When I looked into whiteline suspension years ago, that was there first step. Softer springs and a stiffer roll bar compared to others. Because of the rough roads it kept a less harsh ride over rough roads but still cornered better.
I am surprised how many people are nominating wheel alignment as a big fix. Sure, do it, but it won't do much in the context of the changes being described in this video.
@@JulianEdgar I imagine people are talking about aftermarket alignment parts that take the alignment closer to no-toe more caster/camber for track focused vehicles. I'd like to hear your opinion on this as well, specifically thinking about track cars, there's a lot of contradictory info out there in everyone's setups.
Really? What is the contradictory information? More neg camber = more cornering grip, but less braking and acceleration grip. Toe-out the wheels you want to slide outwards. Toe-in for stability. More castor = more cornering camber. That's basically it?
I'd like to thank you Julian, this video made me impulse buy a rear sway bar for my honda fit (jazz in aus). It instantly made me go "OH, this is how it's supposed to feel?". It's night and day the difference it made to understeer, and i actually felt the back end kick out a little bit. definitely going to buy your books when i have the money!
About 10 years ago when I found out the fk1,fk2 civics in the btcc series all had no front sway/stabiliser bars. At that moment every honda I've owned, all have had the front sway bars deleted. It costs nothing and dramatically increased front end grip regardless of the tyre choice. And you get to steer/rotate the car on its kingpin axis alot more with throttle control.
For many, deleting a front bar is too radical a move for a road car - there will be a *lot* of throttle-off oversteer. (Also, the car doesn't rotate on a kingpin axis; just the steering does.)
It seems mfgrs like to use stability control as a band-aid fix for mechanical flaws. So if you're an enthusiast looking to improve handling, turn off stability control and see how the car behaves. (in a safe environment) Because the stability control may be hiding something.
These days many cars need to have the entire ABS module unplugged to disable Stability, this also disables brake-vector assists which may be more detrimental to performance.
What if happen to have stiffer springs in front and rear, and they are progressive coiling so they don't bottom out, AND they drop the ride height. Seems like a win win. Suspension geometry working a bit harder like the ball joint but other than that Im in love, it steers where I want it to go and its rapid. bumbs are a bit harsh but that's fine.
Used to own an old sports car that was super low from factory. Call me a pansy but they aren't even fun to drive in modern times. Being sandwiched between tractor trailers on the highway sitting 3 inches off the ground starts to feel really freaky really fast. Have to watch it parallel parking because passenger will hit their door on the curb. Pain in the ass to jack it up on uneven driveways because anything but the lowest profile jack will be too high. Scraping the oil pain just by starting up a steep hill. Unfortunately that's how the car sat stock, I can't imagine modding a car to intentionally subject yourself to that
I lowered my car 2". Naturally, as explained, it understeers from the factory. The new springs have a 17% increase in front rates and +34% in the rear. With the ratio shifted to more rear stiffness, the car handles better. And it looks quite good.
@@JulianEdgarI certainly don't plan to do any hard cornering on bumpy roads with a lot of load in the car. In fact, I adjust my driving style according to the conditions, as most should. The car still has 5.5 inches of ground clearance so it's at a good place now. I agree 2 inches on a sports car would indeed be a lot.
That's OK then. I expect my modified cars to do everything they could do normally. (And it's not ground clearance that's the issue, it's suspension bump travel.)
Hello Julian, great video as always! I'd like to point out a minor misnomer you had early into it: changing roll/sway bars doesnt change weight transfer, as that is a function of lateral acceleration, track width and the height of the centre of gravity. Either way, I hope you're doing well and I'd like to thank you for all the work you've done for the automotive (and beyond) enthusiast community!
Altering sway bars changes lateral weight transfer differently at the front and the back. That's why I say 'change the front/rear lateral weight transfer ratio'. If I ever drop 'front/rear' or 'ratio' it's just a shorthand.
That can still be a valid approach if in fact you do intend to change nearly everything. But as the video discusses, on many late model cars that's just not needed.
I have aftermarket coilovers in my car and I'm changing them back to the stock style as they cause understeer. They're heavier than what stock would be anyway, yes they will be lowered springs and shocks as I want the car to look good. My front subframe is from a newer model with all aluminum arms and uprights instead of steel (my car is 1994)
I can't see how coilovers cause understeer. It's the spring rates on the coilovers that most likely will be doing that. (Or, as someone has pointed out, it's on the bump stops.)
