Body roll
Body roll
Hey guys, any suggestions on how to further reduce body roll in the long sweepers at T5/6 and T12/13 at Sepang? I'm on HKS Hipermax 3 Sport suspension with 13F/11R spring rates, so that should be stiff enough? Or do I need 16F/16R like the Tein Circuit Master or HKS Hipermax Super Sport? Will anti-roll bars and all the assorted chassis braces help? Any other hardware or setup changes I can make?
Mentioned this to a couple of bros on the forum already, but thought I'd share my questions here
Mentioned this to a couple of bros on the forum already, but thought I'd share my questions here
suspension set up if kinda personal, if i were to track i`ll be using either 18 front 16 rear or 16 front 14 rear , both set up i`ll be using aftermarket anti roll bar, preferbaly adjustable ones to fine tune roll stiffness, but note, less roll is not equal to more traction, but on stock arb, its sure to roll, lol
lets see what other trakies say, as i don`t track and don really enjoy it, also dunno why, lol think they might have more tips on sepang track
lets see what other trakies say, as i don`t track and don really enjoy it, also dunno why, lol think they might have more tips on sepang track
mango
Anti roll bar surely will be of benefit, but cant comment on its use on track. Apparently, all these reinforcements make the chasis less prone to flexing and therefore make car less comfy too. Engine mounts keep engine from swinging left right centre while you negotiate the course. Fender braces (think thats what they call it) also help in sharpening turns.
My two cents only. All these contribute to a very gf/ wife/ fling unfriendly ride. I had tried most of the above in my old car. Driver shiok = passenger misery. Lol
My two cents only. All these contribute to a very gf/ wife/ fling unfriendly ride. I had tried most of the above in my old car. Driver shiok = passenger misery. Lol
Tim save yourself time and money in the long run and skip japanese dampers... go moton, jrz, nitron..
For a road car that's tracked 1% of the time, better to err on the soft side vs too stiff. If you're using semis mostly 12 - 14kg/mm range is better than 16 or higher.
A softer car is a faster car, and easier on the tires, unless driver cannot get used to the out of phase response (drivers vary), or unless data or long term tire wear shows low grip or bad wear due to poor kinematics
For a road car that's tracked 1% of the time, better to err on the soft side vs too stiff. If you're using semis mostly 12 - 14kg/mm range is better than 16 or higher.
A softer car is a faster car, and easier on the tires, unless driver cannot get used to the out of phase response (drivers vary), or unless data or long term tire wear shows low grip or bad wear due to poor kinematics
KART OR DIE
no need expensive suspension.. there was a shootout test with a bunch of all the usual suspects, moton, J's , KW etc... the OEM CR suspension was on par with almost all the aftermarkets cept for the spoon.. but the spoon car was also quite modded.
the advantage of the CR suspension is that it retains stock height - so you dont havfe to worry about stress on your suspension components.. that u will usally get from lowering from lowering. lowering also usually meens you nede to install extra stuff like bumpsteer kits etc.
http://blog.kw-suspension.com/wp-conten ... ootout.pdf
the advantage of the CR suspension is that it retains stock height - so you dont havfe to worry about stress on your suspension components.. that u will usally get from lowering from lowering. lowering also usually meens you nede to install extra stuff like bumpsteer kits etc.
http://blog.kw-suspension.com/wp-conten ... ootout.pdf
Hi Kelvin,mistral wrote:no need expensive suspension.. there was a shootout test with a bunch of all the usual suspects, moton, J's , KW etc... the OEM CR suspension was on par with almost all the aftermarkets cept for the spoon.. but the spoon car was also quite modded.
the advantage of the CR suspension is that it retains stock height - so you dont havfe to worry about stress on your suspension components.. that u will usally get from lowering from lowering. lowering also usually meens you nede to install extra stuff like bumpsteer kits etc.
http://blog.kw-suspension.com/wp-conten ... ootout.pdf
A test is usually better than no test, but sometimes a bad test can give wrong conclusions. Some issues from largest to least (roughly)
1) Which seller knows its stuff and can even come up with a good setup. Good hardware and lost setup = lost. Robi is known to really know his stuff. With knowledge of the type of driver in the test, further optimization possible.
2) What are the spreads in the driver's single 5 lap stints in the same car. If variance is large and/or if some stints his bests are at the start, others towards the end, then he's not a consistent driver.
3) Unless driver is known to be really good, need multiple good drivers with lap time averaging. Else single driver preference, override component or setup quality.
