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

[fooddude]

Originally Posted by Davey

The suspension designer specified it that way for a reason, I figure he knows what he's doing.

Yes of course they know what they're doing, hehe

But, don't forget the designers and engineers have to be conservative; and they also took into account that this car would be owned by many "tuners".

Sticking with oem wheel width and offset for every car would be a horrible thing. My stock wheels on my old S13 were even worse than the twin. They were sunk in maybe 3x as much and on tiny 15" wheels.. while the wheel well looked as if it was designed for a 17"+ wheel lol. Stock wheels on an S13 looks like you're using 4 spare tires lol.

[Davey]

Originally Posted by fooddude

That way of thinking doesn't make sense.

It doesn't if you're talking about what "looks cool", but that's not what I'm talking about.

It's all subjective

No, it isn't.

Originally Posted by fooddude

Yes of course they know what they're doing, hehe

They absolutely do... And you, do not. Sorry. Try learning something new...

But, don't forget the designers and engineers have to be conservative; and they also took into account that this car would be owned by many "tuners".

Sticking with oem wheel width and offset for every car would be a horrible thing. My stock wheels on my old S13 were even worse than the twin. They were sunk in maybe 3x as much and on tiny 15" wheels.. while the wheel well looked as if it was designed for a 17"+ wheel lol. Stock wheels on an S13 looks like you're using 4 spare tires lol.

Yeah, you keep talking about sunk in or how it fits in the wheelwells... I'm not talking about what it looks like, I'm talking about function.

Changing the scrub radius has an effect on handling. Changing from the stock offset to a lower offset will make the scrub radius more positive (or less negative).

[7thgear]

well, here's the honest truth


if you want to poke your wheels out the correct way... you get yourself custom control arms and change the strut pickup point


and in the rear, you get longer LCA and UCA and custom length axles to match




but fuck all that, i'll just get myself some +20 wheels and call it a day, gnomesane?

[Zero90]

What is everyones take on 18x9 +38 for the fronts and 18x10 +38 for the rears. Tires are Michelin Pilot Sport A/S 3, front tires are 245/35/18 and the rears are 265/35/18. Currently lowered on ST Coilovers. I'm debating on switching back to a squared set up but unsure. Yes, I did roll my fenders a bit. I have the Work XD9's by the way, in matte blue.

[Dave-ROR]

I do all of this and get first place at the HPDE. You clearly don't know anything.

[gramicci101]

Originally Posted by Dave-ROR

I do all of this and get first place at the HPDE. You clearly don't know anything.

Drunk Dave is kind of amusing.

[7thgear]

Originally Posted by Zero90

What is everyones take on 18x9 +38 for the fronts and 18x10 +38 for the rears. Tires are Michelin Pilot Sport A/S 3, front tires are 245/35/18 and the rears are 265/35/18. Currently lowered on ST Coilovers. I'm debating on switching back to a squared set up but unsure. Yes, I did roll my fenders a bit. I have the Work XD9's by the way, in matte blue.

do you make 400 horsepower to match such a tire/wheel combo?


you're just throwing gas dollars away

[jflogerzi]

Originally Posted by 7thgear

do you make 400 horsepower to match such a tire/wheel combo?


you're just throwing gas dollars away

I agree. I already saw a decent drop from stock to 225/45/17's PSS's

[DarkSunrise]

One thing that's getting overlooked here is that some people just want the look... and that's OK too. There's no requirement that you can only mod your car to increase its performance. It does seem to go a bit against the raison d'etre for this car, but hey it's a free country.

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.

Go with 17x8. I'm using 215 max summer tires on 17x8 wheels, and it feels great on the track. There's a slight bit of tire stretch, but that helps with steering feel and turn-in, especially if your tires don't have the stiffest sidewalls. The car is completely predictable on the track and relatively easy to catch on the transition to oversteer.

As you mentioned, 17x8 also gives you the versatility to run 225, 235, and even 245 width tires. I'm actually moving to 235/40/17 tires next, mostly because I'm looking for additional heat resistance. With 17x8 wheels, you have that option to move up a tire width or two.

If I could do it again, I might have gone even wider to be honest, maybe 17x8.5. That's a great width for 225-245 tires.

[sshole]

But guys, where are the nudes?


On a serious note, what's a good alignment spec for high speed stability? I'm talking about straight lines with little to no tramlining, minimal steering input correction, etc.

[SP86]

Well I've made 2 of 7 mistakes not bad

[Davey]

Originally Posted by DarkSunrise

One thing that's getting overlooked here is that some people just want the look... and that's OK too. There's no requirement that you can only mod your car to increase its performance. It does seem to go a bit against the raison d'etre for this car, but hey it's a free country.

I'm all for people modding the car for looks if that's what they want... I'm less thrilled with people taking that point a little too far and negatively affecting the handling and then driving it on the streets I drive on, too.

Go with 17x8. I'm using 215 max summer tires on 17x8 wheels, and it feels great on the track. There's a slight bit of tire stretch, but that helps with steering feel and turn-in, especially if your tires don't have the stiffest sidewalls. The car is completely predictable on the track and relatively easy to catch on the transition to oversteer.

As you mentioned, 17x8 also gives you the versatility to run 225, 235, and even 245 width tires. I'm actually moving to 235/40/17 tires next, mostly because I'm looking for additional heat resistance. With 17x8 wheels, you have that option to move up a tire width or two.

If I could do it again, I might have gone even wider to be honest, maybe 17x8.5. That's a great width for 225-245 tires.

I'd thank you 5 more times for this if I could, it's exactly what I've been looking for confirmation of. I would rather go with the 17x8 for the tire choices and I am definitely concerned about turn-in feel... I had just heard that breakaway was "less progressive" and I don't have time/money to try it myself.

[dradernh]

Originally Posted by Racecomp Engineering

...pick tire compound first, then everything else falls in place.

This.

An observation: The initial post makes this seem more like a track thread than a suspension thread, even though the subject is suspension. No criticism intended. In any event, it's an outstanding post and one that performance-oriented drivers would do well to read and re-read, especially before pulling out the plastic.

[jack43]

#8: Mad swaybars becuz racecar!!