700R4 and 3.73s?
Thread Starter
Supreme Member
iTrader: (1)
Joined: Oct 2004
Posts: 3,361
Likes: 1
From: Worcester, MA
Car: 86 T/A
Engine: HSR 355
Transmission: 700R4
Axle/Gears: 2.77 posi
700R4 and 3.73s?
Who uses them? I'm worried about going from 2.73s that it'll hurt my gas milage. On the highway I was over 2K at 75 mph, so 3.73s are really going to up my rpms.
Supreme Member
iTrader: (3)
Joined: Sep 2005
Posts: 1,685
Likes: 3
From: MD
Car: '88 IROC-Z medium orange metallic
Engine: L98
Transmission: 700R4
Axle/Gears: 3.27
Use the RPM calculator in the tech section on the homepage. I calculated mine with 4.10's and a 26" tire and it was only like 2200 rpms @ 60 MPH.
Thread Starter
Supreme Member
iTrader: (1)
Joined: Oct 2004
Posts: 3,361
Likes: 1
From: Worcester, MA
Car: 86 T/A
Engine: HSR 355
Transmission: 700R4
Axle/Gears: 2.77 posi
I don't know my tire size. And at 75mph I'm around 2500 rpm, other people with the same tranny a 3.73 say they drive 75 mph at almost the same RPMs which isn't possible.
Moderator
Joined: Jan 2000
Posts: 20,981
Likes: 11
From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Your tire will be close enough to 26". In O/D at 60 mph with 3.73s you'll be about 2000 RPM, at 75 mph you'll be about 2500.
Senior Member
Joined: Oct 2005
Posts: 535
Likes: 1
From: Cincinnati, Ohio
Car: 1989 Iroc Z
Engine: 496 BBC
Transmission: th400
Axle/Gears: 4.11
Does Changing your gears to 3.73 make your rpm range higher? I thought it just makes the gears shorter but its still in the same RPM range?
Supreme Member
iTrader: (3)
Joined: Sep 2005
Posts: 1,685
Likes: 3
From: MD
Car: '88 IROC-Z medium orange metallic
Engine: L98
Transmission: 700R4
Axle/Gears: 3.27
No, the RPM range is detimined by the power band of the engine. You use the right converter and gears to keep the engine operating in it's powerband.
Trending Topics
Senior Member
Joined: Jul 2002
Posts: 518
Likes: 1
From: Oklahoma
Originally posted by firebirdjosh
I don't know my tire size. And at 75mph I'm around 2500 rpm, other people with the same tranny a 3.73 say they drive 75 mph at almost the same RPMs which isn't possible.
I don't know my tire size. And at 75mph I'm around 2500 rpm, other people with the same tranny a 3.73 say they drive 75 mph at almost the same RPMs which isn't possible.
Supreme Member
iTrader: (3)
Joined: Sep 2005
Posts: 1,685
Likes: 3
From: MD
Car: '88 IROC-Z medium orange metallic
Engine: L98
Transmission: 700R4
Axle/Gears: 3.27
Originally posted by vic_V8
around town there will be no difference in MPG, only on the interstate.
around town there will be no difference in MPG, only on the interstate.
Thread Starter
Supreme Member
iTrader: (1)
Joined: Oct 2004
Posts: 3,361
Likes: 1
From: Worcester, MA
Car: 86 T/A
Engine: HSR 355
Transmission: 700R4
Axle/Gears: 2.77 posi
Originally posted by Dialed_In
What?
What?
My tach must be way off since I had well over 2K at 75 mph.
Senior Member
Joined: Oct 2005
Posts: 535
Likes: 1
From: Cincinnati, Ohio
Car: 1989 Iroc Z
Engine: 496 BBC
Transmission: th400
Axle/Gears: 4.11
Originally posted by Dialed_In
No, the RPM range is detimined by the power band of the engine. You use the right converter and gears to keep the engine operating in it's powerband.
No, the RPM range is detimined by the power band of the engine. You use the right converter and gears to keep the engine operating in it's powerband.
Supreme Member
iTrader: (3)
Joined: Sep 2005
Posts: 1,685
Likes: 3
From: MD
Car: '88 IROC-Z medium orange metallic
Engine: L98
Transmission: 700R4
Axle/Gears: 3.27
No, the powerband is detirmined by the engine and where it makes it's power. The 3.73's keep the engine within it's powerband.
Thread
Thread Starter
Forum
Replies
Last Post
[CA] 700R4 trans & parts
6998poncho
Engine/Drivetrain/Suspension Parts for Sale
0
Sep 25, 2015 02:56 PM
