Thread: need info and input on doing a swap on a series 3 05 grand prix to a supercharged

ok i may have over looked a thread somewhere on this but im in need of some information on what the best way of going about this is. the car is a 2005 base model plain jane grand prix 3800 series III. its my buddies car and hes pushing 170k on it and he just paid it off so hes wanting to rebuild the motor or buy a motor out of a gtp and swap it in there or just swap the top ends out can that be done. pretty much whats the best way to go about doing this, price wise parts wise and labor wise? also he found a series II motor i believe out of a 99 gtp with the trans and everything and he wants to know if he picks it up if its even possible to drop that in his car? pretty much im at a loss i have no expirence with doing this nor does he and we need help. thanks guys
-brad

Not really worth the hassle to try and swap an L67 into it. You'd have to get some 04+ returnless Supercharged fuel rails (or aftermarket) and a TB adapter to run the gen 3 SC with the drive by wire TB on his car.


Easiest route would be to just swap a whole L32 (supercharged Series III) motor in. Then keep his L26 (N/A Series III) and keep it as a spare, sell it, or build that one up as time/funds permit.

Next easiest would be to topswap with a L32 top end. About as involved as a whole motor swap (having to strip it to a short block and rebuild it back up) and would be much simpler than trying to put the L67 in there.

im assuming the u have to have the correct trans for a l32 swap? as the stock on on his car wont work?

You should be able to use the L26 trans with an L32 no problem.

You can topswap you just have to use l32 rails and gen 5 supercharger. You can use L67 or L32 heads.

You don't need a complete block and L32 blocks can be quite expensive. Last I looked Morad wanted $800 for one with 170,000 miles plus shipping.

Originally Posted by machinegunsquid

You should be able to use the L26 trans with an L32 no problem.

with out moding it/ tuning it? ive been told before that all the trans are different in all gp the switches/ shift points will throw off the computer and it wont run right?

Originally Posted by sseilmnop

You can topswap you just have to use l32 rails and gen 5 supercharger. You can use L67 or L32 heads.

You don't need a complete block and L32 blocks can be quite expensive. Last I looked Morad wanted $800 for one with 170,000 miles plus shipping.

hes prepared to spend a bit of money lol he was ready to pay 800 for one with 194k on it, glad he didnt though. but taxes are right around the corner

Originally Posted by darkhorizon

cheap turbo kit would be way easier and cheaper.

me nor he know nothing about turbos

Originally Posted by LSFoFaSho

im assuming the u have to have the correct trans for a l32 swap? as the stock on on his car wont work?

The stock trans is fine. Im running a non HD trans in my 2.55 setup with no issues... yet.

I drive a swapped 04 Base Model GT, so I've got a little insight here.

Engine: Top swap or L32 swap, don't bother with an L67. I'm running an 04 GTP L32.

Wiring / PCM: It's possible to run with the wiring from your L26, but I don't recommend it. Swap out the engine harness with one from a GTP, and run a GTP base PCM calibration. Depending on your Transmission, you will HAVE to change the PCM programming to match the gears in the trans. This will also require swapping out your ABS module with one from a GTP for TCS to work properly, but that's real easy and pretty cheap. That's the setup I'm running. (Note, a CompG harness / PCM / ABS Module will NOT work without more changes.)

Transmission: You can run any trans with some work.

L26 Trans: 3.05 Gears, non HD Diff, but no other changes required to the car.
L32 Trans: 2.96 Gears, HD Diff, Need new CV Shaft on the passenger side.
L32 CompG Trans: 3.29 Gears, HD Diff, Beefyer first gear Band, a few other upgrades... Need new CV Shaft on the passenger side, Need to replace with Channel Plate / Valve Body / 4th Gear Clutch with GTP parts - This is what I'm running.

As for a donor, find a Running but Wrecked GTP or CompG and have all the parts you need, plus lots of spares. That's the route I went.

-Rob

Originally Posted by RivMan

I drive a swapped 04 Base Model GT, so I've got a little insight here.

Engine: Top swap or L32 swap, don't bother with an L67. I'm running an 04 GTP L32.

Wiring / PCM: It's possible to run with the wiring from your L26, but I don't recommend it. Swap out the engine harness with one from a GTP, and run a GTP base PCM calibration. Depending on your Transmission, you will HAVE to change the PCM programming to match the gears in the trans. This will also require swapping out your ABS module with one from a GTP for TCS to work properly, but that's real easy and pretty cheap. That's the setup I'm running. (Note, a CompG harness / PCM / ABS Module will NOT work without more changes.)

Transmission: You can run any trans with some work.

L26 Trans: 3.05 Gears, non HD Diff, but no other changes required to the car.
L32 Trans: 2.96 Gears, HD Diff, Need new CV Shaft on the passenger side.
L32 CompG Trans: 3.29 Gears, HD Diff, Beefyer first gear Band, a few other upgrades... Need new CV Shaft on the passenger side, Need to replace with Channel Plate / Valve Body / 4th Gear Clutch with GTP parts - This is what I'm running.

As for a donor, find a Running but Wrecked GTP or CompG and have all the parts you need, plus lots of spares. That's the route I went.

-Rob

thanks for the insight this is the kinda help i was hoping for i knew there had to be someone on here who had done this already, and whats a comp g? im still a noob lol

Originally Posted by LSFoFaSho

thanks for the insight this is the kinda help i was hoping for i knew there had to be someone on here who had done this already, and whats a comp g? im still a noob lol

The Comp G is the step up to the top end above the GTP of these years. They had a few more bells and whistles, including the trans gearing for example...

Originally Posted by FASGP

The Comp G is the step up to the top end above the GTP of these years. They had a few more bells and whistles, including the trans gearing for example...

so it was a gtp? or it was just a super charged gt? how can u tell the difference ive never seen a comp g badge or anything

It's a GTP if it has the comp g package
It'll be either a 04-05 if it's a comp g
-red calipers
-tab shift
-some 05 have comp g badges on the doors

That's just a few basics

Originally Posted by LSFoFaSho

so it was a gtp? or it was just a super charged gt? how can u tell the difference ive never seen a comp g badge or anything

The GT with L32 supercharged started in 06. Before that there were no GT's with L32, only GTP and Comp G. GP's with onstar antenna at front of roof are pre 2005, and at rear are post 2005. Comp G also had tapshift inside on steering wheel.

3.05 gears on L26?

Yes, GT trans with L26 was 3.05 ratio.

Originally Posted by machinegunsquid

Not really worth the hassle to try and swap an L67 into it. You'd have to get some 04+ returnless Supercharged fuel rails (or aftermarket) and a TB adapter to run the gen 3 SC with the drive by wire TB on his car.


Easiest route would be to just swap a whole L32 (supercharged Series III) motor in. Then keep his L26 (N/A Series III) and keep it as a spare, sell it, or build that one up as time/funds permit.

Next easiest would be to topswap with a L32 top end. About as involved as a whole motor swap (having to strip it to a short block and rebuild it back up) and would be much simpler than trying to put the L67 in there.

I hate to disagree, but a topswap is much easier than an entire motor swap, and as zero reliability issues. Me and frosty95 are both running awesome topswap setups on stock trans.