Go Back   Corvette Forum > C3 Corvettes, 1968 - 1982 > C3 Tech/Performance
Sign in using an external account
Register Forgot Password?
Register Search Today's Posts Mark Forums Read FAQ Vendor Directory
Search
C3 Tech/Performance
V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette Sponsored by
VBP

Welcome to Corvetteforum.com!
Welcome to Corvetteforum.com.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join Corvetteforum.com today!


Corvette Store
 
 
C7 Parts & Accessories
C6 Parts & Accessories
C5 Parts & Accessories
C4 Parts & Accessories
C3 Parts & Accessories
C2 Parts & Accessories
C1 Parts & Accessories
Wheels & Tires
Sponsored Ads
 
 
Vendor Directory
  
Reply
 
 
 
 
Thread Tools Search this Thread
Old 08-07-2003, 01:20 PM   #1
Glensgages
CF Senior Member
 
Glensgages's Avatar
 
Member Since: Jan 2003
Send a message via AIM to Glensgages
Default 700R4 & 3.73s: too MUCH gear ratio???

I know some members here have put 700R4s in their C3s. The 1st gear ratio in 700R4s is 3.06:1. My '82 Cross-Fire (no-laughing, pleeze!) has the 700R4, and 2.87:1 rear gears. The Cross-Fire needs ALL the help it can get, so, I'm considering swapping the 2.87s for 3.73s. My question is this: the 'effective' gear ratio in 1st will be 11.4:1 (3.06 x 3.73), deeper than my Z28 with custom gears in the THM400 (2.75:1) and 4.10 cogs (11.27:1). I'll eventually up-grade the Cross-Fire to 300-325 HP (where's CARTEK when you need 'em? :lol:), and run BFG Drag Radials, but, WILL THIS THING HOOK-UP? Is it 'too-much' 1st gear? Other offereings are 3.31:1 and 3.55:1 ratios. Anybody with the 700R4 and 'gears', please respond. THANKS in advance..... :chevy :chevy :chevy
Glensgages is offline   Reply With Quote
Old 08-07-2003, 01:28 PM   #2
Alwyn678
CF Senior Member
 
Alwyn678's Avatar
 
Member Since: Jun 2001
Location: Thomson Georgia
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Glensgages)

Sounds like a good combo to me.....I run them with my Th-400 :cheers:
Alwyn678 is offline   Reply With Quote
Old 08-07-2003, 01:38 PM   #3
Glensgages
CF Senior Member
 
Glensgages's Avatar
 
Member Since: Jan 2003
Send a message via AIM to Glensgages
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Alwyn678)

Quote:
Sounds like a good combo to me.....I run them with my Th-400
Yeah, but your 1st gear is just 2.48:1 ratio; your 'effective' gear is 9.25:1 (2.48 x 3.73). For your set-up to have the same 'effective' ratio, you'd need 4.56 gears (11.4 divided by your 1st gear ratio of 2.48 = 4.602...); would you 'hook' then? :confused: :eek: Most of my driving'll be on 255/60R15 BFG TAs; when I go track-testing, I'll run Drag Radials...
Glensgages is offline   Reply With Quote
Old 08-07-2003, 01:51 PM   #4
LAvetteman
CF Senior Member
St. Jude Contributor
 
Member Since: Jan 2001
Location: South Central Louisiana
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Glensgages)

You are correct. That first gear is gonna be super duper grandmaw. If you still do any cruizing at all I would go with something lower. Do a POLL on 700R4 users, see whats the general consensus.
LAvetteman is offline   Reply With Quote
Old 08-07-2003, 02:00 PM   #5
GrandSportC3
CF Senior Member
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03 & '06
 
GrandSportC3's Avatar
 
Member Since: Jul 2001
Location: Secular Capitalist Lakeland, FL
Send a message via AIM to GrandSportC3 Send a message via Yahoo to GrandSportC3 Send a message via Skype™ to GrandSportC3
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Glensgages)

