jeremyrwatts Posted January 25, 2006 Report Posted January 25, 2006 does anybody know what the gear ratio is in a 89 grand prix, compared to a 90 model, lumina, i would assume they might be the same. Quote
TeeJay3800 Posted January 25, 2006 Report Posted January 25, 2006 If both are 4-speeds, then they're the same. What do you mean by gear ratio? If you mean the final-drive chain ratio, it's 3.33 on both cars. Quote
fastbird232 Posted January 25, 2006 Report Posted January 25, 2006 SPLA-DOWWWW!!!!! Manual or automatic? Quote
Crazy K Posted January 25, 2006 Report Posted January 25, 2006 I'm perplexed on this myself. All the ones i have verified have SPID GX3 meaning 3.33 FDR We need to know what your SPID says. there is also a tranny tag that could be read, seen directly beneath the alternator on the 3.1 on the rear of the tranny. I read them by removing the passenger tire. Quote
jeremyrwatts Posted January 25, 2006 Author Report Posted January 25, 2006 thanks for all the replies, it is a automatic, seen a significant power difference in the two cars, but one is a later 3.1, since found out it has a different rocker lift. about to put this grand prix on the racetrack, circle track. Thanks. Quote
Crazy K Posted January 25, 2006 Report Posted January 25, 2006 I have observed cars operating that don't seem to have the same tranny ratio..... but still cannot verify.... my long gone 91 euro appeared to have a 3.09 FDR ratio, while my 92 base has a verifyable 3.33 ratio a 3.33 ratio car will crank 2000 rpm at 72 mph, when in overdrive, tcc engaged. a 3.09 ratio car will crank 2000 rpm at 60 mph, when in overdrive, tcc engaged. (EDIT: wrong info is stated here, See my next post below!) IIRC the number is 3.09, that is.... or at least close. Quote
mfewtrail Posted January 25, 2006 Report Posted January 25, 2006 I have observed cars operating that don't seem to have the same tranny ratio..... but still cannot verify.... my long gone 91 euro appeared to have a 3.09 FDR ratio, while my 92 base has a verifyable 3.33 ratio a 3.33 ratio car will crank 2000 rpm at 72 mph, when in overdrive, tcc engaged. a 3.09 ratio car will crank 2000 rpm at 60 mph, when in overdrive, tcc engaged. IIRC the number is 3.09, that is.... or at least close. Were the tire sizes identical on both cars? Quote
Crazy K Posted January 25, 2006 Report Posted January 25, 2006 They are now! The 92 lumina is using the 91's cluster as well!!!!! Quote
fwdjarvis3 Posted January 25, 2006 Report Posted January 25, 2006 Are you racing on dirt or asphalt? The reason i ask is i am gonna be racing my 91 gp on dirt. Quote
joey b Posted January 25, 2006 Report Posted January 25, 2006 a 3.33 ratio car will crank 2000 rpm at 72 mph, when in overdrive, tcc engaged. a 3.09 ratio car will crank 2000 rpm at 60 mph, when in overdrive, tcc engaged. THought it was the other way around. :? Quote
Canada Posted January 25, 2006 Report Posted January 25, 2006 Too bad 3.09 isn't a 4T60-E ratio. Quote
88Regal Limited Posted January 25, 2006 Report Posted January 25, 2006 a 3.33 ratio car will crank 2000 rpm at 72 mph, when in overdrive, tcc engaged. a 3.09 ratio car will crank 2000 rpm at 60 mph, when in overdrive, tcc engaged. THought it was the other way around. :? Umm, joey is right. A 3:33 is better for Acceleration while the 3:09 is economy. Thats why drag racers (like me) install say 4:56 gears. Not much top speed but great accell, and say a 3:42 would be better economy compared to the 4:56 ratio. Quote
jeremyrwatts Posted January 26, 2006 Author Report Posted January 26, 2006 Asphault, here in Opt Alabama Jeremy Quote
Crazy K Posted January 26, 2006 Report Posted January 26, 2006 a 3.33 ratio car will crank 2000 rpm at 72 mph, when in overdrive, tcc engaged. a 3.09 ratio car will crank 2000 rpm at 60 mph, when in overdrive, tcc engaged. THought it was the other way around. :? WOW I goofed!!!!!!!!!!!!! sorry I found the reference.... it's 3.06 FDR that i was thinking of info here: http://dtcc.cz28.com/transmission/index.htm I did some calculations based on a table I saw in this page http://spacecoastfieros.com/tech/440-4T60/ Keep in mind the FDR is based on the car being in D, not OD... so.... you have to multiply the FDR x .705 the OD ratio... you get the real Ratio from the engine RPM to the axle RPM. based on tire diameter, from info found on tirerack.com a tire size 215/60R16, revolves 795 times a mile. At 60 MPH than means 795 Revolutions Per minute. so: Tire Revs per mile per minute x FDR x .705 OD ratio = engine RPM @60MPH 795 x 2.39 x.705 = 1340 RPM 795 x 2.53 x.705 = 1418 RPM 795 x 2.58 x.705 = 1446 RPM 795 x 2.73 x.705 = 1530 RPM 795 x 2.80 x.705 = 1569 RPM 795 x 2.84 x.705 = 1592 RPM 795 x 2.97 x.705 = 1601 RPM 795 x 3.06 x.705 = 1715 RPM 795 x 3.33 x.705 = 1866 RPM 795 x 3.43 x.705 = 1922 RPM 795 x 3.73 x.705 = 2091 RPM OR rpm / FRD / OD ratio / wheel revs at 60mph = speed at 2000 rpm ( 60 mph / wheel revs per mile per minute = wheels revs at 60 MPH) (60/795 = ) 2000 / 2.39 / .705 x 60/795 = 90 MPH 2000 / 2.53 / .705 x 60/795 = 85 MPH 2000 / 2.58 / .705 x 60/795 = 83 MPH 2000 / 2.73 / .705 x 60/795 = 78 MPH 2000 / 2.80 / .705 x 60/795 = 76 MPH 2000 / 2.84 / .705 x 60/795 = 75 MPH 2000 / 2.97 / .705 x 60/795 = 72 MPH 2000 / 3.06 / .705 x 60/795 = 70 MPH 2000 / 3.33 / .705 x 60/795 = 64 MPH 2000 / 3.43 / .705 x 60/795 = 62 MPH 2000 / 3.73 / .705 x 60/795 = 57 MPH WOW. the bold indicates what W bodies usually have. I have verified that all my cars have 3.33 FDR including the convertable, by the tag 1YDH on it's tranny. what a difference in apparnt range they exihibit!!! Sorry I made and corrected an error, patgizz below caught me and I corrected it! Quote
patgizz Posted January 26, 2006 Report Posted January 26, 2006 that source is off. the 3.4 4t60-E have 3.43 Quote
Crazy K Posted January 26, 2006 Report Posted January 26, 2006 that source is off. the 3.4 4t60-E have 3.43 Error corrected, I misquoted the wrong figure as well... the source IS correct. Read carefully, the differential ratio of the 3.4 4t60-e is 3.04, but with the chain, it is 3.43. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.