Tyre Size Choice

[Des Flurane]

Could any of the drag gurus help me out please.
Both MT ET Street 16" and 17" tyres will fit my BA, which should I choose and why? Or does it not matter?
I have a standard diff atm, which is likely to change in the next 6 months. Standard brakes.
I need to improve my 2.3 60fts ;-)
Thanks.

[superpursuit83]

Someone told me just yesterday (and he is a drag racer), while we were talking tyres. That you should get the biggest tyres you can, even if you have to sacrifice some width for diameter..

But this may be wrong. I am still learning

[brenx]

Depends on what your trying to do. By that I mean are your trying to 60 faster or obtain a higher top speed. The taller tyre will have a higher top speed but will impact on your 60's. The smaller tyre will help the 60's but won't help top speed. Smaller tyre can make a 3.45 diff act like a 3.5/3.6:1 ratio. A taller tyre might make a 3.45 diff react like a 3.2/3.3:1 ratio. You can get some quite tall tyres which I have no doubt would make a 3.45 ratio effectively a 3.0:1 ratio.

Most like myself just come up with a happy medium. Although I'm going to try a 28" tall tyre on a 15" rim next. I've currently got a 26" tall tyre on a 16" rim.

[Des Flurane]

Now I'm confused?
I will be getting more power with the installation of my headers today and a custom tune this Thursday, so I guess it's the 60' time Im needing at the moment, as traction seems to be an issue on the track I run, Meremere, Auckland.
The 275 is about the same diameter and the 255 a 1% increase. Not really much to choose there.
Would the higher profile on the 16" of 50 give better performance?
What does everyone else run on there BAs?

[FS5]

mate have you tried just letting some air out of your standard tyres.say drop them down to about 20 /22 psi.

[nugget378]

A larger sidewall will give more grip, 60 as opposed to 50 in equal widths, but unless you have the right gear ratio a tall tyre can bog the car and hurt your top end a little by not letting you use your top gear fully.
I am in this situation and use a 26" tyre. even with that I cross the line at 900rpm under what I should, a 28" tyre will make this worse.

[Quadcams]

Originally Posted by Des Flurane

Now I'm confused?
I will be getting more power with the installation of my headers today and a custom tune this Thursday, so I guess it's the 60' time Im needing at the moment, as traction seems to be an issue on the track I run, Meremere, Auckland.
The 275 is about the same diameter and the 255 a 1% increase. Not really much to choose there.
Would the higher profile on the 16" of 50 give better performance?
What does everyone else run on there BAs?

When i had MT streets I ran the 255/50/16 (26") managed a 1.816 60' on them, but Blueblooded ran the 275/40/17 he managed a 1.75 60'. Most of the boss guys run the 16's and as nugget said the bigger side walls (255/16's) would be more benifical for the 60' but both sizes seem to get good results.

[Chris]

Originally Posted by superpursuit83

Someone told me just yesterday (and he is a drag racer), while we were talking tyres. That you should get the biggest tyres you can, even if you have to sacrifice some width for diameter..

But this may be wrong. I am still learning

Careful here - a drag tyre should be the narrowest required for the job.

a large tyre will eat kilowwatts for brekky.

the best tyre for your application is a 255/16 MT ET street on a widened 16"stock rim.

start it at 26lbs, and drop it in 2lb increments till the wheelspin stops.

Good luck mate and have fun!

[Des Flurane]

Thanks Chris.