That's a similar gearing that I have in my '68.. I love my gearing :D :D
GrandSportC3 is offline   Reply With Quote
Old 08-07-2003, 02:02 PM   #6
PatsLs1vette
CF Senior Member
 
PatsLs1vette's Avatar
 
Member Since: Jul 2001
Location: absecon nj
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (LAvetteman)

well i got 3.70 and a 700r4 in mine and i love it,im actually planning on swapping to 3.90 this winter.Its a pleasure to drive on the highway also.
PatsLs1vette is offline   Reply With Quote
Old 08-07-2003, 02:02 PM   #7
Fuzzy Dice
CF Senior Member
Cruise-In IV Veteran
 
Fuzzy Dice's Avatar
 
Member Since: Oct 2001
Location: Deltona Florida
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Glensgages)

I'm runnin' 3:73's with a 4L60 (700R4) in my 93....these gears are very driveable ...mine is a daily driver, I've been on two road trips over 1500 miles each and I drag race the car twice a month, every month...the track I run at is a 2.5 hour drive each way on the interstate... on the highway I'm running around 2900 - 3000 RPM @ 80 MPH....I think the 73's give you the most bang for the buck for a drag/street car with an auto tranny....my only drawback is the Dana 36 presently in the car...I don't want to chance stickies out back till I swap a 44 in there...I've still turned a lot of 1.9X 60' times with worn Eagle GSC's....oh, I've got a Transgo shift kit also.... good luck

Fuzzy
Fuzzy Dice is offline   Reply With Quote
Old 08-07-2003, 02:09 PM   #8
gkull
CF Senior Member
 
gkull's Avatar
 
Member Since: Apr 1999
Location: Reno Nevada
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (LAvetteman)

Sub 425 hp 355 ci drag vettes with 700R4 go with 4.30 gearing to maximize the 1/4 mile. because your only going through the end in 3 gear.

I have been driving around with 4.11's since the late 80's with my 700R4. It does a good job of closing up the gear spacing. For bigger 383 - 427 ci small blocks that can spin over 6000 rpm I would recomend 3.90's

3.73 is still over geared in OD unless you have the TQ to pull it.

I first had a 3.55 rear gears and you had to be going 80 mph to drive in lockup fourth gear. So I jumped straight to 4.11 even with them I can go @ 85-90 miles an hour in second gear and 125 in third and never hit redline in 4th gear
gkull is offline   Reply With Quote
Old 08-07-2003, 02:11 PM   #9
The Money Pit
CF Senior Member
 
The Money Pit's Avatar
 
Member Since: Jun 2002
Location: Orrtanna Pa.
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Glensgages)

The combo is explosive off the line if you have the torque,so I tend to ease into the gas.Be carefull not to run too big of a cam though.When the OD kicks in you need to have plenty of low end,or it'll labor the engine too much.This is not the case with the 406,but an overcammed 350 may be a problem
The Money Pit is offline   Reply With Quote
Old 08-07-2003, 02:22 PM   #10
ram82fire
CF Senior Member
 
Member Since: May 2001
Location: spring city pa
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (The Money Pit)

I run the 3:73 plus 700r combo and love it . I donot turn the car much over 5k and I find the gearing to suit my needs . I have a torquey motor and really can't comment on your c/f engine . Overtaking performance will make ya smile :D

gman
ram82fire is offline   Reply With Quote
Old 08-07-2003, 02:28 PM   #11
GrandSportC3
CF Senior Member
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03 & '06
 
GrandSportC3's Avatar
 
Member Since: Jul 2001
Location: Secular Capitalist Lakeland, FL
Send a message via AIM to GrandSportC3 Send a message via Yahoo to GrandSportC3 Send a message via Skype™ to GrandSportC3
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (GrandSportC3)

I just checked.. my exact setup is 3.27 first gear and 3.73 rear gears.. I use a 28 inch tall rear tire for racing.. My best 60' time so far with this combo was 1.591 :D :D
GrandSportC3 is offline   Reply With Quote
Old 08-07-2003, 02:30 PM   #12
Alwyn678
CF Senior Member
 