@@tturi2 I had coilovers on a skyline, made it much worse, especially in the rain, oh and yes as you mentioned they are a lot heavier, I thought that when installing them. Coilovers for road cars are a scam. New stock dampers which can be pretty expensive still, will make a world of difference. Also new bushes. Just new stuff, because normally everything is old
Mr.Edgar, you are wrong.😅 Cheapest tuning of them all is to get more pressure in rear tyres and less pressure in front tyres.😂 Thank you for your great videos, they are very helpful. 🎉 Sorry, didn't buy your book yet. 😊
@@JulianEdgar Second cheapest tuning of them all is to change camber alignment, if tyre pressure doesn't help. Only after that it is worth to think about springs and swaybars.
I don't think you realise the power of changing f/r roll stiffness. What you're talking about - tyre pressures and camber - are quite trivial in their effects compared to what I am referring to.
@@JulianEdgar It depends from the car. I have many interesting cars, e.g. sti spec c, evo 9, bmw 1m. I have driven and tuned many cars like 911, bmw M, audi RS etc. They all don't need any of that, there is enough with camber settings and tyre pressures.
@@JulianEdgar Will there be any option to buy it outside Amazon? In Sweden if that matters. Both this and the new aerodynamics book has been high on my wishlist for a while, but haven't been able to justify it as it's sadly a lot of money for a student and also just really don't like supporting Amazon and their practices.
When you say "late model" does that just mean that the suspension is in good shape, or do you mean more modern design philosophies like dual wishbone which is much newer than other geometries? I'm looking into slowly changing things on my 88 mr2 which is a mcpherson strut and I assume that when you say late model, my mr2 would be included as opposed to something with a live axle. Very informative, thanks
I've been trying to find someone to make me a stiffer rear bar for a while and failed, and there's nothing off the shelf. I already have the stiffest factory parts both ends of my V8 so no 'upgrade' options, but I can get a softer front bar from a V6. Is that really a sound option for an overall improvement, or should I try harder to upgrade the rear? Stiffer rear springs did make a big difference.
Sure you can go softer at one end to achieve the same effect. That's especially the case if the car is already too stiff in roll - ie bad ride quality over one-wheel bumps and skatey in wet conditions.
Thanks :) I've been thinking about this a lot since watching the video, and this balance of front and rear bar may go some way to explaining why my V6 turns in better than my V8 (iron v6 vs alloy V8 so they weigh about the same). Both have the same rear bar, but the V6 has a hollow 29mm front bar whereas the V8's is 29mm solid. Its a simple swap, and I think the V8 probably is too stiff in roll as you suggest. I'll try the softer bar in the V8 and see what it does 👍
This is not a gotcha: this is an anecdote with exceptions I'm sure. I did a track day with my front sway bar disconnected and it did not induce oversteer while taking the FWD car to the edge of performance on the track. Info and video evidence here of real life empirical testing of this with a 2013 Chevy Cruze: czcams.com/video/kbantCOz1uA/video.html Here is the car on ISC race stiffness budget coilovers where I did get the rear to slide out at the end of the first slalom one run. czcams.com/video/CRPIWen9zt0/video.html
Roll stiffness at each end depends on both swaybar and spring stiffness, so that's certainly possible. That's why the car was different with the stiffer springs as well.
sway bars generally come from manufacturers as a front/rear set. Do you recommend you buy the set and install both, and use the adjustability as needed, or do you recommend keeping the front sway bar stock and just replacing the rear? Also, do you use math to predict which sway bar is good before you purchase, or is the recommendation just "guess and check" with some guidance from math? My workflow is to estimate factory stiffness F/R ratio and find a sway bar that is a known percentage in F/R stiffness compared to stock, wondering if this is valid math.
First question is answered in the video. Second point presupposes stuff that is problematic - how do you measure the F/R roll stiffness ratio, since that needs to include sway bar stiffnesses, sway bar motion ratios, spring stiffnesses, spring motion ratios and suspended weights?
