Gears
- Thread starter FLSY2730
- Start date
Are you having a gearing problem on your Sy ? Geez, can't launch at peak torque? :wink:
It'd be worthless IMO, you can pretty easily overpower your traction by launching with more boost, so I'm not sure what you'd gain. The major issue to consider is the top end gearing, if you end up in 3rd/OD.
It'd be worthless IMO, you can pretty easily overpower your traction by launching with more boost, so I'm not sure what you'd gain. The major issue to consider is the top end gearing, if you end up in 3rd/OD.
RAACCR
Member
I tried to find someone who'd change 'em. The rear is easy, but nobody around here wants to touch the front for some reason...I tried performance shops & 4x4 shops. In my case, 3rd gear will take me to 155mph locked-up with stock 3.42s...so 3.73s, or even 4.10s, would work better. I know that Jack is tight with a GM driveline technician, so maybe he can do it. Think about adding a locker up front, too!
Rob
<font size=-1>[ This Message was edited by: RAACCR on 2002-03-31 22:03 ]</font>
Rob
<font size=-1>[ This Message was edited by: RAACCR on 2002-03-31 22:03 ]</font>
ParTyBoy
New member
Would be easier just to grab a unit from a bravada then... seeing as the axle tube is the same.. and the gear ratio on most is 3.73 .. Also just incase some people aren't aware.. if you have 3.42 up front.. you need to have 3.42 in the rear.. same thing if you decide on 3.73 .. 3.73 up front.. 3.73 in the rear.. in you have different sizes in front and rear.. your transfercase is going to tear itself apart..
<font size=-1>[ This Message was edited by: ParTyBoy on 2002-03-31 22:10 ]</font>
Rob, let me know if you need the tranny done by my guy at gm, i gave him all off brians kit and he had it a couple of days and then retuned it for 400.00. Not to bad of a labor bill if you ask me. Of course that was taking the tranny out myself and reinstalling it myself which i thought was pretty easy. I am sure he can redo the front gears to if you need that. jack
Rob, how much RPM do you think you would be at the end of the track? Do you think the tranny could handle shifting into overdrive before the big end? I used to do it all the time with my 89 iroc back in the day, it had 3.92 gears and went 11.80-11.90 on nitrous and would use overdrive to get through the end of the quarter mile.
I would personally not go with a lower (larger number) gear. The reason being, these engines are torque monsters, and love the low end grunt. Personally, with my full build up, I am going with 3.08s. It should keep me from OD at the big end, all be it, I will give up a bit on the short time. Plus, 3.08s are easily matched front stockish and my rear ford 8.8 irs.
chad
chad
RAACCR
Member
Jack,
The ideal situation would be to gear it to go through the traps right at the top of 3rd gear.
With 3.42 gears & 26" tires, you're only turning about 5700 rpm through the traps with the converter locked. 3.73s would put you at 6200 rpm.
I still don't believe overdrive can hold that much power reliably, but others think differently.
I may need to get togather with your driveline tech. I think I'm going to have to pass on the coil-overs and gears until my wallet recovers from the house purchase...I went furniture shopping this weekend, and that stuff costs more than SyTy parts :wink: But, I'll be doing something with the tranny very soon.
Rob
<font size=-1>[ This Message was edited by: RAACCR on 2002-04-01 01:28 ]</font>
The ideal situation would be to gear it to go through the traps right at the top of 3rd gear.
With 3.42 gears & 26" tires, you're only turning about 5700 rpm through the traps with the converter locked. 3.73s would put you at 6200 rpm.
I still don't believe overdrive can hold that much power reliably, but others think differently.
I may need to get togather with your driveline tech. I think I'm going to have to pass on the coil-overs and gears until my wallet recovers from the house purchase...I went furniture shopping this weekend, and that stuff costs more than SyTy parts :wink: But, I'll be doing something with the tranny very soon.
Rob
<font size=-1>[ This Message was edited by: RAACCR on 2002-04-01 01:28 ]</font>
7dhamper
New member
I have an '89 GMC Jimmy 4X4. Now I'm told I have limited slip front and rear with 3:73 gear ratio. Is this true? Cuz I want to swap out my rear end for a posi with discs and am considering a locker up front. I plan to run 295/50SR16 BFG Radial TA's. They are 27.6 inches tall! I want this size mainly for width, but also to keep it similar with the overall height of my summer rims which will be Z06 18X9.5 and 18X10.5. I'm hoping to put a 235/45ZR18 on the front and a 275/40ZR18 on the rear. I know that the rear could be a 35 series tire but to me that is just too damn thin for Cleveland, Ohio. Plus on a 5/4 drop it fills the wheel wells nicer and is cheaper!
Now keep in mid that I'm used to my just over 5 sec. 0-60 on 205/50SR15's (verry short tires)! How much lower gearing can I go? What is available? I'm considering using a ZR2 offroad rear end and all 4 the same size rims front and back. Any input would be greatly appreciated1
Now keep in mid that I'm used to my just over 5 sec. 0-60 on 205/50SR15's (verry short tires)! How much lower gearing can I go? What is available? I'm considering using a ZR2 offroad rear end and all 4 the same size rims front and back. Any input would be greatly appreciated1