How to screw up your cars handling and ride - step by step!

[KonTheory]

So far all I have is RCE Yellows, and Im looking to get some wheels and tires, Also Im not an expert on suspension at all but was just wondering...

I have been looking into RPF1's, I know they are super common but they are really light and look decent
dont know whats better,
17x8 with michelin PSS, or 18x8 with PSS??
245 tires??

[Gopherboy6956]

Originally Posted by Racecomp Engineering

4. Big drop on coilovers

With some coilovers you don't need to worry about bump travel as much, but geometry is still a concern when lowering 2 inches. A big change in roll center height and changes in the dynamic alignment can be felt from the driver's seat...and it feels sloppy.

I know what you're thinking. There are a ton of cars on here that hit the track and handle well with a lowered ride height. If you must have that really low center of gravity than you must use very firm spring rates (and then quality dampers to match) or use geometry correction parts. That's what the fast guys and girls at the track are doing....not slamming their crappy coilovers to the ground and expecting all to be well.


5. Poor or mismatched dampers

Whether it's running very stiff springs on the stock shocks (or riding the firm bumpstops), or turning your adjustable dampers up to full stiff, damping that's not matched to the springs won't feel good. Underdamped will feel bouncy, floaty, and generally crappy in transitions. Overdamped will feel harsh, crashy, and might hurt your back. None of this is good for ride quality or handling.

Sometimes an adjustable won't have a "good" setting because the quality of the valving is just plain bad. This is more noticeable with firmer spring rates.


6. Alignment

Anything less than -1 degrees camber up front is a recipe for understeer. I still see people trying to get their camber "back to 0" after lowering. Don't do this! Tire wear isn't really a concern until you get to -2, so don't be shy...add a little camber and enjoy. Most enthusiasts will get BETTER and more even tire wear anyway. Toe is the tire killer.


7. Tire choice

Really stiff springs with all season or OEM tires can reduce grip as you'll be quickly/easily overloading the tire. Match your spring rates to your tire choice.

Running sticky tires on soft OEM springs is a problem too, but you will still gain grip from the tire. It'll just feel sloppy and move around a lot.


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Follow all of these steps and you can turn your well tuned factory BRZ/FRS into a sloppy, numb, slow reacting, pig of a car. Please don't though, it's too much fun when set up right.


- Andy

I'm going to assume since I bought Tarmac 0's with the optional 350lb springs, and lowered as you see below that I have NOT f'd up my track handling characteristics vs stock.

[h4nh]

checklist complete! lolllllllll

For rolling around on the street it doesn't make a difference. Track set up, yeah I totally ruined it.

[Calum]

So what would be a good tire choice for RCE yellows on stock damper? And RCE blacks on Konis or Bilsteins?

[mav1178]

Funny... I violate both #1 and #2 (staggered, 18" multi-piece wheels) and the car rides/drives fine on LA streets.

-alex

[Mad1723]

Originally Posted by mav1178

Funny... I violate both #1 and #2 (staggered, 18" multi-piece wheels) and the car rides/drives fine on LA streets.

-alex

Fine on the street doesnt mean fine on the track

[calibrz]

Originally Posted by Mad1723

Fine on the street doesnt mean fine on the track

hit it.

[wparsons]

Originally Posted by fooddude

Ok...so we've pointed out some cons..

...but what about the pros? (I'm sure there's some pros...unless we truly are all pessimistic/cynical in here haha )

...wider width..better cornering ..better stability, right?

Might want to look at what pushing out the contact patch does to the roll center as well... hint, it's not what you want.

[Davey]

Yeah I have said for years if you have to change the offset on your wheels to get them to fit, they're too damned wide.

I prefer to run the same offset as the stock wheel whenever possible. The suspension designer specified it that way for a reason, I figure he knows what he's doing.

That's my grumpy old man opinion and I'm sticking with it.

[Davey]

Originally Posted by Davey

I'm interested in doing 17's but I can't decide if I want to go with a 7.5 or an 8" rim.

With the 17x8 I can run a 215/45R17 (stock size) or a 245/45R17 and be really close to stock diameter, or even a 235/40R17 (a bit shorter) or 225/45R17 (taller). That's a great range of tire sizes, so the 17x8 seems attractive. Especially for the 245's.

I would probably do 215's for now and go from there, as my car is and will remain stock power levels for some time. I think some Michelin PSS in the stock size on some nice light 17's would be the trick.

Now we get to the questions...

1. I have heard that running a tire on its max rim width give better turn-in but is less predictable. That's what I'd be doing, running the 215 on the 17x8. How squirrely would this be?

2. Running 245/45R17 (Let's say PSS again) with otherwise stock suspension on a +45 or +48 wheel, what are the chances of it rubbing?

I guess I'm thinking, sticky 215's would be plenty for now, but I don't want to regret 17x7.5" rims if the 8's would be more or less the same.

Anyone?

I'm thinking maybe I should go with the 7.5" wheel.

[jflogerzi]

@Racecomp Engineering

I want to get rid of the tucked look. I am running 17x7.5 Rota Torques with PSS's in 225/45/17's. I am going to be adding the eibach Pro springs (1inch drop). My wheels have stock offset of 48. I want to bring them out to remove the tucked look. Getting new wheels is not an option so spacers with extend wheel studs are my only option. I have 20mm and 15mm spacers. Bad or good idea? To much? If so whats the max that's still safe on the track.

[fooddude]

Originally Posted by wparsons

Might want to look at what pushing out the contact patch does to the roll center as well... hint, it's not what you want.

Pic is a little irrelevant to my question. The pic mainly focuses on neg effects of slamming the car (which I never asked about; I didn't inquire about slamming dis whip yo)

[unsurety]

RCE and CSG in the same thread!!! :fap:

I plan to go 1.5" lower front + rear. Post above reminds me... what do you guys recommend as far as roll center correction?

I know you guys don't recommend staggered setups, but what about spacers in the rear with a square setup? Specifically, this style:

[fooddude]

Originally Posted by Davey

Yeah I have said for years if you have to change the offset on your wheels to get them to fit, they're too damned wide.

That way of thinking doesn't make sense.

It's the opposite. Too wide; and it's safer/easier to use closer to stock offsets to make them fit. And, the narrower the wheel, it's safer and easier to use lower offsets to make them fit.

A 9" would actually fit better with a closer to stock offset (ie: +44et) than a "changed offset" ..because it won't poke as much and also it won't rub on the outer fender (but, it may rub on stock lower spring perches). So does this mean they're not too damned wide like you said? Probably not; but that is subjective.

"Fit" is relative and subjective...and many actually see that stock wheels don't exactly "fit" in the first place, because they are too sunk in. So, many change the offset and get wheel spacers to make them flush or get new wheels that aren't as sunk in. So.. since stock wheels don't "fit" and many change the offset..does this mean they're too wide? Not at all..they're pretty skinny and narrow.

It's all subjective