@@JulianEdgar I assumed the geometry, motion ratio, etc is all the same from stock to aftermarket since the aftermarket option is often the same shape, but with a different material with a different moment arm, so I simply just used the moment arm and torsional stiffness to obtain a relative stiffness delta from the stock baseline. Is this bad math?
If you wish to work out a change in roll stiffness *caused by just the sway bars* that is fine - but that's not what you said. In fact, given that the sway bar shape is usually the same from factory to aftermarket, and most sway bars are solid, just work out D^4 to give an approximation.
@@__dm__ At a minimum if you want something resembling accuracy, in steady state you need sprung masses, unsprung masses, suspension geometry, CG position, spring stiffness for corner, roll (and heave if applicable) springs, bumpstop gaps and curve, tire spring rates and installation stiffness for the springs. You'll probably also need torsion stiffness at least, especially if your roll stiffness is very uneven F/R. Technically won't matter at all or much if true roll stiffness is same or similar. After all that, you need to know your tires's load curves so you can calculate what kind of grip change you end up with. Realistically as a hobbyist you will need to approximate and leave most out.
What are your thoughts on factory lowered cars? Do car companies typically design the geometry for the standard suspension, lower it and call it a day. Or do they design the car with a compromise based on both the lowered and standard height suspension in mind during the design process?
@@JulianEdgarYup! For example 2017 Camaro SS1LE, this car is universally accepted as great handling. The base V8 model (SS) vs to the track model (1LE) had a OEM ride drop of just ~10mm
I would've had some questions about my older model, but i don't have any that, between this video and previous ones, you haven't already answered. So, I'll ask this instead: do you have any bundle packages of your previous books?
Those books I have written that have been published through Amazon and not Veloce (ie all my recent books), I can buy author copies more cheaply than retail. So, if you buy direct from me, I can do bundles, etc, at lower than retail prices. However, depending on where you live, postage can be expensive.
Yes, stiffer springs need different damping - another reason to go for sway bar changes rather than spring changes. Re 9:00 - you mean, less aero drag from a lowered car? Not many places inthe world where top speed is important for road cars.
Yes you can lower the car and adjust the roll centre height (if such a modification is available), but how low can you go on a road car without running out of bump travel when cornering hard on real roads? Not much. (Let alone doing that while carrying a load.)
@@JulianEdgar Very true. But you'd also be reducing lift and drag on the tires from lowering the car. I find 20-25mm the most, as you mention you do, before I run into scraping on undulations or ramps cornering. However, with stiffer springs and dampers, I'm sure you can get away with much lower. I've found Japanese road tuning enthusiasts love very stiff springs, but their cars perform well, so I'm almost conflicted.
Yeah, I hate stiff springs and dampers on road cars. It's a long time since I drove any heavily modified Japanese cars but all that I did drive (and yes, they had very stiff springs and dampers) were awful on real roads. Just couldn't cope with bumps.
often hear the term late model would you be able to give some rough ranges on what that means, would you consider 90's sports cars late model? 2000's and newer cars in general? etc
Very good point about companies kindly helping the consumer completely re-work the suspension geometry, WITH THEIR PARTS
Thanks for the insights. An educated driver is certainly a better driver.
When I looked into whiteline suspension years ago, that was there first step. Softer springs and a stiffer roll bar compared to others. Because of the rough roads it kept a less harsh ride over rough roads but still cornered better.
Have a look at Whiteline now... (And I don't think that Whiteline has ever sold softer springs, have they?)
@@JulianEdgar The whiteline ads I see are pretty bad lol
An aggressive alignment is another relatively cheap modification. Get it right and you will likely get better grip and tire life.
I am surprised how many people are nominating wheel alignment as a big fix. Sure, do it, but it won't do much in the context of the changes being described in this video.
@@JulianEdgar I imagine people are talking about aftermarket alignment parts that take the alignment closer to no-toe more caster/camber for track focused vehicles. I'd like to hear your opinion on this as well, specifically thinking about track cars, there's a lot of contradictory info out there in everyone's setups.
Really? What is the contradictory information? More neg camber = more cornering grip, but less braking and acceleration grip. Toe-out the wheels you want to slide outwards. Toe-in for stability. More castor = more cornering camber. That's basically it?
I'd like to thank you Julian, this video made me impulse buy a rear sway bar for my honda fit (jazz in aus). It instantly made me go "OH, this is how it's supposed to feel?".
