"There is no 'it'. There is only you!" Yoda, Star Wars.
Sounds like you need to learn some throttle control.
The TCS will create throttle inputs that make the car very challenging to drive at high speeds where a little slip angle is desirable.
oversteer at track
- Thread starter L8apex32
- Start date
"There is no 'it'. There is only you!" Yoda, Star Wars.
Sounds like you need to learn some throttle control.
The TCS will create throttle inputs that make the car very challenging to drive at high speeds where a little slip angle is desirable.
titaniumdave; said:
Hahahaaa...........I do the same thing/.
Dave.........remember the THROTTLE IS A SWITCH
ON AND OFF...........That is ALL :redface: :tongue: :smile:
:biggrin:
+2
The TCS caused me a spun out in my first track day, and it had only been my only "off". Maybe I'm not driving as closed to the limit of my car... but very unlikely.
you have a 92 right, do you still have the stock shocks? that might be the other possible cause of your undesired handling...
If you had a race car and you used to track mustang, you might not be an novice driver, and I'm thinking that you might have experienced what most of us did, you out drove the 205/225 , 15/16 tires.
Ok, so a popular opinion is that I am not driving correctly. Specifically, I'm not using the throttle correctly. Let's analyze for a second.
Do you, when at the track, get rear wheel spin when exiting turns with TCS off?
I have driven my car at the track for YEARS and never got power on oversteer. I'm not saying it can't be created, but the car doesn't tend to do this turn after turn, lap after lap, does it? Tell me your experience with power-on oversteer?
Next - ever seen a Porsche 911 have power on oversteer problems? They have a rear engine car... shouldn't this be worse? They don't have this problem normally. I've owned a 1989 911, driven it on the track and driven with PCA clubs for over a decade.
How about the new Cayman? Mid-engine, bigger power... I chased a Cayman GT for laps and he never had power on oversteer.
I do not think that a properly working car should spin the tires coming out of turns. The power shifts the weight to the rear, gives it more grip, and reduces weight/grip in front. It also, due to LSDs, causes a forward thrust which also increases understeer. Applying throttle, to full throttle, in the turns is normal, isn't it?
So, if its not the car, then all of you should be dealing with this too, right? This means you turn your TCS off (based on what you are suggesting) and carefully and gingerly apply throttle. And, if you apply too much throttle in the turn exits you get both rear tires to spin? Tell me your experiences. Tell me you have the same problem I do and let's see where that goes.
Thanks.
Do you, when at the track, get rear wheel spin when exiting turns with TCS off?
I have driven my car at the track for YEARS and never got power on oversteer. I'm not saying it can't be created, but the car doesn't tend to do this turn after turn, lap after lap, does it? Tell me your experience with power-on oversteer?
Next - ever seen a Porsche 911 have power on oversteer problems? They have a rear engine car... shouldn't this be worse? They don't have this problem normally. I've owned a 1989 911, driven it on the track and driven with PCA clubs for over a decade.
How about the new Cayman? Mid-engine, bigger power... I chased a Cayman GT for laps and he never had power on oversteer.
I do not think that a properly working car should spin the tires coming out of turns. The power shifts the weight to the rear, gives it more grip, and reduces weight/grip in front. It also, due to LSDs, causes a forward thrust which also increases understeer. Applying throttle, to full throttle, in the turns is normal, isn't it?
So, if its not the car, then all of you should be dealing with this too, right? This means you turn your TCS off (based on what you are suggesting) and carefully and gingerly apply throttle. And, if you apply too much throttle in the turn exits you get both rear tires to spin? Tell me your experiences. Tell me you have the same problem I do and let's see where that goes.
Thanks.
I have R tyres, and yes, it does spin tires when it come out of tight corners, it usually about a brief half second and it will hook up by itself. Mine is 91 with TeinRA suspension, stock sway bar. I had the problem you mentioned exactly when I had the worn out tires with harden compounds..
