I've got two choices here for BFG Drag Radials:

1) 275/50/15
2) 275/60/15

The price difference between the two is minimal, so that's not a factor at all. The second one is 2 inches taller in the overall diameter which would theoretically increase my MPH by almost 6mph. However, the first tire has a 1.1 inch wider tread. Otherwise all other specs are basically the same. These would be going on a set of 15X7 Z28 rims.

So which is better, taller or wider?

And will either one of these tire combos fit my car without clearance issues?

 

Umm you just indicated that both are 275 mm... which means they're both the same width...

The ratio 50 and 60 is a percentage of the width defining the sidewall height and effectively determining the hight of the tire. The 60 will be taller than the 50 ratio, but since they're both 275, you have the same width across the tread.

The sidewalls are probably reinforced more on the 60 ratio than the 50 ratio due to the increase in sidewall height. The 50 will initially hook better, but once spinning both will have an effective 275 width.

I was looking at the design in the tire as well, if you look closely at the picture you realize that the tread extends around the tire quite a bit more onto the sidewall. This is where the difference in width comes into play, the sidewall being only 50 ratio has a higher level of deflection than a 60 ratio. With the same deflection on a 60 ratio, the inner part of the tire would curve in leaving you riding along the edges. The sidewall would have to be stronger to prevent this on the 60 ratio to prevent this effect thus you have a lower deflection and the width standing still goes down. Once up to speed, either tire will only yield 275 mm.

 

clearance shouldnt be an issue i dont think.

the shorter tire would increase the effect of your rear gears right.....and the taller tire would reduce the effect of the gears.......i think i have this right....correct me if i am wrong

as a result i think the wider tires would be better. however, the 60 profile tires might "collapse" more than the 50 profile tires....which may make them bite a little better, despite their slightly reduced width


anyway i am just throwing out ideas here....either will hook good

 

Actually Rovic, you are partially right. The 275 is the sectional width of the tire (which is measured from the widest part of the sidewall). The actual tread width can vary though, in this case, the 50 series tire has a 10" tread width and the 60 series has a 8.9" tread width. Both tires have a sectional width of 11".

Brad: I'm not sure about your description, confused me a bit. But I do know the taller tire will increase the end speed. I ran some calcs on Carmath, try it out and it might help you understand. My 245/50 stock tires have an OD of 25.7" and the 275/60 have an OD of 28", and I have 3.27 gears, and I used a tranny ratio of 1.0 (aka 3rd gear), and at 4000RPM:

http://www.prestage.com/carmath/calc_Gears.asp

Notice the difference in MPH...quite a big difference eh? About 8MPH...which is the equivalent of me installing a set of 3.00 gears.

If I stick to the 50 series than I would be minimizing the effect as the OD is closer to my stock tires.

 

that what i was trying tosay, but didnt explain myself clearly...taller tires act like higher (lower numerically) gears, thus the increase in top end.

 

Just my opinion, but if the 50's fit on those rims and under the car, they should give you better ET's.
I think unless you have bigger HP or increase the rearend ratio, the 60's may give you better MPH, but slower ET's.
By adding inches to the rear tires, thus lowering the ratio, it will put your shift points farther down track and you'll cross the line at lower RPM.

 

I would go with the 50's... this would give you a better starting width and effectively more traction when you need it the most.

On the other hand, if you feel your engine is hitting max hp before the end of the 1/4 mile, then a taller tire is better. Compare your dyno max hp vs your avg mph rpm.

 

the new SUPER CHEVY has a article on drag radials. and i beleive they rated the NITTOS better than the BFG"S. tested and everything. check it out.

 

Brad: That's what I thought you were trying to say, just wasn't sure.

Martin: You may have a really good point there. I never thought of that aspect. I will probably get the 50 series anyway, just cause I think I would rather keep it closer to the stock tire height.

Rovic: See reply to Martin.

ROCHEAD: Nitto's are good tires but are extremely expensive and hard to get in Canada. Thanks for the heads up though.

 

The 275/60/15's are quite tall.

They will reduce your effective gear ratio. You rear gear ratio is already modest. On your car I would go with the shorter tire.
If your happy with the rpm range but need more traction then
select a drag radial that is closest to the diameter of your stock tires. If your engine is does not hit the peak horsepower rpm at the end of a quarter mile run (in 3rd gear) then select a shorter tire.

even the little P225/50/15 tires bit really good. They are only 23" tall and will add some "gear" to your car if you need that.

 

Thanks F-BIRD, I'm now convinced to go with the 50 series tires, that are closer to my stock height and hopefully I benefit from the extra width.

 

Irocker,

You may want to check into how those tires will fit on those rims. Your putting an awfully wide tire on a 7" rim.
Just a thought to consider as i've heard that most people like to stick to somewhere around a 255 or 245 for an 8" iroc rim.
I've got 255/60's on my 15 x7's and they come out past the rim quite abit.

Let us know how it works out either way

 

Thanks for the advice. Unfortunately the selection of "competition" rated tires in the 255 and 245 is very very limited. My choice now for the BFG drag radials are between the 235-60-15 or 275-50-16. Hoosiers and M/T are too expensive for my budget right now. I'm leaning more towards the 235's right now, but I'll have to talk to the tire guy first. As long as the 275's fit on the rim properly than that's all I care. I'm not worried about if it looks funny cause they're only for the track. I'm just concern with the traction.

 

bfg makes a drag radial in 255/60/15 size....just in case you were wondering

 

ya, looks wont be an issue, but from what i understand with the narrower rim you get less of the tire contacting the ground.

Just something to check out, im sure the tire guys will know more
If you dont mind, what kind of prices do they go for?

I wouldnt mind a set myself

Good luck

 

Hey Chris.
Try to go as narrow as you can get away with. I know it sounds wierd, but depending on your future plans for power, a tire not so wide will also give you better ET's. Remember, they are drag radials, with a much better bite then street tires.

Just an idea if you do go with the 275's, is to mount a 10" tire to see if it fits under the car. If the rims are off-set, ignore that statement

 

Brad: Sorry dude...they might of at one point, but I they no longer do. The only widths they have to drag radials on 15" rims are 235, 275, 315, 325 and 345. And the only ones that will fit on the 15X7 rim that I have, according to BFG, is the 235-60-15.

Martin: As I mentioned above to Brad, I just found out that according to BFG, the only tire they recommend to put on a 15X7 rim is the 235's. The 275's are recommended for rims of 7.5" width and up. This is different from what tirerack.com has posted on their site, but I'll take BFG's word over tirerack's. So it looks like I'll be going with the 235's afterall.

Farm Kid: No exact prices yet.

 

man...you know what Irocker..you are right ...i just looked at a recent magazine article again, and the bfg drag radials are 275/60/15s, not 255, like i had thought along; i must have miss read it. boy i feel like a complete idiot. thanks for correcting me.

 

Honest mistake. I just looked it up on BFG's website, that's the only reason I knew.