[Z06] C7 7-speed in C5?
10-19-2013, 07:52 PM
#21
Race Director
10-19-2013, 08:14 PM
#22
Drifting
I have an MN6 trans with custom 5th and 6th gears. I also run a 3.73 rear gear. Tires are 345/30/19's.
The trans gears are a huge improvement in top end, but hurt mileage. A 7th gear seems like you could have your cake and eat it too, or just have more cake.
The trans gears are a huge improvement in top end, but hurt mileage. A 7th gear seems like you could have your cake and eat it too, or just have more cake.
10-21-2013, 07:56 PM
#23
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10-24-2013, 08:59 AM
#24
Drifting
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C5
LS1/MM6 LS6/M12
1st 2.66:1 2.97:1
2nd 1.78:1 2.07:1
3rd 1.30:1 1.43:1
4th 1.00:1 1.00:1
5th 0.74:1 0.84:1
6th 0.50:1 0.56:1
C7
=====Base Z51
1st - 2.66:1 2.97:1
2nd - 1.78:1 2.07:1
3rd - 1.30:1 1.43:1
4th - 1.00:1 1.00:1
5th - 0.74:1 0.84:1
6th - 0.50:1 0.56:1
7th - 0.42:1 0.42:1
Same ratios, more overdrive, better mileage. More top end?
Good luck finding one.
LS1/MM6 LS6/M12
1st 2.66:1 2.97:1
2nd 1.78:1 2.07:1
3rd 1.30:1 1.43:1
4th 1.00:1 1.00:1
5th 0.74:1 0.84:1
6th 0.50:1 0.56:1
C7
=====Base Z51
1st - 2.66:1 2.97:1
2nd - 1.78:1 2.07:1
3rd - 1.30:1 1.43:1
4th - 1.00:1 1.00:1
5th - 0.74:1 0.84:1
6th - 0.50:1 0.56:1
7th - 0.42:1 0.42:1
Same ratios, more overdrive, better mileage. More top end?
Good luck finding one.
10-26-2013, 11:05 AM
#25
Melting Slicks
Member Since: Sep 2003
Location: Northville Michigan
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At this past January's North American International Auto Show GM had a cutaway model of the TREMEC 6070 7-speed transmission. I took several pictures of the cutaway model, including two where I used a measuring tape to document the overall length of the case and extension housing and the extension housing on its own:
In July of this year I was contacted by an Editor of GM High Tech Performance magazine who had noted my pictures. He asked for permission to use them in an article he was writing on the new TREMEC 6070 7-speed transmission.
http://www.gmhightechperformance.com/tech/transmission/1307_first_look_tr6070_transmission/
Also, later in the summer when I was down at RPM Transmissions in Anderson, Indiana having a 4.10:1 C6 differential installed in my Z, we took a look at the underside and tunnel area of my car. Our opinion is, seeing that the 6070 trans is 45 mm longer than the T56 or TR6060 transmissions, that there is enough room to put the TREMEC 6070 7-speed trans in a C5.
My plan is to try the conversion next spring. The following are a list of items that need to be obtained or changed:
>>> - What are the electrical system differences between the C5-C6 reverse lockout and the 6070's reverse lockout?
When the conversion is completed I will have a 7-speed transmission with the following gear set:
1st --------- 2.66:1
2nd -------- 1.78:1
3rd --------- 1.30:1
4th --------- 1.00:1
5th --------- 0.74:1
6th --------- 0.63:1
7th --------- 0.42:1
A C6 Z06 MN6 trans has a 0.50:1 6th gear and the final drive ratio is 3.42:1. That's an overall gear ratio in 6th gear of 3.42 x 0.50 = 1.71:1
With my 4.10:1 final drive ratio and my 0.42:1 7th gear my overall gear ratio in 7th gear will be 4.10 x 0.42 = 1.72:1. I will be turning the following RPMs:
70 mph ----- 1,535 rpm
75 mph ----- 1,645 rpm
80 mph ----- 1,754 rpm
Wish me luck.
-
In July of this year I was contacted by an Editor of GM High Tech Performance magazine who had noted my pictures. He asked for permission to use them in an article he was writing on the new TREMEC 6070 7-speed transmission.
http://www.gmhightechperformance.com/tech/transmission/1307_first_look_tr6070_transmission/
Also, later in the summer when I was down at RPM Transmissions in Anderson, Indiana having a 4.10:1 C6 differential installed in my Z, we took a look at the underside and tunnel area of my car. Our opinion is, seeing that the 6070 trans is 45 mm longer than the T56 or TR6060 transmissions, that there is enough room to put the TREMEC 6070 7-speed trans in a C5.
My plan is to try the conversion next spring. The following are a list of items that need to be obtained or changed:
- Shorten the torque tube by 45 mm.
