Optimum ride height w/o giving a crap about looks

[thouchin]

Im sure this has been discussed alot but I was tired of weeding through the opinions that took "looks" into account.

I will recieve new dampers and springs (the new SOS JIC set) in a few weeks and the spring perches are adjustable. This setup is suppose to be similar in stiffness to the NSX-R. So I need a good starting point and Im thinking the NSX-R ride height(as it translates to inclination of the A-arm) is the way to go.

So I need to convert the NSX-R hieght to a setting on my dampers.
First question: I have found that the NSX-R is .5-.75" lower... Which is it? are they the same from front to rear.
Second question: I need to know the diameter of the stock tire on the NSX-R. I can't find it anywhere.

If I can't get this info. I could guess the that NSX-R diameter adds .25" to ride hieght and that the stock drop was .5" all around... meaning that if I drop mine .75" then my steady state susp will be very similar to the NSX-R.

Again, I don't care about looks or scraping. I'll adjusts them up later if I bottom too much. Any thoughts?

T.J.

 

[Hugh]

Second question: I need to know the diameter of the stock tire on the NSX-R. I can't find it anywhere.

Check out this thread. In it nsxtasy refers to a very useful Tire Size Calculator.

 

[NSXGMS]

I have the 16/17 OEM setup for wheels/tires and have a 1.25" drop. I think it's absolutely perfect. Any more drop would be too much for sure, for practical reasons. Looks-wise I think the car could go to 1.5" though.

At first I was a little leery about a 1.25" drop and was leaning more towards .875" but once I did it I really loved it. I think .5" would be a little high now to be honest.

 

[nsxtasy]

I "don't give a crap about looks", either. My NSX is at the stock ride height and I think it's perfect, right where I want it.

 

[jond]

You would want the A-arms parallel to the ground when under load right?

I don't know how race teams figure it out. They probably have a level they attach to the top of the A-arm that interfaces to a computer to record where it is during a hard corner.

 

[otto_joe]

Ok, I just saw this thread and decided to go to the garage and measure my setup (NSX-R suspension with slightly worn 02+ OEM tires).

Hub center to fender lip (not including liner)
Left Front 35cm
Right Front 34.5cm
Left Rear 36.5cm
Right Rear 36.5cm

Floor to center of jack points
Left Front 12.4cm
Right Front 11.8cm
Left Rear 11.6cm
Right Rear 11.4cm

Floor to fender lip
Left Front 64.5cm
Right Front 63.2cm
Left Rear 67cm
Right Rear 67cm

Could someone do the same measurements so that we could try and figure out the height differences? I didn't measure my pre Type-R heights. :frown:

In it nsxtasy refers to a very useful Tire Size Calculator.

It's a good starting point, but not all 255/40/17s are the same diameter.
For example:
RE010 215/45/16 section width 8.3" tread width 7.3" overall dia 23.5" Revs per mile 900
A022 215/45/16 section width 8.4" tread width 7.2 overall dia 23.6" Revs per mile 879

RE010 245/45/16 section width 9.5" tread width 8.4" overal dia 24.6" Revs per mile 861
A022 245/45/16 section width 9.6" tread width 8.5" overal dia 24.7" Revs per mile 840

Thanks.

Otto

 

[nsxtasy]

Floor to center of jack points
Left Front 12.4cm
Right Front 11.8cm
Left Rear 11.6cm
Right Rear 11.4cm
.
.
.
Could someone do the same measurements so that we could try and figure out the height differences?

Here are two sets of numbers:

1. My '91 is stock ride height. Measuring from the flat ground to the bottom of the tabs for the four jacking points (not the ones in the middle), all four are between 4.5 and 4.75 inches.

2. Page 3-17 of the 1991 service manual shows a diagram which tells the distance from the ground of the lowest point between the wheels, which is the jacking tabs and is shown as 5.3 inches. This appears on page 39 of the .pdf file, which you can find here.

It's a good starting point, but not all 255/40/17s are the same diameter.
For example:
RE010 215/45/16 section width 8.3" tread width 7.3" overall dia 23.5" Revs per mile 900
A022 215/45/16 section width 8.4" tread width 7.2 overall dia 23.6" Revs per mile 879

RE010 245/45/16 section width 9.5" tread width 8.4" overal dia 24.6" Revs per mile 861
A022 245/45/16 section width 9.6" tread width 8.5" overal dia 24.7" Revs per mile 840

It's true that not all 255/40-17 tires are the same diameter. Furthermore, not all tire manufacturers use the same measurement techniques when determining their published specs. For example, some computer revs per mile and diameter by simply calculating the numbers based on the specified size, while others take actual measurements; some adjust the numbers for ground deflection, while others don't; etc.