It's night and day the difference it made to understeer, and i actually felt the back end kick out a little bit. definitely going to buy your books when i have the money!
Yep, works so well for so little money.
About 10 years ago when I found out the fk1,fk2 civics in the btcc series all had no front sway/stabiliser bars. At that moment every honda I've owned, all have had the front sway bars deleted. It costs nothing and dramatically increased front end grip regardless of the tyre choice. And you get to steer/rotate the car on its kingpin axis alot more with throttle control.
For many, deleting a front bar is too radical a move for a road car - there will be a *lot* of throttle-off oversteer. (Also, the car doesn't rotate on a kingpin axis; just the steering does.)
It seems mfgrs like to use stability control as a band-aid fix for mechanical flaws. So if you're an enthusiast looking to improve handling, turn off stability control and see how the car behaves. (in a safe environment) Because the stability control may be hiding something.
These days many cars need to have the entire ABS module unplugged to disable Stability, this also disables brake-vector assists which may be more detrimental to performance.
What if happen to have stiffer springs in front and rear, and they are progressive coiling so they don't bottom out, AND they drop the ride height. Seems like a win win. Suspension geometry working a bit harder like the ball joint but other than that Im in love, it steers where I want it to go and its rapid. bumbs are a bit harsh but that's fine.
The best lowered car is the one I don't own or drive. Those people can talk themselves into thinking they've improved their car.
Used to own an old sports car that was super low from factory. Call me a pansy but they aren't even fun to drive in modern times. Being sandwiched between tractor trailers on the highway sitting 3 inches off the ground starts to feel really freaky really fast. Have to watch it parallel parking because passenger will hit their door on the curb. Pain in the ass to jack it up on uneven driveways because anything but the lowest profile jack will be too high. Scraping the oil pain just by starting up a steep hill. Unfortunately that's how the car sat stock, I can't imagine modding a car to intentionally subject yourself to that
My favourite one is the ricers slamming their econoshitbox to the ground and think it basically handles like a race car lol.
Some people are more concerned with appearance than function.
@@michaelblacktree
Some? Vast majority in the hobby sadly
Fairly happy with my FG XR6 for a big boat. Have Michelin PS5 tyres. Next upgrade is a front sway bar:)
I lowered my car 2". Naturally, as explained, it understeers from the factory. The new springs have a 17% increase in front rates and +34% in the rear. With the ratio shifted to more rear stiffness, the car handles better. And it looks quite good.
2 inches is a lot. It won't be much good cornering hard on bumpy roads with a load on board. OK if you don't ever do anything like that.
@@JulianEdgarI certainly don't plan to do any hard cornering on bumpy roads with a lot of load in the car. In fact, I adjust my driving style according to the conditions, as most should. The car still has 5.5 inches of ground clearance so it's at a good place now. I agree 2 inches on a sports car would indeed be a lot.
That's OK then. I expect my modified cars to do everything they could do normally. (And it's not ground clearance that's the issue, it's suspension bump travel.)
@@JulianEdgar right. By the way I've been enjoying your videos. Do you ever touch on adjustable sway bar end links?
Not much to say? They need to be stiff and as vertical as possible.
Hello Julian, great video as always! I'd like to point out a minor misnomer you had early into it: changing roll/sway bars doesnt change weight transfer, as that is a function of lateral acceleration, track width and the height of the centre of gravity.
Either way, I hope you're doing well and I'd like to thank you for all the work you've done for the automotive (and beyond) enthusiast community!
It changes the *bias* (I describe it in the video as the ratio) of front/rear weight transfer - that's the whole point.
you are right. He mentions this in comments also.
Altering sway bars changes lateral weight transfer differently at the front and the back. That's why I say 'change the front/rear lateral weight transfer ratio'. If I ever drop 'front/rear' or 'ratio' it's just a shorthand.
wish I heard this 20 yrs ago when I started autocross. did all the not necessary "upgrades" first then the sway bars almost last😅
That can still be a valid approach if in fact you do intend to change nearly everything. But as the video discusses, on many late model cars that's just not needed.
