700R4 trans install - Corvette Forum : DigitalCorvettes.com Corvette Forums
 
 
Go Back   Corvette Forum : DigitalCorvettes.com Corvette Forums > C3 Corvette Forums > C3 Corvette
Register Forums Garage Garage Mark Forums Read Auto EscrowInsurance

Notices

C3 Corvette
C3 Corvette General | Technical | Performance | Aftermarket | Discussions

Other sections:
Corvettes Classifieds
Corvette Detailing & Car Care
Corvette Audio/Video/Radar
General Automotive/Shop/Tools
Corvette Performance Driving/Racing

( Sponsored by: Zip Corvette Parts )

Shops/Tuners
Custom Image Corvettes
A&A Corvette
Corvette tuner

Interior
Corvette aftermarket products

Insurance

Parts & Products
Race Ramps
Edelbrock
ATI/Procharger
Corvetteguys.com
Melrose Motorsports
Parts Taxi
Airaid
Mid America Motorworks
Pfadt Racing
Madvette Motorsports
Hi-tech Custom Concepts
Corvette aftermarket products
Corvette Garage
Corvette Parts and Accessories
Corvette Car Care Products
Corvette HID
Mid America Motoroworks

Tracks/Schools
Bob Bondurant School of High Performance Driving
Corvette driving school

Wheels/Tires
Cray Wheels

Services
BADWERKS.com
Reply
 
Thread Tools
Old 10-15-2012, 01:50 PM   #1
XQIZT
You've been pimped!!
 
XQIZT's Avatar
 
Posts: 12,779
Member #80197
Member since: Jan 2009
Location: Orlando, FL

My Corvette(s)
1985 Z51, 1977 custom

Thanks: 26
Thanked 183 Times in 157 Posts
700R4 trans install

Running the financial numbers, and it just makes good sense to get the old tranny out and install a 700R4 so we have an overdrive gear. 30-40% increase in MPG is huge and will pay for itself.

I see some places have all up kits and all that needs to be completed is the drive shaft shortening and the moving of a cross member.

I know cutting and welding is involved in the drive shaft modification, but what about the cross member? Is that a bolt on situation?

Thanks!
XQIZT is offline   Reply w/quote Quick reply to this message
"Alexa" - 1985 Z51 - In memory of the last Corvette Dad owned.

"Desiree" - 1977 - Wife's car, with an attitude problem

Click here for more info about our cars and autocrossing and other Corvette stuff.
Sponsored Links
Advertisement
 
Old 10-15-2012, 02:17 PM   #2
6880 Mike
DC Crew
 
6880 Mike's Avatar
 
Posts: 1,933
Member #47959
Member since: Jul 2006
Location: Kentucky

My Corvette(s)
1968 convertible; 1980 L-82

Thanks: 0
Thanked 48 Times in 46 Posts
Use the 82 crossmember; it's bolt in.
6880 Mike is offline   Reply w/quote Quick reply to this message
Old 10-16-2012, 05:22 AM   #3
rtj
 
rtj's Avatar
 
Posts: 3,985
Member #52011
Member since: Oct 2006
Location: orlando fl usa

My Corvette(s)
75/502, C6 Z06, 70 ProStreet

Thanks: 1
Thanked 37 Times in 36 Posts
I've had a bunch of driveshafts shortened and balanced at Advanced Driveline here in Orlando. If you need driveshaft work you might consider them.
rtj is offline   Reply w/quote Quick reply to this message
The Following User Says Thank You to rtj For This Useful Post:
XQIZT (10-16-2012)
Old 10-16-2012, 09:57 AM   #4
tektrans
DC Crew
 
tektrans's Avatar
 
Posts: 772
Member #79719
Member since: Jan 2009

Thanks: 8
Thanked 23 Times in 22 Posts
I have a Bowtie Overdrives 700R4 crossmember for sale, if you are interested PM me.

,Mark
tektrans is offline   Reply w/quote Quick reply to this message
Old 10-16-2012, 10:17 AM   #5
XQIZT
You've been pimped!!
 
