275/35/18 and 335/30/18 Hoosiers 18x10.5

[Z06Machine]

Waiting on the CCWs. Sold my 17's and only have 4 rear 18's left except for my street tire set-up. Santa is running late so I am looking for a good tire set-up for an upcoming track date.

I have the DRM ducts and rear stock ducts with the car lowered on factory bolts.

Will this Hoosier combo work without issues on the track or do you have a better suggestion?

Hoosier

Front 275/35/18 on the 18x10.5's( stock rears )
Rear 335/30/18 on the 18x10.5's ( stock rears )

I hear the 335's will squeeze on the 18 x 10.5's. Don't know if they will rub the rear ducts though.

I really don't want to remove either set of ducts so I am looking for a CONFIRMED set-up for the 18's all around. I don't want to mess with the ride height/alignment at the track to make it fit. Also have T1 bars all around.

Been running the GSCS in stock sizes with good luck. Is the Hoosier still the best choice for a track only tire?. Any help would be great.

[Dr Chill]

Why not 305/30/18's all around?

From my thread:

Originally Posted by sleeper02Z06

I run the 18x10.5 rear stock rims on the front with 305/30 hoosiers for HPDE's and I have the DRM ducts. You will only get about 3/4 turn on the steering wheel with this setup, fine for the track but not for the street IMHO. You simply have to be careful in the pits. If it were not for the DRMs, this setup would be "streetable" with no clearance issues. Hope this helps.

Joe

[Z06Machine]

I was trying to keep the rake about the same. If the 305's enough for track use that's a bunch of tire up front .

My thoughts were

275/ 35 = 25.2 dia - width 11.2
305/ 30 = 25.6 did - width 12.4

In the front I thought the 275 would give a better turning radius and help keep the rake the same without re-adjusting the ride height/re-align, yada,yada. The diameter diff on the stock tires is about .5. This gets me close at .4.

335 /30 - 25.6 dia - Width 13.5 The question is will the 335's actually fit on the rim with no clearance issues with the rear scoops, wheel wells, etc?

When you run the 305/30 front and 335/30 rear on Rocket Sleds calculator, it actually looks like this would be a better set up. Delta is -.3% vs. -1.7% for the combo of 275/35 & 305/30.

[Z06Machine]

ttt

Will the 335/30/18 fit on the stock rear rim 18x 10.5?
Anyone tried it, I have a third party source that says it fits.

Any clearance issues on rear ducts, fenders etc. lowered on factory bolts.

Happy Holidays !

[stellablu]

My BFG DRs are 315 X 30 on the stock rims and there is about 3/4 inch of room to the brake duct and also wheel well at the top from the inside tire surface....(if that makes any sense)

[Dreamin]

Handling will suck with 335's on 10.5" rims... that's way to wide a tire for that rim width... 12-13" ideal... 11.5" you can get away with.

From Hooiser site:

If you find that your vehicle, or the rules, will not allow a wide enough wheel for the tire you think you would like, consider using a narrower tire. In most cases a properly sized wheel/tire combination will outperform a wider tire on a wheel that is too narrow.

[Z06Machine]

Thanks for the info. I heard about a few using this combo with some success. Makes sense if you can't get all the contact patch on the ground.

[Redshift]

I wouldn't go with a 60mm front to rear width delta. Talk about understeer. As it is, I have that setup on my 18's right now, but with Toyo RA1s, and I was not happy with the lowered grip up front (I like to enter corners fast, and could not with 275s up front). I would stick with 305 up front and 335 out back, or 275 up front and 305 in the rear.

[DJWorm]

I recommend using 305/30x18 on 10.5x18 with +0.25" offset in the front.

I recommend using a 315/35x17 on a 11x17 with +0.25" offset in the rear.