Toyo Proxes R888 with 20psi in the rear tyres.

With an LSD 185's are fine at 300BHP so I imagine you would be good around 225 or so. 275 would be overkill

 

I'm far from clueless. This should be evident by me even having and building a reliable 500 hp rotary. But i mod my car one step at a time. Going from 400 hp to 500 is just a matter of turning up the boost 6 psi. Not some major transition. The 225 drag radials held quite well when the tread was new, it just didn't last very long. Changing out rims and tires is not cheap, it's much easier and cheaper to replace 2 tires. Also i was still running 15 psi when they were purchased. I think your comment was out of line and based on very little known information. But idealy i'm going to look into wider wheels and tires.

 

I've found 275/40-17 hook pretty nicely b/c of the bigger sidewall. We have similar setups/hp levels and when I was recently running Toyo RA1 road race rubber (60 treadwear) I could hook up from a roll in 1st gear......no lie. It was like being shot out of a catapult

They're awesome tires. ok in the rain, supposedly last 8-10k miles, I'd recommend you get some decent width wheels and try them out

 

/\ when my nittos wear out ill try those goodfella

let me chime in here dude since you helped me. I daily drive Nitto 555r's on my car 275/40/17 on my car and since then had no problems. Oh and also had some suspension setup as well.


but being ill be making alot more power than even you will. Later I plan on getting 10inch wide tire with 305 nitto 555r which are the safest drag radial for the street (even in the rain its pretty good since i daily drive the car.) but i want to do a 45 thickness tire but its not really good for the street so i have to take what i can get

Ill take a pic later to see the thread wear (3k miles so far and street race at least once a week and do a little 8th mile run).

lowering the tire pressure helps alot too!

 

I just put on Toyo R888's 265/35/18 and am having no problems with grip at 450whp. My greddy T78 is a bit more laggy than normal as it needs a rebuild, but it still makes decent power once it spools. So this may be why I have no problems with traction. It doesn't have a big kick like it should, it just builds and builds smoothly.

My car is also lowered a bit (H&R springs with the stock R2 shocks). So that may be helping.

Either that or I just cant shift fast enough to keep the boost built up enough to break them loose when going from 2nd to 3rd. haha


I also don't get why all the talk about driving in rain, its always a bit more dangerous on slippery roads, but as long as you are cautious you should have no problems if you have somewhat decent tires (excluding flash floods of course)

 

Thanks for all the tire feedback. Sounds like all these tires are a form of drag or competition tire right? I've heard good things about the ra1's. One of the guys on the australian site (has been over here too) runs them at 550 hp. Not sure the size he was running though. Treadwear of 60 is definitely better then 0. I think part of my problem was once i did finally start breaking my tires loose they just tore themselves up. I'll look into those other tires too, and compare treadwear. My plan at this point is to stuff the widest tire i can in without major modifications. If i can go a little wider maybe i can get a little longer wear tire too. But i'll have to compare cost on the different sizes also. If i'm spending a lot more for a particular size it might not be worth the longer wear.

 

/\ just curious but what tires & size you have on your car now?

and i agree with Chudsoncoupe. as long as you dont try to boost in the rain you shouldnt have problems

 

The Toyo RA1 and the newer 888 are road race tires. Lotsa grip. The NT05 might be a good option as well but no idea how they'd deal with 500 HP. I only know how they work for road race.

 

I'll be able to better report on the Kumho XS (which is what I chose for my latest set of wheels) once I break my motor in, but so far I've been *very* impressed with the dry grip on highway on/off ramps.

 

I have bfg g force, but they're. done. Bald, kinda sticky but not enough for 500 hp. Size is listed above. 225/45/17

 

Are those a competition tire? I used to run kumhos alot, they were a lower cost tire with good wear and grip

 

The 550rwhp car is Jason's (rotorpsi1) and he uses Toyo RA-1's in the 225-245 ballpark. His car is the reason why I went the Toyo way (I was going to get RA-1's also but my shop told me they were discontinued and would be much older stock than the R888s and possibly starting to go off already).

I think he did post once that the 550rwhp dyno run was on a slightly optimistic dyno, and the 'real' number would be around 500rwhp if you went by dyno dynamics numbers (which is pretty much the standard we use in Australian Capitol Cities).

Then again to get that 500-550rwhp into terms with your complete bullshit American dynos would be probably 600-700rwhp. Most of the American cars I look at don't have half the power they claim, just like plenty of JDM bs workshops here.

 

those 225 are the reason your having trouble. thats just asking for trouble lol.

at least 255 is the mininum i would put as far as narrow tires

 

I went from Dunlop SP 275-30-19 to Toyo T1R 275-35-19. I know 19 is not your interest but I am just comparing tires here, my car is a RX-8 so my gears are shorter than yours which aggravates the traction situation since my third is just slightly longer than your second. With 500whp in my car and Dunlops it would be almost un-drivable until 4th gear....even in third from a roll it would break loose. The Dunlops were sized at 275 but in measuring them with an actual ruler they seemed to be on the smallish side. Going to the Toyos they grew in width by almost 3/4 of an inch....and they were also 275's but they run on the larger side...between that and the slight sidewall height increase and better compound from the Toyo's the car is way different. Now it has a hard time spinning in second. It still spins but it feels like my friends corvette spinning in that it spins but its grabbing and you feel it pulling and its controllable. not to mention that its way less spinning in general...no more smoke cloud from a roll. They are also harder and longer lasting than drag radials so they should last at least 10k in my opinion. Another note was that I had the car aligned so now they sit closer to being flat on the ground when the car is sitting. Before I had camber and they rode in the insides edges of the tires, this has a considerable effect on traction.

I would suggest going with a 9.5" wide rim at least and some 275 wide rears. They don't necessarily have to be drag radials, those don't last for ****...and they are expensive...and if you drive your car on weekends you will still go through a set each summer and that is ridiculous...just don't make them hard all season tires either. And get that car aligned better. sitting flat to the surface is very important to traction...with this I know you will see a difference...I just changed brand and height a bit and it made a world of difference...you have lots of room to get better.

Chris

 

Yup, safe to say that tire size and tread compound help each other. The wider tire you go with, the less aggressive you'll need to be with tread compound and air pressure.

 

wait, i'm a little confused here.. you are putting 500+ whp and you are running 225 in the back?!?

 

I can spin 255's Potenzas with my twins and no clutch. I'd use atleast 275 if I were you.

 

lol.. that's your problem bro.... get some wider tires and you should be fine. min 275

 

well i had 400 something hp before when the 225's were purchased. and yes now i have 500 something with the same tires. My wheels are not wide enough to get much wider tires so I need bigger wheels and tires. I feel like i'm repeating myself?

 

You might be, I was too lazy to read through the whole thread. :P

 

So do we

 

I should put why i have 225's in my signature lol

 

Brent, get some 17x9 (or 8.5) fronts and 17x10 rears and order Toyo RA1s in 255/40 and 275/40. Boom, end thread.

If you need a source on RA1s I can PM you my contact, his pricing is very reasonable.

 

alright yeah drop me a PM on who he is and pricing. thanks

 

rich why did u switch tires if u loved your toyos so much?