# LS9 Crate into 2006 GTO, degree of difficulty? 9"Moser replacement for stock GTO IRS



## tem2006LS2plus (Feb 21, 2011)

*LS9 Crate into 2006 GTO, degree of difficulty? 9"Moser replacement for stock GTO IRS*

I'm considering installing a complete LS9 crate engine in my '06 Goat. Anyone out there gone this route yet? Any issues or surprises? My primary concern is interfacing the wiring, ECM, etc. in a LS2 Goat to the LS9 engine. Hennessey performance already adapts the LS9 into 5th gen Camaros but my email to them inquiring about "technical assistance" was answered with a sales brochure in the mail, advertising everything but a GTO. Also, has anyone out there converted the stock IRS to a Moser 9" complete rear axle? Lastly, does anyone have any information about the power moonroof for the '04-'06 Goat? Thanks all>


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## dustyminpin (Jun 19, 2006)

An LS9 crate engine costs $23,000. If you put that kind of money into an aftermarket turnkey engine from somebody like Lingenfelter, Mast, Golen, Texas-Speed, etc, you could order it with the right pistons to have 9-1 compression and still have money leftover for a supercharger that would just completely eat a LS9's lunch. You're looking at 13,000 to 15,000 for a bullet proof balls out, street-strip motor, with 8 grand leftover for the blower. My .02. And yes, people are doing the rearend thing, you can buy kits/adapters online for stuff like that.


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## Poncho Dan (Jun 30, 2009)

All an LS9 is, is a forged LS3 with a TVS2300 blower on top. LSA is the same thing, only with a TVS1900.


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## GM4life (Mar 18, 2007)

tem2006LS2plus said:


> I'm considering installing a complete LS9 crate engine in my '06 Goat. Anyone out there gone this route yet? Any issues or surprises? My primary concern is interfacing the wiring, ECM, etc. in a LS2 Goat to the LS9 engine. Hennessey performance already adapts the LS9 into 5th gen Camaros but my email to them inquiring about "technical assistance" was answered with a sales brochure in the mail, advertising everything but a GTO. Also, has anyone out there converted the stock IRS to a Moser 9" complete rear axle? Lastly, does anyone have any information about the power moonroof for the '04-'06 Goat? Thanks all>


If you got that kind of cash, your best bet is to build a 402 stroker, L92 heads with a TVS2300 or a Procharger F3C to make some real numbers. You may save yourself alot of time and money. For the diff someone does offer a 8.8 swap. Do a google search you may find out who.


Poncho Dan said:


> All an LS9 is, is a forged LS3 with a TVS2300 blower on top. LSA is the same thing, only with a TVS1900.


Off the top of my head the LSA/LS9 have piston oil cooling that the LS3 don't have. The LS9 is hand built, forged internals while the LS3/LSA does not. The LS9 dry sump, eight bolt crank, only the Grand Sport LS3 has dry sump. The LSA/LS3 is standard six bolt crank.


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## Poncho Dan (Jun 30, 2009)

GM4life said:


> Off the top of my head the LSA/LS9 have piston oil cooling that the LS3 don't have. The LS9 is hand built, forged internals while the LS3/LSA does not. The LS9 dry sump, eight bolt crank, only the Grand Sport LS3 has dry sump. The LSA/LS3 is standard six bolt crank.


8 bolt mains? WTFBBQ! You learn something new about the LS series every day...

I wonder why the tendency towards dry sump lubrication on the Corvettes? Is the CTS-V dry sump?


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## GM4life (Mar 18, 2007)

Poncho Dan said:


> 8 bolt mains? WTFBBQ! You learn something new about the LS series every day...
> 
> I wonder why the tendency towards dry sump lubrication on the Corvettes? Is the CTS-V dry sump?


It's the flywheel/flexplate bolts not the mains, my mistake.

Dry sump has it advantage in racing more than anything else. During high-G manuvers the oil tends to slosh to one side of the oil pan, also in drag racing the oil gets push toward the rear of the oil pan. Also it keeps large amounts of oil off the crankshaft too. The LSA has standard wet sump oil pan.


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## HP11 (Apr 11, 2009)

Interesting that the OP left 2 minutes after posting and hasn't been back since.....


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## Gotagoat (Jan 6, 2006)

I believe he got the idea his idea was a poor idea.


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## HP11 (Apr 11, 2009)

You'd think he'd at least stay around to see the answers.


