LS4 Performance - Need Pics asap...
04-08-2008, 04:19 PM
I am in contact with a vendor that will port our stock manifolds. Does anyone have pics of both the front and rear manifolds? Especially the holes??? Thanks in advance.
04-08-2008, 04:45 PM
You rock, I wish I did....
04-08-2008, 04:54 PM
I have pics of the rear manifold somewhere.
In my opinion, it's not going to give you much, the front manifold has huge ports with no restrictions and the rear manifold might be able to be ported a bit but for the $$ and the hassle of swapping manifolds I'm sure you can find something else to do to get a couple horsepower.
04-08-2008, 06:43 PM
I went the ported manifold route with my old GT and it made a huge difference. I personally would pay 400.00 for a set for these cars. You should consider something like this since you are running a turbo. I bet you would see another 20 - 25 hp at the wheels running a set of ported mani's with a turbo. A buddy of mine ran stock mani's with a CSC and then put on a set of ported mani's. He already had on the car a HF DP and a good catback. The ported mani's reduced knock and gave more hp. Anytime you reduce knock you'll gain hp. I am not talking 5 hp either. I believe it was in the neighborhood of 22hp to the wheels. Granted, both cars have a power-adder but on an LS4 with ported mani's, & a HF downpipe you'll see some pretty good gains. Even more with a good catback... I want some that's all I can say since we don't have anyone willing to make headers without paying an arm and a leg. I can say I know what they do from personal experience. I hope some poeple get on board for this. All I can say is they DO work very well. I need some pics bad... Thanks again.
04-08-2008, 06:51 PM
Seriously, do you not think we have looked into it? lol
As mentioned, the STOCK MANIFOLDS ON THE LS4's ARE WAY, WAY BETTER THEN THE STOCK MANIFOLDS ON THE 3800's.
Which was my point. On the V6 it makes a good difference for sure but on the LS4's I don't see it make that much. I'd hold off the $400 and save up for custom headers.
The front manifold is really really nice on the LS4. Here's the pics of the rear, it could use some work I guess not sure the results would be worth it.
04-08-2008, 11:09 PM
:disgust: To bad know company would build headers for a half decent price. If you match it up to GTP style headers there would not be much difference in design.
04-08-2008, 11:32 PM
The stock manifolds look like they flow well, the only real bottle neck i see is where the front merges with the back manifold. All the exhaust from the front manifold collect and push through the small tube before it hits the flange.
If someone built a system like those shonw for the 3800, I would buy them in a heartbeat. And I am sure many others would too.
04-08-2008, 11:56 PM
:eyes: I wish SOME company would step up and build these. They could at least sell a couple hundred sets I would imagine.
04-09-2008, 06:46 AM
Does anyone have pics of the manifolds where I could see where the holes are that match up to the heads? Those pretty pics look nice but not much of a help. I just need to see the entrance of the exhaust instead of the exit. Thanks in advance.
04-09-2008, 12:52 PM
I don't have pics right now, I can get some next week maybe but the ports on the manifolds coming off the heads are huge.