Anyone Selling Stock Rear Springs (275#)? Track Handling Woes!

[prematureapex]

Took our 818C out for its maiden track day this past weekend. It's running 235/255 Dunlop ZIII tires, no front sway and 350/350 springs. I thought that would be reasonable in view of what people have been running rear spring wise on the forums.

Boy was I wrong. The car was pretty menacing to drive in lower speed corners. It has a bit of high-speed push, but the snap oversteer in the low speed corners made it unnerving to drive, borderline unsafe IMHO. Perhaps more relevantly, overall grip in the low-speed stuff seemed to be way down. We were crawling through steady-state corners compared to other cars.

We dialed in rear toe during the day to try to improve the situation, and it helped a bit (now running 1/4" total, maybe a bit more). I think the rear ride height is too high vs. the front, but wouldn't think that would make a huge difference.

My first thought was to try the stock rear springs, then again, many seem to be having good results with higher rear rates.

Up the tire stagger? Add the front bar? All of the above?

[fletch]

I should have a pair for purchase, or loan if you want. I was planning to run stiffer rear springs after seeing how much body roll we got when gokarting. PM me if you want to talk options.
What was your tire pressure during the track day?

[prematureapex]

Varied it trying to make it a bit more drivable, starting in the low 20s up to 30ish. Shame about the lack of front tire options for the car. I'd keep the 235/40 fronts, but not sure about fitting anything wider than the 255/40 in the rear.

[taco20]

Hey first off welcome to a rear weighted car. The softer springs in the rear will not help the car. You actually need to go stiffer in the rear to handle the extra weight so it will stop squatting and help the car turn. No matter what you do the car will always have a push/tight feel to since there is no weight on the front and a smallish tire. I track my S all the time and have gone to 500 in the rear and 425 in the front. I had issues with the 350 front causing the splitter to drag when hard on the brakes going into a turn. I tried 500 front and 600 rear per Wayne but I wasn’t running a good enough tire to make it work. May try them again next season.

So don’t go softer you won’t be happy. Find a stiffer rear to try and also add as much caster as you can get to keep it stable at speed plus it does help with turn in when going into a corner.

You will have to learn how to drive a rear weighted car with less steering input to keep the tail happy. Take it from someone that is good for at least one spin or time in the grass almost every event. Once you learn to drive it you will be able to out run and pass most cars on the track like I do.

[prematureapex]

Hey first off welcome to a rear weighted car. The softer springs in the rear will not help the car. You actually need to go stiffer in the rear to handle the extra weight so it will stop squatting and help the car turn. No matter what you do the car will always have a push/tight feel to since there is no weight on the front and a smallish tire. I track my S all the time and have gone to 500 in the rear and 425 in the front. I had issues with the 350 front causing the splitter to drag when hard on the brakes going into a turn. I tried 500 front and 600 rear per Wayne but I wasn’t running a good enough tire to make it work. May try them again next season.

So don’t go softer you won’t be happy. Find a stiffer rear to try and also add as much caster as you can get to keep it stable at speed plus it does help with turn in when going into a corner.

You will have to learn how to drive a rear weighted car with less steering input to keep the tail happy. Take it from someone that is good for at least one spin or time in the grass almost every event. Once you learn to drive it you will be able to out run and pass most cars on the track like I do.

Thanks for the post...I'm not worried about the push, in fact, I'm welcoming of it. The car turns in great at low speeds, caster is maxed and running STI front arms.

I'm specifically trying to get rid of a way out of control rear end, which will only get worse by adding rear spring all else being equal.

I have experience with mid-engine, formula cars, mid and rear engine sports cars, etc. This is not that. I thought it was just the combination of higher rear spring rates and a low tire stagger causing it, but perhaps it's something else...just not sure what it could be. The car was a mess to drive, with steady-state low-speed corning (think skidpad) 5-10 mph under what our FWD hatch on 615ks was running at the same outing. Comically slow and comically hard to drive.

Sorry, a bit frustrated. Certainly doesn't handling like an Elise or a Cayman at this point...:lol:

[J R Jones]

pre-apex, You may have this covered in your rear alignment, but just in case, the rear caster is critical. The alignment is odd in my experience.
You must adjust the lower pivot bolt on the upright to exactly the same pitch angle as the inner lateral link pivots.
I use a digital angle gauge on the lateral links close to the inner pivots for reference.
I move the angle gauge to the outer end of the links just inboard of the lower pivot on the upright.
Adjust the upper track link to make the outer pivot match the inner.
Sorry if this is already in your set-up.
I seem to recall this made Sgt Gator's car more stable in corners.
jim

[Sgt.Gator]

Make sure you aren't getting roll steer under compression, which will only be made worse by softer springs. See Wayne's thread on rear setup:
https://thefactoryfiveforum.com/show...et-up-pointers

[Sgt.Gator]

prematureapex what did you come up with to fix your handling. Update Please!