Either the CTS-V will make more than 550hp or this is a very inefficient supercharger

[verbs]

Just brainstorming here with some ricer math.

The LSA is basically a low compression LS3 motor, right?

LS3 makes about 430hp @ 10.7:1 compression.

LSA makes about 550hp @ 9.1:1 compression.

If you made the LS3 down to about 9.1:1 as a naturally aspirated motor, it would lose 1.6 points of compression, and each full point is worth about 4%.....so dropping the LS3 down to 9.1:1 compression would bring N/A hp to about 400-405hp.

Now, the CTS-V is going to run 9psi on 9.1:1 compression......

So boost is what would bring up this theoretical 400-405hp motor to 550hp. That's a 150hp gain with 9psi. That's about 15.5hp gain per pound of boost.

That seems kind of weak to me. Maybe GM really cranked the timing down, but still. That doesn't seem very efficient for a blower on a hp/psi measure, especially for a 6.2L motor.

[HiTechRV]

I think you are onto something. I am just wondering if it is derated, or Caddy is sandbagging so the Germans are shooting at a low target with their counter stroke. Or it just has a lot of easy hp to gain for when the answering counterstroke comes. I suspect the LSA will be capable of 600-650, and the LS9 700-800.

[Dr. Design]

You guys are digging pretty good for this one. Keep in mind that the recommended, not required, fuel for this vehicle is 91/92 but it will run on 87!! They have a secondary fuel map that the vehicle will switch to when it needs to. The engine most likely runs full timing when the conditions are just right. They (GM) can kill power at will via the timing. So the boost really isn't as important as one would make out. Plus the boost reading is most likely taken before the intercooler, meaning the engine is most likely only seeing about 7-7.5 psi. Bottom line is the blower is very efficient. Its the tune that alters the numbers....

Thanks,

Dr. Design
D3 Cadillac

[BLACK_CTSV]

So, it sounds like there may be some very low hanging fruit to be had with a tune...

[TheRooster]

Originally Posted by BLACK_CTSV

So, it sounds like there may be some very low hanging fruit to be had with a tune...

You bet. Timing makes all the difference in the world on a blower motor if everything else component wise is set up efficiently. They will yank a lot for heat soak, fuel grade and torque management. Lots or cars run on this principle right now. It's easier to pull timing and put it back in within milliseconds rather than bleed boost off through the waste gate and wait for repressurization, only to have to adjust the computer to its' effects.
I'll bet we'll see 10-12 degrees in spots and the car will be running around 10:1 AFR.

[Cadillac Tony]

Anyone remember how Ford underrated the HP numbers on the Mustang KR in an effort to fool insurance companies?

[MauiV]

I was under the impression there would be no math involved.

[verbs]

Originally Posted by Dr. Design

You guys are digging pretty good for this one. Keep in mind that the recommended, not required, fuel for this vehicle is 91/92 but it will run on 87!! They have a secondary fuel map that the vehicle will switch to when it needs to. The engine most likely runs full timing when the conditions are just right. They (GM) can kill power at will via the timing. So the boost really isn't as important as one would make out. Plus the boost reading is most likely taken before the intercooler, meaning the engine is most likely only seeing about 7-7.5 psi. Bottom line is the blower is very efficient. Its the tune that alters the numbers....

Thanks,

Dr. Design
D3 Cadillac

Aren't most cars' boost levels rated before the IC anyway? I hear you on GM killing timing.....with only a 1.5psi difference between the LS9 and LSA, something else has to make up the 70hp difference....

[Dave's V]

I don't think GM would let Cadillac give the V enough power to out perform the current Vette.

[Seattle CTS-V]

Unless they can scrub 800-900 lbs off the CTS-V I don't think they need to worry about it outperforming the Vette.

[luxilon]

Originally Posted by Cadillac Tony

Anyone remember how Ford underrated the HP numbers on the Mustang KR in an effort to fool insurance companies?

It is of course possible that by the time the car is officially released the numbers will be adjusted but if GM at that time announces them as 550/550 that's what they are. No underrating. The same debate keeps coming up with the Z06. Countless people keep stating that the Z06 must be underrated. This is not true. With the new SAE certification procedure the engine dyno numbers are within a very small window right on the 505/470 numbers as released by GM. This has been confirmed by both GM engineers as well as independently confirmed by Katech which has had a lot of the LS7's on an engine dyno.

[StealthViggen]

Originally Posted by verbs

Aren't most cars' boost levels rated before the IC anyway? I hear you on GM killing timing.....with only a 1.5psi difference between the LS9 and LSA, something else has to make up the 70hp difference....

HP is made by CFM, not PSI. 2.3 L blower vs 1.9 + 2 core IC vs 1. That plus cam differences can be at least 70 hp.

[GNSCOTT]

Originally Posted by Dave's V

I don't think GM would let Cadillac give the V enough power to out perform the current Vette.

I can assure you that GM has no problems allowing a Caddy to be faster than a base Vette and I am sure they are doing all they can to make that a reality. If they could, they would make the CTS-V faster than a Z06. The car is being built to go up against BMW's and Mercedes fastest sedans, somewhere a Corvette could never compete as a 2 seater. This will be the first time since 1987 that GM built a car faster than the Corvette, and it was a Buick no less.

[HiTechRV]

Actually the first V was faster than the then on the market C5 (I had one). When the 2004 C5 came out, it edged the V back out, but for a few months it was 2004 V against 2003 C5 and the V won by a tenth (4.6s vs 4.7 0-60).

[pietroraimondi]

Originally Posted by GNSCOTT

I can assure you that GM has no problems allowing a Caddy to be faster than a base Vette and I am sure they are doing all they can to make that a reality. If they could, they would make the CTS-V faster than a Z06. The car is being built to go up against BMW's and Mercedes fastest sedans, somewhere a Corvette could never compete as a 2 seater. This will be the first time since 1987 that GM built a car faster than the Corvette, and it was a Buick no less.

The showroom stock LS3 Base C6 is rated and real world tested at 4.1 seconds in the 0-60.

I'm not 100% sure what the published numbers are yet from GM and there obviously has not been any real world track testing done by Car & Driver etc, but I sincerely doubt that a 4300 pound showroom stock CTSV is going to have been ET numbers than a C6...IMHO.

In addition Callaway is getting ready to release the Eaton 1900 series supercharger for the LS3 and will match the GM 5 year 100,000 mile powertrain warranty.

Installing the Eaton 1900 on the LS3 C6 produces a 200+ mph 3200 pound rocket ship.

The new 09 CTSV is a stellar piece of GM engineering and I plan on having one in my gargage at the end of 2009 after alot of the anticipated price gouging ends. In will be warmly welcomed when compared to my now sold 05 CTSV.

But in the interim, I purchased an 08 LS3 C6 last month with intentions of sending it to Callaway in Conneticut in March to have the Eaton 1900 Magnacharger installed by them along with having the heads ported and polished.