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## tyty (Aug 21, 2010)

thats a pretty expensive swap but that would be one crazy goat


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## HP11 (Apr 11, 2009)

tyty said:


> thats a pretty expensive swap but that would be one crazy goat


$23K is just for the motor. There are so many other things you'd need to do to make that swap work.:willy:


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## GM4life (Mar 18, 2007)

HP11 said:


> $23K is just for the motor. There are so many other things you'd need to do to make that swap work.:willy:


Correct. Along with time, headache, and more money ontop of that. All of that for bragging rights.


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## HP11 (Apr 11, 2009)

To actually take a GTO and put an LS9 in it proprely with all of the modifications that you'd need to really make it 'right' you might come out better just buying the ZR1. With the cost of the fab work and the labor (you're not going to do alot of this yourself) the Vette might actually be cheaper.


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## GM4life (Mar 18, 2007)

If the LS9 crate motor is $23k you can buy C5Z06 less than that. About time you get thru modding the GTO with the LS9, drivetrain mods and whatever else you would have came out ahead with modding a C5Z06.


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## tem2006LS2plus (Feb 21, 2011)

Hey all, thanks for the feedback. I've decided to ditch the LS9 crate into my Goat and decided to build my own big-inch blown (SC) LS based motor. I'm leaning towards reseleeving my original LS2 and modifying/strengthing the block, inserting one each stroker forged rotating assy. to end up with a motor between 7.0 to 7.2 Liter (427 to 440 cid). Still looking over camshafts and heads available. Goal is to have a solid 500 (or 500+?)rwhp (on motor w/o NOS) while still being able to knock down close to mid-20's MPG when in freeway cruise mode (I presently average 28.5MPG at 75MPH sustained!). It's still a daily driver and a great one at that.


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## 87GN06GTO07IRL (Aug 10, 2009)

tem2006LS2plus said:


> I presently average 28.5MPG at 75MPH sustained!


Oh really? :rofl: Care to elaborate on how you achieved this. I find this a little far fetched.


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## zx14man (Apr 26, 2011)

I also call BS on that kinda mileage... Thats more than my 4cyl commuter car.. LOL...


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## Falco21 (May 11, 2010)

If it's an M6 it is very possible. There were a few members over on the other forum that were getting this on long road trips. They even had pictures to prove it. I get around 25-26 on the highway cruising in 6th gear, so if this is a manual, it is very possible.

There was also quite a few goat owners who went on a very long trip and were averaging 31mpg going about 75-80mpg.


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## HP11 (Apr 11, 2009)

Not what I bought the car for but coming back from Vegas last year, I achieved 27.0 without making a serious effort.


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## dustyminpin (Jun 19, 2006)

Night and Day difference between the M6s and A4s. My auto averaged 19-19.5 highway miles when it was stock running 80 mph with the cruise on. When I added the Borla catback and Kooks SS headers it jumped to 21-21.5. Best it's ever been. When I put the heads/cam/intake/throttle body/cai/torque converter/injectors/and all the other crap that went with it, it fell back to 19-19.5 interstate with cruise set @ 80. But IMO, that's still awesome gas mileage for something that's in the neighborhood of 560-575 crankshaft HP with an automatic.


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## 87GN06GTO07IRL (Aug 10, 2009)

That makes sense then if you guys are going off the dic. Mine is at 25mpg mostly but that translates into 22 if i do the math for mileage and gas used. The dic is not accurate.


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## Falco21 (May 11, 2010)

I have tested mine many times and it has been off by 2 mpg at the most. The OP claimed to get 28 mpg, so say he really is getting 26, your telling me you think 28 is BS but 26 isn't? In your eyes?

The computer in cars is used to give an estimate. It rates the idle mpg at 0, hence why it may be a little high at times. It does not take into account the amount being used while sitting still. Whether I am really getting 25 mpg as opposed to 27, I could care less. This car amazes me with the way you can save gas in 6th gear, yet still be able to drop it into 3rd and make damn near everyone look stupid


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## HP11 (Apr 11, 2009)

In my case, I had filled up the car and driven it nearly 280 (278.8) freeway miles @70-75 or so MPH and checked it at the next fill up. I used 10.47 gallons. Doing the math, it was 26.63 mpg so, in that case, it was pretty close to the DIC reading. Believe or not; not trying to convince anyone of anything, that's just what the numbers said. I haven't taken the car on a trip like that since and, like I said, I didn't buy if for gas mileage.


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## fiddler_red (May 9, 2007)

I took my '06 M6 out from Minneapolis to Sun Valley ID and averaged 26 mpg going 75-85 with some 100+ sprints. Some tanks did better than others. At each fillup I did my own calculations, made note of the computer readings, and even used the iphone mileage app and got almost EXACTLY the same results! Great highway car! Of course city mileage is for sh#t......


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