700r4 Gearing!
Thread Starter
Melting Slicks
Joined: Dec 2001
Posts: 2,321
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From: Reno NV
St. Jude Donor '08
700r4 Gearing!
So alot of us are running 700r4s in our cars, and many of those that do, race. Ive noticed something... Ill be anywhere from 2-5 car lengths ahead of damn near anyone i race, but the second my car shifts into third, its all over. My 88 just falls flat on her face, like someone secretly put parachutes on it or something.
Anyone else have this problem?
Im considering having my tranny dropped, and a new set of gears put in. Something with a shorter 3rd for racing and a taller OD for cruising (if possible) Any thoughts on this idea? Any other solution for my 3rd gear lag?
Im also running 3.73 gears in the rear end
Thanks :)
:cheers:
:cheers:
Anyone else have this problem?
Im considering having my tranny dropped, and a new set of gears put in. Something with a shorter 3rd for racing and a taller OD for cruising (if possible) Any thoughts on this idea? Any other solution for my 3rd gear lag?
Im also running 3.73 gears in the rear end
Thanks :)
:cheers:
:cheers:
Team Owner
Joined: Sep 2001
Posts: 62,153
Likes: 1,731
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: 700r4 Gearing! (88'Cubka)
I dont know what to suggest other than maybe a TH400/4L80e.
But i can give you the ratios for these trannys if you dont have them
700R4:
3.06
1.63
1.00
.7
Youll notice that big drop from the 1-2 shift, this is not really good for racing but allows the L98 to use a higher rear ratio and get good acceleration.
(a 4L60 is the same thing as a 700r4)
TH400/4L80E have the same ratios for the 1-3 gears
2.48
1.48
1.00
(4L80)-.75
But i can give you the ratios for these trannys if you dont have them
700R4:
3.06
1.63
1.00
.7
Youll notice that big drop from the 1-2 shift, this is not really good for racing but allows the L98 to use a higher rear ratio and get good acceleration.
(a 4L60 is the same thing as a 700r4)
TH400/4L80E have the same ratios for the 1-3 gears
2.48
1.48
1.00
(4L80)-.75
Thread Starter
Melting Slicks
Joined: Dec 2001
Posts: 2,321
Likes: 0
From: Reno NV
St. Jude Donor '08
Re: 700r4 Gearing! (vader86)
Well even with a tranny swap i would still fall on my face in 3rd.
Ive been thinking about it, and really this isnt a gearing problem as much as its a horsepower problem. However, i think that a huge improvement could be found in changing my 4th gear from a .7 to a .5. it doesnt sound like alot, but with the 3.73s in the rear-end, i think the highway driveability would vastly improve.
Heres some numbers
3.73 rear end
.7 4th gear (stock)
2000rpm = 57mph
2500rpm = 71mph
3000rpm = 85mph
.5 4th gear (proposed)
1500rpm = 60mph
2000rpm = 80mph
2500rpm = 100mph
3000rpm = 119mph
I think this would really help out alot of the guys that have 3.73s in their cars. i still get pretty decent gas mileage, but bringing my legal cruising speed down to 1500-1600 vs 2300 would make it much more friendly, while still giving the gobs of accel down low. The L98 cranks out enough power in this RPM range to not make it a hassel to zip around highspeed traffic as needed either. not to mention i would get my 150mph top speed back :lol:
Thoughts or concerns?
:cheers:
Milan
[Modified by 88'Cubka, 1:18 AM 10/7/2002]
Ive been thinking about it, and really this isnt a gearing problem as much as its a horsepower problem. However, i think that a huge improvement could be found in changing my 4th gear from a .7 to a .5. it doesnt sound like alot, but with the 3.73s in the rear-end, i think the highway driveability would vastly improve.
Heres some numbers
3.73 rear end
.7 4th gear (stock)
2000rpm = 57mph
2500rpm = 71mph
3000rpm = 85mph
.5 4th gear (proposed)
1500rpm = 60mph
2000rpm = 80mph
2500rpm = 100mph
3000rpm = 119mph
I think this would really help out alot of the guys that have 3.73s in their cars. i still get pretty decent gas mileage, but bringing my legal cruising speed down to 1500-1600 vs 2300 would make it much more friendly, while still giving the gobs of accel down low. The L98 cranks out enough power in this RPM range to not make it a hassel to zip around highspeed traffic as needed either. not to mention i would get my 150mph top speed back :lol:
Thoughts or concerns?
:cheers:
Milan
[Modified by 88'Cubka, 1:18 AM 10/7/2002]
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: 700r4 Gearing! (88'Cubka)
I have had the same consideration for years. This is the reason a TH350 tranny car runs faster in than a 700R4 car.
There is NO custom gear set available for the 700R4. I have been looking for years. If you find some place that makes them....I'll buy a set.
Like was said above, the 4L80E is the best choice you have. Changing gear ratio's in the rear end is not going to give you a clos ratio trans...it will only help a little.
There is NO custom gear set available for the 700R4. I have been looking for years. If you find some place that makes them....I'll buy a set.
Like was said above, the 4L80E is the best choice you have. Changing gear ratio's in the rear end is not going to give you a clos ratio trans...it will only help a little.
