thinkin out loud

As of this moment the T-Bat has 126k on his clock. Even though I just got my ragtop I am thinking along the lines that I may soon have to do major work to the GP. I think a tranny overhaul may be the first to arise.

I also put up a couple posts over at motorswap.org where I asked about details concerning an LS4 or Northstar swap. The replies I got basically told me to heave those two ideas and consider a top swap or an L67 altogether.

Any of this would be next year at the earliest, which by then the car may well have more like 140k miles...I wonder if a top swap at that kind of miles would just put too much oomph on those aged rings and bearings.

I suppose I could try and get a dropout from Ed and try to have it over hauled and install as a unit but that is a good bit of extra cost.
I've pretty well ruled out the turbo since I could almost do both engine and trans for the cost of the kit.

I welcome your opinions now just as I did before I purchased my car...since I kind of see this as my one chance to build a show worthy engine bay...I plan on doing this job once...so much planning and prep is needed.

The LS motor might be easier but you'll need the cradle and everything from the GTX if it will bolt in. As for the Northstar it won't fit. It's too bulky iirc the N* uses a different tranny that is larger the the 4T65 and the 65 won't mate to it. Plus it doesn't make much more power then a modded L67 and has very little in the ways of performance upgrades but I do like the idea of the DOHC. If I were you I'd do a rebuild with a top swap. Upgrading to the new hardened rods and dimond pistons.

i would say rebuild what you have and do a topw swap, or find a junkyard L67 and build it up and pretty it up for the show+the go and then get the 4T65E-HD and also swap it in, also with doing this you kan also pretty up the interior with the correct gauges to monitor the essentials of the Forced Induction engine, put this is my >02, i hope you figure out what you wanna do

id say do a top swap and tranny from zzp, or get the tranny from a gtp, because the gtp came with the HD stock. but i would do the zzp tranny and a nice new motor. but tranny alone is some cash.

IMHO, swap a low mileage L32 in with a beefed up trans. This way you get all the improvements that were made to make the L67 into the L32, the fifth gen blower, and all the potential that comes with a motor that was built for a power adder.

Just my opinion though...

sounds like t bat is doing the same build im looking at doing .. im getting the l 32 rods, dimiond pistions 8.0:1, bored over 0.020, hopefully have the block balanced and the bs removed, not sure the heads im going with ... and if i have enough money im gonna get a whipple...

I say rebuild your engine now, do the top swap, and swap out with the ZZP tranny

The N* fits. There was a pic of a guy on CGP with a custom N* build, then they added a turbo. It was making somewhere around 500whp on the dyno.

Personally, I'd turbo it, run it until it pukes, then swap in a low-mileage 3800 and do it again.

How good are you with fabrication?... you could probably buid your own turbo setup (or most of it) for a whole bunch cheaper.

But i love my top-swap.

just gut it and make it rwd

'just' lol

i have 2 l67's that are for sale both almost already built

or i have a bareblock thats .030 over $25 and its yours if you pay shipping
its not cracked its the one i was running that had the rocker come apart

a bareblock for 25??? ooh i really want that build it up my self little by little and waalah serious power

how much are your L67s? what have you done to them?

o ya back on topic... i say build up your own engine...

Thanks guys, and 2fast I will keep that in mind but I dont have the cash just yet.

Brian Teel over at motorswap.org said that swapping to a "drive by wire" engine (LS4, L32) is a real PITA...he also said the N* was doable but electronics were a monster headache for very little power gain...In all honesty I was only considering those two engines for the V8 sound

Gotta love Rook, run er til she pukes and do it again

I'll have to keep an eye on the local salvage yard for a GTP donor car...although grabbing a built L67 from 2fast and a ZZp tranny would be a sweet option...I dolike the concept of being able to pretty it up as I go since making the engine bay measure up to the rest of the car would be nice.

I'll keep you posted as I go on "Operation Boost the ThunderBat"

I think yer best bet WOULD be to grab one of Brad's mills. Or grab the short block he's got and go about the cosmetics, which accomplishes that which you wish to do, any-freakin-way.

It is a sad day, indeed, when the Dark Knight has to rely on under-handed methods. Natural Aspiration...is doomed.

lol, jk, Tim.

Smack Brian over the drive-by-wire crap. All you have to do is put an LS1/N* throttle body on it. Just use an adapter. Painless as it can get.

