I want to add more details on the length of the OEM shock as a reference for you guys when doing a custom coilover.
The OEM shock length Front is 560mm; Rear is 440mm; Travel for front and rear should be about 63.5mm

This is the reference from Ohlins DFV. the length of I am talking about is this 420mm place

Motion Ratio reference from HKS HiperMax R

here is some data I found from the s2ki forum and convert it into the metric unit.

 

I'm in the market for some coilovers and am looking forward to the comparison with the TTXs

 

That would be my next one

 

I want to update some of my notes about this suspension.
The full length I am referring to is the distance from the top hat surface, where the contact with the car body occurs, to the middle point of the clevis bolt.

The full length is A

The OEM shock's full length:
Front 560mm and Rear 440mm

The PSI TTX that I saw:
Front 530mm and Rear 410mm

The Default Nitron R3 with the 30mm thread in the clevis :
Front 545mm and Rear 410mm

After I specifically asked for four 10mm longer clevises, which means adding 10mm to the bump stop :
Front 555mm and Rear 420mm

Why should we get the same length as the OEM shock?
Because the suspension geometry is designed to use the OEM shock's length, I understand that people will say the car should be lowered to lower the center of gravity for better handling; however, that is not how it works. The better way to say it is to align the roll center with the center of gravity. Which means reducing the distance between the roll center and the COG by applying the Roll center correction ball joints. That will automatically lower the car's ride height.

Sometimes I really regret not getting the WiseFab Track Kit.

In most cases, these aftermarket coilovers reduce the full length from the OEM by about 25mm at the bump stop, which is not ideal because you might experience an extremely low ride height after the roll center correction. And it still has the bump-stop problem, where you cannot extend the lower clevises further to prevent your tire from contacting the car body in full compression, such as high-speed cornering. One of your front tires may be contacting the frame, locking the tires. That is dangerous. The travel length of the coilover is acceptable.

I have ordered the new TTX from InertiaLab and asked that the full length be at least as long as the OEM. I understand that most pricy coilovers, such as Ohlins TTX, JRZ, Moton, AST, and MCS, do not offer adjustable tophats or clevises. The longer the full length becomes, the more critical it is for these users to adjust their bump stop.


This is the part I am talking about on the front of the frame, contacting the tire during high-speed cornering. That is why the right bump stop length is essential.

For the Rear coilover, I believe the travel can be extended further, since there is more space in the rear than the front. I can sometimes feel the rear is in the air, which I cannot do much about. I might ask Inertia Lab to add more travel in the rear during the coilover rebuild. I think the rear deserves more full droop.

 

I hope my notes can help you when you are choosing custom coilovers. I haven't had a chance to measure the travel of my Nitron R3 yet. I purchased the Nitron default setting. They have a great price and excellent valving, but when it comes to the full compression length, full droop length, and travel length, I believe, as customers or players, we can realize how much length we might need. The Nitron R3 is my first customizable coilover. I have to say that the experience was a little bit bad. I asked them, "I want the remote canisters." They said, "How long?" I said I don't know!!! What spring rate do I want to use? I can calculate that, which is 16/16kg, after my calculations. They never asked me how long you want the shock to be, how long you need full compression without contact between the frame and body, or how much travel you want. Well, most customizable coilver salers don't ask about it. And on this S2ki forum, I did not see any helpful information about it. So I decided to write down what I have experienced and share some data for future people who need it.

I will keep updated if I have new measurements or valuable data to share.

 

My friend has a 3-way ttx by PSI on his F82. According to his comments on my Nitron R3," this Nitron R3 performs as well as my TTX."

 

I am currently frustrated with the fact that most front coilovers have this issue with contacting the frame and that most people think its ok. Sucks to see that nitron's are also not long enough.

 

It's not a coilover issue. It's a wheel and tire issue - too wide with too high of an offset. Get a narrower wheel/tire and a lower offset. Roll/pull your fenders more if you want a wider wheel/tire. Pick where you want to have contact issues, the outer fender or the top of the wheel well.

 

Yea, you're not wrong. I think most of us are running 17x10 et45-55, 255 tires. I agree, slightly larger than what Honda designed the car for. Still, longer coilover would help with the problem.

 

In Fact, for the aftermarket wheels with aggressive width and high offset, and wider tires. It is very common to see those issues. After I have increased the 10mm clevis and resprayed the scratch area. It is still scratching on the Laguna Seca when using the Apex wheel with 17x10J+48 with Hoosier TAP 245 tires. Yes, I have the steering rack limiter to reduce the lock-to-lock steering.
If it really cares, do not scratch that area. It is better go for the OEM ride height. Either by longer the cleivs or thicker the tophat.