4+3
Thread Starter
Team Owner
Joined: Feb 2001
Posts: 62,195
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Cruise-In II Veteran
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19
4+3
How sturdy is it? Will it support 450hp? And EXACTLY how does the damn thing work....what is the "+3"????
Safety Car
Joined: Jun 2003
Posts: 4,510
Likes: 240
From: Coconut Creek FL
Re: 4+3 (j3studio)
Sturdy...well, I believe it was bolted to the 475HP Callaway....and the +3 part is regarding the Overdrive function that can be selected in 2nd, 3rd and 4th gears....The tranny itself is an odd ball...there is a standard 4 speed manual that has a 3 speed automatic bolted to the back half....The OD unit was built by Doug Nash...They went in all manual vettes (C4's) up to 89...then they gave us the ZF6 (6 speed German I believe)
They have been known to have issues with the design and were more problematic in the early years...my 84 with the 4+3 has a mind of it's own...but that's why I love it!
Cheers :cheers:
They have been known to have issues with the design and were more problematic in the early years...my 84 with the 4+3 has a mind of it's own...but that's why I love it!
Cheers :cheers:
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Re: 4+3 (84zz4vette)
It worked behind the Callaway motors and should withstand some serious power as long as you take care of it. Changing both fluids (gear oil in the tranny and auto trans fluid in the OD) and the filter in the OD unit is important for long life.
The 4-speed portion is a Borg-Warner Super T10 box. The "+3" portion is a two-speed overdrive unit that works with 2nd, 3rd, and 4th gear. A button controls the operation of the unit, switching it on or off as needed. In the OD position, you can use the throttle to "kick down" the OD unit much like an auto tranny. A couple of ratios were used depending on the year of the car.
The 4-speed portion is a Borg-Warner Super T10 box. The "+3" portion is a two-speed overdrive unit that works with 2nd, 3rd, and 4th gear. A button controls the operation of the unit, switching it on or off as needed. In the OD position, you can use the throttle to "kick down" the OD unit much like an auto tranny. A couple of ratios were used depending on the year of the car.