- Shorten the shift rod by 45 mm
- Purchase a 45 mm shorter carbon-fiber driveshaft from the Driveshaft Shop
- Purchase a 6070 Reverse Lockout
- Purchasing a 6070 extension housing
- Purchasing a 6070 main-shaft
- Purchasing a 6070 cluster gear
- Purchasing a 6070 0.42:1 7th gear set
- Purchasing a 6070 2.90:1 reverse gear
- Purchasing a 6070 7th gear-Reverse gear synchronizer
- Purchasing a 6070 Reverse gear
>>> - What are the electrical system differences between the C5-C6 reverse lockout and the 6070's reverse lockout?
When the conversion is completed I will have a 7-speed transmission with the following gear set:
1st --------- 2.66:1
2nd -------- 1.78:1
3rd --------- 1.30:1
4th --------- 1.00:1
5th --------- 0.74:1
6th --------- 0.63:1
7th --------- 0.42:1
A C6 Z06 MN6 trans has a 0.50:1 6th gear and the final drive ratio is 3.42:1. That's an overall gear ratio in 6th gear of 3.42 x 0.50 = 1.71:1
With my 4.10:1 final drive ratio and my 0.42:1 7th gear my overall gear ratio in 7th gear will be 4.10 x 0.42 = 1.72:1. I will be turning the following RPMs:
70 mph ----- 1,535 rpm
75 mph ----- 1,645 rpm
80 mph ----- 1,754 rpm
Wish me luck.
-
Last edited by Pumba; 05-07-2014 at 10:54 PM.
Quite a project!!
11-14-2013, 09:31 PM
#29
Drifting
The ZR1 Torque tube is shorter.... You might be able to try that one... I did not nee the offset bushings... so.. if you use that torque tube AND the offset bushings it should be able to fit.
11-15-2013, 11:21 AM
#30
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
At this past January's North American International Auto Show GM had a cutaway model of the TREMEC 6070 7-speed transmission. I took several pictures of the cutaway model, including two where I used a measuring tape to document the overall length of the case and extension housing and the extension housing on its own:
In July of this year I was contacted by an Editor of GM High Tech Performance magazine who had noted my pictures. He asked for permission to use them in an article he was writing.
http://www.gmhightechperformance.com/tech/transmission/1307_first_look_tr6070_transmission/
Also, later in the summer when I was down at RPM Transmissions in Anderson, Indiana having a 4.10:1 C6 differential installed in my Z, we took a look at the underside and tunnel area of my car. Our opinion is, seeing that the 6070 trans is 45 mm longer than the T56 or TR6060 transmissions, that there is enough room to put the TREMEC 6070 7-speed trans in a C5.
My plan is to try the conversion next spring. The following are a list of items that need to be obtained or changed:
- What are the electrical system differences between the C5-C6 reverse lockout and the 6070's reverse lockout?
When the conversion is completed I will have a 7-speed transmission with the following gear set:
1st --------- 2.66:1
2nd -------- 1.78:1
3rd --------- 1.30:1
4th --------- 1.00:1
5th --------- 0.79:1
6th --------- 0.63:1
7th --------- 0.48:1
With my 4.10:1 final drive ratio I will be turning the following RPMs in 7th gear:
70 mph ----- 1,754 rpm
75 mph ----- 1,879 rpm
80 mph ----- 2,005 rpm
Wish me luck.
-
In July of this year I was contacted by an Editor of GM High Tech Performance magazine who had noted my pictures. He asked for permission to use them in an article he was writing.
http://www.gmhightechperformance.com/tech/transmission/1307_first_look_tr6070_transmission/
Also, later in the summer when I was down at RPM Transmissions in Anderson, Indiana having a 4.10:1 C6 differential installed in my Z, we took a look at the underside and tunnel area of my car. Our opinion is, seeing that the 6070 trans is 45 mm longer than the T56 or TR6060 transmissions, that there is enough room to put the TREMEC 6070 7-speed trans in a C5.
My plan is to try the conversion next spring. The following are a list of items that need to be obtained or changed:
- Shorten the torque tube by 45 mm.
- Shorten the shift rod by 45 mm
- Purchase a 45 mm shorter carbon-fiber driveshaft from the Driveshaft Shop
- Purchase a 6070 Reverse Lockout
- Purchasing a 6070 extension housing
- Purchasing a 6070 main-shaft
- Purchasing a 6070 0.48:1 7th gear set
- Purchasing a 6070 7th gear-Reverse gear synchronizer
- Purchasing a 6070 Reverse gear
- What are the electrical system differences between the C5-C6 reverse lockout and the 6070's reverse lockout?
When the conversion is completed I will have a 7-speed transmission with the following gear set:
1st --------- 2.66:1
2nd -------- 1.78:1
3rd --------- 1.30:1
4th --------- 1.00:1
5th --------- 0.79:1
6th --------- 0.63:1
7th --------- 0.48:1
With my 4.10:1 final drive ratio I will be turning the following RPMs in 7th gear:
70 mph ----- 1,754 rpm
75 mph ----- 1,879 rpm
80 mph ----- 2,005 rpm
Wish me luck.
