Suspension

[Xian]

GS-R rates are 200lbs/in front and 95lb/in in rear. TL and TSX are ~300lb/in front and ~150lbs/in rear for reference. Even the CTR is under 300lbs/in.

I would stay under 450lb/in and under on a lowered street car with nice non extreme performance tires that will have a softer side wall to improve the ride quality on the street.

Out of curiosity, are the CTR rates you mention for the older, EK chassis or the new car?

IME, spring rate (to a degree) doesn’t correlate to ride quality. I’ve been in cars with “low” rates that ride like crap because the shock package has too much high speed compression. The flip side is that I’ve owned/driven cars with 750/550 or 800/650 rates that were just fine. The biggest issue when you get into higher rates is finding dampers that have enough low speed compression but bleed it off so the car isn’t choppy over less than billiard table smooth surfaces. The other piece of ride quality that is often overlooked is shock travel and bumpstop tuning... there are a ton of solutions here also and “keeping the car off the bumpstops” isn’t always the right answer.

[aklackner]

On the subject of tuning with bump stops,
Here's an option (though more geared toward Miata's) that has a pretty approachable line of bump stops in varying heights and hardness.
https://5xracing.com/c-1105233-bump-sto ... nting.html

A setup I'm putting together to play with will use softer rate 350(linear)F/175>350(progressive)R with mid stiffness (~200in\lbs) bump stops sized to engage a bit earlier to help aid spring rates under increased load.

[Xian]

Yep, looks like a solid selection. I’ve always bought through these folks (who sell basically the same stuff):

https://www.resuspension.com/

Their COT foam bumpstops are what I’ve used in the past with good results.

[aklackner]

Yep, looks like a solid selection. I’ve always bought through these folks (who sell basically the same stuff):

https://www.resuspension.com/

Their COT foam bumpstops are what I’ve used in the past with good results.

Nice one, saving that for future exploration (maybe if I ever try to figure out how to setup a stacked bump setup or bump springs).

[Xian]

Here’s the COT style ones I used. IIRC, I ran the shorter ones up front in medium and the longer ones in the rear in stiff (on stock dampers). I’ve used the longer ones trimmed for length with Moton and MCS shock packages.

https://www.resuspension.com/index.php/ ... eries.html

[3pedalJohn]

GS-R rates are 200lbs/in front and 95lb/in in rear. TL and TSX are ~300lb/in front and ~150lbs/in rear for reference. Even the CTR is under 300lbs/in.

I would stay under 450lb/in and under on a lowered street car with nice non extreme performance tires that will have a softer side wall to improve the ride quality on the street.

Out of curiosity, are the CTR rates you mention for the older, EK chassis or the new car?

IME, spring rate (to a degree) doesn’t correlate to ride quality. I’ve been in cars with “low” rates that ride like crap because the shock package has too much high speed compression. The flip side is that I’ve owned/driven cars with 750/550 or 800/650 rates that were just fine. The biggest issue when you get into higher rates is finding dampers that have enough low speed compression but bleed it off so the car isn’t choppy over less than billiard table smooth surfaces. The other piece of ride quality that is often overlooked is shock travel and bumpstop tuning... there are a ton of solutions here also and “keeping the car off the bumpstops” isn’t always the right answer.

The new CTR FK8.

[Xian]

GS-R rates are 200lbs/in front and 95lb/in in rear. TL and TSX are ~300lb/in front and ~150lbs/in rear for reference. Even the CTR is under 300lbs/in.

I would stay under 450lb/in and under on a lowered street car with nice non extreme performance tires that will have a softer side wall to improve the ride quality on the street.

Out of curiosity, are the CTR rates you mention for the older, EK chassis or the new car?

IME, spring rate (to a degree) doesn’t correlate to ride quality. I’ve been in cars with “low” rates that ride like crap because the shock package has too much high speed compression. The flip side is that I’ve owned/driven cars with 750/550 or 800/650 rates that were just fine. The biggest issue when you get into higher rates is finding dampers that have enough low speed compression but bleed it off so the car isn’t choppy over less than billiard table smooth surfaces. The other piece of ride quality that is often overlooked is shock travel and bumpstop tuning... there are a ton of solutions here also and “keeping the car off the bumpstops” isn’t always the right answer.

The new CTR FK8.

Gotcha. It’s worth keeping in mind that comparison across drastically different chassis’ aren’t too useful. The new CTR is a strut variant up front where the motion ratio appears to be wildly different from the other stuff we’re talking about. I’d bet a 300# spring on that car is probably like a ~250# wheel rate whereas the 200# GSR rate is more like 100# at the wheel.

The rear of the FK appears to be closer in design to the troublesome RSX (but not as bad). I’d wager the motion ratio back there means you’d want something like triple the rate of the front in order to get a wheel rate that’s half the front.