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View Full Version : Ever thought about putting a GTP motor in your FBody?



dsaxman
05-28-2005, 10:27 AM
(posted on the M90 thread in the Holden section as well, but thought I'd share my experience here as well since every few months someone asks)

I almost did a 2005 l32 (series III) swap but decided go turbo instead - main reasons I didn't were the money (about 2k more than I had anticipated in parts, and I budgeted $5500 originally) and length of time to do the swap (probably 5-6 weeks considering I'd only be able to do the majority of the work on weekends - if you were having a shop do it, it could probably be done in a week and a half).

So back to the basics.. The motor w/ blower will *barely* fit under the cowl (about 1/2 an inch clearance). If you want to intercool it, you're going to have to notch the cowl (and possibly windsheild) to get the IC block between the blower and the block.

The big problem as you all know is the intake. My solution was going to cut an 8" wide x 6" tall x5" deep box into the firewall to allow the throttle body to come out of the engine normally (although backwards), then put on a 90deg. silicone elbow, a short length of pipe, then two 45 degree elbows to get the intake tube out to the driver's side of the engine. There I was going to mount an SLP LS1 MAF. It was pretty much business as usual from there. I discussed my plan at length on a couple of occassions with Loyde from Fast Fiero's and he made a few suggestions (like the LS1 MAF upstream instead of on the throttle body). My only problem was since I have a 99, I'd need a fly by wire throttle body or convert to a cable driven throttle.. was ready to go down the cable conversion until I found out that the 2005 L32/L67's are now fly by wire.. so you could go that route (but that's 300 of the 2k I hadn't budgeted for).

The other "gotchya" with cutting the box to allow for the intake to come out and snake around is that you would also have to cut your AC/heater vent box.. The way we measured (which was almost perfect) is to cut out the top set of vent channels (so you would lose your side defroster vents), and plastic weld the open channel closed.. the box would fit right above there with about 1/4" clearance. Tight fit, but it seemed to work. (un)Fortunately, we had a buddy of mine's wrecked firehawk that had been stripped that we were using to do all of these calculations on, so we didn't actually have to tear my car apart to get the measurements.

Also, the one big downside I really didn't want to deal with is to do any work on the intake side of things (like a blown gasket), you'd have to pull the motor to get to it..

The other option was to get a custom k-member made with the engine mounts 6" forward. Plenty of room to move the motor up, but that means adapating the steering column and rack, custom driveshaft, custom headers (depending on where your ball connections end up - mine weren't going to clear the fender wells) and the *little* problem of the balance being off with the motor farther forward. Granted, the LS1's have the weight further ahead, but there's also not that big cavity in the back there.

Would have been a neat project to do, but like I said, I didn't have enough cash to do it right and couldn't live without the car for a month and a half.

L67
05-29-2005, 10:18 PM
Interesting, good read.

dsaxman
05-30-2005, 12:26 AM
Figured it may help people out.. anyone who's even contemplating this, I'd highly recommend you call Loyde and tell him your plans.. even though I ended up not buying a motor from him (just yet), he was more than helpful.. I think we ended up talking about 2 hours or so... he definitely knows way more about transplanting motors into cars that shouldn't have them than I do ;-)

And BTW Loyde, if you're watching, I'll probably get an L32 from you (without the blower) when this motor goes, so you haven't heard the last of me yet ;-)

dougsgtp
05-30-2005, 12:42 AM
honestly with the aussies on this board, getting one of their inlets would be the way to go, its a formed metal piece that is the almost 90 or slightly more curved piece from their RWD L67 cars.

scarecrow420
05-31-2005, 07:01 AM
problem is you cant really pick them up from over here very cheaply

its about $1000AUD for a complete blower, and since they were only optional on just a few of our commodore models, the amount of them around is so scarce, that you wont just find bare cheap housings... you have to get a compelte M90 which as i said costs a bit

GTPprix
05-31-2005, 08:44 AM
I've done a couple of these, both with Holden M90s both were a pain in the ass but worked great when completed, hang in there it's worth it!

dougsgtp
05-31-2005, 05:25 PM
problem is you cant really pick them up from over here very cheaply

its about $1000AUD for a complete blower, and since they were only optional on just a few of our commodore models, the amount of them around is so scarce, that you wont just find bare cheap housings... you have to get a compelte M90 which as i said costs a bit

can you not just order the neck?

scarecrow420
06-01-2005, 02:19 AM
you may be able to just roder a elbow (neck/whatever :) ) but the blower housing on the aussie M90 is also different to yours (ie where the elbow bolts on). But it might be possible to machine yours to take a elbow

have a look in the Holden forum here, we have posted some pics and diagrams etc of the differences between our setups

i will give holden a ring when i get the chance and see if the elbow is available individually

futseal04
06-01-2005, 08:13 AM
This is kinda related, but after much thought, I decided instead modding the crap out of my L67, I am going to look into an engine swap to the new LS4 that is in the GP GXP. Now I just have to see how feasible it is..........

Merlin
09-20-2006, 04:32 PM
Has anyone actually done this, who thinks that its feasable

Grimm
09-20-2006, 05:04 PM
A few people have done it...none on this site to my knowledge. Mostly because it's a pain in the ass and expensive...for not a lot of HP gain stock.

Merlin
09-20-2006, 05:29 PM
how expensive, minus the engine