Nightdoc

Let my preface the question with the fact that I am definately getting a magnuson in October. Simultaneously, I am considering LS6 heads and the new 21 st century cam http://forums.corvetteforum.com/zerothread?id=598188 . Let me also say my knowledge of tech issues is somewhat limited. What would the HP difference be between LS6 heads and 6L heads? Would it be worth the extra $$$. I am looking to get 500 rwhp. John estimates 460-480 with the magnuson, LS6 heads, and new cam. Currently I have stock exhaust, but am waiting on GHL GP?? - what happened to this?? Also I know headers may give me the extra HP to get to 500, but I may want to wait on this - don't know if I want to go header route. As of now, I am going to keep my 2.73 rear end ( I know this sounds weird), but I want to see how it drives after getting above mods before I possible switch to 3.42 - I know I will have traction issues and I really don't want to tub. Anyway, this turned into a long post ... thanks for any suggestions.

SpinMonster

LS6 heads definitely.....if you are afraid of the compression ratio just get thicker gaskets like.071's from http://www.cometic.com. They can lower the LS6 heads 10.5 CR to under 10 if you so desire.

extremecorvette

You should post this on the Forced Iduction/Nitrouse also. I think some people have done it over there. Are you going to have a forged bottom end?
I would look at a ATI D1SC you would hit that on a stock motor with 7 lbs with headers. I just missed a new D1 kit with injectors for 3200 :banghead: Most places you can find them for 4500-5500

kromberg

LS6 and LQ4( aka 6.0L ) heads have the same intake and exhaust ports, so both should yield the same flow numbers and port velocity. The LS6 heads have 65cc chambers and the LQ4 heads have 71cc chambers. For FI cars, the LQ4 will be better since they have larger combustion chambers and will lower the compression ratio. Using a thicker heads gasket to get lower compression is a bad plan.

Keith

Flyin'Brian

:iagree:

Patches

:iagree: The LQ4's are the FI head of choice - certainly the set I'd go with. The Magnuson actually is used on the LS6 heads with no ill effects to date so it's not as much an issue with that blower due to the "one pressure fits all" design. With The higher pressure units like the ATI and Vorthech, the LQ4 is the way to go. You can use the Cometic gasket with it to complete the setup.

SpinMonster

Just curious why you think that. I'm not saying I'm right but I must hear what backs that statement up. I would go with a .071 multi-layer steel gasket over stock .054 any day. The tensile strenth of these gaskets is 700% stronger and even at .071 thickness it is 5x less likely to go under heavy boost.

There is no reason to not use the LS6 with the magnusen and lowering the CR with that S/C will just cost you power. Using the cometices with LQ4 and the 5.3 liter heads has produced leaks as reported by other forum members.

Should you wish to get rid of the supercharger in the future your CR can be raised to normal or higher.


[Modified by SpinMonster, 7:35 PM 7/24/2003]

Patches

SpinMonster, I agree with you although I've heard of no problems with the LQ4 and Cometics combo. The link below is a thread I posted a while back about a problem I had with my 5.3 heads and the Cometics.
http://forums.corvetteforum.com/zerothread?id=489800

:cheers:

Nightdoc

Thanks for the responses. I guess my bottom line I would still like to know is what is the HP difference between the two, and if 6L heads would give me more HP, is the difference worth the extra $$$.

runamuk

:iagree:

The LQ4 heads will allow you to make more HP by lowering the CR which will mean lower temps in the combustion chamber and less chance of detonation :cheers:

Nightdoc

ttt
Anyone know how much HP difference between the two?