how much hp can u get out of std manifold

[Guest Anonymous]

what is the most hp u get get out of std tubo manifold and how much more do you get out of a header type .im looking at geting 400 plus hp can the std one handle that sort of hp.or do i have to bite the bullet and pay for header type.any help would appreciated thanks

[Lockjaw]

If you will look at a post a few down you will note one of our members Jeffp put down 415 hp thru a stock exhaust manifold that I am sure he worked on it some to open it up a bit. He has several posts about the set-up so I would recommend you check it out.

 

There is also a thread on a T04 header that a guy was wanting to build, but wanted some commitments on who would be interested.

 

Finally, Cartech ( Bell engineering group) has some sort of manifold also, and I believe it is T04 flanged as well.

[Cody 82 ZXT]

Hopefully by the end of next week I'll have mine ported with some pics. to show how much can be taken out of the manifold. If you've ever looked into the mainfold you can see there is ample room for improvement by removing material in the inlets and at the turbo flange. I'm hoping to open mine up to flow enough for 350 to 400 hp without to much restriction. Not that the stock design is all that good but it sure does hold up to some abuse without cracking like some header type of mainfolds can. Don't get me wrong I'd pony up for a good stainless header if the price and design was right.

[fl327]

stock turbo manifold will make some good power, unless youre going super duper you wont need much, i would port it out if its off the car, its the best time to of course.

[R0N]

Porting make a big difference. James (240Z Turbo) said there's a lot of porting that can be done on the turbo manifold. I don't think you can get over 400hp without porting it. It would be a bottleneck.

[jeffp]

I did port work on my exhaust manifold. There is allot of material that can be removed from the flange area, and on the sides that the runners dump into. You have a few hours of work there with agood air grinder. You will want to open it up and smooth out the dump into the outlet. Really I am undecided how far you can go with the stock manifold. I do know I dont like the inlets to the manifold (head side) they are restricted to make room for the big washers to mount the part. That area needs work also, but watch the thickness when you remove material, and again, smooth the inlets and that will help also.

[Lockjaw]

I wonder if we knew a good welder if we cut the manifold into 3 pieces and port it, and then weld it back together. Hummmmm.....

[R0N]

That sounds good idea but I heard cast irons don't weld back very good???? Don't know if this is true or not.

[Cody 82 ZXT]

If they can weld new flanges on the outlet then why couldn't it be welded back together? No dought it would take a very qualifided welder to do the job right. The size inside the manifold doesn't seem to be a restriction. I think it's more the size of the ports and the outlet into the turbo. Also I'm sure most of us have seen the pics of cars that have a new flange welded on in the middle of the manifold and use the stock outlet as an area for a external wastegate. This would require some serious mods to the downpipe and might come in contact with the air conditioning compressor but, for cars that don't have air and are still in the preproduction stages it might be something to look into. Just think of how straight and long you could make the first 6 inches of the dowpipe if you moved the turbo 4 or so inches forward in the engine compartment.

 

I wonder if we could find out how much a low production run of cast manifolds would cost if we designed one and had some made? Anyone have any contacts here? Someone we know has to know someone that could help us out.

[R0N]

I figured that. I was told by a muffler shop. He mention it had to do with the exhaust carbon built up in the metal would cause the weld to break off.

 

I figure if you port and shaved the metal in that area you would have good metal to weld on.

 

I did see a few people with external wastegates modified welded on the exhaust manifold.

[Guest Anonymous]

thanks for all your help will stick with std one and port it out two maxs then hpc coat it

[Lockjaw]

Corlky Bell has one, and it is set-up for a T4. I wonder if Rev Hard would do one. I was thinking of having 6 runnerscome into a centrally located flange and have the flange face down instead of out. Like they do on the 240sx manifold.

[Cody 82 ZXT]

I know Corkey has one but, I've never heard any particlars on it. Any one have any details? I would think that if the flange was pointed straight down then the turbo might hit the block once it was clocked right.

[speeder]

My manifold porting is in progress - I'll try to get some pictures to post. Good info is in an earlier thread in this forum -