My guess is that the 225/50/16 can't take the abuse. If you don't want to gingerly apply throttle, then either modify your race line and braking point, or upgrade to better, bigger tires.
come to think of it, if you ever watch those test driving report of nsx, you will see them smoking the rear tires constantly aka drifting... Heck, you mentioned Porsche, go look at those 997 GT3 canyon drive, they are doing the same thing.
*I don't think the purpose of LSD is to create understeering... It's the other way around, it should be a device helping you controlling the rear slide by using throttle and steering control.
My guess is that the 225/50/16 can't take the abuse. If you don't want to gingerly apply throttle, then either modify your race line and braking point, or upgrade to better, bigger tires.
come to think of it, if you ever watch those test driving report of nsx, you will see them smoking the rear tires constantly aka drifting... Heck, you mentioned Porsche, go look at those 997 GT3 canyon drive, they are doing the same thing.
*I don't think the purpose of LSD is to create understeering... It's the other way around, it should be a device helping you controlling the rear slide by using throttle and steering control.
All the early model TCS does is Back YOU off the throttle when the rear tires are turning at a different speed.
When the TCS turns OFF the throttle it's vary abrupt and it keeps the throttle OFF during an entire spin or until the rear wheels are turning the same speed.
What locker are you running? Is it the stock unit with 140+k miles? Or did somebody rebuild it?
When the TCS turns OFF the throttle it's vary abrupt and it keeps the throttle OFF during an entire spin or until the rear wheels are turning the same speed.
What locker are you running? Is it the stock unit with 140+k miles? Or did somebody rebuild it?
OK, let's take you out of the equation. Sounds like you have lots of experience in many cars and you are not Jeff Shoots, so you know the throttle is a volume knob, not an on/off switch:wink:
What are your hot tire temps? What tires are you running?
I think the weak LSD is a part of the problem. I have spent very little time in a stock 91-96 LSD equipped car, I have had a 97+ torque sensing diff, or a LSD packed with an extra spring (120+ ft/LB). Both of these sets could get inside wheel spin on very tight turns and full throttle. I run 275 RA-1 rears, so I need to throw the car into a corner to get the rear to step out. Once the car takes a set it's pretty easy to throttle steer it with out both tires spinning, unless the rear tires are above 42 PSI, then it's drift city! The OS Giken 1.5 I now have is the only set which seems to not let the inside wheel spin.
Stock size tires are more temperature dependent from my experience...
Another easy thing to try would be to unbolt one upper link from the rear sway, zip tie it against the knuckle and see what the car feels like then. That will give you the most bite you can get with both rear tires. Might be an interesting data point.
I have to admit, the first thing I have people with their car is lower it and put stiffer springs on, so the stock ride height is not real familiar to me. I know dropping the car by 20-30 mm makes a huge difference in reducing roll, and helping maintain tire contact patch in hard corners.
What are your hot tire temps? What tires are you running?
I think the weak LSD is a part of the problem. I have spent very little time in a stock 91-96 LSD equipped car, I have had a 97+ torque sensing diff, or a LSD packed with an extra spring (120+ ft/LB). Both of these sets could get inside wheel spin on very tight turns and full throttle. I run 275 RA-1 rears, so I need to throw the car into a corner to get the rear to step out. Once the car takes a set it's pretty easy to throttle steer it with out both tires spinning, unless the rear tires are above 42 PSI, then it's drift city! The OS Giken 1.5 I now have is the only set which seems to not let the inside wheel spin.
Stock size tires are more temperature dependent from my experience...
Another easy thing to try would be to unbolt one upper link from the rear sway, zip tie it against the knuckle and see what the car feels like then. That will give you the most bite you can get with both rear tires. Might be an interesting data point.
I have to admit, the first thing I have people with their car is lower it and put stiffer springs on, so the stock ride height is not real familiar to me. I know dropping the car by 20-30 mm makes a huge difference in reducing roll, and helping maintain tire contact patch in hard corners.
