1996 Bonneville 5 spd.

[radsterz34lover]

I own a 1996 Bonneville se. I have significantly modified the car but my tranny isn't strong enough to handle the power. I have tried a 4T65E but it wasn't strong enough either. I am now considering a manual transmission. I need to know what tranny will match the 3800 series 2 bellhousing bolt pattern.

[richtazz]

There is no manual FWD transaxle that will handle the torque of a 3800, that is why GM never offered a manual with it. You may need to get a modified automatic transaxle from the aftermarket to get the job done.

[radsterz34lover]

I have heard that there are not any manuals strong enough but I have personally seen a lumina z34 with the 3800 series2 and a manual that had all the mods that my engine currently has, around 390 HP and 375 ft.lbs. of torque. I was told that a getrag HM284 5-spd would bolt up. does anyone know if this is true? I seriously want a manual in the car and will try almost anything to get one in there.

[richtazz]

A Lumina Z-34 never came with a 3800. They used the 3400 DOHC. The 97-up Lumina LTZ was available with the 3800, but never with a manual trans. Whatever that car was, it was a total custom job, and WAY beyond a DIY project. The resulting car would cost more for the mods than just going out and buying a Camaro/Firebird with the LT-1 and a 6 speed that would gut-stomp the resulting car. Plus you could keep the Lumina as a daily driver to save gas.

[redly1]

I think he means that someone put a modified 3800 into a Z34. pretty common W-body upgrade

[richtazz]

Not with a 5-speed, the torque of the 3800 would grenade that transaxle. Plus, there isn't a FWD spec 3800 manual flywheel available. He would have to have used an F-body flywheel and a custom fabricated adaptor plate.

[DrJay]

You actually can bolt a manual transmission to the 3800, the Fiero guys do it all the time. Head over to www.l67swap.com for more info.

There are a whole host of issues for you though, some including (in no particular order):

PCM control over the transmission
Major weight difference between a Fiero and your Bonneville
Clutch pedal and related bits
Transmission mounts
Axles
Alignment

And a few others. It would really be a big task.

On my site I have a transmission that can handle just about anything but even the 65E's are being beefed to the point of handling upwards of 900hp. I read about one GM made for a 1,500hp race car. If you want a 60E check out my site below, for a 65E look at www.intense-racing.com

Good luck!

[richtazz]

In a lighter car, the torque issue wouldn't be as big a deal. To move a big car like a Bonneville (especially with a modded engine), without extensive mods to the transaxle, you'd murder the input shaft on a 5 speed. Ask anyone who's tried putting a 350 in a 3rd gen f-body that came stock with a 305 and 5-speed. Different trans obviously, but its the same issue. They didn't offer the 5 speed behind the 350 because it couldn't handle the torque. Basically, what I'm getting at is this will be a very problematic swap, from the issues DrJay mentioned above, to reliability once those are overcome. I stand by my original statement that a GM 5 speed manual transaxle will not work behind a modded 3800 in a heavy car like a Bonneville without exten$ive mods. I guess if you want to spend $20,000 on a car that will get stomped by any RWD V-8 with $500 worth of bolt on parts, be my guest. It just seems like a lot of trouble for nothing.
BTW, I applaud your attempt. I'd love to have a 5-speed in my 99 Grand PRix GT too. I don't want to sound like a naysayer jerk or anything, I'm just being realistic.