Influence of car 'stance' on cornering ability

[MvM]

I recently bought a full set of new tires but choose a different tire brand this time to try something new.

One of things I noticed now is that the stance of the car has altered.
Because my front tires are wider, they are also a bit taller which is causing the rear of the car is sitting slightly lower than the front.
I have a aftermarket suspension which can be adjusted in height.

I am planning to change my right height both in front and the rear and then I started wondering about something.

Sometimes you see these cars with a very low nose but the rear relatively high.
How much does this 'stance' of a car affect performance when it comes to straight line stability or simply cornering ability.

Is there any benefit in having the rear of your car being a little bit higher?(say: .5" )
I was planning to raise my car a little and make the rear being about 1.5cm (.6") higher than the front.
But I won't do it if it will affect my handling too much.

 

[A.S. Motorsport]

Well there are a whole array of effects in both aerodynamic and chassis technical areas.
Question that comes up first is how big will that effect be on your street car.

Few extremes:
NASCAR and a couple of other cars lower there front's so that there airdams can block more under body air flow, aiming to create low-pressure zone below the center of the car. (ground effect = downforce)
Albeit rather primitive solution instead of diffusers.

By altering the angle of the car the rear wing could get more effective angle (% off set to absolute horizontal)

In suspension setup,
A taller rear end with stiff springs helps FWD cars generate more traction on there front axle.
In RWD it isn't a issue although they would go with softer front springs to aid weight transfer to the rear.
Those points are mostly drag race related.

To a certain extent it can influence weight transfer when braking and accelerating
But spring rate and damping force is more of a factor.

Then again with 0,5 inch isn't that huge. talking 0.6% over the wheel base roughly?

Better question in terms of handling is what tire sizes are you running?

 

[nsxtasy]

Better question in terms of handling is what tire sizes are you running?

Yes. And what were the tire sizes you were running before you replaced the tires?

It's very unusual for different tire sizes on the NSX to affect the ride height significantly. For example, even if you go from a 215/45-16 front tire to a 215/35-18, the outer diameter only increases by 1.3 percent. That raises the ride height by only .15 inch (about 4 mm). Not much. Changes in the rear are usually also very small.

 

[MvM]

I have switched to the Federal 595 RS-R tires to try them out.
Size in the front is 235/40ZR17, in the rear it is 265/35/18.

I used to run the 235 in the front before, but it looks like these Federal tires are a bit wider than the ones I used to have, or at least they seem to be more 'square' than the Falken tires I had before.
Also, perhaps it is because I changed all tires at the same time. Normally, the fronts outlast the rears by a 2:1 ratio in my experience, so the last time I changed the rear, the tires in front where already half worn by that time.

My car is lowered quite a bit and I am planning to raise the car by at least .5" in the front. Makes all the speed bumps we have here (in growing numbers.. ) a little easier to negotiate.

 

[goldNSX]

pic?

With a 235 instead of an OEM 215 the car is biased to the front anyway. With a higher rear-end oversteering is maybe even more a problem.

 

[nsxtasy]

Are you sure you didn't have 215/40-17 in the front? That's what most folks use - for example, with the Falken RT-615K.

Very few people are using 235/40-17 and 265/35-18 on the NSX, and it will cause problems for the TCS on the '91-93. For street tires, people usually get 215/40-17 in the front, which works fine with 265/35-18 rears. Those who get 235/40-17 in the front are usually getting them for track-only tires, in which case they usually also get very large rear tires such as 275/40-17.

 

[Thunder]

Here is my tire size for my rims, no problems and healthy behavior on the road, my car is not lowered and I added the two reinforcement bars at the front of the chassis (SOS)
front wheels 17x8", tires 225/35/17Y
Rear wheels 18x10", tires 285/30/18Y

 

[nsxtasy]

Here is my tire size for my rims, no problems and healthy behavior on the road, my car is not lowered and I added the two reinforcement bars at the front of the chassis (SOS)
front wheels 17x8", tires 225/35/17Y
Rear wheels 18x10", tires 285/30/18Y

Those are really not the best tire sizes for the NSX. You'll get better handling, better TCS operation, and a much better selection of tires if you stick with 215/40-17 front, and either 265/35-18 ('91-93 NSX) or 255/35-18 ('94-05 NSX) rear.

 

[A.S. Motorsport]

235/40/17 front is a bit on the wide side, I recall you haven't installed the supercharger yet? correct?
215 or 225 would be better.

Secondly how are those Federals holding up? I've heard a lot about them lately pricing is very reasonable.

 

[MvM]

I have been using the 235/40 tires for about three years now and like the extra grip in front. The car is very neutral in high speed corners.

I haven't come around to installing the CTSC yet.
Am attending a track training day this month and my mechanic simply didn't have the time to do it properly before that date. And also, because I didn't want to attend such a training with a freshly installed CTSC when I have had no real time to get used to it.

The Federal's are holding up very well so far. Like I said, it seems that the front size is more square than the Falked I used before.
Am being very careful in the rain though since these tires don't have the rain grooves normal tires have.