XQIZT's Avatar
 
Posts: 12,779
Member #80197
Member since: Jan 2009
Location: Orlando, FL

My Corvette(s)
1985 Z51, 1977 custom

Thanks: 26
Thanked 183 Times in 157 Posts
pm sent.
XQIZT is offline   Reply w/quote Quick reply to this message
"Alexa" - 1985 Z51 - In memory of the last Corvette Dad owned.

"Desiree" - 1977 - Wife's car, with an attitude problem

Click here for more info about our cars and autocrossing and other Corvette stuff.
Old 10-16-2012, 01:37 PM   #6
KacyC3
DC Crew
 
KacyC3's Avatar
 
Posts: 306
Member #118574
Member since: Mar 2012
Location: Midwest

My Corvette(s)
C3

Thanks: 0
Thanked 20 Times in 20 Posts
Bowtie overdrives is the place my crossmember came from and i also recommend their tv cable linkage kit. It gives you a cam that allows how aggressive the transmission shits.
KacyC3 is offline   Reply w/quote Quick reply to this message
Old 10-16-2012, 01:39 PM   #7
XQIZT
You've been pimped!!
 
XQIZT's Avatar
 
Posts: 12,779
Member #80197
Member since: Jan 2009
Location: Orlando, FL

My Corvette(s)
1985 Z51, 1977 custom

Thanks: 26
Thanked 183 Times in 157 Posts
I also like that they provide a new shift detent and indicator window that truly shows OD, D, 2, 1
XQIZT is offline   Reply w/quote Quick reply to this message
"Alexa" - 1985 Z51 - In memory of the last Corvette Dad owned.

"Desiree" - 1977 - Wife's car, with an attitude problem

Click here for more info about our cars and autocrossing and other Corvette stuff.
Old 10-17-2012, 02:57 PM   #8
KacyC3
DC Crew
 
KacyC3's Avatar
 
Posts: 306
Member #118574
Member since: Mar 2012
Location: Midwest

My Corvette(s)
C3

Thanks: 0
Thanked 20 Times in 20 Posts
Quote:
Originally Posted by XQIZT View Post
I also like that they provide a new shift detent and indicator window that truly shows OD, D, 2, 1
Mine has a B&M ratchet shifter, so I don't have any info on that.
KacyC3 is offline   Reply w/quote Quick reply to this message
Old 10-21-2012, 09:22 PM   #9
gkull
DC Crew
 
gkull's Avatar
 
Posts: 588
Member #44069
Member since: Mar 2006
Location: Nevada

My Corvette(s)
1979 Highly Modded

Thanks: 0
Thanked 1 Time in 1 Post
You don't magically get increased MPG with a reduction of rpm with an OD tranny.

a 3.55 or lower number rearend can attain 20+ mpg with an efficient motor and a th350

a 700R4 is a serious power user compared to well built th350

The 200r4 is a more bolt in tranny with better gear spacing and not as power robbing as a 700
gkull is offline   Reply w/quote Quick reply to this message
Old 10-23-2012, 07:23 AM   #10
XQIZT
You've been pimped!!
 
XQIZT's Avatar
 
Posts: 12,779
Member #80197
Member since: Jan 2009
Location: Orlando, FL

My Corvette(s)
1985 Z51, 1977 custom

Thanks: 26
Thanked 183 Times in 157 Posts
Quote:
Originally Posted by gkull View Post
You don't magically get increased MPG with a reduction of rpm with an OD tranny.

a 3.55 or lower number rearend can attain 20+ mpg with an efficient motor and a th350

a 700R4 is a serious power user compared to well built th350

The 200r4 is a more bolt in tranny with better gear spacing and not as power robbing as a 700
Explain this please. Are you saying that running 55mph at 3000rpm vs. 55mph at 1700rpm will no show a MPG difference?
XQIZT is offline   Reply w/quote Quick reply to this message
"Alexa" - 1985 Z51 - In memory of the last Corvette Dad owned.