I dont think that anyone answered you regarding their springs and sway bar settings. Dont know if this will help you.
Front: 12k TODA coilover with Comptech sway (mid I think)
Rear: 10k TODA coilover without ANY sway (CT remains unmounted).
I run my RA1s at 32F 31R COLD with a wacky 205/275 combo. Dont check hot temps.
I perceive NO oversteer and perhaps a small amount of understeer as I approach a hairpin at 50ish mph at Mosport.
Front: 12k TODA coilover with Comptech sway (mid I think)
Rear: 10k TODA coilover without ANY sway (CT remains unmounted).
I run my RA1s at 32F 31R COLD with a wacky 205/275 combo. Dont check hot temps.
I perceive NO oversteer and perhaps a small amount of understeer as I approach a hairpin at 50ish mph at Mosport.
mine is 10k front, 12k rear, I ran RA1 35psi front, 38rear Hot. stock 15/16 size.
NT01 36 front, 38 rear hot. 235/40/17 & 275/35/18
Stock sway bar. Tein coilover set bump at 2 from full stiff, full stiff at back.
With street tires: Kumho MX when I had stock suspension, I used to run 32 /35 Hot, anything more than that is getting slippery...
NT01 36 front, 38 rear hot. 235/40/17 & 275/35/18
Stock sway bar. Tein coilover set bump at 2 from full stiff, full stiff at back.
With street tires: Kumho MX when I had stock suspension, I used to run 32 /35 Hot, anything more than that is getting slippery...
With those new tires, you should swap springs front to rear, 12K front, 10k rears! It will give you better braking too!
That's just NOT RIGHT......Completely CORRECT but still.........
sorry for thread hi jack..
Dave, wouldn't I expect more push if I do that? with maxed out camber (-1.6) in front, I still don't get enough intial turn in I liked... Before I bite the bullet and getting the bushings, I would like to try adding sway bars, what is your suggestions?
I have been running for 3 years:
Shocks/springs: Koni yellow shocks, Eibach springs(230 f, 280 r, 32mm lower),
Sways: 7/8"(22mm) front bar set full firm, stock rear bar,
Tires/pressures: RA-1 235 f, 275 r, hot temps max pressures 36 f, 42 r (getting greasy)
Suspension notes: Rigid toe links, rear beam bushings, front compliance clamps.
Alignment: front -2 degrees camber, .1 degree toe out, 8 degrees caster
rear -2.8 camber, .1 degree toe in
New set up:
Shocks/springs: Koni 3012 shocks, springs(1000 f, 600 r, 32mm lower),
Sways: 1 1/8"(28mm) front bar set full soft, stock rear bar,
Tires/pressures: RA-1 235 f, 275 r, hot temps max pressures 36 f, 42 r (getting greasy)
Suspension notes: Rigid toe links, full mono-ball pivots, front compliance clamps.
Alignment: front -3 degrees camber, .1 degree toe out, 9 degrees caster
rear -2.8 camber, .1 degree toe in
Shocks/springs: Koni yellow shocks, Eibach springs(230 f, 280 r, 32mm lower),
Sways: 7/8"(22mm) front bar set full firm, stock rear bar,
Tires/pressures: RA-1 235 f, 275 r, hot temps max pressures 36 f, 42 r (getting greasy)
Suspension notes: Rigid toe links, rear beam bushings, front compliance clamps.
Alignment: front -2 degrees camber, .1 degree toe out, 8 degrees caster
rear -2.8 camber, .1 degree toe in
New set up:
Shocks/springs: Koni 3012 shocks, springs(1000 f, 600 r, 32mm lower),
Sways: 1 1/8"(28mm) front bar set full soft, stock rear bar,
Tires/pressures: RA-1 235 f, 275 r, hot temps max pressures 36 f, 42 r (getting greasy)
Suspension notes: Rigid toe links, full mono-ball pivots, front compliance clamps.