Alwyn678's Avatar
 
Member Since: Jun 2001
Location: Thomson Georgia
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (GrandSportC3)

Guess you got your answer :cheers:
Alwyn678 is offline   Reply With Quote
Old 08-07-2003, 05:42 PM   #13
8T1-7T9 BIONIC VETTE
CF Senior Member
 
8T1-7T9 BIONIC VETTE's Avatar
 
Member Since: Aug 2000
Location: HONOLULU HAWAII
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Glensgages)

I'm running 700R4 with 3:70 gears in the rear.....I also have a Super Yank 3500 stall Converter. A stock converter will be very doggy out of the hole.......You should also consider upgrading to a later year 700R4 and a B&M 3000 Holeshot....They can do wonders with the internals.....
I use first gear to launch me out of the hole....Almost instantly I shift to 2nd since my 5800 RPM light flashes. I do not preload the car....I launch from idle....So that first gear throws me up in the air....the pull is in 2nd and 3rd and I'm through the lights at the end of the quarter. :flag :seeya Cappy
8T1-7T9 BIONIC VETTE is offline   Reply With Quote
Old 08-07-2003, 09:52 PM   #14
Red73
CF Senior Member
Support Corvetteforum!
 
Red73's Avatar
 
Member Since: Feb 2000
Location: Fairport NY
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (8T1-7T9 BIONIC VETTE)

I currently have 3.73s with my 700R4 and if I was to do it again I would go with 3.90s. Rod
Red73 is offline   Reply With Quote
Old 08-07-2003, 10:56 PM   #15
CORKVETTE1
CF Senior Member
Cruise-In IV Veteran
Cruise-In V Veteran
 
CORKVETTE1's Avatar
 
Member Since: Sep 2000
Location: PITTSBURGH PA
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Red73)

i said it before and i will say it again a lot of gear is just a crutch for lack of horsepower look at my 3:07 rear gear 700r4 does 1.50 60 ft and it will be in the 1.4s soon as we have better air in the fall :cheers:
CORKVETTE1 is offline   Reply With Quote
Old 08-07-2003, 11:06 PM   #16
Glensgages
CF Senior Member
 
Glensgages's Avatar
 
Member Since: Jan 2003
Send a message via AIM to Glensgages
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (CORKVETTE1)

Quote:
i said it before and i will say it again a lot of gear is just a crutch for lack of horsepower look at my 3:07 rear gear 700r4 does 1.50 60 ft and it will be in the 1.4s soon as we have better air in the fall...
I agree, Cork, but, have YOU ever tried making horsepower with a 'primitive' computer and a Cross-Fire? :banghead: :lol: :mad :cry I know it's currently stock, but 2.3xx 60' times? Even if I WAS deep-staged; that's bad!!! I had just 'assumed' that it'd 'run-thru' 1st gear, spinning the tires at will. The '82 DEFINITELY needs some gears; on the rolling country-side roads near my home, 40 MPH is just 1000 RPM in OD with lock-up. It 'lugs & chugs', until the ECM 'finally' tells it to un-lock, down-shift, or BOTH! I end-up driving around in 3rd gear, unless on the open road. Even with 3.73s, 40 MPH in OD/lock-up will STILL ony be 1300 RPM, if my figgers are correct. I figger in 3rd, it'll be approx 1850; no more 'lugging & chugging'..... So 1st gear won't be 'too deep'.......?
Glensgages is offline   Reply With Quote
Old 08-07-2003, 11:12 PM   #17
BSeery
CF Senior Member
CI 6-7-8 Veteran
CI-VIII Burnout Champ
St. Jude Donor '06-'10, '13
 
BSeery's Avatar
 
Member Since: May 2001
Location: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
Send a message via AIM to BSeery Send a message via Yahoo to BSeery
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Alwyn678)

I have the 700R4 and 3.73's. It takes a good throttle control to the leave an intersection without smoking the rear tires.

I personally would recommend, and wish I would have, gone to 3.55's or a 3.4x size instead.

