Considering the DTE Diff upgrade a few ?s
Thread Starter
Racer
Joined: Mar 2006
Posts: 419
Likes: 0
From: Crestwood KY
Considering the DTE Diff upgrade a few ?s
OK, I realize that the 05s have a little bit weaker rear diff than the upgraded 06+. Now, I am not going to be running huge HP/TQ. Right now, I am at 373.4 HP with bad DYNO conditions. With a few additional minor mods, I expect to be at around 390RWHP +/-, so the stage I is probably the route I will take. I do have a few questions and welcome any comments...
1. I have and really like my closer ratio base transmission. Going to 3.73, will I feel in the SOTP much difference, how much of a performance increase for auto-x and road course? Is 3.90 worth the loss in fuel economy/drivability...this isn't my daily driver, but I do drive a lot when the weather is good.
2. How much more reliability is to be expected?
3. With a reputable shop, approximately how many labor hours or total $ should I expect?
Thanks in advance!!
1. I have and really like my closer ratio base transmission. Going to 3.73, will I feel in the SOTP much difference, how much of a performance increase for auto-x and road course? Is 3.90 worth the loss in fuel economy/drivability...this isn't my daily driver, but I do drive a lot when the weather is good.
2. How much more reliability is to be expected?
3. With a reputable shop, approximately how many labor hours or total $ should I expect?
Thanks in advance!!
Melting Slicks
Joined: Nov 2002
Posts: 3,398
Likes: 2
From: Allentown PA
Originally Posted by CoolBlueC6
1. I have and really like my closer ratio base transmission. Going to 3.73, will I feel in the SOTP much difference, how much of a performance increase for auto-x and road course? Is 3.90 worth the loss in fuel economy/drivability...this isn't my daily driver, but I do drive a lot when the weather is good.
2. How much more reliability is to be expected?
3. With a reputable shop, approximately how many labor hours or total $ should I expect?
Thanks in advance!!
2. How much more reliability is to be expected?
3. With a reputable shop, approximately how many labor hours or total $ should I expect?
Thanks in advance!!
You will lose such a slight amout of fuel economy that it should not even factor into your decision.
$300 to swap the rear, $900 for the gear install. $1,200 total. Throw in a hardened output shaft for $300, if you do it now the install is free while the rear is apart.
Thread Starter
Racer
Joined: Mar 2006
Posts: 419
Likes: 0
From: Crestwood KY
Originally Posted by CYA-Vett
You want to go 3.90 or 4.10, not 3.73
You will lose such a slight amout of fuel economy that it should not even factor into your decision.
$300 to swap the rear, $900 for the gear install. $1,200 total. Throw in a hardened output shaft for $300, if you do it now the install is free while the rear is apart.
You will lose such a slight amout of fuel economy that it should not even factor into your decision.
$300 to swap the rear, $900 for the gear install. $1,200 total. Throw in a hardened output shaft for $300, if you do it now the install is free while the rear is apart.
Keep in mind, I will be on the road course and want to maintain some top end. So, what should I expect from a 3.90 ratio?
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
3:90 gears were one of the best mods in my C5. I loved them on the street, drag strip, and road course. Felt like the car lost 500 lbs - the SOP difference was amazing, like a different car.
That's why I'm getting a set installed in my C6 next week!
That's why I'm getting a set installed in my C6 next week!
Burning Brakes
Joined: Sep 2000
Posts: 1,073
Likes: 5
From: NJ
Originally Posted by Joe_G
3:90 gears were one of the best mods in my C5. I loved them on the street, drag strip, and road course. Felt like the car lost 500 lbs - the SOP difference was amazing, like a different car.
That's why I'm getting a set installed in my C6 next week!
That's why I'm getting a set installed in my C6 next week!
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
Originally Posted by Stage7
What were the original gears?
I've done a clutch swap and torque tube rebuild with a buddy, if you have a lift and a transmission jack it's actually pretty darn easy to get the tube out and swap out the rear end. The vette is one of the easier cars I've worked on, you can get to most of the stuff pretty easily. We had a master mechanic give us a few tips and pointers along the way but it's not a bad job, nor should it be that expensive. I'd say 5-6 hours labor, 8 if they are taking their time. A good mechanic can do it before lunch, no question about it.
There's how to's on the forum for diff swaps including installing hardened shafts. Leave a ring and pinion swap to the professionals.
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Thread Starter
Racer
Joined: Mar 2006
Posts: 419
Likes: 0
From: Crestwood KY
I am considering the purchase of a lift for just this type of stuff plus oil/tranny/and diff fluid changes. Oh yea, so my wife can park in the garage:o She can park underneath. My clearance is just about at the minimum.
Anyway, that time fram gives me a good idea as far as the shop that I use. He is awsome and his shop rate is $65.00 per hour. I'd much rather do it my self though, just for the hands on aspect. I have some track days planned for July and August and the extra grunt would be fun.
Anyway, that time fram gives me a good idea as far as the shop that I use. He is awsome and his shop rate is $65.00 per hour. I'd much rather do it my self though, just for the hands on aspect. I have some track days planned for July and August and the extra grunt would be fun.