Alignment: front -3 degrees camber, .1 degree toe out, 9 degrees caster
rear -2.8 camber, .1 degree toe in
Stiffer front sway and stiffer front springs will have similar effects as far as turn in. I would make the swap of springs first, no out of pocket for parts you don't need. That said, a stiffer front sway will also reduce front end roll and help maintain tire contact patch as cornering forces build.
Sounds like you can use some of my front mono-ball pivots, they will let you add over 2 degrees of camber, in or out! Plus crisper steering feel and they pull the top edge of the tire in under the fender to reduce the full lock tire rub with the 235 tires.(talk about hi jacking a thread...)
anyone of us who has had significant exposure to nsx mods for track work can tell you that the car does best with stiffer front springs,the ratio of 1000/600 is comptechs choice I use the nsx-r and find it good but still not stiff enough all around.What is the ideal dream setup,I don't know,but if my ride in old #42 around RA is any indication then 1200-800 might be great
anyone of us who has had significant exposure to nsx mods for track work can tell you that the car does best with stiffer front springs,the ratio of 1000/600 is comptechs choice I use the nsx-r and find it good but still not stiff enough all around.What is the ideal dream setup,I don't know,but if my ride in old #42 around RA is any indication then 1200-800 might be great
Kip has 1200 f on his car with Koni 3012(CT Pro), worked well when he went to race slicks.
anyone of us who has had significant exposure to nsx mods for track work can tell you that the car does best with stiffer front springs,the ratio of 1000/600 is comptechs choice I use the nsx-r and find it good but still not stiff enough all around.What is the ideal dream setup,I don't know,but if my ride in old #42 around RA is any indication then 1200-800 might be great
I know that seems to be the impression around here.
Still more than likely, I think I need to push back and say that I doubt everyone is comparing apples to apples. Too many variables from the dynamic tire spring rate to dampener type to target suspension frequency to weight distribution to aero... which to the best of my knowledge... is why the pros start by filling out a weight transfer work sheet.
My theme here is that this is an area that tends to have a lot of depth. I've read about the spec PCA guys that are really serious about their chassis setup doing bumpstop load vs. length and testing them to measure their effective spring rate and figuring that in to their test results. Apparently as I understand it rules limit them to the 996/997 05' - 07' specs and so they throw a ton of shock dyno time at it instead of using such guesswork.
Frankly, I'd say that I feel pretty confident that due to the wide disparity among NSX owners both in terms of driver competency as well as ride setup, traction/go-fast budget, consumer willingness to accept compromises, limited real world quantifiable test data, etc..... that a one size fits all approach touting a specific ratio might not be the best advice going. I'm not saying that your reccomendation given seat of your pants results at Road Atlanta is a bad starting spot, but I don't know that it would work well or scale for everyone.
For example, if you run in a high downforce configuration you are going to want a stiffer rear spring and large O.D. piston that offers equivalent performance but with less piston travel to help keep aerodynamic changes more to a minimum. Even if you think you have it all worked out on a bone stock car... it really doesn't hurt to have a couple sets to experiment with.
That is to say nothing of the spring itself. A quote from Kent Chen with Endless USA:
"Spring rates may just seem like a set of arbitrary fixed numbers, but different brand springs with the same spring rates can actually differ in performance and feel quite a bit.
How so? Different springs use different material and have a different number of coils amongst other things. It's to my knowledge that a spring that reaches a specific spring rate level quicker and with less spring stroke is generally considered to be superior. You do not want to have any unwanted tendencies during expansion and contraction. A spring with a motion characteristic that is smooth and linear with the ability to catch road surface information directly. A spring with accurate levels of response and a smooth yet solid feeling is what you would want to accompany a very specific shock absorber."
Without going too far on the tooth with it... I think that suspension tech is all about details. Simply staggering a set of brand X springs at a pre-determined ratio might get you a little, but I'm pretty sure any of the pros would back me up and say that there is a lot more to it than that.