"Desiree" - 1977 - Wife's car, with an attitude problem

Click here for more info about our cars and autocrossing and other Corvette stuff.
Old 10-23-2012, 09:14 AM   #11
gkull
DC Crew
 
gkull's Avatar
 
Posts: 588
Member #44069
Member since: Mar 2006
Location: Nevada

My Corvette(s)
1979 Highly Modded

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by XQIZT View Post
Explain this please. Are you saying that running 55mph at 3000rpm vs. 55mph at 1700rpm will no show a MPG difference?
What kind of a rearend do you have that causes 3000 rpm at 55?

years ago i built a 7000 rpm 355 ci and routinely got over 20 mpg on trips with a built th350 and 3.55 gears driving 75-85 all the time. I would drive 500 miles on my 25 gallon tank.

Then i installed a 700R4 and my mileage went down because rpm dropped to the point where it was below the cam efficency range. so i installed a 4.11 rear to bring the rpm somewhat up and the MPG was still less than before and I lost a couple of 1/10ths at the drag strip.

The problem is a 700r4 even built up looses about 25 RWHP compared to a built TH350. It is a power robbing tranny just like the TH400.

MPG is dependant on running the engine in an efficient rpm. Dropping below like 1700 rpm would require more gas to maintain a highway speed because the motor is near lugging. I had a modded 98 C-5 vette and it ran better in 5th than 6th gear. I installed a 4.10 rear end in it and then it could actually use the 6th gear.
gkull is offline   Reply w/quote Quick reply to this message
Old 10-23-2012, 09:26 AM   #12
XQIZT
You've been pimped!!
 
XQIZT's Avatar
 
Posts: 12,779
Member #80197
Member since: Jan 2009
Location: Orlando, FL

My Corvette(s)
1985 Z51, 1977 custom

Thanks: 26
Thanked 183 Times in 157 Posts
I was just tossing out those numbers...

But all else being equal, and no other changes, every person that has swapped in a tranny with an OD has seen increased MPG.
XQIZT is offline   Reply w/quote Quick reply to this message
"Alexa" - 1985 Z51 - In memory of the last Corvette Dad owned.

"Desiree" - 1977 - Wife's car, with an attitude problem

Click here for more info about our cars and autocrossing and other Corvette stuff.
Old 10-23-2012, 09:36 AM   #13
gkull
DC Crew
 
gkull's Avatar
 
Posts: 588
Member #44069
Member since: Mar 2006
Location: Nevada

My Corvette(s)
1979 Highly Modded

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by XQIZT View Post
I was just tossing out those numbers...

But all else being equal, and no other changes, every person that has swapped in a tranny with an OD has seen increased MPG.
Not everyone (Me)! the 700R4 is a worst case. The 200R4 is much more efficient. I ran my 700's in my Vette for 18 years and finally got smart and installed a TKO 600 and then I saw an instant increase in highway mileage. My 434 ci exceeds 18 on long trips Like when i drove 1200 miles to southern Cal for a Vette get together.
gkull is offline   Reply w/quote Quick reply to this message
Old 10-23-2012, 11:16 AM   #14
garys 68
DC Crew
 
Posts: 272
Member #94630
Member since: Nov 2009
Location: St Louis/MO

My Corvette(s)
68 vert

Thanks: 0
Thanked 29 Times in 24 Posts
Real world experience. My 89 camaro got about 10% better milage with the 700R4 in OD (0.7) vs 1:1 drive.
A 30% reduction in rpm does not equal a 30% increase in milage.
garys 68 is online now   Reply w/quote Quick reply to this message
Old 10-24-2012, 01:36 PM   #15
shakedown067
DC Crew
 
shakedown067's Avatar
 
Posts: 451
Member #87846
Member since: Jul 2009
Location: Largo, FL

My Corvette(s)
1996 Black LT-1

Thanks: 1
Thanked 3 Times in 2 Posts
What cross-member do you have to remove? Why not just buy a used auto driveshaft and C-beam? They are relatively cheap. Or did those only change for the ZF6? Good luck on the swap.
shakedown067 is offline   Reply w/quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Corvette Forum : DigitalCorvettes.com Corvette Forums forums, you must first register.
Please enter your desired user name (12 CHARACTERS MAXIMUM), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Powered by vBadvanced CMPS v3.2.2

All times are GMT -6. The time now is 04:21 AM.




Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
2003-2011, DigitalCorvettes.com - All Rights Reserved