My car a 95 GSR with Koni Yellos and Eibach Prokit with 18s
Perches all on tallest settings 25% stiff in front 15% stiff rear
I feel alot of roll from the back like when I turn for example turning right....right rear tire lifts up. This causes my left side to go deep into fenders sometimes rubbing up front and if theres a bump on the turn ohhhh shiiiiit!

From what I am noticing....stiffing the shocks do little to prevent roll.
I have stock sways and front strut all around.
I dont autox but I want to reduce what is happening to my car. My only idea is to get a 21 or 22 mm rear sway bar....suggestions?

 

Get a Type R rear swaybar. They are cheap and for your purposes, will solve your problem.

 

Shocks don't reduce the amount of sway or roll, they change the rate or roll. Stiffening the shock will slow the rate of change but the car will eventually roll just as far. You are on the right track though, a larger rear sway bar will help. A copmtech or Type R bar is probably the best choice. Though it will increase the oversteer.

 

Honestly...and you probably won't like hearing this...the 18" wheels have got to go. Those, coupled with the relatively soft rates of sport springs like Prokits, are the problem.

To answer the real question...a large rear swaybar will help lots. Make sure you mount it correctly.

 

A larger rear swaybar is only going to make the inside rear tire lift that much farther into the air.

The problem is that the wheel/tire package is too big for the car, and the spring rates are not stiff enough to prevent deflection of the suspension.

 

That's what I thought too. A stiffer roll bar will just help lift the tire.

 

18s = Rubbing

 

Somebody said sell the 18s......and I agree that is where the heart of the problem lies. Its hard to seperate myself from my rims.....18 inch lightweight (19 lbs) 3 piece polished aluminum lip webs with brandnew S03s! aaaaarrrrrrrrggggghhhhhhh! Is there another way? If I do get smaller rim/tire combo I want something that is not screeching around every turn and just spinning in place as I climb into boost.....suggestions? experiences?

 

Yeah, that's light for an 18" wheel, but it's like a lead brick on an Integra.

Kosei 15" K1's are 12 lbs and $139. Think about that if you bend one of the 18's.

And what are you talking about screeching around every turn? What the heck does wheel size have to do with this? You can't compare the stock tire to S03's in any size. Just run Azenis or any other good sport tire if you want better wet traction. Hell you can even run S03's if you put throw spacers in the back and roll the fender lips and run 225/50-15.

Warren

 

I cant explain it but with the 15s and 16s its easier to lose traction on turns i.e. screech tires, than with my 18s. I can take a hard turn at 60-70 mph and the tires dont even make a peep. Actually I have never heard the tires screech. I like the idea of Kosei though I spend that much everytime i need to fix a bent rim....3 so far.

 

No. It's just too much wheel for hard cornering. Look at it this way. Darn near all the race-prepared Integras I'm aware of are running 15s - some run 14s. Autocrossers sometimes run 13s (light weight + gearing = fast).

Don't use tire noise as an indicator for what's good and what's not. There's too many variables. Ambient temperature, track condition, tire pressure...and probably more.

If you want, keep the 18s for looks, and get a set of 15s for track or autocross use. I can just about promise you that you'll be happier that way.

(edit) I almost forgot. I run 225-45-15 Hoosiers on a 15x7 wheel, and I get a bit of rub even with those. Granted it's a *big* 225 tire, but this does illustrate that there isn't a hell of a lot of extra room in there.


[Modified by krshultz, 3:09 PM 12/24/2001]

 

hi Karl this is Jasper
i understand everything u're saying and i'm not trying to argue...but why are the Realtime type Rs running 17s instead of 15s....do the 17s just do better on certain kinds of tracks or car setups? U think the Rs could be faster with 15s?
just curious
have a good holiday!


[Modified by Lonerider, 1:19 PM 12/24/2001]

 

The 17s are a spec size in the World Challenge if I am not mistaken.

 

ok thanks! so it doesn't mean that 17s necessarily are the best tires for fwd cars on road courses...the type Rs are just restricted to using that diameter to compete in the series

 

I just checked it. 17s are the max diameter, not the required.

Also understand that inherently the less sidewall the better - it decreases rollover however there is a price for that. The WC guys have budgets that are astronomical. They can drop $1000/wheel for ultra light 17s. 19# is not a light wheel by any stretch of the imagination. If you can afford to buy a 9-10# 17 then there are probably gains to be had,

 

The WC cars changed last year from Hoosier DOT race tires that almost everyone ran in a 15 in. size to Toyo T1s street tires (Shaved and Buffed). I think that the reason they are running the 17's is to have as little sidewall flex as possible with a street tire. I am sure given the choice it would be back to a 15 in. DOT race tire.

