Gear Ratios

[SSEimatt93]

Well, the Trans in the SSEi is getting completely rebuilt this May, as it has now been parked since September, when it failed.
I know I want to change the Ratio
I was thinking 3.29s...but what about 3.69? How much top end could I lose? Right now, I have quite a bit of pull around 70+mph, but I could use a lot more on the bottom end.
This isn't really a daily driver anymore. I need some pcm work to get my fueling nailed down, but this ratio change is something I really want to do. With a higher ratio I should increase my Stall a few hundred rpms as well.
Any suggestions?

[2000Silverbullet]

Go 3.69 Matt. I would.

Gears make it go!

Your final drive will be 2.6 so at 5500 rpm that is 167 mph and 6200 rpm is about 180 mph

If you're going to change go all the way or go home.

[willwren]

Let's keep ourselves grounded in reality on those top speeds. Nothing close to those numbers can be achieved in reality unless your car has no wind resistance. Keep in mind your fuel costs to and from WCBF with your gears.

[2000Silverbullet]

My point exactly. He will never see those speeds so he should go for the 3.69's !

I recommend if you are going with a gear change, to go with a cam change also.

[SSEimatt93]

that should peg my revs at 2300 or so at 120kph, sounds decent

[2000Silverbullet]

You want your peak torque to be at cruising rpm so 3600 rpm would be about 74 mph in 3rd gear. Pop it in OD and it's a cool 105 mph or 170 kilonometers

[SSEimatt93]

yeah it will definitally hit harder going to WCBF, i might just go 3.29

[2000Silverbullet]

If you're worried about saving $50 then you should stay with the stock gears.

[superchargedSSEi]

Truth be told, I hate my 3.69s. We can't fit nearly enough tire up front to put the power down with them...even a lightly modded car will have to fight for traction on the street. If I had built my trans instead of buying it used, I would have gone with the 3.29s. They're better suited for a daily driver imo.

Gas mileage isn't too bad with them though...your cruising rpm's will go up to ~2600 at 70mph with 3.69s, a couple hundred rpm less with 3.29s, so you'd drop several mpg on the highway. City mileage is pretty much unaffected by a gear change though since you don't have to work the engine as hard to get up to speed, and you'll only be running a couple hundred rpm higher around town.

[BillBoost37]

On the city streets and at the track I like the 3.29's. Good all around gear in my opinion. On the highway I do miss the 2.93's a bit for the long and tall gear and cruising. With any gear change you will need to relearn your launches and want to beef up your front and torque axis trans mounts. They will take a harsh beating with a fresh trans on lower gears.

I can see and understand your mention of it not being a daily driver, therefore the gear change will have a lesser effect on your decision than it would if you needed to fuel the car each week.

My setup is 3.29's with a 3000 stall.

[JAmon]

I just changed from 2.84 to 3.29, and my fuel economy actually went up. I've only filled up once, and averaged 24mpg, I used to get 21-22. I think it is mostly because the engine doesn't have to work as hard to accelerate. Cruising RPM's only went up 200-300 @ 70MPH. I hit a new top speed after the change also. I only have an SE, and I think traction might be an issue, at the track. I'll have to relearn how to launch, it was impossible to spin the tires with the old gear. I also changed the stall to around 2700rpm. Personally, the gear change is probably the best mod/change I've done to my car.

[2000Silverbullet]

For a non daily driver, I would still go with the 3.69's
More power to the ground. Of course traction will be more difficult, as it should be if you multiplied your engine torque by 26%

If it was a daily driver, I would stay with the stock 2.93

[Allmachtige]

My first impulse would be to say 3.29, but if you are truly parking it for race only...go all out just for the hell of it.

And I agree you should look into a cam as well if you do this.

[PDXGTP]

I actually got a moment to browse the boards and see this post.. good conversation.

I have 3:69's in my Grand Prix. with a 3000 stall TC
it cruises at 3000 rpms at 80 mph.
In Arizona I get about 24 mpg hwy.
in cali & Oregon i get 25.9 hwy.

Since installing the 3:69 I haven't been able to hook up. I have spun the tires every time... every time.
and... i can still scrub out a 1.7 60' time.
I don't think you weill loose any top end that you need to worry about. the only time you should be breaking 100 mph is at the track anyway right?

The thing is that unless you do a ton of stuff to the front end, it will be hard to hook up.
You absolutely need a hard input shaft.. or you will likely break the stock one shifting into second. that's when it happens.
Diff
Slicks
poly bushings on the front
Springs for the front.
Shocks for the front??? maybe..

If you want to eventually build up a fast car, spend the big bucks now.

Other then hooking up on a launch, I have no issues with 3:69 gears... if... HP tuners supports your PCM.
Tuning the PCM for gears is also a deal to acknowledge. if your car is not supported by HP tuners or you can not get the sinister guy to do a custom tune for the trans... don't do it.

[dirtracr95]

You could go with the KYB AGX struts. and i believe Intense has reluctor wheels to help correct the shifting with the 3.69

[SSEimatt93]

Intense stocks the reluctors, and the kit to change the ratio. They also sell a speedo re-calibrator. As far as PCM Changes.. I am not sure what else needs to be changed once i change the reluctor wheel, and use the speedo re-calibrator. There is not much as far as engine mount options on the Bonneville. My Tourque Axis mount is fairly new, as is my Solid front Transaxle mount. I think If I make a change, it will be to 3.29s. It will give me a little, which is what I want. Intense no longer has the Hardended input shafts on there site, they have the GM one, which eliminated the TCC lock up, as the fluid port is filled in solid.
The SSEi will be getting new suspension compontens this Summer as well. Struts, springs, ball joints, and tie rod ends, as they are all quite wore out.

[PDXGTP]

Good choice on the 3:29 Mr...

I did the reluctor thing, it did not work with the 3:69 gears, it helped but would not go all the way.
The speedo recalibrator thingy.. its for the speedo only. How do I know you ask??? because My speedo is mint, it took some adjusting but it worked.
The problem is my PCM sees a different speed then the speedo does.
So, it took some lenghtly tuning to get the shift points right, especially in the part throttle area.

As I understand it... some dude at HP tuners sat down and did all the math and figured out how to calibrate the 3:69 gears with the stock reluctor and i have to tell the PCM I have 411 gears etc... blah... blah..

I suspect that the 3:29's are going to be an easier path to deal with.

Good luck.

[BonneMe]

I've never thought a modded L67 needed more down low... The chassis can't put it down anyways. Gears are nice, but once you're into 2nd gear, you'll want more top end HP to push them. As many have said, you'll never hookup at the lights anyways. 3.29, nothing more IMO. 3.69 is for a drag car, MAYBE a sunday driver.

So why make the nice clean Bonneville the strip car, and not the W body which is faster mod for mod, and have more mods available to them?

[PDXGTP]

So why make the nice clean Bonneville the strip car, and not the W body which is faster mod for mod, and have more mods available to them?

That's what I was thinking but figured its because he already has the money in the Bonneville and the GP is basically stock... its still a good daily driver.

But... what you said does make more sense if your starting from scratch with both cars.

[BillBoost37]

I removed my reluctor wheel and speedo recalibrator after the reluctor got scored up badly during a diff issue. Looked around for some programming, got some off Thomas and since putting the car back in service the other day I noticed the shifting didn't seem happy.

I asked Trannyman (Dave from TripleEdge) on many forums how to program it and he gave me a quick easy way to do the 3.29's on the stock reluctor. That change will go into my tune probably tonight.