I'm thinking of buying a pair of drag radials for my Fiero. I've never owned or driven on drag racing tires, so this is new to me. Maybe you guys can help.

My car has a moderately tweaked 2.8 V6 with a Getrag 5-speed. My street tires are 215/45-ZR17, which are great for carving up curves, but not for drag racing. I have to launch from idle, because if I rev up the engine the slightest bit before dumping the clutch, I'll spin the wheels.

So I'm looking for something with more grip, which will allow me to launch harder. The only catch is that it has to be a DOT approved tire. I drive the car to and from the track. No trailer queens here! It would also be nice if the tires could fit on a stock Fiero wheel (14x6" or 15x7"). That makes it easier (and cheaper) to find rims.

Taking all this into consideration, what tire size would you recommend for my car? And are there any brands to avoid, or any that stand out above the rest?

Thanks for your help.

There are several good DR out there these days. You have Nittos, BFGs, MTs and all of those are DOT approved and can be used as DD if wanted. I would say the best are going to be the MTs but they are also more expensive but worth it. I run MTs when I go to the track and after heating them up there is no tire spin. I run them on a set of stock lace wheel and the tire size is 235/50/15(I think). Once you eliminate tire spin, another part of the car has to take the load so be ready.

[This message has been edited by MstangsBware (edited 05-17-2008).]

I had a set of mickey thompson ET street drag radials on my 1973 charger that had 500 hp and they hooked VERY well. Knocked my 60' down from a 2.49 with street tires to 1.72 with the ET streets. Down side is the soft rubber will last you about 3,000 miles on the street. I just change 'em out when going to the track.

Just remember...the better they stick on high rpm launches...the more expensive stuff that can break.

Thanks for the responses so far.

I'm not really worried about tread wear, since I'll only put on the "drag wheels" for track day. But I don't want to be pulled over by the cops (or worse, wreck the car if it rains) on my way to & from the track.

I looked on Summit Racing's website. I see several tires that will fit on the stock 14x6" or 15x7" wheels. They range from 24-26" in diameter. My gut instinct is to go for smaller diameter, both for better acceleration and for less stress on the drivetrain. If this is right, then I'll have it narrowed down to 2 choices: M/T and BFG. Both are 215/60-R14, and both are DOT legal. If you think 215mm will be wide enough, then I can get the ball rolling on this.

Just as a side note: on my street tires, I don't always get wheel spin. If I launch from idle and roll into the throttle, the tires will grab and I'll get a good launch. The problem is I have to do it *just right*, or I'll get wheel spin. It's pretty frustrating. I'm hoping the drag radials will make it easier to launch, so I can be more consistent. I don't plan on dumping the clutch at 6K RPM or anything like that.

[This message has been edited by Blacktree (edited 05-18-2008).]

I don't remember what the topic was, but you helped me out on something on PFF last year, so hopefully this will return the favor.

The Good News...
The B. F. Goodrich drag radials I used definitely helped my car attain more consistent launches at the strip. Like you, I've never trailered the car, but just drove it on the street to and from the track. I also never received a ticket for them because D.O.T.-approved drag radials are legal in my area (and my guess would be probably everywhere else inthe U.S.).

The Bad News...
I found out firsthand that drag radials can be a handful in heavy rain. I learned that driving back from the track on drag radials during a surprise thunderstorm which rained out the drags. For the record, the car wasn't a Fiero, and the drag radials were fairly wide, P295/50R15s. As you might imagine, wide tires with minimal tread like that on drag radials don't help handling in the wet. I didn't wreck, but that also was a driving experience I don't want to repeat.

All Other Things Being Equal...
Taller tires are better for off-the-line traction at the drags than are wider tires.

Thinking It Through...
First determine the RPM level at which you want to cross the finish line. Then consider your gearing and tire diameter options.

Making It Happen...
To make the maximum use of its power, I geared my car and used tires whose height enabled me to cross the finish line just a bit above the car's peak-horsepower RPM.

Many street-driven cars I've seen at the drag strip don't use anywhere near their engine's potential, crossing the finish line well below the RPM level where their horsepower peak is at.

RPM at the finish line is a function of MPH of course, but it's also a function of tire height and the car's gearing, or "final drive ratio" (F.D.R.).

The formula to figure this out is:

RPM = [336 X F.D.R. X Trap Speed in MPH] / Tire Diameter (in inches)

As you'll see in using this formula, a 10% reduction in tire diameter increases the car's RPM by the same 11.1% as does an 11.1% increase in its final drive ratio.

Conversely, a 10% increase in tire diameter reduces the the car's RPM by the same 9.1% reduction in RPM as does a 9.1% reduction in its final drive ratio.

By the way, if you Google the term, "RPM calculator," you'll find plenty on-line so you won't need to work out this formula by hand. I included it above simply to better illustrate what happens with different tire diameters and final drive ratios.

In any event, the bottom line is a car whose RPM through the traps isn't set up right shouldn't be expected to be as fast at the drags as the car whose RPM through the traps is set up right. The most common mistake I see is people who forget the drag strip is only 1/4 or 1/8 mile long. They set up their cars for the drags like they were competing to set a top speed record at Bonneville. Then they're surprised that the car isn't very fast at the drags. What they typically forget is that Bonneville is a lot longer than 1/4 or 1/8 mile. The drag strip, however, isn't.

[This message has been edited by project34 (edited 05-18-2008).]

I would bet DR's on a stockish HP motor would slow you down.