I'm told that the best total 1st gear to have is 6.60 with a 275/60.

Does this hold true for all cars or only boosted cars?

The only reason I'm asking is because my car is out of steam around 1000 maybe even earlier. So I need to get a different rear gear for asphalt.

You now know where you make peak HP so adjust the
gear to just over the peak HP rpm... if you need to
you can go to a low first gear to help get you off
the line... forget the 6.60 stuff... it isnt working
is it

The 6.60 would require a 2.76 gear with the 904.

Richmond says 4.56. I currently have 5.33 is way too much. I can literally feel the car stop pulling and just rev. Around 660 I can really feel it pulling.

4.56 will put me at 11.17, I was just curious if anyone went by that or not.

I always figure what the finish line rpm will be
with the slippage and calculate that for 10% above
the peak HP rpm.... some times you can run a bit less
gear and let the torque pull more.. but on your engine
I wouldnt think so

I like to run as much starting line ratio, 1st gear x rear gear ratio, as I can get away with without spinning the tires on a fair track As far as finish line ratio it depends on how high the motor pulls hard to, sometimes to get the best ET and MPH you may need to over gear it a little at the finiah line, say by 200 to 400 RPM above peak pulling in 2nd gear I use to race a NHRA legal Stocker and some of the Mopar sponsored stock and Super Stock racers would suggest running a little more rear gear than I liked Bottom line it is up to you to run what you like I have ran less rear gear with more, deeper, 1st gear than others racers did with the same combination motor and car in the same class and outran them

When you say over gear, you mean instead of running 4.91 you'd run 4.56 correct.

We took gear out of Brett Millers car with his 904 trans and made the fastest passes to date. Went from a 4.86 to 4.30 in the rear.

Is Brett still running the stock 2.45 gear set?

Set the rearend gear to what RPM and mph you expect. Tune your combo until you achieve said results. If your motor makes peak hp at 8800, then shoot for 8800-9000 in the traps. A good convertor will have single digit slipage and the tires will GROW in diameter at speed (not too much). These motors make an honest 800 hp, use the wallace calc to determine the hp/wt and tune until you achieve this performance. Time and time again, I see everyone adjusting these combo's to improve it and they're no where near getting 800 hp out of it.

Mike

No Brett is running a low gear set in his car. He is running the same tire as you.

I'm supposed to be 8.80-.90 (at least that's what Wallace calculator says), I'm hoping to just hit the .10-.20s, if I can get better than that I'll be very happy.

I'm not sure if I should tempt fate and keep hammering on the stock cast aluminum gear set, or step up to steel like Brett.

Let me know I have a low gear set for a 904.

Brett has been 1.24 60 with his.