I have aftermarket coilovers in my car and I'm changing them back to the stock style as they cause understeer. They're heavier than what stock would be anyway, yes they will be lowered springs and shocks as I want the car to look good. My front subframe is from a newer model with all aluminum arms and uprights instead of steel (my car is 1994)
I can't see how coilovers cause understeer. It's the spring rates on the coilovers that most likely will be doing that. (Or, as someone has pointed out, it's on the bump stops.)
@@JulianEdgar yeah the springs are very stiff and they aren't a typical motorsport spring size so I can't only change them
@@tturi2 I had coilovers on a skyline, made it much worse, especially in the rain, oh and yes as you mentioned they are a lot heavier, I thought that when installing them. Coilovers for road cars are a scam. New stock dampers which can be pretty expensive still, will make a world of difference. Also new bushes. Just new stuff, because normally everything is old
My Polo Gti has a sports esc setting on the stability control system. Feels noticeably more nimble in the that setting.
Mr.Edgar, you are wrong.😅 Cheapest tuning of them all is to get more pressure in rear tyres and less pressure in front tyres.😂 Thank you for your great videos, they are very helpful. 🎉 Sorry, didn't buy your book yet. 😊
For a relatively trivial change in handling, yes. (And, usually it would be the other way around.)
@@JulianEdgar Second cheapest tuning of them all is to change camber alignment, if tyre pressure doesn't help. Only after that it is worth to think about springs and swaybars.
I don't think you realise the power of changing f/r roll stiffness. What you're talking about - tyre pressures and camber - are quite trivial in their effects compared to what I am referring to.
@@inam7904 Aftermarket suspension with camber plates aren't cheap
@@JulianEdgar It depends from the car. I have many interesting cars, e.g. sti spec c, evo 9, bmw 1m. I have driven and tuned many cars like 911, bmw M, audi RS etc. They all don't need any of that, there is enough with camber settings and tyre pressures.
Excellent video!
Thanks - and the book's even better!
@@JulianEdgar Will there be any option to buy it outside Amazon? In Sweden if that matters.
Both this and the new aerodynamics book has been high on my wishlist for a while, but haven't been able to justify it as it's sadly a lot of money for a student and also just really don't like supporting Amazon and their practices.
You can buy direct from me but it will be even more expensive because of freight.
Thanks!
Thank you.
When you say "late model" does that just mean that the suspension is in good shape, or do you mean more modern design philosophies like dual wishbone which is much newer than other geometries? I'm looking into slowly changing things on my 88 mr2 which is a mcpherson strut and I assume that when you say late model, my mr2 would be included as opposed to something with a live axle. Very informative, thanks
I mostly mean that the suspension is in excellent condition - bushes, springs, dampers (shocks).
@@JulianEdgar Ok, thanks
I've been trying to find someone to make me a stiffer rear bar for a while and failed, and there's nothing off the shelf. I already have the stiffest factory parts both ends of my V8 so no 'upgrade' options, but I can get a softer front bar from a V6. Is that really a sound option for an overall improvement, or should I try harder to upgrade the rear? Stiffer rear springs did make a big difference.
Sure you can go softer at one end to achieve the same effect. That's especially the case if the car is already too stiff in roll - ie bad ride quality over one-wheel bumps and skatey in wet conditions.
Thanks :) I've been thinking about this a lot since watching the video, and this balance of front and rear bar may go some way to explaining why my V6 turns in better than my V8 (iron v6 vs alloy V8 so they weigh about the same). Both have the same rear bar, but the V6 has a hollow 29mm front bar whereas the V8's is 29mm solid. Its a simple swap, and I think the V8 probably is too stiff in roll as you suggest. I'll try the softer bar in the V8 and see what it does 👍
This is not a gotcha: this is an anecdote with exceptions I'm sure. I did a track day with my front sway bar disconnected and it did not induce oversteer while taking the FWD car to the edge of performance on the track. Info and video evidence here of real life empirical testing of this with a 2013 Chevy Cruze: czcams.com/video/kbantCOz1uA/video.html
Here is the car on ISC race stiffness budget coilovers where I did get the rear to slide out at the end of the first slalom one run. czcams.com/video/CRPIWen9zt0/video.html
Roll stiffness at each end depends on both swaybar and spring stiffness, so that's certainly possible. That's why the car was different with the stiffer springs as well.
sway bars generally come from manufacturers as a front/rear set. Do you recommend you buy the set and install both, and use the adjustability as needed, or do you recommend keeping the front sway bar stock and just replacing the rear?
