500+ hp..tires?
 

I'm running somewhere around 500 hp and had some bfg drag radials. They lasted somewhere around 1000 miles of moderate use. They worked well at 15 psi but at 20 psi they started spinning and at that point they didn't last at all. Although i dout they would have lasted anyways. Even though they are pretty well toast they are pretty sticky, as i can hear them picking up gravel and throwing it into my wheel wells. I dont want to replace tires every 2 months, but i need some grip. It's dangerous having the car start sliding at 100 + from a 3 to 4 shift. While its an adrenaline rush to break tires loose at any speed it's not good for acceleration. So how can i get some traction??? Suspension? Tires? Taller ? Wider? Any brands that grip while still having a decent wear and tread life?

Let's start off by what size wheels you are using?

Turn the boost down.

I have 17 inch wheels. Stock suspention. Not sure the exact width on the wheels cause i bought them 8 years ago, but they seem to be close to stock width. I'm running 225/45 17 now. Same overall height and width as stock. My old street tires were 235/ 40 or 45's they were about half an inch taller then stock and 10mm wider. But they were pretty old and tired when the single was put on so i wouldn't know how they grip with new tread.

Turning the boost down is not the solution i'm looking for but thanks for the bump.

You aren't going to get much stickier on dry pavement than something like a drag radial or a road racing competition tire. However, neither of those are good if you get caught in some rain.

I would suggest first that you look into increasing your rear tire size. I would suggest looking for something around a 9.5" or 10" wheel which will allow you to get more rubber on the road.

You are at a crossroads my friend, and there are no easy answers.

The problem you're running into is that you are throwing so much more power at a car than it was ever designed for. Look at the C6 Z06's and the latest Vipers. The C6's run 325's in the back and the Vipers run 345's. Both have all the suspension geometry and everything else to support it. My neighbor had a C6 Z06 and I've been in it. It feels very planted unless you drop the hammer in first. Figure those tires last what, 10-15k? That's not so bad really.

I was once in your position about a year ago when I ran over 20psi and couldn't hook until at least 3rd. You're reaching the design limitations of the car and you have to make some tough decisions now. You can get a little big bigger tires and wheels. That might help some--maybe. But I doubt it will give you much return for the money given the power you are making. You can do some kind of crazy widebody setup and put huge tires on there. That's IMO expensive and gaudy, not my style at all, and won't necessarily increase traction that much either given the money invested. You can switch to different drag radials. There are a bunch of different kinds out there and you can get some info from the drag racing section or people more experienced with running that kind of power all the time. But remember that drag radials aren't designed for tire life no matter what brand you get, and the ones that hook can be deadly in the rain.

What I did in your situation was turn the boost down to a bit under 16psi (I am running a T04R now, very similar to your 500R in size). I never have traction problems unless I slam the pedal down in 1st. I've got a very large streetport so the torque band at that boost doesn't blow the tires off. The car is pretty controllable and I am running shit 225 Sumitomos. On my old setup the power just got to be too much. After the initial thrill, you end up spending so much time and energy trying to control the vehicle that it's just not fun anymore. But on the other hand, once you turn the boost up it can feel like you cut your balls off when the boost comes back down. And that's why I know that "turn down the boost" is the last thing you want to hear. I've been there.

I can't tell you what to do with the car from here, but I can say that you are beginning to ask too much of the vehicle. Make power AND be controllable AND have safe tires that last [somewhat]? You can't have it all. I made my choice, you need to make yours.

I'm not too concerned with rain i don't drive the car daily and rarely drive in rain. Shit tires are definitely scary in the rain, but the drag radials aren't too bad until the tread is all gone. The bfg's would work well enough, except they wear out too fast and then lose most of their grip. I'm not into widebodies either, except the burnout flares are nice. Does anyone know what the biggest tire a stock bodied fd will reasonably fit? Something like 275? And what size wheel is required to fit said tire? A 275 would give me another 2" of tire patch which might help idk.

Put some 18 x 10 285 30s w/ decent rubber like s03s all the way around and keep the power at 400 rwhp and you'll have enough grip. Nobody in their right mind needs 500 plus HP when driving around town but then again it seems evident to me that your decision making powers have moved outside your mind and are likely generated somewhere below the beltline or above depending upon how you wear your pants.

I would stick with 10" for a stock body FD. You can fit 275's on 9.5" or 10" wheel. You'll probably want to address the suspension as well.

I don't know that suspension geometry necessarily has anything to do with it, but you COULD use wider rubber. I think that if you really want to hold down 500 whp, with a true street tire, then you're going to need wider rubber than the stock rear fenders will support.

With some significant massaging of the rear fenders, and the right offsets, you can likely squeeze an 11" rear wheel with a 295-305/30 on there, but that's it.

Thanks for the feedback guys. I suppose I'm not in my right mind, and never have been, I too used to feel that anything over 400 something was unnecessary. That is until I actually felt the thrill of 500 hp and mostly full traction in 3rd in my own car. After feeling the ridiculous amount of acceleration compared to the 400 ish power that I had before, I could NEVER go back. But once the new tires wear for 1000 miles the grip goes to shit and the thrill is diminished and becomes more of a fear. I grew up around race cars and controlling things with way more power then they should have so I know the limits of the car and don't push it beyond it's abilities, right now the limiting factor is grip so that's what I need to address.

Bigger tires seems like the logical answer and unfortunately sounds like new wheels are also in order. anyone know any good deals? I'll probably first try some good performance street tires, as big as I can fit. And if traction is still an issue with those I'll go with drag radials in the larger size.

