should be around 400fw, 350 rwhp
Is there a follow up video to this one of you dynoing it again after mods?
Unfortunately no. I never ended up doing the plugs and wires - job seemed like a nightmare. so the only real mod was the muffler delete. My son was born shortly after uploading this, and never found the time. I actually just uploaded a new video RE: selling the car and cost of ownership. Sorry about that!
That guy has more hair on his shoulders then I have on my Ass !
It's everywhere.... but my head. lol
I know I'm late but who is going to tune this car? Something to keep in mind if you want to cam your car. LT ECUs are very difficult to tune from my understanding but I don't know the strategy they use. Not sure on LTs but LSs are tuned from the factory with cat over temp protection, it will run richer at wide open throttle to keep the catalytic converters cool/from melting. Longevity thing is my understanding. Regardless of the factory strategy I think exhaust mods should be a safe mod on stock tune. I love how you said "This particular car and this particular day". I'm also a nerd and was a little bit gearhead before finding out you can combining the interests.
Definitely not going to cam the car. Too much money and hassle! Need to get the plugs and wires done. Already did the muffler delete. Will run it here again afterwards to see what small gains might be made. Cheers!
@@HoffmansHoopties Leave the tune as stock its designed to protect parts at higher rpm..gm knew guy would hammer on these.
10-12 less rwhp than my stock 90 Z sounds about right. 375 chp
I'll put my two cents in from owning both cars and Ashley owning a C4 zr-1 as well let me tell you some the Grand Sport motors which were the lt4 is that you can get in a manual transmission car with exact same motor as the Grand Sport package my lt4 which was a package I bought from a dealership they had their own Track Pack with warranty which came with better tires rims some whatever stock modified exhaust and a coal there and I think it's light tune but anyways when I would race a stock ZR1 with a ram air the cars would be neck-and-neck with the lt4 pulling slightly at very high speeds you're talkin up in 140 above they were definitely closer to 400 horsepower flywheel without a doubt I have videos from back then but they're not digital so I'm trying to get them converted over for CZcams
I had an 02 ss camaro and got taken to gapplebee’s by an lt4 vette. I thought it was an old lt1 or l98 car boy was I wrong
what was the torque at 2800?
I have a 96 that put down a bit over 320 in Denver when I bough it. 96 Cars are way under rated.
The LT sbc engines were special. Everytime I've seen a stock lt1 vs a stock ls1 camaro. The lt1 was always the faster car.
My stock LT4 did 307 to the wheel here in Los Angeles.
Awesome!
Do you want to keep it stock with a stock money you could always go with a General Motors hot Cam Kit which was made for these cars and a lot of people ran them it will definitely give you 30 to 50 horsepower more plus you get the nice cam sound just remember those cats that you have on that car or the same catheter use on the Chevy trucks back then they're huge
Like Jay Leno says "Its only stock once" I say its like not banging your girlfriend to save her for the next guy. 😅 Your car, enjoy it, do what you want to it. Car is beautiful!
I see at 8:38 you’re doing the pull in 3rd gear. Isn’t 4th gear on a C4 with a six speed 1:1?
Good ear. I only heard two shifts. But you can see him pulling his arm backwards on the last shift before WOT. Must have skipped 2nd? 🤷♂️ I know he was in 4th tho
In some societies, excess back hair is a sign of power
This is what I'm talking about these are where these cars in my experience that are stock Dyno at right on the money now if you put a free-flowing exhaust this car after pick up close to 50 horsepower the exhaust from General Motors is so restricting because anytime you put any kind of exhaust on these cars it's drones really bad and this will GM had a hard time making an exhaust for the car but they made it so quiet that the car was on pleasurable to people because it sounded like a truck or like a normal Cadillac at the time
No exhaust in the world is going to net you 50 extra hp, even at the crank
Whatever you're doing to this thing i'd be making sure it is reversible.
Since there is nothing really special about a GS apart from the paint and emblems yet they go for stupid prices (especially with that red interior) you could sell that and buy two other LT4 Corvettes to do whatever you like with them.
That car looks to be incredibly pristine from what i can see in the video.
