Bench Racing the GM FWD V8

I saw a Pontiac Grand Prix GXP yesterday.

They were not well received when new due to their FWD layout, but they did carry a 300+HP V8.

It made me think that there will be some Impala SS and Grand Prix GXP donor vehicles hitting the scrapyards within a few years.

A GM FWD V8 with an Auto would make a nice addition to a AW11 MR2.

I have an AW11 MR2.

And a welder.

I am smart enough to figure it, right?

I'm a Ford guy (by a totally random sequence of circumstances, not by choice). Look at what powers a 95-02 Lincoln Continental. 32V Modular V8, just a set of cheap cams from a Cobra motor. What is yawnable in a 2-ton granny mover should be pretty interesting in the back seat of an Escort.

Well the Northstar FWD V8's are already popular swaps into the backs of Fieros and whatnot, I'd think that when the LS4 gets cheaper they will be the new go-to.

My buddy had the Grand Prix GXP when it was new and it was a hoot. The paddle shifting was stupid (Yay 4 gears- ). The engine was great, however. The engine might be just different enough (something about the length comes to mind) that maybe other LSx parts might not jive. From what I remember, the 6 speed in the G6 GXP bolts to the LS4 since the block had the 60° V6 bolt pattern, but I am probably wrong .

The GM F40 transaxle from the Cobalt SS bolts right up to the FWD LSx engine. Fiero guys have been doing that for years.

In an AW11, awesomeness ensues.

My neighbor has one of those GXPs in absolutely mint condition. Beautiful car. He drives the snot out of it. Over 100,000 miles with no issues.

Conquest351 wrote: The GM F40 transaxle from the Cobalt SS bolts right up to the FWD LSx engine. Fiero guys have been doing that for years. In an AW11, awesomeness ensues.

And that trans will grenade in somewhat quick order if you were to build the 5.3L.

That, and there are already a few 5.3L fiero's running around. Its basically as cool as the northstar, just without the engine failing every other day....

sporqster wrote: Look at what powers a 95-02 Lincoln Continental. 32V Modular V8, just a set of cheap cams from a Cobra motor.

Set of cams and a forged crank away. For whatever reason, even with the Mach 1s, Ford only put a forged crank in the 32v 4.6L if it was backed up with a manual transmission.

I'd also assume that the LS4 is much more likely to fit in an MR2 than a big DOHC motor like the Ford. I mean, the stock 4A-GE doesn't exactly have a lot of room around it.

pinchvalve wrote: I saw a Pontiac Grand Prix GXP yesterday. They were not well received when new due to their FWD layout, but they did carry a 300+HP V8. It made me think that there will be some Impala SS and Grand Prix GXP donor vehicles hitting the scrapyards within a few years. A GM FWD V8 with an Auto would make a nice addition to a AW11 MR2. I have an AW11 MR2. And a welder. I am smart enough to figure it, right?

I like the way you think, and I also have an AW11...so I did a little research on the motor:

http://www.carcraft.com/techarticles/ccrp_0804_325_chevy_small_block_engine/viewall.html

In reply to sporqster:

The 99-02 Conti's have the exact same head castings as the 99-01 Cobras and I believe the cams part numbers are also identical. It's really just a FWD cobra engine minus the forged crank and with 2 less bolts for the flywheel.

Problem with any of this stuff is what transmission do you use? With the GM engines, you need to find something like a cobalt SS trans as Conquest351 said, but that's a pricey option and it's not that strong. I don't know if there are any manuals for the Ford engines.

And that trans will grenade in somewhat quick order if you were to build the 5.3L.

Based on what? The Cobalt SS turbo meets or exceeds stock 5.3L torque with one mod.. Are they blowing up constantly?

JohnyHachi6 wrote: In reply to sporqster: The 99-02 Conti's have the exact same head castings as the 99-01 Cobras and I believe the cams part numbers are also identical. It's really just a FWD cobra engine minus the forged crank and with 2 less bolts for the flywheel. Problem with any of this stuff is what transmission do you use? With the GM engines, you need to find something like a cobalt SS trans as Conquest351 said, but that's a pricey option and it's not that strong. I don't know if there are any manuals for the Ford engines.

Correct, the Conti runs a cast GT crank with a stub nose, IIRC. Those still will take 600hp without too much worry. According to my auto trans parts catalog, the Conti has it's own unique bellhousing pattern that doesn't share with anything. BUT, the difference is the top bellhousing bolts, so you might be able to do a thin adapter and thick flywheel.

The F40 trans was used in the G6 and can be had for $400 all damn day. I don't find that really expensive. But then you run into a problem with the starter of the 5.3, as it's mounted on the bellhousing side and not against the engine.

Vigo wrote:

And that trans will grenade in somewhat quick order if you were to build the 5.3L.

Based on what? The Cobalt SS turbo meets or exceeds stock 5.3L torque with one mod.. Are they blowing up constantly?

I think he means "not stock" by "build the 5.3L", but I am intrigued, because, as good as the LS series is, the stock Cobalt SS drivetrain is smaller and lighter I am sure. What mod are we talking about? Perhaps Ecotech into AW11 is what we're after, even though it won't sound as good as LS4 into AW11.

RossD wrote: My buddy had the Grand Prix GXP when it was new and it was a hoot. The paddle shifting was stupid (Yay 4 gears- ). The engine was great, however. The engine might be just different enough (something about the length comes to mind) that **maybe** other LSx parts might not jive. From what I remember, the 6 speed in the G6 GXP bolts to the LS4 since the block had the 60° V6 bolt pattern, but I am probably wrong .

the only special parts compared to any other LS engine are the shortened crankshaft, block, and front accessories.. they probably also use a smaller flexplate due to having the smaller fwd bellhousing pattern.. everything else is typical LSx stuff.

people are swapping LS6 heads (and maybe even the LS6 intake) and the GMPP HOT cam onto them, reflashing the ecm, and making some seriously fun power.. someone out there made or makes an LS7 block with the fwd bellhousing....

I think he means "not stock" by "build the 5.3L",

Sure, but unlike a turbo motor, there is not much you can do to an n/a 5.3 to significantly boost the torque without a major teardown and major parts replacement, and if you're doing that than all you need that is ls4 specific is an engine block, crank, and i suppose accessories as mentioned above.