What exactly is involved in porting a plenum for a TPI? Is this something I have to get a machine shop to do and if so what is the typical cost and what are the gains from doing this... I am considering porting my plenum as my next project and I am trying to get a good idea of what needs to be done...

Thanks,
Mike

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Mike
88 Iroc-Z 350 tpi, Hedmann Headers, 3.5 " Cat Back, MSD Ignition, K&N Cold Air kit

 

Mike,
There is a good tech article on this site about this subject. If you have half a brain it's within the realm of things you can do yourself. You can do it with a dremel, just take awhile. If you have a compressor then yu can speed up the process. I'd read the tech article. Explains it better than I could.

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Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

also:

http://www.gmtips.com/3rd-degree/dox...-port/port.htm

 

thanks.. i am gonna tackle it in 2 weeks... what are the probable gains from doing this??



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Mike
88 Iroc-Z 350 tpi, Hedmann Headers, 3" Cat Back, MSD Ignition, K&N, AirFoil

 

"thanks.. i am gonna tackle it in 2 weeks... what are the probable gains from doing this?"


i am running with the same mods as you are now but with the exception of i do not have a ignition kit..i proted plenum and also at same time installed AFPR and it knocked off 4/10ths in ET.. took about 8 hours but this was firt time for me at porting and took my time.... it was actually easy.

 

The gains you receive will not be "seat of the pants" horsepower increase but rather a more sensitive throttle response. Make no mistake it is noticable, just not raw horsepower.

 

hey im thinking about porting teh plenum too. would you mind sending me the article please.