CALL911

iTrader: (17)

Looking at approx. 450 RWHP through an M6. What gears would you all recommend?

I will be in the market for a new 12 bolt. I was thinking 3.93's (I don't think Moser offers these so I would need to go Strange).

But I am also open to 3.73's or 4.10's.

Any advice? The car is street driven but does go to the track. Wondering what the best combo would be for usable acceleration with that power level through an M6.

HCI2000SS

iTrader: (2)

I'm at that power level n/a with 4.10 gears, and to me it's the perfect gear

high impact

iTrader: (5)

4.10 at the least with a m6. I am a street strip, 450 rwhp plus can spray 100-200 shot and still run out fourth gear. If you don't plan to spray it then I would recommend 4.56 with 27-28 inch tall tires at the track.

scotty2000ss

iTrader: (2)

I would wait to swap the gears till you hit the 450hp mark. Reason being is that you'd wanna select the correct gear ratio based on what your trap speed is. Don't wanna have to shift into 5th before you finish. Just my .02

CALL911

iTrader: (17)

Well, I'm already at 441 RWHP on my tired stock LS1. I plan on getting a newly freshened LS1 and going with a more power making cam.

The car has trapped 118 MPH where it is. I doubt I'll break 120 MPH, so using the gear calculator, it would seem 4.10's should work well.

Next question is, how much RWHP loss will be seen on the dyno in the difference between 4.10's and my current 3.42's?

HCI2000SS

iTrader: (2)

I had one tuner tell me that he sees about a 2-4% loss with gears

scotty2000ss

iTrader: (2)

Someone told me a member on here made a chart of the power loss due to gears. I've yet to find it. I lost about 10 on the dyno going from 3:42 to 3:90.

Bob@BruteSpeed

iTrader: (16)

Ben, I got your voicemail message, I'll give you a call back tomorrow. Thanks. Bob

HioSSilver

iTrader: (8)

You should be over 120 easily with that much power. I went 116 in a buds car with 100whp less than you on 3.73 gears

3.93 should work though I unless you car is heavy. If it is then go 4.10.....but you shouldn't spray with a 4.10.

HCI2000SS

iTrader: (2)

Hio why do you say he shouldn't spray at all with a 4.10 gear? I agree it's not ideal at all but it's going to faster than if he didn't spray at all lol. If he is running pure street tires I'd be inclined to agree, as it could be downright dangerous, but with a drag radial it will get some traction at least and will be a fast and fun *** ride lol

redbird555

iTrader: (14)

Since strenght isnt a factor in a 12bolt. I think that he said that for the reason being if you spray 4.10's you'll be running out of gear very quickly and shift more often. 3.90's would allow a bit longer legs on the spray

CALL911

iTrader: (17)

Where does all this talk of spraying come from? Read the thread, and when you do you'll see I never made mention of it. The car will be NA 450 RWHP.

HCI2000SS

iTrader: (2)

You're right OP, the subject of nitrous was not even mentioned by you. I just was curious as to why others were saying what they were.

I still stand by previous statement of going with the 4.10's

BODUKE

I have beaten plenty with my 3.42s

scotty2000ss

iTrader: (2)

3.42's are not a bad gear IMO, as long as you trap in the top of 3rd...

VincesSS

iTrader: (1)

Street racing I'd say 3.73 for some nice highway pulls, but if you're not a highway racer, have ample traction and actually plan to use the car at the track I'd say go with the 4.10s.

kinglt-1

iTrader: (26)

4.10's

Guitar

iTrader: (9)

Because anybody who hasn't had a racecar for 15 years and still stuck in the 11s is doing it wrong.

HioSSilver

iTrader: (8)

If he's running a stock height tire it's a bit to much.....unless he's turning it 7k. Really we need more info on his car and maybe a dyno sheet. But 450rwhp and not running 120+ something seems off to me.
Yep.....spray stock tire height shouldn't cut it with 4.10's.
I could agree with that. But if you get to spinning the motor hard then even 3.73 seem a bit long.
Look at guitar tryin to look significant. ....lol

did those slicks get you outta da 12's? .....oh that's right. Sorry for asking.

CALL911

iTrader: (17)

If it really makes a difference (and really I don't think it does), here is the dyno.

http://www.streetfire.net/video/1998-formula-dyno_169314.htm
The car currently makes 441 RWHP with its current setup and 3.42 stock rear. I'm going to be getting a new LS1 shortblock and taking the heads and intake and installing a custom cam in the new motor. I suspect from a newer motor (mine is high mileage) and the custom cam I'll get 450 ish RWHP. And yes, the car spins to 7,000 RPM.

4.10's will be fine. The car does 118 MPH now in the 1/4 mile. Better gears and a few more ponies and I would say 120 MPH is accurate.