John,,you analyze too much:tongue: That sounded like the vista explanation:wink: Actualy I do enjoy the time you spend crafting your responses.As I have learned in my profesional life,technowledgy and science are all about the smallest detail.To fully master the universe you need first know its smallest components.Luckily in this discussion all things being equal my best lap times have been when the entire car(all systems) are working well.We all know tires/brakes come and go during each session.My dream would be to have an nsx I could absolutely drive 10/10 all day with my delicate gelatinous being as the weak link.Has your car as you have built it satisfied you in this way?
John, I hear the Yellow shocks and springs are FASTER than the Blue ones 
thats not true :smile:
thats not true :smile:
I'd say I feel really satisfied at the moment. Ten tenths over the long haul in an NSX takes two things. Talent and money. In my little sandbox... what I've learned about my NSX brakes and suspension...
Ok, I really need you guys to buy Vista, because I need like another $15,000 a year for tires and other consumables. :smile:
John, I hear the Yellow shocks and springs are FASTER than the Blue ones
Oh, well that's probably because the blues ones are JDM. Seriously, this isn't the matrix; everyone knows Penske is faster. :biggrin:
I love it when you talk dirty...ooohhhhh:redface:
Like MSJohn says, we are all looking for meat ax answers to scalpel questions. That is why I posted so much information about my car set up. When any one thing changes it has an effect on the whole system. I think this thread lends itself to trends, not specific detail about what will be perfect for every one. Most who want to make these changes won't be able to feel the difference between a '1 click' change in rebound damping, or '1 hole' in a sway bar. There is no replacement for logging seat time to develop the sensitivity you need to tell those subtle differences. Once one is there, then it's time to do the technical work and have the pros dial in the car to match you skills!
In the end, it all comes down to skills and personal preference and what you are willing to give up on the street and from your wallet...
There are certain trends we can all learn from:
tire choices,
tire pressures,
alignment specs,
general spring choices,
shock choices and starting damping settings,
sway bar general choices and matching front to rear
And agree on a few point:
it's always good to corner weight your car
lower is better till you bottom out
more downforce is better till you don't have the power to push it through the wind
stiffer is better till you start to loose traction
lighter is better ever where till it breaks
...:smile:
Good stuff, NSXDreamer2. So you can spin your rear tires, too... interesting. Mine does it on brand new Avon type R tires, FWIW.
I apply throttle gradually, but I refuse to wait for the track out point to be WOT. Something is wrong if I have to do that. I may consider wider rear tires. Unfortunately, I just bought 2 sets of stock size for the track.
I have not seen test reports of NSXes or Porsches and haven't seen the rear ends out. Maybe this is common to our cars and I'm the one who doesn't know it. That is what and why I'm asking.
The purpose of the LSD isn't to *create* understeer - it is to keep the inside tire from spinning which is what you get in an open diff. LSD is to get 2 tires to power your forward instead of one and a by-product of this is understeer. My diff is not spinning the inside tire only... both spin, hence the oversteer.
Thanks for the input.
Stock LSD, 142k miles, no rebuild. It has 37 ft-lbs of grip, per the test procedure in the manual and my old Craftsman torque wrench.
But, it is strong enough to keep my stock engine from spinning just the rear inside tire.
Thanks.
36f 38r, give or take, slightly decreasing tire temp from inside edges to outside edges. Avon R track tires.
My LSD is holding on for dear life - but the inside tire isn't spinning (yet).
Yep, may try that next to see how much that tightens me up.
Thanks.
Yeah, I agree. My car has stock springs, Dali middle strength sway bars and Koni yellow shocks and Avon R tires. I think that my car is close enough to stock that observations from people with stock spring rates and stock ride height will be most relevant to my perceived problem.
Anyone else with stock springs and ride height want to comment on when and if they get power-on oversteer?
