G-Force Gears...Noise?
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,877
Likes: 9
From: Ottawa Ontario
G-Force Gears...Noise?
Hey guys
I would like to get my car out to a 1 mile event in the next couple years. I spoke with RPM about the full throttle shift into 5th and they recommended the G-Force 5th and 6th gear. My concern is under normal street drving conditions which is what this car is used for 99% of the time how loud/annoying will this be? Anyone have these? They are straight cut gears and needed to make full pulls saftely in 5th with higher powered cars. Another I need to figure out is that the ratio on these 2 gears is higher than stock which would make me also need to change the Rear End Ring to a 3.15 so i wouldn't top out before the 1 mile marker. With the present M6 tranny gear ratios, 3:42 rear, and 26.7" total diameter tires the car should be able to hit 211mph in 5th. Wether the car can do this in 1 mile is another storey.
Thanks for any input.
I would like to get my car out to a 1 mile event in the next couple years. I spoke with RPM about the full throttle shift into 5th and they recommended the G-Force 5th and 6th gear. My concern is under normal street drving conditions which is what this car is used for 99% of the time how loud/annoying will this be? Anyone have these? They are straight cut gears and needed to make full pulls saftely in 5th with higher powered cars. Another I need to figure out is that the ratio on these 2 gears is higher than stock which would make me also need to change the Rear End Ring to a 3.15 so i wouldn't top out before the 1 mile marker. With the present M6 tranny gear ratios, 3:42 rear, and 26.7" total diameter tires the car should be able to hit 211mph in 5th. Wether the car can do this in 1 mile is another storey.
Thanks for any input.
Last edited by MotleyDrew; Aug 25, 2009 at 02:11 PM.
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Got me wondering if it would be better to step into a T6060. Larger shafts, bearings and gears plus direct oiling on the cluster. A couple of fast Viper (~1400rwhp) acquaintences have used the G-force gears, blown them up and returned to stock gearing with better luck for much less money.
Melting Slicks
Joined: May 2002
Posts: 3,210
Likes: 1
a friend of mine with a different car used g-force gears in his trans and they only lasted two 1320 passes. stock trans was good for a whole season.
FWIW, I haven't had any issues with the stock z06 trans using 5th on the road course up to 155+ dozens of times a session. I'd say try the stock gearing out first before you go spending money that might not be needed.
FWIW, I haven't had any issues with the stock z06 trans using 5th on the road course up to 155+ dozens of times a session. I'd say try the stock gearing out first before you go spending money that might not be needed.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,877
Likes: 9
From: Ottawa Ontario
I like the idea of just testing it out as well but a buddy was gettin me worried about a saftey issue if the tranny lockup at those speeds. Wonder why the G-Force gears break so easily?
Last edited by MotleyDrew; Aug 25, 2009 at 08:20 PM.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,877
Likes: 9
From: Ottawa Ontario
Got me wondering if it would be better to step into a T6060. Larger shafts, bearings and gears plus direct oiling on the cluster. A couple of fast Viper (~1400rwhp) acquaintences have used the G-force gears, blown them up and returned to stock gearing with better luck for much less money.
Melting Slicks
Joined: Feb 2006
Posts: 3,191
Likes: 43
From: Scottsdale Az
I have a fully built G-Force tranny in my C6 and I don't notice any noise over the rest of the car etc. I don't see you pulling 6th in the mile unless you have a rocket on your roof and 5th is pretty strong from them.
Le Mans Master
Joined: Dec 2005
Posts: 8,475
Likes: 332
From: Port Arthur, Texas 77642
G-Force has 2 sets (5th & 6th) available for T56's. On the most popular (set 1) 5th is .83 & 6th is .70 final drive ratio...which I used in the Excel doc below from on MN6 calcs. I also have the MN12 spreadsheet with the GF set 2 and also one with MN12 stock gearing. You can plug-n-play with the numbers to experiment for your best combo. The MN6 is a closer ratio box with a more linear progression (less rpm drop between shifts) desirable for top speed runs. The 1-2 clusters in each box have an effect on on 3-4 & 5-6 ratios. I could be off with some of my info, but I believe I'm pretty close...been awhile since I visited this topic for "mile runs". Good Luck! 
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Le Mans Master
Joined: Dec 2005
Posts: 8,475
Likes: 332
From: Port Arthur, Texas 77642
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,877
Likes: 9
From: Ottawa Ontario
It would be awesome bud ! I hope I can do it ! I have had so many stupid issues along the way that now that the car seems like everything is sorted out I just want to get down to Toronto and have Arun tune it then save some $ and get it down to one of these 1 mile events .
Drifting
Joined: Apr 2003
Posts: 1,391
Likes: 10
From: Jacksonville FL
I have them and strongly recommend them. I went from the stock MN12 with 3.42s to an MN6 with Gforce gears and 3.73 rear. This is one of the best mods I've ever done. The car pulls strong to the top of 6th. I haven't noticed any additional noise, but my car makes a little noise anyway, so I might not notice.
Former Vendor
Joined: Oct 2004
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From: FI Performance : Norwalk Connecticut www.FIPERFORMANCE.com