I also am running 285 wide tires, but they are only 26" diameter so that even lowers the total drive ratio even more.
BSeery is offline   Reply With Quote
Old 08-07-2003, 11:22 PM   #18
Glensgages
CF Senior Member
 
Glensgages's Avatar
 
Member Since: Jan 2003
Send a message via AIM to Glensgages
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (BSeery)

BSeery: I thought I'd heard you mention that before. I'm running 27" BFGs; that'll help 'some'. If my '82 wasn't in such immaculate condition, I'd just drop the ZZ502/THM400/3.36:1 combination in it, and be done!!! But, I'm not gonna 'cut-it-up' (swap motor and/or transmission) in any way.....
Glensgages is offline   Reply With Quote
Old 08-07-2003, 11:34 PM   #19
BSeery
CF Senior Member
CI 6-7-8 Veteran
CI-VIII Burnout Champ
St. Jude Donor '06-'10, '13
 
BSeery's Avatar
 
Member Since: May 2001
Location: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
Send a message via AIM to BSeery Send a message via Yahoo to BSeery
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (Glensgages)

I am going to go to 275/50's so that will take me up 27.8 from a 26.0 size.
I only lose 10 MM in width, but that extra size will hopefully fill up the wheel well area. Once I get those on there, then I will see how the launch and car control change.

I am also adding a 900 CFM fuel injection system. It's a throttle body and all four barrels open at the same time. The guy at the Holley tech line said if it hooks up, the combination of the ZZ4, 700R4's low first gear, the 3.73's and 900 CFM of fuel injected mixture ought to be pretty "dramatic" leaving the line.
BSeery is offline   Reply With Quote
Old 08-08-2003, 12:24 AM   #20
8T1-7T9 BIONIC VETTE
CF Senior Member
 
8T1-7T9 BIONIC VETTE's Avatar
 
Member Since: Aug 2000
Location: HONOLULU HAWAII
Default Re: 700R4 & 3.73s: too MUCH gear ratio??? (BSeery)

Quote:
I am going to go to 275/50's so that will take me up 27.8 from a 26.0 size.
I only lose 10 MM in width, but that extra size will hopefully fill up the wheel well area. Once I get those on there, then I will see how the launch and car control change.

I am also adding a 900 CFM fuel injection system. It's a throttle body and all four barrels open at the same time. The guy at the Holley tech line said if it hooks up, the combination of the ZZ4, 700R4's low first gear, the 3.73's and 900 CFM of fuel injected mixture ought to be pretty "dramatic" leaving the line.
Looks like a good upgrade...When are you having this upgrade done???.....Please post pictures of the burn outs.....They should be awesome.....Be Bad, Be Different, Be the Proud.....Make your Vette the way GM should have..... :D :flag :seeya Cappy
8T1-7T9 BIONIC VETTE is offline   Reply With Quote
Old 08-08-2003, 12:24 AM
 
Go Back   Corvette Forum > C3 Corvettes, 1968 - 1982 > C3 Tech/Performance
Reload this Page 700R4 & 3.73s: too MUCH gear ratio???
 
 
 
Reply

Tags
308, 350, 373, 7004r, 700r4, awsome, changing, drag, gear, gears, interstate, radials, ratio, ratios, running


Thread Tools Search this Thread
Search this Thread:

Click for Advanced Search

Posting Rules
You may not post new threads
You may not 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
BW T10 in my 82 malicatasr C3 Tech/Performance 10 03-20-2013 07:45 PM
Cross fire VS tuned port [READ THIS] lance m p C3 Tech/Performance 78 02-24-2013 11:43 PM
Final drive ratio question! C4vettrn C4 Tech/Performance 6 10-01-2012 06:18 PM
Best all around rear end ratio? TKO 600 CJS C1 & C2 Corvettes 22 07-26-2006 09:24 PM
Speedometer gear selection for 700R4/3.73 combo? MIKER C3 Tech/Performance 0 11-12-2001 09:58 PM


All times are GMT -4. The time now is 06:22 AM.


Emails & Password Backup