4) As the article itself mentioned.. even car spec wasn't close. Aero, wheels, mounts, brakes, pre-damage, etc. Age of cars? Slop in bushings = time
Lastly, the test was conducted in winter and on street tires, only a few laps. In this situation of course you want to put lots of energy into the tire quickly and get flying. But the opposite is true of semis, across 15 laps, in scorching Sepang.
KART OR DIE
ya, i agree there are a lot of permutations and the test wasnt run on same car..
having said that, thought it was qutie helpful ... its rare to see a bunchof coilovers tested against each other independently.
for myself, i hate the idea of fiddling with adjustment of coilvoers and always prefer an OEM option if there is one.
haivng said that, wont be changing suspension till i max out on present one lol...
having said that, thought it was qutie helpful ... its rare to see a bunchof coilovers tested against each other independently.
for myself, i hate the idea of fiddling with adjustment of coilvoers and always prefer an OEM option if there is one.
haivng said that, wont be changing suspension till i max out on present one lol...
Like most others have mentioned, a car with less roll might not give you better grip. It only gives you a false sense of 'stability'. I also find it harder to find the limits of the car when it's too stiff. Either you take a set nicely, or the car goes off. This effect seems to be amplified on semi-slicks.
A softer car is easier to learn, but I find that inputs have to be made earlier, and at the right time. This is my personal conclusion, because like many others before me I took the wrong approach and went for a stiff setup and semi-slicks too early in the game. Now I'm just making the best of what I already have in the car.
As for spring rate, I have 16kg/mm, and I do find them a bit too stiff. Sometimes even dangerous when going a bit faster on the streets. It might be more suitable if you have lots of aero on the car? Japanese coilovers generally rely too much on the springs, while the angmoh ones let the dampers work harder. End result, angmoh coilovers usually give similar performance with better ride comfort. I'm talking about the level of performance of weekend trackies like most of us.
But to answer your question, you can reduce roll mainly by:
1. Stiffer springs
2. Stiffer ARB
3. Lowering the ride height.
From my experience, 2 and 3 gives better results in reducing roll. Contrary to an earlier post, stiffer ARB should not affect ride comfort drastically unless only one wheel is going over bumps. I think a better approach will be to try different alignment setups to optimise your present suspension. After all, the main idea of roll control is to optimise tire contact patch. Of course this means the driver has to be consistent first. I think we'll be going in circles until the driver becomes consistent.. lol
A softer car is easier to learn, but I find that inputs have to be made earlier, and at the right time. This is my personal conclusion, because like many others before me I took the wrong approach and went for a stiff setup and semi-slicks too early in the game. Now I'm just making the best of what I already have in the car.
As for spring rate, I have 16kg/mm, and I do find them a bit too stiff. Sometimes even dangerous when going a bit faster on the streets. It might be more suitable if you have lots of aero on the car? Japanese coilovers generally rely too much on the springs, while the angmoh ones let the dampers work harder. End result, angmoh coilovers usually give similar performance with better ride comfort. I'm talking about the level of performance of weekend trackies like most of us.
But to answer your question, you can reduce roll mainly by:
1. Stiffer springs
2. Stiffer ARB
3. Lowering the ride height.
From my experience, 2 and 3 gives better results in reducing roll. Contrary to an earlier post, stiffer ARB should not affect ride comfort drastically unless only one wheel is going over bumps. I think a better approach will be to try different alignment setups to optimise your present suspension. After all, the main idea of roll control is to optimise tire contact patch. Of course this means the driver has to be consistent first. I think we'll be going in circles until the driver becomes consistent.. lol
Last edited by Ass2000 on Wed Jan 11, 2012 9:39 pm, edited 1 time in total.
Aftermarket Japanese dampers tend to have inferior valving, higher hysteresis, and generally be overdamped, Also they like to spec really stiff springs. Overdamping and stiff springs are good only for the smoothest of surfaces, cooler conditions, shorter stints. It's strange because you would think that over decades, the knowledge would have leaked out of their racing industry, or the couple of OEMs who know what they're doing (look at the CR).
KART OR DIE
Re: Body roll
Hey Tim, what tires are you running? What pressures?
Re: Body roll
Hey Peng Toh, nice meeting you and your 1M at the track the other day and having you chase me around! I'm running 225/40/18 and 245/40/18 AD08. My hot pressures that day were 30.5psi all round. Not sure if thats too high or too low (and thus the body roll), or if I should run higher rear pressures to decrease oversteer (a separate problem). Any ideas?slowman wrote:Hey Tim, what tires are you running? What pressures?