What's the max hp you would put on 215-225's?

[procan]

I'm looking at an engine upgrade/swap on my '69, and i want to keep my narrow flares. The max width I could comfortably get away with is 215-225's. What is the max hp you would feel comfortable putting to those wheels?

[widgeon13]

I'd say you can put 250 HP at least but don't think you will ever get there. I had approx 230 HP on a 74 narrow body, no problem.

[Cherry Bomb]

My 3.2L equipped '83 SCWB is running 215/55 rears while new tires are being selected for the Fuchs. I will then go to 225 or 245, looking like 225 based on selection vs. purpose. First gear is near useless at times and the rest works well in all situations.

Remember, the smaller the footprint, the more weight distributed across the contact patch = traction! It's all in the compound. My '63 VW Bug had 215/65/15's and spun'em for miles. I swapped in a set of 165R15's for a time and '60 increased as well as gear change traction.

Run the smallest, read: lightest tire you can and have the least amoount of rotating mass. Accelleration will be fun!

My $.02

[procan]

I heard about "R" wheels or something that give an extra inch on the inside. How much clearence do these give?

[Charles Freeborn]

What's your driving skill level, and what do you expect to be able to do with it?

[maui44]

I think it more about what the tires/wheels are tied into than the size of the tire.

[Lukesportsman]

'R' wheels often require spacers so just take car if you go that route to slip 7"s in there.

Compound is as important to traction and design to slip angle as the actual size. I run 240hp on 225's 15's on my track rat and she is a ball. Controlled slides with lsd whenever you want and it rotates quicker than my big tired cars at safe street speeds. You could always change gear stack if you need to control power delivery....don't restrict the hp

[bill romero]

I had 951 16X8" Fuchs on all four corners of my early (narrow body) car with 225/50/16 & didn't have any issues.

[tt475197]

Originally Posted by bill romero

I had 951 16X8" Fuchs on all four corners of my early (narrow body) car with 225/50/16 & didn't have any issues.

Any opinions if the same could be done with 911 16x7" ET23 Fuchs on a 72-73 car without modifying fenders? Some say Yes some say "No, it will rub" but my understanding is that on a later car it should be doable without any modifications.

[Randy W]

Originally Posted by tt475197

Any opinions if the same could be done with 911 16x7" ET23 Fuchs on a 72-73 car without modifying fenders? Some say Yes some say "No, it will rub" but my understanding is that on a later car it should be doable without any modifications.

215/50-16 on a 16x7 Fuchs on LWB narrow body is near the limit. 215/55-16 rubbed on the rear fender occasionally on my '72 911 with stiffer torsion bars and nearly two degree neg camber. Depends on the car and tire of course. '74-77 911 can usually get away with a bit tire more for some reason.

[procan]

What's your driving skill level, and what do you expect to be able to do with it?

This is for street use and the occasional DE. I'm by and far an amateur when it comes to skill level.

[Jack Olsen]

I think the limiting issue will be budget, not tires. If there were no financial/technical limitations, then a 1000-hp narrowbody would be a blast to drive, so long as the throttle is not an on-off switch.

[dean]

Some more data. I have at least 350 rwhp and the same amount of torque. On a 40 deg day my car will spin the tires in 3rd gear going 60 mph down hill. Slightly terrifying. On a wet day my car will spin the tires at 60 mph in 4th gear at anymore that 1/4 throttle. Very terrifying. On a warm day it will spin in second gear all the way to the redline. These are all going staight in corners it is worse.

[LJ851]

Originally Posted by dean

Some more data. I have at least 350 rwhp and the same amount of torque. On a 40 deg day my car will spin the tires in 3rd gear going 60 mph down hill. Slightly terrifying. On a wet day my car will spin the tires at 60 mph in 4th gear at anymore that 1/4 throttle. Very terrifying. On a warm day it will spin in second gear all the way to the redline. These are all going staight in corners it is worse.

Yee Ha!! Sounds like fun.

[kjchristopher]

Originally Posted by dean

Some more data. I have at least 350 rwhp and the same amount of torque. On a 40 deg day my car will spin the tires in 3rd gear going 60 mph down hill. Slightly terrifying. On a wet day my car will spin the tires at 60 mph in 4th gear at anymore that 1/4 throttle. Very terrifying. On a warm day it will spin in second gear all the way to the redline. These are all going staight in corners it is worse.

What tires?

[fintstone]

I am running 205/55R-15 Yokohama AVS ES100s all around on 15x7s. These were the biggest that would fit on either of my narrow body '74s with 7 inch wheels. I am running an estimated240-250 hp. Plenty of tire.

[Craig T]

This is the second thread where you've hinted a concern for too much HP under 205 and 225 tires. I agree with Jack Olsen, as long as the gas peddle is not an "on-off switch", you should be fine on that much rubber with anything you can throw at it realistically. The key is modulation.

I have over 300 HP on 2250 lbs in a narrow body and it's a blast to drive. I would not want to stomp on the gas at 4500 rpm in mid-corner. That requires some counter steer to keep in on the road, but that's half the fun.

I don't know the quote exactly, but it goes something like this:

Unless you can break the tires loose exiting the corner, and keep them spinning until you brake for the next corner, you don't have enough horsepower.

[unclebilly]

We are running 205-50-15 Star Specs on all 4 corners of the lean, mean vageen machine. It has plenty of traction and this is a 100% endurance race car.

It depends on how heavy your car is. The vageen car has to be around 1900 lbs.

My GT2 car runs 235s up front and 255s in the back with Nitto NT01s but it weighs in at 2500 lbs.

The GT2 car with a wider stance and bigger rubber steps out easier than the vageen machine. There are some suspension differences too, the vageen suspension is as stock whereas the GT2 car has 29 and 23 bars and Weltmeisster sway bars with RSR spindles.

I guess my point is this, optimal traction depends on: desired application, suspension setup, weight, and the tire you select.

[mreid]

For once, it's not about size. It's about skill and material. It is just as scary to break the tires loose with 315's in a corner as it is with 215's. Spend your money on driver education now, so you can then spend it on new tires because you wear them out rather than body work (yours and your cars) today because you don't know how to drive at the limit.

My cobra weighs 2300 lbs., has 295's on the rear with 540hp. It scares the hell out of me, but I love every second and know how to manage the throttle.

[dean]

Originally Posted by kjchristopher

What tires?

Falken FK 451. And it is a blast to drive.