Totally agreed. I am actually about to sell. Have all the factory exterior lights and factory mufflers. Will leave the LEDs since that's just a nice quality of life improvement, and a 20 minute job to "reverse". I can see myself getting a base LT4 car down the road and having a riot with it, but not here unless it was my forever car, which it isn't.
@@HoffmansHoopties re-instate the factory lighting. The LEDs look poxy as hell, they're not an improvement at all.
Spend the 20 minutes!! :)
@@HoffmansHoopties by all means, leave the interior LEDs in the doors and footwells, that IS an improvement.
Also do the under bonnet lights with LEDs as well, but those headlights and taillights don't look even close to period correct on a GS.
@@CaseTheCorvetteMan I will be replacing the exterior lights. I wanted to go all LED so I could be at night meets with my lights on and not worry about a dead battery. I will say that the factory headlights are absolute TRASH and 100% should be fixed. the tail lights I am not so happy with, as I couldn't find LEDs to fit the third brake light or reverse lights. I also don't really care about 'period correct' but to each their own, it's my car and your opinion ;) I did take best in class at the local Corvette meet so I guess the old farts didn't seem to mind much, haha
@@HoffmansHoopties of course it is and by all means you do as you see fit, being an absolute C4 bloke that i am and working on a hell of a lot of them here in Australia i tend to like period correct look where possible ;)
The H4 semi-sealed units are the go, any H4 bulb fits then. The originals are hit and miss, obviously here we can't use those because they angle the wrong way for the side of the road we drive on.
For the rears i always use Philips LED tail lamp bulbs that simply fit straight in the standard socket.
I never put much weight on winning anything at a local Corvette meet, it is often just the opinion of whoever is marking the sheet, which is fine, but won't always be accurate.
The fact you won something with that car though is a given, the condition looks outstanding and it should win on virtue of that.
I took my Callaway Supernatural to a Corvette show here a couple months back and most of the judges had no clue what it was let alone the fact it has been like that since brand new. They're apparently Corvette enthusiasts, but most of them wouldn't know their arse from their elbow.
That particular show hosted by that particular club here has a long standing reputation for favouritism when it comes to trophies and awards, i don't really know if that is a fact either way, but then i don't care either, i bought my car for me not everyone else :)
They underrated SOME of the LT4s. Not all. Not even all GSs. GS registry has a HP listing.
Any advice?
Nope, I'm mostly leaving the engine alone! If I could justify the $$ I would definitely get a hot cam, but I've read these cars are a PITA to tune and a lot of tuners won't touch them
@@HoffmansHoopties with a nice air intake, throttle body, long tubes, exhaust & a 3:55 or 3:73 gear.. it should make for a very fun ride!
i did something more fun. i took a square body s10 put a vortec 5.7l in it and some goodies. i spent nothing and i have had over 43k miles of fun. excellent fuel economy too. im willing to bet a make a bit more power too. not that it matters but for under 2 grand more power less weight and a more desired body shes a keeper.
did you see the guy who made his own budget Syclone? did something similar but also swapped in an AWD system from an Astro.
@@HoffmansHoopties yeah but ever since a kid i just never cared about em. 20 grand for an s10 is a joke even then.
when i was building mine i almost went a route like that and then i remembered.
i do all my own work and i have simple 2wd drivetrain. keep it simple stupid. it stayed cheap and easy and i have a very fun and reliable toy with less failure points and easy repairs if i ever need to do any. i few examples i made my own motor mounts. i took trans mount and mounted trans and hung motor and trans till i had it where i needed it and made mounts. motor is lower and it lets me slide dizzy in and out easy. fan is electric and infront of radiator core support. its wider so it scoops air in and doesnt need to run unless stopped. i can fit about 3 fingers between fan and water pump. but guess what. its 2 mins to remove rad and i can strip the whole front of motor. in an hour i can have the core support out and the thing is literally ready to pull motor and trans or either could stay. both vehicle harnesses are spliced so i have fully functional just like oem but better layout and planning than oem. better emissions power reliability and fuel economy. with easier repairs. parts cost nothing too. and i have insane traction so im not missing out on awd. all my friends are going nuts cause all the awd builds coming out but they dont understand just how expensive it can get and how much of a mess it is to work around when doing repairs. not a one actually finished their builds. but i showed them a launch in my truck and they all agree its not worth the extra cost and will be slower in the 1/4 mile than mine with the same engine. 3/4 ton springs and all the sticky tire i can fit on the back does wonders. i put the same size on the front too and widened the stance about a foot so she handles like a sports car rides like a suburban on the highway and goes like a supercar but can do a small wheelie on the street no prep. i wanted boost but have long tube headers laggy rear mount turbo im good. supercharger maybe. electric or supercharger im actually very interested. the tech is almost there.
