pcguy2u

Looking at putting together a project car - probably an older Vega. I'm attracted to laying my hands on a late model Camaro pull with an automatic already on the back and with all the parts. This would be an L99. The Camaron LS3's only came with an M6.

Anyone know why the L99 is rated at only 400HP - it came on the automatic Camaros so the reason could be to save the tranny.

I'm just wonder what the differences are in the internals and if the engine has the same upside potential as the LS3 - tune and all?

Bruiser2012

I think you would br the first person to put a L99 in anything... The L99 has variable valve timing and multi-cylinder displacement. There have been some problems with the lifters on the 2010 engines.

You can't really do any hop ups on it until you get rid of the variable valve timing and multi-cylinder displacement, ussaully referred to as modding it to a LS3. That encompases cam, lifters, spring change along with updating the computer.

THat's the basics, I'm sure someone will come along with more specifics.

-Bob George

phileaglesfan

Wrong forum but the L99 has displacement on demand or whatever they are calling it these days. LS3 powered manual Camaros do not. The probably with the on demand feature is that you need it to run good on 4 cylinders. I'm guessing the LS3 does not run that good on 4 cylinders so they had to modify internals which decreased HP.

pcguy2u

My primary interest in the L99 is that you can get a dropout with low miles and the tranny already set up and attached.

Maybe I should be thinking about an LS3 with a B&M auto??? Anyone ever bolted an auto to an LS3 from a C6?

Seadawg

you should ask this topic in the tech section forum

pcguy2u

Have a thread going in Drag Racing with not so much luck. Maybe your right.

Thanks

McGirk94LT1

From what I understand, the displacement on demand requires a limited lift cam. Thus its factory springs are also meant for close-to-stock applications as I guess they dont plan on people modding it internally as much. I remember reading about ls4's(front wheel drive 5.3 in grand prix/impala/monte) which have displacement on demand for a possible fiero project and that seemed to be the thing. Despite having the great ls6 heads which meant ls6 or ported ls2 intake manifold would work wonders to improve its 303hp to really get more power out of it, lifters/springs/cam would all needed swapped out for more heavy duty pieces. All I know is I consistantly remember everyone saying their tunners usually just turned it off to save them a ton of head aches.

So no biggie if you want to swap it in and just get intake/exhaust/tune, but the hp curves likely wont be what the ls3 would be. Also, you'd need the displacement on demand turned off I assume as no manual tranny cars have come with it yet from the factory.

BiGDaWgZ

It's a long shot...but look for an LS3...and Auto Tranny....out of a wrecked G8 GXP.

They only made 1829 of them....but ...I've seen an engine/tranny ...sell out of one in the past (guy went with an LS7)

That way you could have the regular LS3...along with a 6spd automatic.


Just something to keep an eye out for !

pcguy2u

You weren't kidding, couldn't find one (engine) anywhere. thanks for that. I'll use it for my searches. Still haven't found the right one, so still actively looking. Would love to find a street legal vega with a blown V8 so I could put my choice of engines in it.

Corey_68

I'd go with the LS3, heck would go LS2 over the L99

TrueBlueConvert

You could get an 1s2/4spd drop out from 05-06 gto's

McGirk94LT1

The REAL big deal about the ls3's isnt displacement, its the different port design in the heads/intake. Much much better potential flow(took what they learned from the ls7 heads and applied it to them). The heads can also only work with a certain minimum size bore. The 6.0 gm motors all happen to meet the minimum bore size. So, buy ls2/trans out of GTO/CTS-V, sells heads/intake(not bad parts by any means), and find an ls3 top end.

NOT ONLY THAT, but the intake from the truck/G8 GT 6.0 motor(l76) is pretty much identical to the ls3 intake, part number might as well be the only difference. Also, the 6.2 in a select few trucks/suv's(l92) heads are almost identical to the ls3 heads except the valves arn't light weight like the ls3 valves.

So, buy GTO/CTS-V ls2 and trans, sell ls2 intake/heads, buy 6.0 g8gt/truck intake and 6.2 truck heads. Or get lucky and find an ls3 intake/heads for cheap. With a tune, you'll basically be up to the factory 430hp rating.

If you really are looking for only an auto, then the 6 speed in the G8 GT is pretty hearty. Or the 4l65E in the GTO can be built up by a dozen companies pretty cheap(but is already capable of dealing with 400hp).

pcguy2u

Actually looking at a crate LS3 complete (no starter) with the 4l65 attached. Need to find the shell with a dead SBC and a good 3.5 diff.

At 2400+- LB. it should do high 10's with the right tires.