Torque, Tires, and Traction

[DoubleV]

I'm currently running stock Olds 15x7 Rally wheels with 235/60/15 Firehawk tires ( now discontinued ) all around. I will very shortly be swapping in a new engine with much greater power and torque. As far as traction goes, my current wheels simply ain't gonna cut it. Since tire manufactures are stupid and won't make any decent 15" 'oldschool' tires, the only thing you can do to get kick a$$ tires is to switch to larger ( 17"+ ) wheels.

I've never owned a car before with the amount of power this new engine will be putting out. Traction on the street will never be great, but I need to be at least respectable and of course safe. I want to be able to drive with confidence. Just not sure what to do exactly.

So what are you guys who have beefy engines running on the street ( not the track ) and how is it working out for you? Trying to get a feel for what woks and what doesn't on a G-body. My current plan is to run a 17" wheel and run a tire that will maintain the stock tire height ( about 26" ). Maybe Torq Thrust II's and Continental Extreme Contact DW' tires ( 255 size in back ) but don't know if this would be enough to get acceptable/safe traction.

P.S. With my current weenie engine and wheels, I almost lost control on the highway once just by accelrating to get in front of traffic while merging in from an on-ramp. The roads were a little damp and I wasn't driving stupid. Very scarey!

 

[MightyCarlo86]

On my 86 Monte Carlo SS I run BF Goodrich Radial T/A's and I love how they feel and the way they handle in all types of weather. I have heard a lot of good things about them and personally I love they way they handle and have no problems planting the power from a 400 hp small block.

 

[pontiacgp]

If you plan on keeping the stock tire height a 255 17" tire will not give you much sidewall. I don't like the lo/no profile tires especially on a G body. The tire is part of the suspension in these cars plus the lo/no profile tires offer the rims no protection from potholes

 

[online170]

DoubleV;

You can comfortably fit 275s back there, just watch the back spacing. I have had both 275/40/17 and 275/60/15s back there on my Regal. The MT ET Streets (15's) are much wider than a regular street 275. With the wheels I had the MT's on, the tires were too close to the frame, but I probably had an inch between the tire and fender on one side, and maybe 2+ inches on the other side it looked like.


I think your tire choice is about as good as its going to get. MT also offers a 295/45/17. If I ever bought tires again, that's what would go on the back. But you may not want to compromise rain handling though.



With 17s, you street and track traction will not be great.
With 15's if you go with drag radials, you could get it to hook up on the strip with burnouts. Everyone I know who runs ET streets only runs them once. The cost is too high for the life. After 2-3 seasons you could have bought dedicated street tires, and dedicated race tires and been ahead.

At the end of the day, a good quality tire will offer you excellent handling and traction (like the one you've chosen), but when you push out 500+ torque to the tires, you're going to break them loose.




PS
My buddy had those Firestone Firehawks on his Cutlass (olds 350), and they were a great tire. It seemed like they got stickier as they got balder. He kept using them until the wires started showing!

 

[GhettoRacingKid]

How much power are we talking?

 

[vanrah]

Good Morning Guys; Another subject I'm interested in Traction. Any tire with a UTQG above 220 will just spin & if the UTQG is above 300 It will be like driving on ice. The UTQG is basically a hardness #. If you buy a tire under UTQG 200 you won't be allowed to auto cross for points. If that means nothing, I'd look at some tires with a UTQG in the 140 to 180 range. But once you exceed 450 Lbs Ft of torque even a tire with a 200 UTQG will be over whelmed. My buddy has Fire Hawk's with a 300 UTQG and 410 Lbs Ft of torque at the rear wheels, he fries them. I have the Brown Brick with 500 Lbs Ft of torque at the flywheel and my old (1993) Goodyear's (220 UTQG) are so dangerous that I have to be careful not to floor it at speed under 45 MPH. But being that they are 21 years old they are much harder than when new and probably compare with a newer tire rated at 500 or 600. This last summer I put Dunlop Direzza Sport Z1 Star Spec (200 UTQG) on my old work car (2005 GuTOo) LS-2 with 400 Lbs Ft of torque at the flywheel & 3900 Lbs of automobile. I had been using another Dunlop with a 300 UTQG and they spun so the traction control would kick in after about 10 -15 ft of spinning. But the Direzza's at 200 UQTG hook so well that the traction control does NOT even kick in! I should add that the OE BF Goodrich (440?) spin so hard that the traction control kicks in right away, the car barley moves 5 feet before it shuts down (traction control). Most BFG tires are for Joe average with 350 HP or less & wants to drive in the mud & snow. Look at the side wall, stay way from MUD & SNOW if you want summer traction, buy summer tires.. My .02 cents Bob Jr.

PS: Personal experience; It's best not to be side ways while passing, the person you pass will be startled!

 

[L92 OLDS]

If you plan on keeping the stock tire height a 255 17" tire will not give you much sidewall. I don't like the lo/no profile tires especially on a G body. The tire is part of the suspension in these cars plus the lo/no profile tires offer the rims no protection from potholes

I agree with this ^^^^. It's only my opinion but for some reason, G body 442's just don't look right unless they have factory SSIII rims on them. To each his own but for whatever it's worth, I run a pair of fat Nitto drag radials on some extra 15" 442 rims for track days. As you can see in my video's, they hook good if you heat them up. Otherwise, I run oversize BF goodrich radials on the car for cruising. They are a good all purpose tire but will go up in smoke if you get into it. Before my rear disk conversion, the Nitto's rubbed the frame a little only if I was cornering hard. There are better drag radials out there but Nitto offers a good price and they wear well for street driving.

What engine is going in?

 

[307 Regal]

If you buy a tire under UTQG 200 you won't be allowed to auto cross for points.

That all depends on your region, really. I'd be surprised if there wasn't at least one class he could run in, if not two.

I should add that the OE BF Goodrich (440?) spin so hard that the traction control kicks in right away, the car barley moves 5 feet before it shuts down (traction control).

My Coopers have a 440 treadwear rating. On an autocross track, they really don't do you much good. Those tires spin for 80% of the course, even when I still had my vin Y 307 in the car.

 

[DoubleV]

An Olds diesel block bored and stroked to 440 cubes is going in. Torque will be over 500 ft lbs. Basically it's equivalent to your basic street performance 455, so lots of torque.

I'm not a huge fan of the 'low pro' look either, at least on certain cars, but 26" tire height on a 17" isn't that bad if the car sits right and is pretty common on G-bodys and other cars. I'd go as much as 27" in the back if a certain tire came in that size. I love the look of the stock Olds rallys but there are NO good summer performance tires available. Find me a set of 15" summer performance tires with RWL ( I gotta have RWL with that much sidewall ) and I'll stick with the stock wheels.

As far as fitting 275's in the back, it really depends on the actual tire width. Some tires run narrow and others wide so it's hard to predict whether size X tire will actually fit or not. I see lots of different tires coming through at work ( UPS ) and I always try to guess their size. There was one tire I guessed to be 275. It ended up being 225! Those tires obviously run WAY wide. Stupid really. I mean what's the point in universal sizing when they can be that far off? Imagine buying a 1/2" bolt but really it's 14mm.

BFG TA's are nothing more than hard all season passenger car tires that are made to look cool without actually being any good. They are inferior to the Firehawks and the Firehawks don't cut it. I need some real performance tires.

Another HUGE thing to consider is the fact that there may be some kickass tires out there but they won't come in the sizes you need, so you gotta X it off your list right off the bat.

 

[Gbarrie]

DoubleV, Why the diesel engine ? The diesel gas is very high right now !

But to each his own. Good luck with her.

Gbarrie.