What is the weak link?

[BioBanker]

I just spent another great two days with the Genessee Valley BMW guys at Mosport, and today some Pcar friends of mine and myself were having an interesting discussion.

No matter what the car, there is always a weak link in the suspension. It is there somewhere.

In 944Turbos, Im told that it is the control arms. A buddys busted on him a few weeks back in a scarey corner. Thankfully he didnt stuff the car.

So my NSX gets driven on the track with R compounds and its lowered with a Toda suspension. If youve driven Mosport, Ive done 1:36s in my CTSCd car, but most of my laps are probably 1:38. For reference, the ALMS GT2 cars qualify on pole around 1:18. My time in my car is flat with Billy Johnsons qualifying time for the Koni Challenge, which he ended up winning in the Kensai TSX. So while Im aware that the car is a high performance car that is "made for doing this", aside from the bits that Ive changed, my car is a stock car running full blown race car times (albeit my car has more power and is not as well driven as the Kensai car, forsure).

My car has been great, but I cannot help but wonder what I dont know about the suspension in the NSX. What fails? I have not heard of anything specific that needs to be addressed, but I hadnt heard about oil starvation either until this year. Im now armed with my Accusump, but Im nervous that something holding a wheel on will bust on me one of these days.

What needs to be looked at in advance and what needs to be replaced?

 

[OneRedNSX]

apparently the steering wheel and its telescopic / tilt function has become a problem as of late... telescoping and tilting when it shouldn't be...

 

[nsxtasy]

There isn't anything I would call a "weak link". But, as with any car, you should inspect the suspension for parts which wear and can fail, like bushings, wheel bearings, shocks, etc.

 

[Ponyboy]

Any normal wear and tear item is going to age a bit more quickly in a track situation (I think you realize this). So you want to check the stuff Ken notes for excessive wear or outright fatigue. That said, I've had an end link bend over and I know a few NSX guys have bent shock rods while at the track.

An easy way to determine if nuts are moving or get loose, tighten everything up and paint a straight line on the bolt and nut. That way if the nut moves you'll be able to tell immediately b/c the line will look broken.

If you really want to go through your car, I'd suggest picking up Carroll Smith's set of books.

Hope that helps!

 

[L8apex32]

Just because some year 944's have a weak suspension arm that breaks - it does not mean that other cars must also have a similar problem.

Regarding suspension specifically, many NSXes have thousands of miles of track use without breaking suspension parts.

YMMV

 

[docjohn]

The rubber joints between susp pieces can loosen up bringing alignment out of spec.If you are a frequent tracker who is on r compounds and or slicks just be vigilant with checking for excess play around the susp.This is why some of our more industrious members have developed noncompliance heim joints for the car.

 

[nsxtasy]

P.S. Another thing to do - on the NSX as well as with other cars - is to check your axle nuts.

 

[ak]

The rubber joints between susp pieces can loosen up bringing alignment out of spec.If you are a frequent tracker who is on r compounds and or slicks just be vigilant with checking for excess play around the susp.This is why some of our more industrious members have developed noncompliance heim joints for the car.

I've had question about this for a while now. Changing the rubber bushings to non-compliance items and the mono-ball bearing items that titanium dave is working on will definitely have performance benefit, but would it not cause more stress on the suspension pieces themselves since there'll be nothing to absorb the forces that wears out the rubber bushings to begin with? I'm not knocking on the non-compliance parts since I think they are great for the track but I would be scared of its negative effect. What do you guys think?

 

[docjohn]

Good points Akio,I don't know how long the aluminum pieces inbetween the noncompliance parts will last over time.You are right that it is the rubber which reduces stress on the metal,but iether way some of our susp pieces don't allow for just bushing replacement,you still have to replace the whole arm.I'll waite for some of our more tech savy guys to wiegh in.