Victor Penner

 

Stiff/short sidewalls are only good to a point, the spring rate and damping of the tire is essential for rougher tracks.

If you want to keep the 18s and not rub, buy some coil-over sleeves and stiff springs. Ride quality will suck compared to what you're used to but you can keep the car off of the tires.

 

The reason for 17" wheels I believe has more to do with a compromise between a heaver wheel, tire which would fit over a bigger brake calliper, rotor combination and the ability to legally change final drive ratio VS running a lighter soft side walled 15" street tire and wheel. A 17" street tire with a low side wall height, large brakes, final drive change and light wheels should hold an advantage over a 15" street tire with a relatively high, soft sidewall and the roll over associated with them. If they were on race tires the sidewalls would be constructed to be equal in their ability to resist roll over at 15" and 17". Using race tires the advantage of larger brakes and changing final drives would likely be out weighted by using the lighter, smaller tires and wheels on most of the tight tracks and street couses they compete on.





[Modified by DB1-R81, 3:05 PM 12/24/2001]

 

You all are a very informative bunch!
Thanks for the replies......The stiffer sidewall with lower profile is probably why I thought the car handled better on turns but after reading your replies i know there are alot more factors and I gotta give credit to smaller diameter rims/tires. I was also thinking about taking my car to a shop and have them torch that little groove that acts like a knife to my tire....its the only crap that rubs.....Its directly in the middle inside of my two front fenders and hangs about an inch. With that gone I should reduce rubbing hopefully up to 50% - 100%. What are the pros and cons with torching that piece?....obviously remove plastic inner fenders first and leave it to a pro....

 

Jasper (and all), bear in mind that the Realtime cars are running REALLY high spring rates. In the 1000# neighboorhood. And they're likely not running fender liners, and I'm pretty sure they've rolled the fenders.

Put it this way,I had to roll the **** out of my fenders to get the 225-45-15 Hoosiers under my car. By racecar Integra standards, my spring rates are pretty soft for now...but they're almost intolerable on the street. For what that's worth.

I agree with what the others have said WRT sidewall flex given the requirement to run a street tire.

And DB1-R81 raises a good point. These guys in SWC are allowed, under certain circumstances, to run aftermarket brakes. So the 17" wheels let them fit more brake under the car.

--Karl, who owns a lot of 15" wheels...

 

I'm with Karl on this one. Also, I wouldn't justify a larger wheel diameter just because SVWC Touring cars use them. Has to do with brake rules, Toyo spec tire sizing issues, gearing, spring rates, etc.

 

I remember something about a new appearance package that WC Touring ran this year. I thought "big" 17 inch wheels were very much encouraged by the organizers as were the mandatory rear wings since every car had these features. Back when this was not an issue, the Realtime ITRs were running 15 inch wheels and just about all the other cars were running smaller wheels than what they did this year with the series' new "look". But who knows... why is it that the BTCC ran super big diameter wheels (19 inch?) or why do the FIA Rally teams run similar 17 inch+ size wheels on the tarmac stages? I would really like to know the real answer to what is better, but for now I'm also thinking with the concept of not running a bigger diameter wheel if you don't have to.

 

Take the fender liner out, and pound on that seam with a hammer. If you ding up the paint (you will), spray paint where you dinged it up, this will prevent rust. I know this probably sounds pretty ghetto.

Alex you raise an excellent point on the gigantic tires seen in BTCC. I can only speculate, but here are some guesses.

1. Those cars are so damn fast that they *need* giant brakes, which of course necissitates a large wheel
2. The series organizers know it looks mad tite yo, so it's required
3. With the amount of money those teams spend, I'm sure the wheel/tire combo is plenty light

I can certainly see low profile rubber being an advantage. Which leads me to another "I wonder why" question. Why is it that open wheel cars appear to run relatively tall-sidewall tires?

 

In addition to the other postulations on the large BTCC wheels I'd add: we use small and lightweight wheels since most of use have relatively torqueless 4 cylinders and need every mechanical advantage we can get. Even though the BTCC cars use fairly small engines, power isn't too much of an issue, and I'm sure their gear ratios and final drive are optimized for the huge tire diameter.
As for the open-wheel cars with high aspect ratio tires, I'd imagine the large amount of rubber is for greater heat absorption/dissipation since some open wheeled cars are the fasted racecars out there. The taller sidewalls are also probably an added safety margin for their incredibly stiff and somewhat fragile suspensions.
And really, F1/Indy cars would look silly with low profile tires, and vice versa for touring cars.

 

Someone posted before, maybe JonSE-R that the BTCC wheels weigh something like 6 pounds and cost thousands of dollar apiece. Apparently their suspension setups work with such large wheels, and they do indeed do a lot of gearbox-invasive gear-ratio and final drive tuning.