-
Why not the ZR1 ratio set with the additional gear? Given the power the car makes, this would make for a much better track setup and give you the mileage on the highway.
11-15-2013, 12:35 PM
#32
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
The ZR1 close ratio box is by far the quickest out there but for those that do trips in the car...turning 2100-2200 rpm in 6th at 70mph may not be the best on mileage.
Why they didn't use the ZR1 ratios to start with in the C7...I have no clue.
11-15-2013, 02:00 PM
#33
Race Director
For me, the big difference would be in the gearing for 3rd through 5th gear. If someone made 5th 1:1, and spaced out the previous two gears appropriately, the car would be more fun to drive, and the ratios would be closer overall. This would be beneficial for both street, and race cars, IMO. I really don't see the need for a 7th gear, if 4th is still 1:1, and 1st is unchanged.
11-15-2013, 11:54 PM
#34
Drifting
It isn't about the power it can hold....it's about fast, high hp track cars that want to go on longer trips.
The ZR1 close ratio box is by far the quickest out there but for those that do trips in the car...turning 2100-2200 rpm in 6th at 70mph may not be the best on mileage.
Why they didn't use the ZR1 ratios to start with in the C7...I have no clue.
The ZR1 close ratio box is by far the quickest out there but for those that do trips in the car...turning 2100-2200 rpm in 6th at 70mph may not be the best on mileage.
Why they didn't use the ZR1 ratios to start with in the C7...I have no clue.
11-16-2013, 06:03 PM
#35
Drifting
It isn't about the power it can hold....it's about fast, high hp track cars that want to go on longer trips.
The ZR1 close ratio box is by far the quickest out there but for those that do trips in the car...turning 2100-2200 rpm in 6th at 70mph may not be the best on mileage.
Why they didn't use the ZR1 ratios to start with in the C7...I have no clue.
The ZR1 close ratio box is by far the quickest out there but for those that do trips in the car...turning 2100-2200 rpm in 6th at 70mph may not be the best on mileage.
Why they didn't use the ZR1 ratios to start with in the C7...I have no clue.
01-07-2014, 05:27 PM
#36
Drifting
Why not? After all the money invested in Pumba's car. Why get a C7? the C5 Chassis is still awesome and I really like it.... I really like the C5 Dash for some reason....
I like my C5 the way I have it and a 7th gear would be awesome for highway mileage.... I wish to get back the 30+mpg I used to have with the LS6 stock.
I like my C5 the way I have it and a 7th gear would be awesome for highway mileage.... I wish to get back the 30+mpg I used to have with the LS6 stock.
01-07-2014, 07:20 PM
#37
Melting Slicks
Member Since: Sep 2003
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Obviously, I like the C5 Z06 body style also.
My goal when installing the TREMEC 6070 7-speed transmission is two-fold:
>>> 1) I want better gear spacing between 4th and 5th and between 5th and 6th gears. I don't want my rpms to fall in a hole on any of those two shifts. By not falling in a hole I should be able to achieve my goal of driving my Z to 200+ mph.
With my 4.10:1 diff gear ratio and my Michelin Pilot Sport 2 325/25R20 tires, which are 26.4 inches in diameter, I will achieve the following speeds in the first six gears at 7,000 rpms:
1st -- 50 mph
2nd -- 75 mph
3rd -- 103 mph
4th -- 134 mph
5th -- 181 mph
6th -- 213 mph
With 700 SAE engine horsepower I should be able to reach 200 mph.
>>> 2) I want the quiet cabin and improved highway fuel economy, between 70 to 80 mph, that a 0.42:1 7th gear (4.10:1 x 0.42:1 = 1.72:1) will give me.
My goal when installing the TREMEC 6070 7-speed transmission is two-fold:
>>> 1) I want better gear spacing between 4th and 5th and between 5th and 6th gears. I don't want my rpms to fall in a hole on any of those two shifts. By not falling in a hole I should be able to achieve my goal of driving my Z to 200+ mph.
With my 4.10:1 diff gear ratio and my Michelin Pilot Sport 2 325/25R20 tires, which are 26.4 inches in diameter, I will achieve the following speeds in the first six gears at 7,000 rpms:
1st -- 50 mph
2nd -- 75 mph
3rd -- 103 mph
4th -- 134 mph
5th -- 181 mph
6th -- 213 mph
With 700 SAE engine horsepower I should be able to reach 200 mph.
>>> 2) I want the quiet cabin and improved highway fuel economy, between 70 to 80 mph, that a 0.42:1 7th gear (4.10:1 x 0.42:1 = 1.72:1) will give me.
Last edited by Pumba; 05-09-2014 at 07:36 PM.
01-08-2014, 03:33 PM
#38
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