Anyone ever run 215/65R15's on their Grand Am

[97-4doorGT]

I've got a 95 Grand AM SE that I've almost got ready to roll.

I'll be racing the car in a FWD stock car division at the local track. We are limited to a 15" Rim and 65 series tires. The 205/65/15s fit, but I'm sure it will be a close fit if the 215/65 tires will fit at all.

I'm just trying to cram the most tire possible under the car. I checked into tire diameter sizes, and it says I've got half an inch to spare....it's gonna be close if it fits.

Anybody ever ran this combo on the GA?

Thanks.

[rabidpanda69]

Whats the stock size?

[DontPassTheFence]

stock is 195/60/R15 IIRC for the SEs

so itll be much taller than stock. And what the hell is that 65 aspect ratio limitation? Thatll cause so much sidewall flex :( Be sure to keep a check on the tire pressures, that'll make or break the race for ya. Try not to go any taller than it already is, since that will make your effective gearing taller (which your gearing is already pretty bad if you have either the hydramatic trans or the Izusu)

[97-4doorGT]

Well I cambered the right-front wheel tonight and there is no way to fit a 215/65r15 under the car without some serious strut modifications....not to mention only having a c-hair clearance when turning the wheels.

Yeah....the 65 series limitation blows. Would you believe that it used to be a 70 series limitation. I had a sticky set of 205/70R14 Sumitomo tires under the beretta I used to race. Air pressure varies from tire to tire...we usually keep the rt front

It seems like everybody at the track runs Berettas or Cavalier Z-24's....I just wanted to put something different on the track. They don't allow DOHC engines. 3.1L is the max allowed engine displacement, automatics transmissions only. Everything on the car is supposed to be stock....but it's only cheating if you get caught.

I numbered and lettered the car last night. Hopefully I'll get the Lexan cut for the windshield this weekend and just maybe I'll be ready to swap paint by next weekend. I'll post pics once completed so everyone can point and laugh.

[VanishingImage]

what kind of wacky rules they have for this class???

sorry but was reading and it caught my eye.

Can you or are you able to run cheater slicks?? They DO have tread on them and you can just use 2 for the front since its a FWD car

[97-4doorGT]

Originally posted by VanishingImage
what kind of wacky rules they have for this class???

sorry but was reading and it caught my eye.

Can you or are you able to run cheater slicks?? They DO have tread on them and you can just use 2 for the front since its a FWD car


The tech inspectors are so petty. They won't allow any kind of cheater slick....Hell I've seen them DQ cars for showing up with street legal 195/70R14 tires just because they said "Hoosier" on the side of them. They insist that all 4 tires be the same size....no staggering.

They've got a new tech guy that works at a GM garage checking cars now. The guys that used to check engines couldn't tell by looking that my old 3.1L in the 90 Beretta had 1998 3100 heads on it (not to mention 1.6 roller rockers and a 214 degree duration cam).

[DontPassTheFence]

man they dont allow DOHC? this is worse than the FIA (guys that thin up the rules for F1, and outlawed the mazda 4 rotor engine, all pushrod engines, and just pushed for more engine longevity for this race season.)

Well good luck on your race, Ill bet you are the only one out there with a Grand Am, eh? (although berettas are still the shit as far as L-bods go)

[The Artist]

unless you are running airbags and you have the car slammed on the ground, a 65 series side wall will be fine

as far as 215's not fitting, i can't believe that 10mm would make that much of a difference... AND unless this is a road track and not a 1/4 mile track, you don't need to turn anyway

Fence-- i don't know where you are getting the idea that a 65 would be too tall... first number is width, second number is height, and going from a 60 to a 65 isnt that big of a difference

[DontPassTheFence]

65 is ridiculous, thats 65% of the goddamn tread width! Which, in this application, would be 5.5'' of sidewall to flex all over the place a huge 13'' diameter :( it sucks for racing.

And he is road racing on a real track methinks, noting the strict specs for his class. Acceleration WILL suffer from this change in tire diameter, make no mistake. This rule seems to benefit larger cars, but since larger cars arent in his class, he should be fine as most of his competition is in the same boat, or another solution would be to get smaller rims (Im sure 13'' can fit on there)

[97-4doorGT]

Not exactly road racing with this one guys. We're running on a quarter-mile oval, asphalt track.

Due to the short track we rarely hit speeds over 60mph. IF you get over 60mph, you're usually cranked up too fast to get through the curves at the end of the track. 60mph doesn't sound all that fast, but it's fast enough when running three wide down the backstretch into turn 3.

The suspension is supposed to be stock....the whole damn car is supposed to be stock....I've got the exhaust opened up to 2.5" from the bored out stock flange to the rt side exit...straight pipes sound very cool.

Full roll cage and welded doors. Aluminum racing seat...the rest is pretty much stock. We'll see how it does soon. I'm going to thrash on the car tonight and see if I can get it ready for tomorrow night's race.

[DontPassTheFence]

ah, thats cool. I still count that as real racing even though its in a circle. You could push past 60mph, but with those tire restrictions, its not safe as you said. So now I see why it is so strict. If they allowed r omps, you could EASILY ditch the pack. :D