 

[Hugh]

1. My '91 is stock ride height. Measuring from the flat ground to the bottom of the tabs for the four jacking points (not the ones in the middle), all four are between 4.5 and 4.75 inches.

2. Page 3-17 of the 1991 service manual shows a diagram which tells the distance from the ground of the lowest point between the wheels, which is the jacking tabs and is shown as 5.3 inches.

If that's the case then your car is not at stock ride height. It's about 3/4" lower. Could the difference be accountable to worn springs?

 

[fastcat99]

OEM cars have to meet standards for driveway ramp angles, curbs, etc. However, at the end of the day I figure that the might of Honda Engineering combined with the genius of Ayrton Senna have combined to develop suspension settings for the NSX which are probably perfectly optimized for 99.9% of users. So - stock ride height is best unless you are re-engineering the entire system.

YMMV, however. Feel free to have fun messing your car up with changes!

 

[MCM]

If you say so......................:wink:

 

[kreh]

Fastcat99 has a good point. Also, the driving requirement is meeting the factory alignment specs. When the car is lowered more than 0.5 inches, the wheel alignment specs cannot be achieved and the car will have ~-2 degrees of camber and aggressive toe in. This all leads to excessive tire wear.

 

[Binh]

It seems that we still do not have an answer. I NSX-R is suppose to have the best set-up, however this car still needs to be used on the streets and therefore has some compromises. I believe optimal height would be lower than the NSX-R.

I do not have any concrete evidence, just an opinion.

thanks.

 

[NSXGMS]

It seems that we still do not have an answer. I NSX-R is suppose to have the best set-up, however this car still needs to be used on the streets and therefore has some compromises. I believe optimal height would be lower than the NSX-R.

I do not have any concrete evidence, just an opinion.

thanks.

I think we need clarification on "optimal" ride height. The NSX-R seems to be fine with a .5" (1cm, actually) drop. I really like a 1"-1.25" drop personally.

The NSX-R setup is not that uncomfortable considering the performance level. That being said it's not the most comfortable setup out there. The best compromise for the street without sacrificing much is going to be something like a Bilstein/Dali progressive spring combo. Feels very cushy but definitely increases the performance level. One of the only setups which doesn't compromise much, if anything.

The next step would probably be the Tein RA/RE setup or Bilsteins with Zanardi springs. More performance, less comfort.

The Tein setups can lower about 1.00" and if you use the Bilsteins on the lower perch with the Zanardi springs you'll get a ~1.375" drop.

 

[ediddynsx]

Here is my car on JIC's so this should give you an idea of what it will look like. I have 18,19s on so if you go with 17,18s it will sit a little lower. But you cannot go any lower than what I have there. You will start breaking parts if you go lower than that. That is the lowest that I can go recommended by Jon Martin.

 

[thouchin]

It seems that we still do not have an answer. I NSX-R is suppose to have the best set-up, however this car still needs to be used on the streets and therefore has some compromises. I believe optimal height would be lower than the NSX-R.

I do not have any concrete evidence, just an opinion.

thanks.

I'm not so sure... the NSX suspension pickup points are designed for the stock ride height. This means that when it is lower the arms are not parallel with the ground they are inclined. Which translates to geometry changes during bump/droop that are not of the original design and hence possible degrade in performance. The NSX-R did not change pickup points so I suspect that they lowered it until these negative effects overcame the positive effects of the lower CG.

I guess I should have clarified "optimal" to me is MAX performance.

I ended up lowering mine by .75" all the way around.

To fastcat99,
no way 99.9% that would mean of the 10,000 NSX only 10 people went to aftermarket susp... and... Senna's input was for marketing, period.

One last thing... I find it strange that no matter how much I emphasise that I did not want to take looks into account that people can not resist giving their opinion about it. Its actually kind of interesting.

T.J.

 

[jond]

It seems that we still do not have an answer. I NSX-R is suppose to have the best set-up, however this car still needs to be used on the streets and therefore has some compromises. I believe optimal height would be lower than the NSX-R.

The RealTime Racing NSX is probably the perfect ride height with 0 compromises. Anyone know what it is?

Obviously, ride height goes along with spring rates though, and theres no way you could run racing springs on the road without breaking things.