Porting the stock manifold & plenum
Thread Starter
Instructor
Joined: Dec 2001
Posts: 198
Likes: 0
From: St. Charles County MO
Porting the stock manifold & plenum
I have taken the manifold off to replace the gaskets. I thought I would ask if it would be of any benefit to port the manifold & plenum. I have never done anything like this before, so I hope you guys can help me. I do not plan to make any major mods to the engine other than the things I have done already. Benefits? Drawbacks?
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Porting the stock manifold & plenum (Putter)
Well it's a lot of effort for a small gain with those mods.
If you like learning new things and working on your motor then go for it, but don't expect much improvement in HP.
You will gain much more (~20hp) from tossing the "frisbee" from your water pump pulley and cutting back your spark plug ground electrodes (both on my site).
If you like learning new things and working on your motor then go for it, but don't expect much improvement in HP.
You will gain much more (~20hp) from tossing the "frisbee" from your water pump pulley and cutting back your spark plug ground electrodes (both on my site).
Racer
Joined: Apr 2002
Posts: 415
Likes: 0
From: loughborough Leics ENGLAND
Re: Porting the stock manifold & plenum (Vic'89)
As Jim and Vic suggest, i think you would be lucking to see 5bhp by porting a standard manifold, the plenuum would be worth doing behind the t/b though as it requires far less time to do. Think bolt ons and do a few more hours at work to pay for them. That way you spend your time doing something your good at and you don't smell of aluminum and your car will get something that will make a difference :)
:cheers:
:cheers:
Melting Slicks
Joined: Apr 2002
Posts: 3,019
Likes: 0
From: down that one road next to that big tree
Re: Porting the stock manifold & plenum (BLUE ONE)
you can gain more than 5hp, back when i was into TPI i picked up nearly 3/10ths totally working my TPI system, i spent around 15hrs on the whole thing however & would never do it again. the egr buildup, mis matched ports and general rough sharp edged areas bottle up airflow. insted of wasting cash on porting bits just buy the accel base, it's better stock than any GM base could ever hope to be. upgrade runner or a super ram top end when cash provides. spend the $375, you'll be really happy you did
Race Director
Joined: Aug 2002
Posts: 17,367
Likes: 1
From: Kentucky
Re: Porting the stock manifold & plenum (gtsyellow)
I was going to send mine to LPE and let them do it for $200 and I was going to siamese my runners myself, but have now decided to just save the money and keep things the way they are. I want to keep this intake stock incase I decide to sell the car down the road. I am putting that $200 towards the purchase of a SR setup though.
Thread Starter
Instructor
Joined: Dec 2001
Posts: 198
Likes: 0
From: St. Charles County MO
Re: Porting the stock manifold & plenum (castivers)
I was looking at the following website testpipe.com They make a pipe to fit in place of the catalytic convertor. I have been told that this will improve my horsepower considerably. I have to be able to pass Missouri Emissions, so I could switch the pipes pretty easily. Any input? The pipe will cost $62.00 inlcuding shipping. It is made with a flange & slip joint just as the convertor is made. Just unbolt convertor & bolt in testpipe. Thanks for the input on the porting of the manifold. I think I can live without the possible 5 hp for the amount of work involved. It took me 50 years to get a corvette, I think that I would rather drive it than port it. :yesnod:
