Poor Handling in Turns

[GRG]

As a new owner of a '91, I expected a somewhat rough ride and excellent handling. However, I'm really surprised at the poor ride quality in high-g cornering.
The car pitches and rolls which makes it difficult to know what it's going to do next. While the level of grip is good, the car's stability is poor.
To produce this effect, I typically use a 90 deg to 270 deg freeway on ramp; go as fast as seems comfortable; then haul the car into a tighter line to see where the limit is. Once the g's increase, the car becomes upset.
Is this rear suspension tuck?
I have Azev wheels with worn (on the inside) Michelin 225 45 18s on the front and new Pirelli M&S 275 35 19s on the rear. I have changed tire pressures between 31 and 35 on the front and 31 and 40 on the rear with no improvement. There is also, I believe, a red Dali sway bar in front. The suspension is stock otherwise.
Any thoughts on the cause and potential solutions would be greatly appreciated.

 

[matteni]

I have Azev wheels with worn (on the inside) Michelin 225 45 18s on the front and new Pirelli M&S 275 35 19s on the rear. I have changed tire pressures between 31 and 35 on the front and 31 and 40 on the rear with no improvement. There is also, I believe, a red Dali sway bar in front. The suspension is stock otherwise.
Any thoughts on the cause and potential solutions would be greatly appreciated.

You have steam roller wheels, worn tires, mismatched tires, and one upgrades sway bar and you are wondering why the car does not handle well?

I would say you would have a wrecked car in with any other car and the fact that it is so well designed allows you survive these things.

You really need to invest in the right size wheels, quality matched tires, and investigate if your shocks are worn, why your sway bars are mismatched, allignment, etc if you are going to use this as a sports car.

I am sorry if I seem harsh. Perhaps this post will keep you and your car out of harms way.

Good luck / welcome

 

[sjs]

Edit: Dang, Nick beat me to it while I was typing (slowly it seems, but I was trying to be tactful). But it won't hurt to back that up...

OK, try not to be offended, but not only do you have crappy tires on it, you have miss-matched crappy tires, and some of them are worn while the others are new. They are also way over-sized (heavy) and although I don't know those wheels, I'd wager they are boat anchors (heavy) compared to the OEM. An almost unthinkably horrible combination that will not only exhibit wildly unpredictable grip at the limit but has so grossly increased the critical (for handling) unsprung weight that it's probably nothing short of scary to drive fast.

Seriously, even if your alignment is perfect, which seems unlikely given the wheels and tires the previous owner was willing to run, there is no way the car will handle. No it is not "rear suspension tuck". The NSX suspension maintains excellent geometry in cornering. They spent a lot of time and money to make sure of that and if you learn a little bit a bit suspension design then peek under your car, you'll quit suspect that the car is at fault.

The words "tune" and "tuner" are distorted these days to the point of being nearly meaningless to old-school sports car guys, but the NSX suspension is finely tuned and came with special tires made explicitly for it. Although I don't suggest that the OEM rubber is "the best" thing you can put on it, every owner should experience them on a car in good shape for awhile. That way they will know what the compromises are for "upgrades". I know lots of people buy big flashy wheels and fat tires for the look alone, and that's fine, but the bigger and heavier they are the more handling will degrade. Ones like you have will also beat your shocks and bushings to death much faster than necessary, and may already have. And the miss-match is asking to land in a ditch the first time it rains of you get a bit too aggressive.

Believe it or not, nothing I said above is overstated or exaggerated. Your car needs a complete overhaul from the hubs out. Sorry, but you asked, and anything less than the cold truth wouldn't be fair to you..

 

[vtecNSX1]

It should be obvious what the problem is. Everything is mismatched. I can tell you from experience going from an 18/18 heavy wheel with worn tires to 17/18 lightweight wheels with new tires it made a huge difference in terms of how the car feels. Get some correctly sized wheels, new tires, and a matching sway bar on the rear and it will feel like a whole new car.

 

[NSXDreamer2]

Not meaning to flame a new comer. To be more EXACT, it's a big no no matching difference tires on any car. If you have a front wheel drive and you know what you doing and you did some homework, then guess it's fine, (I did it on my accord, I can tell you in one situation, it's perfect for what I exactly looking for, different temp and weather, the car sometime is hard to predict.) But you are matching different brand, different grade (Michelin high performance matching a Pirelli Mud + Snow??) on a Mid engine, rear wheel drive car? going through a corner as fast as you could? It's suicide!! You are either very brave or very foolish.

Remedy: If you still have stock rims, put a set of stock size high performance tires, drive the same corner and tell us what you think.

