I bought a pair of 28x11.5x16 ET Street slicks,. I have a Dana 60 with 4.10 gears and will be launching on a 150 shot with around a total of 500-520rwtq.

After talking with some friends they think the 28 is to big and will rob to much gear. The guy I bought them from hasn't shipped the 28s yet, and also has a pair of 26x10.5x16 ET Street slicks, would those benefit me more in all around ET?

The car is a 96 M6 TA and will have adjustable LCAs, adjsutable torque arm, and LCA relocation brackets.

 

man, only 15 views...does anyone read this forum?

 

The two guys I know who run 28's are also running 4.56's.

 

Use a calcualtor and see what rpm you will cross the line at with the tire/gear ratio.

 

Patience is a virtue.

Going from a 26" to a 28" tire is like lowering your numerical gear ratio by 7.2%. Your 4.10's will feel more like 3.73's. In addition, the additional inertia added by the increased mass and larger diameter of the 28's can easilly eat up another 20HP.

With a decent suspension, 26's should be more than adequate. I ran 26x10.5-16 ET Streets with 430rwHP with no traction problems, 3.73's with a T56 and a Street Twin, 5-6K dumps. Went to 28's with the 125-shot (550rw) and still had no traction problems, and by then was running a TH400 with a huge stall and 4.10s' instead of the 3.73's (to compensate for the larger tires).

 

Thank you Injuneer, that is a big help.

 

I am currently trying to launch with 520RWHP and 4.10 on M/T et streets 27X10.5. I am not able to consistantly hook. I have a 6-speed like you and they seem to be a pain with that much torque. I also have some suspensions mods and it has not helped that much. Good luck, Ken

 

How much torque do you have? I'm only a bolt on LT1, but will be launching on a 150 shot.

 

With 4.10s and 26" tires, 6000RPM=113MPH and 6500RPM=123MPH in 4th gear.

How high will you rev your engine and what do you expect to trap?

Since you've got a stock long block, you should probably go no higher than 6000... which would mean you'll likely run out of gear with 4.10s and 26"s. 28"s would make 122MPH at 6000RPM in 4th with 4.10s.

 

I don't think I will run out of gear, with the 3.42s I was just shifting into 4th. I rev to about 6100-6200, with my old setup I trapped 115. I'm not sure what I'll get now.

 

If you were trapping 115 before, and now you're adding a 150 shot, you'll be trapping well over 120 for sure. That would mean you'd need to run over 6500 RPM in 4th with 4.10s and 26" tires.

I'm not taking into account how much the tires will "grow" at the big end of the track, though.

 

I had the 150 shot before as well. It is just a bolt on LT1 with spray.

 

Ahhhhh, I see. I'm still thinking that you might run out of gear with 26"s and 4.10s, though:

6000RPM = 113MPH
6100 = 115
6200 = 117
6300 = 119
6400 = 121
6500 = 123
6600 = 125

If you only want to rev to 6200, you're cutting it pretty close with the 26" - 4.10 combo.

This might help you:
http://f-body.org/gears/

 

Isn't it possible with the better 60 foot and gears that I might trap lower in MPH?

 

I'm doing a few more mods to the car...so I guess I should go with some 27" slicks. Thanks for your help.