Which Gears?
Thread Starter
Drifting
Joined: Apr 2003
Posts: 1,387
Likes: 10
From: Jacksonville FL
Which Gears?
I plan on upgrading my trans and rear soon. I'm going with the RPM mn6 with G-force 5th and 6th for better top end. I'm torn between staying with 3.42's in the rear or switching to 3.73's.
The car is just a fun street car that I'd like to be able to hit 200mph in at 7k rpm or less.
I think the 3.73's would get me there but cause traction problems in the lower gears. The 3.42's I'm guessing would be great up top but not drive so hot in 1st. I will be running Hoosier R6 tires in 345/30/19. I appreciate any input or experience.
The car is just a fun street car that I'd like to be able to hit 200mph in at 7k rpm or less.
I think the 3.73's would get me there but cause traction problems in the lower gears. The 3.42's I'm guessing would be great up top but not drive so hot in 1st. I will be running Hoosier R6 tires in 345/30/19. I appreciate any input or experience.
Race Director
Joined: Dec 2003
Posts: 12,599
Likes: 1
From: Texas
Well I am not sure of the answer you are looking for but answer me this: what ratio does the G-force 5th and 6th have? I have stored somewhere the theoretical chart of a car with 3.42s running through each gear (stock tranny) and would like to know what difference it makes to the final drive in each gear.
I would think that you would want to stay with the 3.42s because if you go to 3.73s you would just be that much shorter of your goal mph (200) when you get to 5th and 6th. Just wonder with the G-force gearing how much shorter 5th is and would the 3.73s ultimately hurt your acceleration. Just opinion and wondering here on my part, any more insight would be appreciated by me and the OP
I would think that you would want to stay with the 3.42s because if you go to 3.73s you would just be that much shorter of your goal mph (200) when you get to 5th and 6th. Just wonder with the G-force gearing how much shorter 5th is and would the 3.73s ultimately hurt your acceleration. Just opinion and wondering here on my part, any more insight would be appreciated by me and the OP
Last edited by vetterlatethannever; Dec 30, 2008 at 08:01 PM.
Race Director
Joined: Dec 2003
Posts: 12,599
Likes: 1
From: Texas
Ah, I missed the Z06 part. I think the mn6 combo with the 3.42s would be better even down low because you have plenty of power effectively giving you longer gears. My mn6 combo'd with 3.42s and about 6500 rpm redline runs as follows:
1st- 50ish (traction is a problem, who knows for sure LOL)
2nd- @85 mph
3rd- @115
4th- @150
5th- ???
Running 4th to 7 grand (sweet btw) should net you around 10 more mph, say 160. Now what ratio are the stock 5th and 6th? Its been a long while but I want to say .78 and .50 but I'm probably wrong.
Are you trying to hit the 200 in a certain distance or just before the end of the 'runway'??
1st- 50ish (traction is a problem, who knows for sure LOL)
2nd- @85 mph
3rd- @115
4th- @150
5th- ???
Running 4th to 7 grand (sweet btw) should net you around 10 more mph, say 160. Now what ratio are the stock 5th and 6th? Its been a long while but I want to say .78 and .50 but I'm probably wrong.
Are you trying to hit the 200 in a certain distance or just before the end of the 'runway'??
Thread Starter
Drifting
Joined: Apr 2003
Posts: 1,387
Likes: 10
From: Jacksonville FL
The stock (mn12) 5th and 6th are .84 and .56 I believe. The stock mn6 would be .74 and .50 according to the FAQ in the C5z section.
I just want to hit 200 before running out of nerve!
As an intresting side note my spedo or tach (both?) may be off. At 7k rpm in 5th I'm seeing 170 mph wth 345/30/19 tires. According to T.J. @ RPM I should be around 195 mph. Who knew.
I just want to hit 200 before running out of nerve!
As an intresting side note my spedo or tach (both?) may be off. At 7k rpm in 5th I'm seeing 170 mph wth 345/30/19 tires. According to T.J. @ RPM I should be around 195 mph. Who knew.
Melting Slicks
Joined: Oct 2003
Posts: 2,859
Likes: 4
From: Greensboro NC
I just uprgraded my diff with all the goodies including 3.73 gears. The car is 575/496 procharged Z I am still breaking it in, but from what I can tell I love the tq increase I feel wiht the swap. It basicaly has turned 2nd gear into first and six gear is usable now. I am pleased with then out come so far and hope to bring my 60' down and not have to lauch at such a high rpm at the drag strip.
