FWD tire pressure advice?

[Cholewa]

At the pressures I was running there was still excessive wear in the middle of the tread patch, but after rotating them they seemed fine.

[claym]

You always need to maximize your front end adhesion while getting as much steering response as possible without over/under inflating tires. First you need to get as much front negative camber as possible (I use to run almost -2.5 in front of 97 Neon ACR legally and never had tire wear issues on the street. Tire wear usually comes from underinflation or excess toe in/out). Then, I usually run mid to upper 40s on the front tires (depending on the rollover of the front tires). Remember, higher tire pressures give you a higher effective spring rate and sharpen steering response. Also remember that tires on narrower rims require more pressure that tires on wider rims (like Chowela's wide Wabbit wims). Shoe polish will help with this. After getting front tires maxed for grip, adjust your rear tires to assist with rotation (less rear camber and some toe out can help also). I dial the rear toe to 1/4 out at the event (I have zero toe and 1/4 toe marked on the cam bolts so All I have to do is loosen one bolt per side and turn it to the amount I want). I usually run about 4-6 less PSI in rear and will adjust either up or down to get the rotation I need. I would guess Jordan has her mid 40s pressure about right for her car, while Chowela is using less pressure with the wider rims.

Always max the front end stick and then adjust the rear for rotation.

Just an opinion.....

[Cholewa]

7.5's are wide?

I think what really helped this season was the stiff sidewalls of the kuhmo spt's. I never had any issues of rollover even at lower pressures. But now that I have new tires that are appropriately sized (was running 215's, now 225's) I'll have to change it up a bit.

What you might want to do Rod, is let clay or sean or any other experienced FWD master drive the Si and tell you what they think needs to be done setup wise with the tires. They know where the perfect balance is between rear rotation and stickyness coupled with turn-in and traction up front.

[claym]

The olny factory optional wheels I can find listed for an 06-08 Rabbit is a 16x6.5 wheel, with the car coming with 15s (probably 15x6) standard. My Mazda3 came with 16x6.5 standard. A 7.5in wide wheel sounds more like an aftermarket or dealer accessory wheel, which is technically not legal in stock (it would have to be an option on the Rabbit package you have and no other car). A 7.5in wide wheel would definitely allow for a stiffer sidewall with lower pressures.

[Cholewa]

It's a port/dealer install option, one of the VW wheels that you can have added to your car is a 17x7.5, and there is also a 17x7. They made it legal this year to have dealer installed options, I checked

With all the conjecture in various forums on whether or not optional equipment installed at an importer's port facility is considered "standard or optional parts" as per 12.4, and with a somewhat serious intent to perhaps campaign an 09 Rabbit in HS this year, I wrote to the SEB in December and asked for a clarification on 12.4 (Ref. 08-712).

The March Fastrack contains their response, and it's good news. The SCCA now officially recognizes port installed optional equipment to be the same as factory equipment. See page 13, item 1 of the March Fastrack.

What this means for us interested in running HS is that MKV Rabbit & Jetta in HS can now legally run offset appropriate 17x7.5 and 18x8 wheel sizes (same as available as VWoA port installed options) with the largest tires that will fit.

[claym]

It's a port/dealer install option, one of the VW wheels that you can have added to your car is a 17x7.5, and there is also a 17x7. They made it legal this year to have dealer installed options, I checked

VW is very generous to it's customers by offering that wide a wheel. I'm surprised more people aren't running that combo on a national level.

Back on subject, all stock cars but Cholewa's VW are usually stuck with narrow rims that require higher pressures to decrease rollover and add sidewall stiffness.

[Welacey]

Clay, how come we didn't get all that good advice back in the Miata days?

[claym]

Clay, how come we didn't get all that good advice back in the Miata days?

I'm always glad to share FWD advice with other Miata drivers

[engled]

I'm always glad to share FWD advice with other Miata drivers

After the last event I'm afraid to take Miata advice from you!

[claym]

After the last event I'm afraid to take Miata advice from you!

I'll have to get a durometer before I offer any more tire advice. But the 2nd half of the advice.....

[Cholewa]

the stock tires on the rabbit, when it had the 15'' steelies, were 195/65/15 i believe. Which is pretty standard on a 15x6. But you can even get 18x8's and one or two sets of 19x8.5's from the factory.

The volvo had 195/75/15's on it's steelies... and that was an H stock CHAMPION.

[Mowgli87]

I guess us VW guys are just a bit more fortunate than others. My car came with 17x7.5 wheels wrapped in 225/45-17 tires.

As far as tire pressures go though, I run about 34-36F/40-42R with the 17's (Perelli P-Zero Nero). I also have some 205/50-15 Azenis RT-615 on 15x6.5 wheels. With the help of Yoder at the last, I run about 32F/35R.

[g1teg]

With the Integra, I try to maximize the contact patch at all 4 corners. Because the car is so front heavy(I think 63/37), that means 38F/28R on street tires and 36F/26R on R-comps. In the wet, I usually take 2 to 4 lbs. off of those pressures.

[claym]

With the Integra, I try to maximize the contact patch at all 4 corners. Because the car is so front heavy(I think 63/37), that means 38F/28R on street tires and 36F/26R on R-comps. In the wet, I usually take 2 to 4 lbs. off of those pressures.

But remember Chris' car has narrow rims and only uses one rear tire at a time