Also, do you use math to predict which sway bar is good before you purchase, or is the recommendation just "guess and check" with some guidance from math?
My workflow is to estimate factory stiffness F/R ratio and find a sway bar that is a known percentage in F/R stiffness compared to stock, wondering if this is valid math.
First question is answered in the video. Second point presupposes stuff that is problematic - how do you measure the F/R roll stiffness ratio, since that needs to include sway bar stiffnesses, sway bar motion ratios, spring stiffnesses, spring motion ratios and suspended weights?
Just one. If the car understeers a bit, increase the rear swaybar stiffness.
@@JulianEdgar I assumed the geometry, motion ratio, etc is all the same from stock to aftermarket since the aftermarket option is often the same shape, but with a different material with a different moment arm, so I simply just used the moment arm and torsional stiffness to obtain a relative stiffness delta from the stock baseline. Is this bad math?
If you wish to work out a change in roll stiffness *caused by just the sway bars* that is fine - but that's not what you said. In fact, given that the sway bar shape is usually the same from factory to aftermarket, and most sway bars are solid, just work out D^4 to give an approximation.
@@__dm__ At a minimum if you want something resembling accuracy, in steady state you need sprung masses, unsprung masses, suspension geometry, CG position, spring stiffness for corner, roll (and heave if applicable) springs, bumpstop gaps and curve, tire spring rates and installation stiffness for the springs. You'll probably also need torsion stiffness at least, especially if your roll stiffness is very uneven F/R. Technically won't matter at all or much if true roll stiffness is same or similar.
After all that, you need to know your tires's load curves so you can calculate what kind of grip change you end up with.
Realistically as a hobbyist you will need to approximate and leave most out.
What are your thoughts on factory lowered cars?
Do car companies typically design the geometry for the standard suspension, lower it and call it a day. Or do they design the car with a compromise based on both the lowered and standard height suspension in mind during the design process?
The former I think. But they seldom lower cars much, which tells you something.
@@JulianEdgarYup! For example 2017 Camaro SS1LE, this car is universally accepted as great handling. The base V8 model (SS) vs to the track model (1LE) had a OEM ride drop of just ~10mm
I would've had some questions about my older model, but i don't have any that, between this video and previous ones, you haven't already answered. So, I'll ask this instead: do you have any bundle packages of your previous books?
Those books I have written that have been published through Amazon and not Veloce (ie all my recent books), I can buy author copies more cheaply than retail. So, if you buy direct from me, I can do bundles, etc, at lower than retail prices. However, depending on where you live, postage can be expensive.
Stiffer springs need more capable dampers?
9:00 Top speed, and lower cog?
Thanks for the video Julian.
Yes, stiffer springs need different damping - another reason to go for sway bar changes rather than spring changes. Re 9:00 - you mean, less aero drag from a lowered car? Not many places inthe world where top speed is important for road cars.
@@JulianEdgar I guess, it improves fuel economy too - but wouldn't a lower cog have a significant effect if the roll center is adjusted accordingly?
Yes you can lower the car and adjust the roll centre height (if such a modification is available), but how low can you go on a road car without running out of bump travel when cornering hard on real roads? Not much. (Let alone doing that while carrying a load.)
@@JulianEdgar Very true. But you'd also be reducing lift and drag on the tires from lowering the car. I find 20-25mm the most, as you mention you do, before I run into scraping on undulations or ramps cornering. However, with stiffer springs and dampers, I'm sure you can get away with much lower. I've found Japanese road tuning enthusiasts love very stiff springs, but their cars perform well, so I'm almost conflicted.
Yeah, I hate stiff springs and dampers on road cars. It's a long time since I drove any heavily modified Japanese cars but all that I did drive (and yes, they had very stiff springs and dampers) were awful on real roads. Just couldn't cope with bumps.
often hear the term late model would you be able to give some rough ranges on what that means, would you consider 90's sports cars late model? 2000's and newer cars in general? etc
In the video.
@@JulianEdgar apologies, I missed it the first time
@@JulianEdgarMust've missed that too then
what company makes custom sway bars?
I got mine from Signature Swaybars.