[oldman]

Originally Posted by Snowblind

You may be thinking about the A8 where I believe they are referring to the M6. If you look at the chart Fraxum has provided then you can see that 5500 rpm is where most M6 guys cross the finish, optimally geared would be numerically higher to cross the finish closer to redline.

I did some quick math using the stock tire height and changing ratios.

3.73 is 143 mph at 6500
4.10 is 130 mph at 6500
4.30 is 124 mph at 6500. (The Ford 8.8 unit)

First gear effective ratios; ( 1st gear × final ratio)

A10 is 13.40
A8 is 12.63
M6 is 9.92

Changing the M6 to a 4.10 final drive gives you a 10.90 first gear effective ratio, a 4.30 final yields 11.48. (You are now approaching A8 first gear ratio and leveling the playing field)

You can see the M6 is at a clear disadvantage in regards to gearing in quarter mile specific terms. I threw in the 4.30 Ford ratio to show that if you were staying somewhat stock, it would probably even benefit more than the 4.10.

A smaller than stock tire with a 4.10 would also achieve the same thing. As it stands, all the M6 guys should be running the shortest tire they can find in a drag racing application.

4.10 have been used for 40 years as it puts most V8 just about at their HP peak thru the traps with the trans at 1:1. This has been true from mild to wild. I had 4.10 in my Dana 60 backing my 440 Dart, and they were too steep, I should have done 3.54 but they were too expensive back in the day. But the 340 guys 4.10, same with just about every 350ish CID performace street driven car.

This is a little long but this is what I've noticed over the last 17 months with the M6:

But realistically, for the street, I'm still in just build torque to make up for the gear, say right now most street guys with just tossing this around 305 tires in back with a minimum 220 wear summer rating: with bolt ons M6 are in the 3.8 second 0-60... The amount of time spent from 4500 to 5000 in 1st gear is not a problem cause it is really hard at a human level there is a only a fraction of a second. When I launch and feather the clutch, slight wheel spin, the tires hook and the tac is at 4500 RPM and to the 6500 shift point I believe I can't even be at WOT, basically saying traction limited to 52 MPH,

2nd gear HP sag:

The bang into second drops the RPM to 4500 RPM and as of right now I can no longer use "no lift shift" as the car will be upside down in a ditch, it is a lift shift and lay slowly on the throttle so once again traction limited to above 60... maybe about 65MPH which an enigne RPM of 5000 RPM well into the plus 400+ WHP range and increasing.. So the stock torque sag in second from 4500 to 5000 is no longer an issue.


Increase in GR on a true daily driver:

I don't see how an increase in gear is going to remedy a traction situation on the street given at best 220 wear summer tires. 100 wear DR even.


With ET streets:

only with 00 wear can I see the gears to be an advantage and only in the 1st to 2nd upshift.. say .15 of a second in this range and .35 off the line yielding a 0-60 of 3.4 seconds.. This I'm in agreement with M6, 4.10 and 00 wear DR, it will be a very quick ride, on the street. I've been saying it for a while the only way to make a DD M6 any faster now is with a 00 wear DR period.



I'm still not sure if I want to jump to 00 wear DR. I've run 100 wear Nitto 555 on my 4th gen and on my supercharged challenger with OK results but at least I could go 12K on the tires babying them (read that as no fun). I know guys are saying the NT01 00 or the E/T streets can go 6K to 10K... but I'm unsure of conditions and usage. My stock rear tires are almost gone at 8800 miles and at least 1500 miles of that I was on aftermarket wheels and 220 wear summer tires that my younger bro borrowed last year...... So with the way I drive stock 300 wear tires last say 8500 miles, I figure E/T streets would be gone in 5000 miles... sorry I'm going to have to bolt in a block of wood under the gas pedal at that point... heck traction control is on 95% of the time...


take away... for the street better figure out what rear tire you are going to run on a daily basis before you start looking at GR and or power adders above boltons.