I also want to stress that the pitch and dive is the sign of the car's doing its job. Without the suspension travel, you need more skills, quick hands and feet to recover the car.

Suggestion: Put a matched set of tires and go to your local DE for more driver education. Unless something is wrong mechanically, the stock nsx is perfect for learning performance driving. (well, it ain't cheap for repair, so take baby steps )

 

[slashmatt]

Well, as everyone's said, the tires are a big no-no. The biggest worry with your tires besides mismatching, which isn't *always* a bad thing (because you can actually adjust your handling by having different f/r tires) is the sizes. Your fronts are huge.

...but, you said that roll was the worst thing you experienced.

You also happen to be riding on potentially 14 yr. old shocks. Depending on the milage, that could be a really bad thing. I too experienced far too much roll from my stock setup, and for a long time I figured that's just how it had to be unless I went with some rediculously harsh coil-overs.

I just had the NSX-R shocks and springs installed and had the alignment done to match the current Type-S (very good, and I couldn't find the correct numbers for the R). The result: flat, smooth, grippy on bumpy corners, and extreme (better than a Ferrari 360) high speed stability.

As a side note, I'm on stock 16/17 rims, and yes they're probably better(stronger lighter) wheels than pretty much any aftermarket wheel you can buy. The very best aftermarket wheels are just about as good.

 

[goldNSX]

I believe that a 18/19 combo is nice from the optical point of view. But if you like to race your car around corners go down to 16/17, 17/17 or 17/18. As the others mentioned your setup is far from perfect.

 

[Jetpilot2112]

I agree with all the above. It's yet another reason why the big rims and "tuner" mods are not always the best idea.
When will this "fast and furious" fad end? These people give little regard to...er, scratch that, they have no concept of unsprung weight and tire technology. Simply hanging out as a guest at some DE's would quickly cure that.

 

[Mirroredshades]

Get some matching S03's and and matching sway bars and you should feel some drastic improvement. Or go hog wild and slap in a suspension package.

 

[2slow2speed]

Hmm..

I guess folks failed to mention the obvious, public roads are not the place to test the handling limits of a car like the NSX.

It's a lot safer if done in an empty parking lot while doing an autocross or at the track

The handling limits of the NSX are pretty high, as such a freeway onramp or offramp with positive camber can really get you into trouble if you lose control of the NSX while driving fast through the turns.

As others have suggested get the car back close to stock settings and work from there. I'm not sure what others cars you're comparing the NSX to, but from my own personal experience there are very few cars that out of the box handle as well as the NSX does.

Safe driving.

Ken

 

[whiteNSXs]

As a new owner of a '91, I expected a somewhat rough ride and excellent handling. However, I'm really surprised at the poor ride quality in high-g cornering.
The car pitches and rolls which makes it difficult to know what it's going to do next. While the level of grip is good, the car's stability is poor.
To produce this effect, I typically use a 90 deg to 270 deg freeway on ramp; go as fast as seems comfortable; then haul the car into a tighter line to see where the limit is. Once the g's increase, the car becomes upset.
Is this rear suspension tuck?
I have Azev wheels with worn (on the inside) Michelin 225 45 18s on the front and new Pirelli M&S 275 35 19s on the rear. I have changed tire pressures between 31 and 35 on the front and 31 and 40 on the rear with no improvement. There is also, I believe, a red Dali sway bar in front. The suspension is stock otherwise.
Any thoughts on the cause and potential solutions would be greatly appreciated.

This is a joke, right??
Steve

 

[docjohn]

I agree,a little late for april fools

 

[GRG]

I'd like to thank you all for pointing out the problem with the car. It sure looks great with the wheels but.......
Does anyone have a recommendation for a suspension shop in south Orange County?
Thanx

 

[docjohn]

post this ? to the southwest regional forum :smile:

 

[nsxtasy]

Does anyone have a recommendation for a suspension shop in south Orange County?

There are two shops that are convenient to you and have tremendous expertise in the NSX (including its suspension):

Autowave, in Huntington Beach
Applied Motorsports, in Oceanside

 

[02#154]

Not to disagree with you all in your responses to GRG, but...
Unsprung weight is terrible for suspension performance, but...
Mismatched tires aren't typically useful for 10/10 driving, but...
Unless you *REALLY* know what you're doing, just an upgraded front bar isn't advised, but...

The main issue was that the car pitched and rolled more than he thought was normal for an X. Would that not be more in the shocks and bushings, assuming the springs are not worn out? There are a gang-load of people with heavy @$$ wheels and they don't compain about a wallowy ride (maybe they don't realize it because they're blvd. cruzers, not racers?). And I might be wrong, but this guy prolly isn't the first with mismatched tires.