what i want is the electric car motors that go in the wheel. mount it where my spindles go. put the wheel on and have 100-125 hp per wheel in the front. i have 1 high output alternator. i can fit and run dual alt bracket. 400a output after that. its a good bit of charge. couple runs charge batteries back up couple more runs...
no fuel economy loss and instant extra 250 hp on a launch sounds pretty tasty to me. plus if you had a trans failure or driveshaft you could potentially drive it to safety.
Put in new O2 sensors
Put a crossover pipe in between pipes so it dont drone so bad on hi way
How much torque ? Dyno measures torque , hp is a calculation
That is a fair question. I’m not actually sure. This dyno wasn’t 100% setup and the chart was drum RPM vs HP. I presume it’s using the 5252 extrapolation. Forget the actual formula 😂
GM is well known for perfecting a engine after years of production just to kill it and repeat the process all over again with another new engine !
I'm jelly of the LT4. I'm getting a cam and springs and then I'm going to use a Chinese whistle to blow past all of my inferior ports and valves. LT junk life.
All it needs is a tune
Not trying to keep on chiming in but if you look at my page you'll see that I have one of the more popular cforce on CZcams and my motor is just fully built 355 and I've never had it on the dyno but I could race a C6 ZO6 with a tune and ram-air and I could put a couple car links on him or a CTS-V second gen with a pulley cold air and a exhaust I'll put about a car and a half on those guys so like I said over the years I have have dabbled with these motors the man that owns a dino shop his Dino is right on that is what those cars Dino when everything is running right occluding the apis park good fuel if you tune that car the way it sitting you'll probably get a true 350 rear wheel horsepower car if you want to skip all the other BS mods do yourself a procharged supercharger and tune and call it the day you'll make 500 rear-wheel horsepower and have close to a 9-second car with their proper drag radials also you're going to have to run a better Tire combo if I was you I would order aftermarket wheels and save those Wheels those wheels are coming streamly rare
They were 340 hp not 330 hp.
330 HP / 340 TQ
My LT4 definitely feels quicker than 330/340 at the crank, and I have some quick cars - stock 427 C6, 570 rwhp Terminator Cobra, and lightly modified Lightning. Your corrected results don't surprise me at all.
The best era….PERIOD!!
get under the car and look at the cats, they are huge, i mean they are HUGE>
Due to the BABVVO and TEBBVO laws, all petrol cars will unfortunately soon be banned from public streets in the EU, CH USA and Scandinavia :-( In Germany, the Green People's Party has given the order to shorten the fuel supply from 2025 by reducing all conventional gas stations to just one state-run central gas station per city or county Now they even want to slow down all gas pumps by 20 liters per minute to 2 liters per minute... From 2027, some car spare parts will also be banned in the EU... such as exhaust systems, turbochargers and even some engine and gearbox oils. .. California and New York will do the same from 2027... So no more investing in petrol cars... They even created a new type of crime here called emissions and smoke crime . "Bundesabgasbespaßungsverbotsverordnung" BABVVO in Germany and HESCHLAVVO in Switzerland!!!!!!!!!!
"Come and take it". Globohomo will face revolts worldwide. Don't give up your C4 to the climate cultists or jabber wokies
That’s a bunch of nonsense
sadly not please google SCHLABOUBVE and BABVVO @@BrainFuck10
Here in California, we had an energy shortage last year. Our governor was telling people not to charge their cars, even at home.
In EU most people will not be allowed to own any car our government told that normal peolple will only get permission for an e scooter or e bike or use public transports@@glengerdes4158