There are some good LS7 header
Originally Posted by DavidNJ
pictures on Z06vette.com.
The aftermarket header manufacturer's don't have anything to worry about.
The aftermarket header manufacturer's don't have anything to worry about.
it appears that the header is missing an extension of some sort(collector). it might extend it down similar to a long tube set.
Last edited by John B; Jan 15, 2005 at 10:17 PM.
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From: Washington
I'm going to reserve judgment. Looks like the LS7 manifold has a very big flange there with what appears to be a 4- or 5-bolt flange. Looks like there might be some 4-2-1 tri-y design in there or something. Sure, long tubes will make a difference, but not nearly as much as they did with an LS1 or LS6. We'll see.
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From: Texas
The cats bolt directly to that flange shown in the picture. That info comes from another GM powertrain picture of the LS7. I am betting 1 7/8" primary or stepped long tube headers into a merge collector and then into high flow cats is going to make a substantial difference on the LS7. There simply isn't enough length to those little tubes to make that LS7 get much benefit. I am glad GM went with a tubular manifold, though.....
Todd
Todd
Launching!
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From: Raleigh, NC
I agree. Either in the exhaust or tuning, theres got to be a lot room for improvement. A 427 that comes already with CNC ported heads should make a hella lot more power than around 440-450 at the wheels. I am sure GM detune the crap out of it.
If aftermarket tuners can make a 427 with 500-550rwhp, then it shouldn't be hard to make these in the same range
If aftermarket tuners can make a 427 with 500-550rwhp, then it shouldn't be hard to make these in the same range
The cam is very small for a large cubic inch engine. Most aftermarket 346 cams are larger than the ls7 stock cam. The fact that hp is rated at 6200 rpms would tell you the engine is seriously detuned. Put a decent cam with 1 7/8 longtubes and get the power peark at 7000rpm and you will add 100 + hp and a big smile on your mugg.
think about it though, they claim stock ls1's are rated at like 325 at the fly wheel. there have been guys tune bone stock cars and put down 305 or more. to only lose 20 hp from the flywheel to the ground says one of two things: gm has some how produced the most efficient drive train in the world or it is under rated. i am going to go with under rated. crate ls1's put down over 400 on an engine dyno. i think we will see true dyno numbers be close to about 480 to 500 on a dyno. we will soon see
they claim stock ls1's are rated at like 325 at the fly wheel. there have been guys tune bone stock cars and put down 305 or more. to only lose 20 hp from the flywheel to the ground says one of two things: gm has some how produced the most efficient drive train in the world or it is under rated.
There's no doubt these engine will be capable of 500-550rwhp with the right mods though.
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I bet you would be very surprised at how well that exhaust manifold flows. It looks like a lot of time and design went into that manifold. It may even be one of the few parts they did not compromise on. I really doubt any aftermarked company can out-do that manifold. I definitely would like to see a shorty comparison. I bet it would either be dead even, or lose power over the stock piece. I clicked that link expecting to actually see the crap I am used to GM making. Geez.
I am a little surprised to see the exhaust valve. I would be very interested to see the effect it has on low-end torque. I have been eyeing out those similar contraptions on the market for awhile.
I am a little surprised to see the exhaust valve. I would be very interested to see the effect it has on low-end torque. I have been eyeing out those similar contraptions on the market for awhile.