I'm not sure what to do about the suspension or how much that would help. It seems like it might not be as big a factor after a launch, once the car is moving and squatted down it seems there wouldnt be a benefit to suspension changes, but I could be wrong.

Lastly, based on the wear of my tire it looks to be wearing considerably more on the inside indicating negative camber. If i get it aligned and go with zero camber would this help with traction much? the weight of the car would then be generated more evenly, right now it's more weight on the inside which can't be good for traction or wear. I know some drag guys even run positive camber so that it goes to zero camber when the car squats, but i'm not sure how that would effect the handling around corners. Not that I do any road course racing, I just like to know the effects changes make.

Massaging of the fender? are you saying roll it or flare it or cut the inner part out?
Fritz mentioned to go with 18" wheels is there any particular reason for going with 18 over 17?

There'll be more tire sizes and brands available in 18".

Gene Felber used 18x11" wheels w/ +48 offset. The required cutting (not rolling) the inner fender lips, and running a not-too-low ride height and significant camber. This was with a 295/30 PZero which Gene indicated ran large, almost as big as a 305 Hoosier.

In these cases, it's going to be nip and tuck as to what fits. Flaring, either by massaging the metal or getting aftermarket flares becomes the next option.

the more you build your car for straight line (drag or highway) the less you can trust it in turns once you get to a certain point because you are constantly trying to manage the power. I think I had as much or more fun in my old nonturbo Rx-7 as my current setup on my turbo car. I took that thing to tail of the dragon and never really worried about it much. Once you get so much straight line power and tires to match, you either wreck it or always worry about putting it in a ditch when you take a turn. I couldn't deal with that anymore.

Everything on a Viper and a Z06 is built around handling the power the vehicle makes. In a similar way, if you look through some of the design features of the FD described in the service highlights document and compare it to the 2nd gen turbo cars, there were a number of changes made to handle the additional power beyond just bigger tires. The same was done from in the transition from the 135hp 1st gen GSL-SE cars to the 182hp series 4 Turbo II. The hub design, the tire compound, the camber and toe... I won't claim to know everything though. I have just come to realize recently that there is a difference between a hopped up 500 horsepower car and a car that was engineered from the ground up to be 500 horsepower through millions of dollars in development.

That doesn't mean we shouldn't mod our cars. It just means we have to be cognizant of design limits.

I don't really corner too much, my turbo is too laggy for that kind of thing anyways, maybe when i get tired of just flat out hauling ass, i'll change my setup around or do another FD for road course racing. Maybe with a supercharger or twincharger setup instead. I'll probably need a good 30 k just laying around before that ever happens though. Either that or pick up some kind of sponsorship.

At least those 295/30 PZero's have a 220 treadwear rating. My gforce tires had a 0 rating. LOL. Those perelli's are sure expensive though damn.

My experience mimics arghx with past cars. That is one of the reason's I've kept my FD so mildly modded. I've got a good balance of suspension, brakes and power which makes it pretty easy and fun to drive.

Anyway...

18" x 10" wheels in the correct offset will allow you to easily fit 285 width tires while maintaining correct overall running diameter. 17" x 10" wheels in the correct offset can fit 275 width tires but are ~1/2" taller slightly affecting gearing but you have more sidewall. Different trade-offs... Pick yours.

As for camber, Pettit's specs for rear camber in a street/track scenario are around a mild -.8* and that seems to work well for track use based on some people's tire temps. Figure out what your camber is set to and go from there.

17 x 10 doesnt have a 285 tire?

purchasing tires every 2-3 months def hurts, but you have to pay to play not only that but you have to sacrifice to gain.

you're not going to find any sticker tire than a drag radial for the streets and you are not going to be able to fit anything wider than 10.5 with a 285/30 with out a fender roll.

if i was you i will get two set of wheels/tires. whenever you going to drag and do highway pulls slap the sticky ones on and do the daily driving on the others.

Thats what i was going to do originally with my stock wheels. Put some slicks on them and use regular street tires on my aftermarket wheels. Then decided to see how the drag radials would do on the 17's. Now i realize most the time when i would want grip i'm not in a position to change wheels out. I might get some all out slicks for prepared events, but if i go with bigger wheels i'll need 2 extra which is more costly already. So many choices. Sounds like wheels and tires in a wider set is how to start out.

There are, but they aren't the best aspect. In 17's, you are basically either at 275 or 295. However, don't get too caught up with that small of a difference. I don't think 285 is going to give you a much more noticeable improvement over a 275. However going from a 225 to a 275 will. The downside will be the fact that the 225 was/is a drag radial.

True but then i'll be able to run the drag radials in a bigger size also. Maybe i can find some that would wear a bit better. And if they don't spin that might help a bit too. Drag radials spinning on the harsh highway is a sure way to wear them out.

+1 for the 275 40 17's, they made a big difference on my FD. On 225's it felt loose and out of control all the time; fun at times, but not safe or practical. I agree that around 400hp is about the limit on the tires/sizes we typically use.

dont take this wrong way but for someone with a high hp car u seem pretty clueless. obviously 225 width isnt appropriate. u need a new set of rims that are atleast 10inch in the rear with atleast 275s. but i would go wider. the wider the better. then u will either need to roll the fenders or get fender flares.

lol...so valid now-a-days.

i dont know where u are coming from with these posts but u should be aware that the double a arm suspension on the fd is pretty damn near the best available.