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[RPM90]

I see a lot of you run 225/255.
But, seeing that there are a lot of comments about under steer on the 1, has anyone tried stock 225 front with 245 rear?
More grip in front with no change in back, could improve front to rear grip ratio helping the rear come around easier.

Also, any try a stiffer rear sway or smaller sway in front to help reduce the under steer?

[BrokenVert]

Honestly. I'm in a vert and with 225/40, 255/35 Pilot Sport PS2 I have yet to hit the outmost limit of the car's abilities. That being said, I think most sways on sale are a replacememnt for the front sway. Which apparently does a lot.

[philaf_666]

I don't think the that only 225 instead of 215 is going to do much in regards to understeer. A square setup, let's say 245/245, maybe that would help more.

I know a big front sway will make it worst, so I guess a bigger rear sway would definitely help. But going too big in the rear could result in a bigger one wheel spin because of the lack of LSD. A big rear sway can lift the inside wheel more easily when hard cornering and the open diff will throw all the power to wheel that's in the air.

So you might consider a bigger rear sway, but not the biggest out there. Maube the UUC (19mm) and not the M3 one (23mm)

I'm also waiting for my car to come back from the shop with increased rear spring rate. That alone could solve the problem without loosing traction.

[Eyeman]

+1.

Coilovers/springs and going more square with tire size seems the way to go. Plus lowering with the coilovers/springs should help in many ways too. I'd assume camber plates would be the next best handling bang for the buck before sways.

[RPM90]

Originally Posted by Eyeman

+1.

Coilovers/springs and going more square with tire size seems the way to go. Plus lowering with the coilovers/springs should help in many ways too. I'd assume camber plates would be the next best handling bang for the buck before sways.

I agree completely that a nicely tuned suspension is THE way to go. Sways, and then tires are more minor parts of the fine tune, and are the low cost factors.

But, my question isn't about a full on suspension change. I'm simply wondering if anyone has tried the 225/245 setup. The reason is because I'm not going to spend money on a new suspension. I am going to swap out the RFT's right away.
Since I'm spending the money I'm just wondering of any obvious effects it might have.
Most people on here go with 225/255, but that keeps the ratio of the stock setup while giving a bit wider tire.

You want to either soften the end where you want more grip, or stiffen the opposite end. But, I've only test driven the 135i vert, and ddin't have any chance to experience any under steer, let alone how noticeable it really is on spirited driving. If I "track" this car it will just be simple SCCA lot course setups, which are very low speed.

I'm just curious. Thanks for the replies.

[RPM90]

Originally Posted by philaf_666

I don't think the that only 225 instead of 215 is going to do much in regards to understeer. A square setup, let's say 245/245, maybe that would help more.

I know a big front sway will make it worst, so I guess a bigger rear sway would definitely help. But going too big in the rear could result in a bigger one wheel spin because of the lack of LSD. A big rear sway can lift the inside wheel more easily when hard cornering and the open diff will throw all the power to wheel that's in the air.

So you might consider a bigger rear sway, but not the biggest out there. Maube the UUC (19mm) and not the M3 one (23mm)

I'm also waiting for my car to come back from the shop with increased rear spring rate. That alone could solve the problem without loosing traction.

I like your idea on stiffening the rear. How are you doing this?
Are you just switching out the rear springs?

The 1 doesn't have an LSD, but it is using the "poor man's" method, which a lot of company's are trying, by using the brake system to help slow down the inside wheel. But, that's only going to help if the tires stay on the ground. I'm not a fan of this cheap imitation attempt to mimic what a real LSD does. But, there it is.

If I were tracking this car, I would simply put one in.

[JME]

This is going to sound wacky....

Upgrade the front sway to keep the back tires planted on the ground, then align your rear wheels with a very slight (1/8") toe-out to help the back end rotate. It sounds counter productive, but the end result works better than having a neutral alignment with less front sway.

Putting some bigger rubber up front will also help. 225/245 might be better than 225/255, but it isn't a HUGE difference. Buying a tire that withstands a lot of abuse will make a bigger difference. Not over-driving the front tires, no matter the size, will make the biggest difference.

This just a cheap way to have more fun at an autocross, which I think is what you mean by "SCCA lot courses."

[RPM90]

Originally Posted by JME

This is going to sound wacky....

Upgrade the front sway to keep the back tires planted on the ground, then align your rear wheels with a very slight (1/8") toe-out to help the back end rotate. It sounds counter productive, but the end result works better than having a neutral alignment with less front sway.

Putting some bigger rubber up front will also help. 225/245 might be better than 225/255, but it isn't a HUGE difference. Buying a tire that withstands a lot of abuse will make a bigger difference. Not over-driving the front tires, no matter the size, will make the biggest difference.

This just a cheap way to have more fun at an autocross, which I think is what you mean by "SCCA lot courses."

Yes.

Really? A front sway? I like the idea of the front sway to keep things flat, but given what everyone says about under steer, I'd be worried that anything affecting the overall firmness of the front wouldn't help the situation, but maybe that along with a stiffer rear would balance better and keep things flat.

Does the cars rear tend to lift?

I can see toe out for straight line stability, but you've used this for decreased under steer too?
Interesting.

I think I am going to go with 225/245. I'd even try 225/235, but I'm worried about the grip with the power from the TT engine.

[135forthewin]

I'm running a 225/40/18 front and 245/40/18 rear tire setup. It works out well and really gets rid of some of that stock mid-corner understeer. Having Dunlop Direzzas all around helps keep the front end tucking in tight and stopping the rears from going up in smoke.
Well, most of the time they don't go up in smoke.

[lib]

Originally Posted by RPM90

But, my question isn't about a full on suspension change. I'm simply wondering if anyone has tried the 225/245 setup.

I'm ordering a set of 225/245 tires after this weekend's autocross and if I remember I'll let you know how they work out in the following event.

Another option you may want to check out are the M3 front lower wishbones. These should help add the missing negative front camber, they're fairly cheap and you could probably do the install yourself without too much trouble.