318.54rwhp with 3:42 gears a4

**Durango** · 09-07-2011, 12:37 PM

I ran a 13.21 at 104.7 mph with a 1.96 60 foot and 83.96mph at 660ft I realized my tires were an inch to 1 1/2 inch taller than my buddies on his TA would that make a difference in the 1/4 I think it would since it changes the gear ratio. Let me know if anyone tried that yet I have a YANK SS3200 as well

Cheers boys and girls

**redbird555** · 09-07-2011, 04:18 PM

what are your mods besides the stall? If your stock with just a stall the numbers are right on target but the et could use some work. That stall should be hitting 1.7-1.8 60' with a good tire and netting a high 12 or BOTTOM low 13. However if you have , headers, lid, intake etx then your numbers are pretty low a bolt on a4 should be around 110mph with 660 da like you had perhaps about 108

**Firebirdjones** · 09-07-2011, 04:32 PM

Post the metric size of the tire and I can tell you exactly how tall it is.

Stock F-body tires....

245/50-16 for Z28 and T/A is exactly 25.64 inches tall

275/40-17 for SS and WS6 is exactly 25.66 inches tall

This is the math equation for the sizes posted. Of course these numbers vary slightly with different tire manufactures, they all don't adhere to the same sizes even though that's what is posted on the tire.

The most accurate way to find tire height is while it is properly inflated and installed on the car while the car is resting on the ground with full weight on the tire. Then mark the floor and the bottom dead center of the tire. Roll the car until that mark on the tire comes back around to bottom dead center, make another mark on the floor. Measure that distance and you have your tire height with the weight of the car involved.

Taller tires kill the rear gear, while shorter tires will enhance. Just an inch makes a big difference. Hope that helps.

**Durango** · 09-07-2011, 06:24 PM

I have a lid and a cat back that's it and my tires are 296/35/18's vs the stock 16" we were side by side and you could see the tire height difference easily then we just measured off the ground and it was easily an inch. I'm running Firehawk wide ovals and I can't launch more that 2000rpm I will try drag radials next time and hope for less humidity

**Durango** · 09-07-2011, 06:27 PM

Originally Posted by Firebirdjones

Post the metric size of the tire and I can tell you exactly how tall it is.

Stock F-body tires....

255/50-16 for Z28 and T/A is exactly 26.03 inches tall

275/40-17 for SS and WS6 is exactly 25.66 inches tall

This is the math equation for the sizes posted. Of course these numbers vary slightly with different tire manufactures, they all don't adhere to the same sizes even though that's what is posted on the tire.

The most accurate way to find tire height is while it is properly inflated and installed on the car while the car is resting on the ground with full weight on the tire. Then mark the floor and the bottom dead center of the tire. Roll the car until that mark on the tire comes back around to bottom dead center, make another mark on the floor. Measure that distance and you have your tire height with the weight of the car involved.

Taller tires kill the rear gear, while shorter tires will enhance. Just an inch makes a big difference. Hope that helps.

That helps a lot I will do that my 6y old has a lot of chaulk for my driveway I'll use that I did notice that mine seem taller than my buddies we just took a tape measure from the ground then we parked them close togheter and couldn't beleive the tire geight difference

**Durango** · 09-07-2011, 06:30 PM

Originally Posted by redbird555

what are your mods besides the stall? If your stock with just a stall the numbers are right on target but the et could use some work. That stall should be hitting 1.7-1.8 60' with a good tire and netting a high 12 or BOTTOM low 13. However if you have , headers, lid, intake etx then your numbers are pretty low a bolt on a4 should be around 110mph with 660 da like you had perhaps about 108

Cool yes I have drag radials waiting to go on that my buddy is lending me and I just bought MT street but the are big 26x11.5x17 brand new for 150 bucks so I picked them up never installed guy sold his car I figured it would work!!!! His drag radials are the size that Firebirdjones was it said it was for a z28 and 16" that was 255/50/16 I find that my 660 foot on is a little low even my buddies ta seems to catch up to me a little with his TA with now stall and exactly the same mods as me he ran a 13.22 at 15.88mph with only 303.8rwhp but with those drag radials I was talking about

**Firebirdjones** · 09-07-2011, 06:32 PM

I assume that you meant a 295

In which case 295/35-18's are exactly 26.1299 inches tall,,,,,as per the math. If you have a T/A (non WS6) that had stock 16" wheels with the 245/50-16's then you aren't too far off from the factory tire height of 25.64. About 1/2 inch taller.

**35th-ANV-SS** · 09-07-2011, 06:34 PM

You have a 26.13" tall tire.

Edit - I see FBJ beat me to it!

**Firebirdjones** · 09-07-2011, 06:36 PM

Oooops sorry, the stock tire size for the Z28 and T/A 16" wheels are 245/50- 16's.

**Durango** · 09-08-2011, 07:22 AM

Cool thanks guys I think the idea of having a Torque converter and not being able to launch it where you want is a pain I just hope that with drag radials I'll be able to launch it at 2500rpm at least and land a 12.99 loll that is my ultimate goal If not supercharger and go in the 11's or low 12's lolll I need to win money 1st or get a killer deal on 1

**PFM** · 09-08-2011, 09:48 AM

Now if you want to get technical this is the site to figure out all your tire sizes and effects on different gear setups.

http://www.pszweb.com/car/gears.htm