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-   Performance, Brainstorming & Tuning (https://www.gmforum.com/performance-brainstorming-tuning-96/)
-   -   Homemade PEMS (https://www.gmforum.com/performance-brainstorming-tuning-96/homemade-pems-222175/)

ChaseSmith 09-13-2005 09:08 PM

Homemade PEMS
 
Has anyone ported exhaust manifolds on their own? I just finished porting my back manifold, I have seen many posts af people that weld their back manifold. When I was grinding, I could see smoke leaking through. Is this a necessary step, or is it wasted time. I am going to weld them anyway because I saw smoke leaking, but just for knowledge purposes, has anyone done this and not welded? Could you hear exhaust leaks?

willwren 09-13-2005 09:16 PM

Be VERY careful. If you get them too hot, they'll warp. The proper sequence is to stitch weld with cooling in between FIRST, then port them. That's the way I did mine. I gained 16-20% on all ports, front and rear (all of mine are tubular, not cast, you have one of each).

ChaseSmith 09-13-2005 09:22 PM

Sweet, how much KR did it kill? Just curious.

willwren 09-13-2005 09:41 PM

Hopefully 10. We'll know more in the days and weeks to come. I had that much at WOT on a 100 day with my 2.2" pulley.

Peterg22000 09-14-2005 01:45 AM

quick question then you can get back on topic...what does "WOT" mean??? ive seen lots of ppl using the term but i still cant figure it out.
:?

Puddy46 09-14-2005 01:52 AM

Quote:

Originally Posted by Peterg22000
quick question then you can get back on topic...what does "WOT" mean??? ive seen lots of ppl using the term but i still cant figure it out.
:?

Wide Open Throttle. Pedal to the floor basically.

willwren 09-14-2005 10:28 AM

Read techinfo for the jargon/acronym dictionary of terms we use here.

BillBoost37 09-14-2005 10:33 AM

Bill...

Any ideas on the 97-99 manifolds if I have enough to bother?

willwren 09-14-2005 10:36 AM

No idea without looking and measuring. Measure the ID of the manifold, particularly if the OEM weld is on the INSIDE of each port. Meausure the ID of the exhaust port in the heads. If head port>EM port, then port! :D

ChaseSmith 09-14-2005 11:20 AM

Finished porting the rear last night, sent them off to get welded by my friend. His welds look like a row of dimes overlapping each other, not blobs of material like mine, so hopefully they will look professionally done. Next step is header wrap or jet hot. I would prefer not to wrap them because of potential hot spots. If the $$ is right I will get them coated with jet hot. My swap has spun out of control, and I am fearing that I might go over budget, oh well, it's a hobby right.


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