rear gear change

[krazykyle]

just looking for some input on rear gear change.i'm running 456 rear gears would making a change to like a 410 or 390 make the car slower or would you see better time say in the 1/4 mile? i'm running a ten inch converter also

 

[84cutlass454]

it all depends on what the rpms are at when u cross the traps as long as u ant on the rev limter now the a smaller gear wont help u whant to be about on the limter when u croos the traps at the end.

 

[FE3X CLONE]

I've messed around with the desktop dyno drag simulator and its interesting to see some of the effects of gear ratio on 1/4 mile times.

I know with my car it actually showed a 3.42 gear being the quickest by over a .5 second compared to the 4.30 gears I have in there. Part of it had to do with the fact that with the 4.30 gears and my 6500rpm shift rpm, I'd be shifting into the 5th gear before the end of the 1/4. Plus, with the lower (numerically) ratio it helps keep you in the power band longer when in 1st gear.
With the 4.30 gears I have and the 2.66 1st gear, I believe I'm in 1st gear for 1.2 seconds before I'm having to shift.

Of course these programs aren't always accurate but they do give you something to consider.

 

[84cutlass454]

yeah u dont whant to be shifting right before the traps u what your finale gear to to be about on the rev limter right before u cros the trap or at u peak power rpm

 

[krazykyle]

with the 456's i'm just banging threw the gears way to fast.it's a fun car but just over way to fast.i'm running a big tire on the back end L 60'S mickey thomsons 275 60 15.love these tire they just sh*t and get.i'm sure the tires take out some of the gearing.what size gear can i use to get out of the hole quick but still have better top end? http://www.summitracing.com/parts/MTT-1568/

 

[84cutlass454]

i got 28/12.5/15 mt et streets with 4.10 gears and the 28 inch tall tire makes the gear only like a 3.73 if i remeber right and out of the hole the damn thang will break ur neck lol and i cross the traps at about 5500 and i shift at 5800 with a 6000 chip in it and its perfect pulls like hell once i am in drive its a really good combo really like it but i was whanting to change to 4.56s and changed my mind its all about ur combo though so if i was u i would change them to the 4.10 i thank it would be faster because u ant shifting every sec it fun but i thank 4.10 would be better for u.