Before I end up looking like a burnt match from the flames, I agree that his wheel/tire combo isn't ideal for hi-performance (or even just spirited?) driving. But if you take in the whole picture and consider the age of his car, shouldn't his shocks and bushings be more suspect than his wheels/tires?

I'm prolly just ignorant to how much tires/wheels make a difference because I've never bothered with bling and always got sensible wheels. But this is what my logic told me when I read the original post and I was surprised to see so many people blame a wallowy ride on heavy wheels and mismatched tires. Please enlighten me as to why these are suspected so heavily over the other.

J

 

[docjohn]

See post #6 shocks were mentioned as a culprit.Bushings are not part of routine upgrade on an nsx,unless the car is tracked regularly then the rear bushings can be improved.

 

[02#154]

I saw post #6... Please see all other posts

What I'm getting at is that the overwhelming majority point to tires/wheels, some even going as far as implying that a car with mismatched tires *can't* drive well. I'm wondering why not more posts referring to the shocks? I believe that the tire/wheel combo isn't ideal, but I also believe that the shocks and maybe bushings are worn out... heck, maybe even the springs.

But I'd like for someone to enlighten me so that I can better understand if I'm mistaken (not just an explanation why heavy/mismatched is bad, I know that, but why they would be more of a suspect for a pitching and rolling car than shox, bushings or spings).

J

 

[nsxtasy]

What I'm getting at is that the overwhelming majority point to tires/wheels, some even going as far as implying that a car with mismatched tires *can't* drive well. I'm wondering why not more posts referring to the shocks? I believe that the tire/wheel combo isn't ideal, but I also believe that the shocks and maybe bushings are worn out... heck, maybe even the springs.

But I'd like for someone to enlighten me so that I can better understand if I'm mistaken (not just an explanation why heavy/mismatched is bad, I know that, but why they would be more of a suspect for a pitching and rolling car than shox, bushings or spings).

Well, I'm not sure that the number of posts is always an accurate indication of the reason(s) that something may be happening. But, when troubleshooting any problem, the steps you want to take first tend to be those that (a) you need to do anyway; (b) are easy/inexpensive to fix/eliminate; and (c) are most likely to be causing the problem.

IMO, these wheels and tires certainly fall into category (a) and may or may not be in category (c). These tire sizes are totally unsuitable for an NSX. Quite aside from the major rubbing that is undoubtedly occurring, and the differences due to the different brands/models front vs rear, no one has even mentioned the fact that TCS will have major problems with those sizes (whose outer diameters are 12.6 percent larger in front and 6.9 percent in back). These problems may affect the handling and are serious regardless of whether or not they do. If this were my car, the tires (and maybe the wheels, maybe not) are the very first thing I would change. Furthermore, regarding category (b), it would be easy to isolate (or eliminate) the wheels/tires as the cause of the handling problems, by swapping with another set of wheels/tires known to be good (either the originals if they were included with the purchase of the car, or someone in the area who has an extra set available for testing).

In other words - it's not that the tires (or wheels) are definitely the cause of the handling problem, but rather, that you'll want to replace them anyway, so you may as well do so. If the handling problem is still there afterwards, then you would want to look at the shocks and other possible causes.

 

[DarthMaul]

With worn front tire and upgraded sway in the front, there will be a lot of understeer in the handling.

Get a new set of tires first. Then see if you can either get the rear sway to match or find a OEM front sway bar to replace the upgraded one.

 

[02#154]

NSXTASY, your point (a) makes a lot of sense. You're right that nobody mentioned TCS, though I wondered to myself if there was a problem with it. I don't think/know if it would be causing the problem that was posted about, but it certainly should be corrected and just may in fact address what GRG is complaining about.

So, your way of troubleshooting is correct because I admit that I'd hate to spend on shocks only to find out that the tires that I should have replaced for completely other reasons fixed something else as a side-effect, but I still think the shocks (or something other than wheels) is (c).

I like your approach and think he should change the tires because they should be changed. Then see if it addresses the ride. If not (and I think not ) then look to other things hint: shocks :hint

J

 

[nsxtasy]

GRG,

I think the tire sizes most often used on NSXs with 18"/19" wheels are 215/35-18 and 275/30-19. Two tires that are available in both those sizes are the BFGoodrich g-Force T/A KDW 2 and the Bridgestone Potenza RE750.

 

[MJK]

If you are OC, maybe someone will let you test drive some OEM rims and tires on your car to help you feel the difference?