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Going to Semi slicks, how does 305/35-18 fit up front?? and other questions

Mad Hatter

Gotta go Faster
3,922
2,409
Santiago, Chile
Hi all! Thanks to some rule changes this season, I can only compete in a class that allows up to semi-slicks. The slicks class has three 800HP GTRs and a Honda CRX with 285hp, can't even get close yet (or ever)! Was planning on going whole hog next year with a set of 305/35-18 Toyo R888 tires on 18x10 drifts since the R6 are out. I currently run 275/35-19 Dunlop Dirreza IIZ. Will the 305's fit up front with out spacers? I already had to put a narrower pvc pipe to avoid rubbing with the brake ducts so I have a little more space then normal. What offset would I need to clear the suspension?

In the mean time, would it be too crazy to run a cheaper option of Toyo R888 305/30-19 or 295/30-19 in the rear with the 275 dunlops up front?? I was thinking of running them with a set of boss 302 19x10 wheels with +47mm offset and 7.38in backspace. The idea of mixing tires seems unholy to me but quite a few people seem to be having no problems, I guess as long as the stickier tire is on the rear for braking??

I still have the stock sway bars so some more rear end traction would be nice!
 

Mad Hatter

Gotta go Faster
3,922
2,409
Santiago, Chile
I did no think it through! better to get the pair of 18x10 tire with 305/35-18 to match the diameter of the 275/35-19. Any thing wrong with running 18in tires in the rear and 19 in the front??
 

JScheier

Too Hot for the Boss!
As long as the rolling diameter is close, there should not be an issue. You may feel the rear of the car move around more as most likely you'll have more sidewall height in the rear vs the front.
 
I would not mix tires. Skip the R888's and get Nitto NT01's. Several members have tried the R888 with poor results. I think our cars are too heavy for them. Most like the NT01's or Nitto NT555R II's.
 
I should know the answer to this question shortly. My 18X11 Forgestars are on their way. I already have the 305/35R18 NT01's. Hopefully know by this weekend.
 
F14 18x11
I am waiting for those for months now...
I hope they are shipping soon!!!!
SHOULD BE THE HOT TICKET WITH 305 SLICKS ALL AROUND.
 
My 18x11 F14s took 6 weeks, I got them from Vorshlag. I am running RS3s on them right now. They are a little stretched, so the plan is to switch over to the Rivals after these are worn out. I am using 6mm spacers to clear the AST 4150s, front and rear.

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Mad Hatter said:
I saw that tire rack has Hankook RS3 on sale right now. How do they do??

Yeah, not so happy with Tire rack right now, because I got old tires. The reason there on sale is because they are old. The pre 2009 production run from. The others might be a bargain. However, they are old too and need to be moved out of inventory. Lots of racing groups will not let you use tire that are older than 5 years and some not older than 3 years. Also for my 18x11s the tires are stretched, which means when I make the switch to the rivals I'll be able to get more tire on the ground.

I had these on at TWS about a month ago. However, they didn't fit so I needed to get spacers. That means I wasn't able to use them. I will be using this set up this weekend at TWS, so I can let you know after that.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
5,593
4,121
Exp. Type
W2W Racing
Exp. Level
20+ Years
Blair, Nebraska
What Class and Group are you running with, as confused by your term of semi-slicks ( which is what a DOT R6 is , they are not technically slicks ). Not sure why you could not run those, but no listing of what group you are running with?

Do not even remotely consider mixing tires -- heck you should not even mix different model tires even with the same brand.
 

Mad Hatter

Gotta go Faster
3,922
2,409
Santiago, Chile
I think your 100% right, but I was surprised how many people do mix tires. One of my team mates was running on stock size Linglong :-[ tires on a auto GT mustang. He has at least 10 years more time on tracks then I do. I was always at least 1 second ahead of him until he put a pair of Pzero 295/35-19 tires on the back. Right away he was 0.4 faster then me.

The rules here are still vague to say the least, everything below 220 is considered a semi-slick, all the way down to the Toyo R888. The R6 is considered a slick here in Chile.... :-\

Too bad I just put on my last set of Direzza ZII tires, I am in the same class thats now going to fill up with R888s right away.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
5,593
4,121
Exp. Type
W2W Racing
Exp. Level
20+ Years
Blair, Nebraska
Can you run 18s in your Class? If so there are alot more tire choices and even in Chile I would imagine they would be less expensive than the 19s. I run 305s in the rear and 285s in the front and frankly if you have to run a 220 Durometer or higher tire that also really limits you, as most track groups in the US figure 200 or above to be a better wearing tire and not subject to the semi-slick criteria you run under. I ran on the Hankooks and they are okay if it is warm out. Cool weather ( even 60 degrees ) they just don't warm up enough in my estimation.

Most of the guys seriously tracking the Bosses in the US , are running on 18s, so no concerns there , frankly. I am sorry I did not read further or check out your profile earlier -- great to hear you are tracking your car in Chile. I am sure many of us would really enjoy any shots of you and your car at various tracks in your Country !
 

Mad Hatter

Gotta go Faster
3,922
2,409
Santiago, Chile
Here is a pic of my buddies and I after we a good day at the track. Car still has a few big dings form meeting the tire wall. Pretty much decided to get 18x10 drifts sooner then later. We went from a race every couple of months to 50 cars plus twice a month! Nice to see the local motor sport scene finally taking off. Hope the links work.....


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Starting grid against the clock. 4 seconds between cars
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