The hard part will be coughing up the money for an LS4 and the other electronics involved. You can't use the LS4 PCM because you have to alter the drive-by-wire stuff. But can you alter a 3800 PCM to utilize an 8 cylinder? You'd probably have to install a Haltech (like the guy with N* did).

Richard, keep in mind the "real Dark Knight" has relied on jet propulsion for a long time...I've actually been insulting his image going N/A all this time

I suppose Brian was thinking of making the LS4 with its cylinder deactivation fully functional.
I would love to go that route...the last drop out I saw that Ed had went for about $3k

I say build you own turbo kit. Do like ZZP and use the stock manifolds. Just weld up the downpipe on the rear and have a flange for the turbo welded into the crossover. From there, have a pipe fabbed to connect back to the exhaust. You can make your own intake tubes by using silicone couplers and straight pipe.

As for the turbo, find a decent rebuild. You could get one for around $500. You can also find lots of cheap intercoolers taken off of wrecked cars. It should be workable for about $1500. With the Sebring, you've got more time to tinker. Make use of it.

If I had a 3800 engine in my car to start with, I wouldn't have gotten the M90. There were two options for me: L67 or boosted 3100. The intake gasket issues on the 3100 left a bad taste in my mouth, I wanted nothing more to do with it.

One day, I might even do an N/A build. Ported heads, milled down for compression, huge cam, high stall convertor. Yummy.

i say build your own engine and go with a whipple, those things sound awsome, kind of expensive though
and a tranny from zzp

Lots of issues with the Whipple kit. Animul was even considering to stop offering it. One of the guys on CGP with the Buick with one still hasn't got it running due to problems with how the TB meshes (if I remember right).

i thought that was an intercooler problem

do the ls4 swap!!!!!
ive wanted to do it too, but dont have the money. v8 sound and if you supercharge/turbo it you will see bigger gains. plugs it's an ls series motor, so it will take very well to bolt ons. and camming it will be even better!
dont you want to hear the sweet sound of a cammed V8 in your 97-03 body style grand prix?

If he does an LS4 swap, there won't be enough from to spit in the engine compartment, much less put a turbo or blower in there.

Hey T-bat, I like RooK's idea of the turbo, but have you considered a remote-mount turbo system? (I know, I'm all about these things lol)

STS has their universal system with pretty much everything you need at about $3k. You'll need some pipe fabrication for the exhaust work and intake plumbing but ZZPs turbo kits run around $3k anyway so it wouldn't be that much more expensive. Plus, you could push more boost due to the pressure loss from the distance, as well as the slight intercooling effect of running though all that pipe.

I've spent ENOUGH on exhaust ...whatever engine mod winds up happening I'll upgrade my downpipe but the rest of that puppy stays just like it is.
I've seen the LS4 in the 04-up GP engine and I was surprised how nicely it fit. I'll keep my ear out for more info concerning that changeover. I wont rulle it out completely cuz that 300 pony V8 would sound oh so nice.

The SS M90 is a real option as well...Chico has it on his L36 and I think everyone will agree his engine bay looks pretty sharp.

and Rook you are dead on about my Sebring, which was one of the reasons I went ahead an moved on one when I did...having that extra set of wheels puts time on your side. Any more info you can drag up about the LS4 thing would be greatly appreciated.
I suppose I should do some surfing over at CGP as well...there is bound to be someone working on the idea if they havent done it already.

But in the final analysis a top swap probably is my cheapest performance boost while up grading my engine at the same time...my game plan is to basically come away with a "new" drivetrain to arm the T-Bat for his next 150k miles

well, if you do a top swap, youre probably going to do headers of some type... which means that your exhaust tone is going to change

Turbo it by yourslef, like what Rook is saying. And from what I keep reading, the exhaust will actually sound pretty sweet!

I would consider a low mileage short block from Ed preferably a L26,some ported heads and a cam to match your choice of FI,as far as the trans.run her till it fails then get a used one from ed with low miles and you know if you want heads done I'll set you up with a reasonable price .Chico(Pops)

if u do the N* swap ull be my hero hahahaha

I'm pretty sure the N* is out at this point...and if I go top swap I'll most likely just get a ported rear manifold since I already have a powerlog for the front.

If I get a low mileage HD trans, how much hassle is it to swap to the lower gearing?...isnt that just chain set?

im pretty sure that changing gear sets requires tearing the whole thing apart. And the gears arent cheap