Gear help needed (circle track) - Racing Forum

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Gear help needed (circle track)
Saturday, May 01, 2010 11:49 AM
I have read many posts on here that talk about swapping different gears from various cars running the Isuzu transmission. Quite frankly I don't know enough about this to make any sense of it. So I'm looking for some help from any one that does know.

I have a 1995 Cav. 2.2 OHV. Trans is a 5-speed from a 1996. I'm running on a 3/8ths mile semi banked dirt track. I run 15" tires around 77"-81" street d.o.t. tires. Running in Second I'm bouncing off the rev. limiter (6500 rpm) just past half way in the strait aways. In Third I'm only hitting 4000 rpm at entrance on the turn. I can't run a bigger tire, a smaller tire yea but its not going to make a 2500 rpm difference, so thats not really an option.

So what I need is to make Second gear longer or Third gear shorter? I have found many posts on different gears and/or different final drives, but like I said I'm not sure on this. Thanks for any help.

Re: Gear help needed (circle track)
Saturday, May 01, 2010 12:29 PM
This is deja vu because I was just about to type the same question...have the exact same problem, but on a smaller track. To help you Joe Biv I have run195/60/14 on a high banked 3/8 mile track and got to 5500 rpm. I think 185/60/14 could work for you.
Re: Gear help needed (circle track)
Saturday, May 01, 2010 6:31 PM
i built my own trans. took apart 3 or 4 of them and found out there were a lot of different gear combos in there so i counted teeth and found the ratios that would work for me and pressed teh shafts back together with the ones i needed and it runs a lot bewtter now
Re: Gear help needed (circle track)
Sunday, May 02, 2010 5:25 AM
Thanks Bob, that was alot of help!! lol
Re: Gear help needed (circle track)
Sunday, May 02, 2010 11:12 AM
it is also for sale haha
Re: Gear help needed (circle track)
Sunday, May 02, 2010 11:58 AM
your race trans. is for sale? if so PM me a price and any info on it.
Re: Gear help needed (circle track)
Sunday, May 02, 2010 11:11 PM
You can run a hybrid transmission from the 2.4/ 2.2 But you have to open both transmissions and swap the gears. I made a post about all the different gear ratios in this section and under transmissions
Re: Gear help needed (circle track)
Monday, May 03, 2010 7:04 AM
Ok, to make this hybrid, what gears would I use from each transmission so I could either be able to use 2nd gear and not wind out or get 3rd gear up to the 6000 mark?
Re: Gear help needed (circle track)
Monday, May 03, 2010 11:11 AM
the gears in my trans are
1 3.72
2 2.15
3 1.52
4 1.02

FD 3.83

i dont know what trans teh gears came from, i have a box of trans gears and i just used things that fit together

1+2 are out of that trans 3+4 from another trans 5th has been removed and the final drive is a combo of things
Re: Gear help needed (circle track)
Monday, May 03, 2010 7:53 PM
Re: Gear help needed (circle track)
Monday, May 03, 2010 9:35 PM
heres the thing, i ONLY have 8v 2.2 cavalier 5 speeds, take some apart and they hav different gears in them that equal out to the same but can be switched around...

Re: Gear help needed (circle track)
Tuesday, May 04, 2010 11:08 AM
Bob what did you get that 1.52 gear out of thats in your trans? I can't find that gear on any post?
Re: Gear help needed (circle track)
Tuesday, May 04, 2010 10:02 PM
i got it out of a trans that i pulled apart... like i said. i pulled open 3 trans, all 3 had different gears inside of them... they all were corrected by the FD to equal the same output ratio.
Re: Gear help needed (circle track)
Wednesday, May 05, 2010 9:47 PM
Ok let me see if I can make this post w/ out confusing the crap out of every one!!! Mostly myself.
I will assume that if you are reading this you have already done some research and can follow along w/ out me breaking down every detail of these numbers. (and that what I have researched is correct)
My stock 1996 2.2 ohv Isuzu 5-speed has these complete final drive ratios (rounded)...
1- 14.00
2- 7.80
3- 5.19
So my problem is 2nd is to short and 3rd is to long. The middle point would be 6.50 weather that would work for me or not I dont know, but it gives me something to shot for. I also have a little wiggle room in different size tires but would like to limit this to a few hundred RPMs not a few thousand.
Since this is a race only transmission I thought why not just build it exactly how I want it and make it as "user friendly" as I can. I will be running at other tracks other than my home track that will be slightly bigger or smaller than what I will have set this up for, so I want to build that in as well. Also Bob has mentioned removing a unneeded gear for weight/ rotating mass reduction I would do that as well. Here's my thought...
Use my trans w/ a final drive 4.11
1st- Geo sohc 3.27=13.44
2nd- ??? 1.52=6.25
3rd- ln2 1.45=5.96
4th- ld9 1.33=5.47

As you can see this will give me Three gears to choose from at tracks to race with all just longer than my stock 2nd and just shorter than my 3rd gear. I will still have a good first gear to get up to speed and to load on the trailer ect... To me this seems like it will work?
Now I just need to find what ever Bob found that 1.52 gear in, where I can buy these other gears and last, how to get everything installed!!!

If you see any problems/ideas please share!
Re: Gear help needed (circle track)
Wednesday, May 05, 2010 10:02 PM
here is your big isssue, gears 3 and 4 are one piece, you wont be able to seperate them. the 1.52 and 3.83 combo works very very weel on all the tracks we run on. everything from high bank 1/4 mile to low bank 3/8 and if the engine is up to it it goes good on teh 5/8 mile that is thompson speedway... i will eb honest my second gear sucks!!!! my car is junk on restarts but coming out of turn 2 its a rocket and will shoot up 8 car lengths...
Re: Gear help needed (circle track)
Thursday, May 06, 2010 6:05 AM
Well that just burst my bubble.
Re: Gear help needed (circle track)
Thursday, May 06, 2010 6:41 AM
figured id burst it now instead of when you have a trans apart haha
Re: Gear help needed (circle track)
Thursday, May 06, 2010 6:42 AM
and here is an even bigger problem.... the 2.2 needs to have teh bearings and stuff opened up before you run at those high rpm's or you spin rod bearings we blew 6 motors last year with teh good trans so this year we rebuilt all our race motors with more bearing clearance
Re: Gear help needed (circle track)
Thursday, May 06, 2010 11:15 AM
I had the motor rebuilt all new bearings already. I think that I may just try the 4.11 final drive and run 3rd for 5.96 and see where that gets me. Also I still am limited by the factory 6500 rev limiter. I'm going to try the 14" tire tomorrow to see where I'm at.
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