c6 Differential gear change
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Joined: Apr 2020
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From: Central New Jersey
very nice calculator it confirms whats been said at 65mph engine turning 1660 rpm. anyone know why 4.56 ratio's aren't available? with 4.56 gears at 65mph engine turns 1860 rpm still low for cruising . Did some searching found something said these differential housings can't handle the torque of gears bigger than 4.10. anyone know anything about this? will give RPM call today
Safety Car
Joined: May 2006
Posts: 3,696
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From: Potomac MD
RKT56 in Frederick Maryland also specializes in rears/trans and his name is Rick 301 257 0930. I think maybe the 4.10 is the way to go it at least gets you most of the way there and still gives you use of 6th gear. That rear calculator thing was also a nice demonstration of things.
Race Director
Joined: Sep 2007
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From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
very nice calculator it confirms whats been said at 65mph engine turning 1660 rpm. anyone know why 4.56 ratio's aren't available? with 4.56 gears at 65mph engine turns 1860 rpm still low for cruising . Did some searching found something said these differential housings can't handle the torque of gears bigger than 4.10. anyone know anything about this? will give RPM call today
The above quoted calculator using 65 mph at 1660 rpm, either wasn't in 6th gear or used 22.5" tire diameter.
Melting Slicks
Joined: Feb 2007
Posts: 3,297
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From: Raleigh Suburbs
That's certainly problematic, in this situation. My 4.10's were great, in this regard. Just a little too busy for my liking. But hey if you enjoy shifting, more power to you.
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Joined: Apr 2020
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From: Central New Jersey
really not more shifting, speeds shifting at 3000 rpm normal driving gears 3.42 / 4.10 1- 26/22, 2- 39/33, 3-54/45, 4- 70/58, 5-95/79,
6-145/117
the upper gears are farther apart probably won't go that high in RPM'S but lower gears are close don't know if really feel difference unless pushing it check out this calculator really good https://www.blocklayer.com/rpm-gear.aspx
6-145/117
the upper gears are farther apart probably won't go that high in RPM'S but lower gears are close don't know if really feel difference unless pushing it check out this calculator really good https://www.blocklayer.com/rpm-gear.aspx
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Joined: Apr 2020
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From: Central New Jersey
like I said not much different although everyone that got them said they like them. maybe I should start with tune and CAI see if bottom end feels better. Guy's that got tunes how did you feel it helped low end?
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Race Director
Joined: Sep 2007
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From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
With nothing more than a CAI and a tune, I dropped an average of .15 seconds off my 60' time and .4 seconds off the 330' time. So yeah, go there first.
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From: Central New Jersey
yes think cars under geared from factory doing CAI just to do before tune don't think will feel difference with stock motor . going with Vararam seems like everyone likes that one
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Joined: Apr 2020
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From: Central New Jersey
So decided putting 4.10's in, getting differential from ZIP with tune and Vararam CAI do you think Vararam Power wedge worth it? Have appointment at Tune Time in NJ. he said he will have car for week? Seems long time, have to talk to him again both ZIP and RPM say they do car in a day. What you guy's seen as far as install time. Hate leaving car in shop for a week, things happen.
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Joined: Apr 2020
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From: Central New Jersey
scheduled next week for 4.10 differential install. have question about break in for gears. Got rear from ZIP their break in is, install differential fill with lube, run for 10 minutes check level top off, drive car gently no hard take off's stay below 50 mph for 500 mile's then drain and refill and you done. Spoke to RPM they said take differential through 10 heat up and cool downs drain and refill. online it says 3 heat up and cool down cycles. Anyone have any ideas about differential break in?
Pro
Joined: Feb 2017
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From: Fallbrook SanDiego county
scheduled next week for 4.10 differential install. have question about break in for gears. Got rear from ZIP their break in is, install differential fill with lube, run for 10 minutes check level top off, drive car gently no hard take off's stay below 50 mph for 500 mile's then drain and refill and you done. Spoke to RPM they said take differential through 10 heat up and cool downs drain and refill. online it says 3 heat up and cool down cycles. Anyone have any ideas about differential break in?
Seems to me if I remember correctly RPM had me do some figure 8's before the heat cycles
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Joined: Apr 2020
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From: Central New Jersey
was joking about previous post about doing figure 8's but saw something on you tube saying same thing. But ZIP says 500 miles below 50 mph and RPM say 3 heat up cool down cycles and when I called they said 10 heat up cool down cycles which sounds like better break in. any input on this?
Platinum Supporting Vendor
Joined: Sep 2001
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Well I wrote the break in procedure for the Zip differentials and it does not say below 50 mph for 500 miles. You can go to our website and actually download or look at the PDF that has the break-in instructions that we send with every differential.
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From: Central New Jersey
well if you wrote it you should know it.I'll shorten it
1. run for 10 min check oil level top off if needed
2.second trip 30-40 miles 4.10's no more than 50-55 mph do 3 short trips
3.after initial break in you an drive unlimited miles but no high loads to diff.for first 500 miles do easy 500 miles
4. once you reached the 500-mile break in (your words) drain and replace fluids.
I may have spoken to you about going down to you to install it and you said about my drive home about 250 miles that I should use back roads to no exceed 50 mph. but you break in is still 500 miles before hard use. So after step 2 any speed is ok just no hard starts
1. run for 10 min check oil level top off if needed
2.second trip 30-40 miles 4.10's no more than 50-55 mph do 3 short trips
3.after initial break in you an drive unlimited miles but no high loads to diff.for first 500 miles do easy 500 miles
4. once you reached the 500-mile break in (your words) drain and replace fluids.
I may have spoken to you about going down to you to install it and you said about my drive home about 250 miles that I should use back roads to no exceed 50 mph. but you break in is still 500 miles before hard use. So after step 2 any speed is ok just no hard starts
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Joined: Sep 2001
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well if you wrote it you should know it.I'll shorten it
1. run for 10 min check oil level top off if needed
2.second trip 30-40 miles 4.10's no more than 50-55 mph do 3 short trips
3.after initial break in you an drive unlimited miles but no high loads to diff.for first 500 miles do easy 500 miles
4. once you reached the 500-mile break in (your words) drain and replace fluids.
I may have spoken to you about going down to you to install it and you said about my drive home about 250 miles that I should use back roads to no exceed 50 mph. but you break in is still 500 miles before hard use. So after step 2 any speed is ok just no hard starts
1. run for 10 min check oil level top off if needed
2.second trip 30-40 miles 4.10's no more than 50-55 mph do 3 short trips
3.after initial break in you an drive unlimited miles but no high loads to diff.for first 500 miles do easy 500 miles
4. once you reached the 500-mile break in (your words) drain and replace fluids.
I may have spoken to you about going down to you to install it and you said about my drive home about 250 miles that I should use back roads to no exceed 50 mph. but you break in is still 500 miles before hard use. So after step 2 any speed is ok just no hard starts