WOT 4th gear kit
Thread Starter
Intermediate
Joined: May 2000
Posts: 34
Likes: 0
From: Charlotte, NC, US
Re: WOT 4th gear kit (nsimmons)
Nick this is not the 3/4's kick down valve you see advertised in Summit and Jegs. I called B & M direct and they gave me the part number 70249 which is a $118 kit (Summit's price) that is a bit more involved. I would just like to know if anyone has tried it before I dive in.
Thread Starter
Intermediate
Joined: May 2000
Posts: 34
Likes: 0
From: Charlotte, NC, US
Re: (scorp508)
I is my understanding none of the 700R4's will do WOt 4th. I know mine sure won't. I run track events and all you have is a 3 speed when your wanting more down the straight of way. B & M says Corvettes come the that three quarter throttle valve already in them. I can't say exactly where in the throttle it works but if I start backing off from full throttle, at some point it finally drops into 4th. Roll the throttle back on and it come right back out of 4 th to 3rd. Needless to say at 5900 rpms in 3rd. on a L98 there ain't no power up there.
Burning Brakes
Joined: Apr 2001
Posts: 904
Likes: 0
From: Langley, BC, Canada
Re: (Vette Track Car)
the corvette 700r4 will shift into 4th at wot, and will retain 4th if going fast enough. mine does, my friends does. If yours doesnt, its broken or its not a vette tranny.
[Modified by nsimmons, 12:14 AM 3/8/2002]
[Modified by nsimmons, 12:14 AM 3/8/2002]
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Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: (devilfish)
The only thing in the kit is a sleeve and a new TV valve.
I modified a standard TV sleeve for the purpose in my 79 vette. It kicks down to 3rd at any speed below 120 MPH, then it will upshift to 4th, under full throttle. It actually shifts too early for me...since the car pulled hard to about 150 MPH ( close to 7000 RPM with 3.55 gears ) before it needed to be shifted to fourth. I don't think L98's would have that problem...since they poop out at 5000 RPM ( max ).
The L98 definitely needs the early shift to fourth valve.
I modified a standard TV sleeve for the purpose in my 79 vette. It kicks down to 3rd at any speed below 120 MPH, then it will upshift to 4th, under full throttle. It actually shifts too early for me...since the car pulled hard to about 150 MPH ( close to 7000 RPM with 3.55 gears ) before it needed to be shifted to fourth. I don't think L98's would have that problem...since they poop out at 5000 RPM ( max ).
The L98 definitely needs the early shift to fourth valve.
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
The L98 definitely needs the early shift to fourth valve.
The 4+3 will automatically upshift you into 4th/overdrive which is 0.68:1 at 103mph if you leave the program running at these speeds. That is a little too soon for me, so I'll string her out another 7-10mph before engaging O/D.
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Re: (scorp508)
Isn't the Corvette 700R4 already designed to go into 4th at WOT?
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: (Glock'94)
One thing no one mentioned here...the 3-4 upshift sleeve only applies to those transmissions with TV cables. If you have an electronic controlled trans, this whole post is not applicable.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: (BBA)
The info is correct. My IROC's 700R/4 didn't have a 3-4 upshift sleeve and wouldn't upshift at WOT; the Vette does.
Level 10 sells these sleeves for non-Vette 700R/4s, I'm not home now so can't give you the part number.
Level 10 sells these sleeves for non-Vette 700R/4s, I'm not home now so can't give you the part number.
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: (devilfish)
There is no 'good' way to do it other than replace the sleeve/tv valve assembly.
If you back off the TV cable adjustment, you can make it upshift, but you will also be reducing hydraulic pressure and will likely burn the transmission up before you reach top speed...and thats no kidding.
If you back off the TV cable adjustment, you can make it upshift, but you will also be reducing hydraulic pressure and will likely burn the transmission up before you reach top speed...and thats no kidding.