This may sound like a stupid question, but How do you port a Plasic Intake. Would this not thin out the thickness and increase the chance for breakage, and would it be worth it to gain a couple extra HP? This is my ignorance showing someone please educate me?

 

You don't and it wouldn't. Metal manifolds are pretty much the only ones that can be successfully ported if necessary. HTH

BTW, judging from your mods, you may want to check into several of the aftermarket manifolds. Some metal some plastic. HTH

 

As far as I know the only ones that can be safely ported are the F.A.S.T ones. The walls are much thicker and they are designed to be port mached to the heads. Stay away from the aluminum ones as they tend to loose power due to heat soak, not to mention add a few pounds.

 

I have ported quite a few FAST intakes with excellent results and no reliability problems.

Reasons....more airflow to the head (manifold represents less of a restriction) and more power to the wheels.

Your engine just thinks you bolted on a slightly better cylinder head because you see more "net" airflow to the cylinders.

Tony M.

 

Back in 99, Doug and I cut apart a ls1 intake and ported the hell out of it. We built a thin AL plate to glue back into the bottom of the intake. Put it on the dyno and got a 4 horse gain. It took about 8 hours. It never made it to any ones car, but it still here in the engine shop. Was it worth it, yes but not really.

Randy

 

Tony M. - Do you port the entire intake OR do you Port-Match, to the heads and clean up the interior of the Fast? TIA.

 

I dont think 4hp is worth 8 hours of work. That's too far into the margain of error. You can get a few more HP just by letting your car get up to operating temp instead of dyno'ing it cold.

Shane

 

I just got finished porting 2 fast intakes. Takes a couple of hours to do it right. First I mock up the heads on a spare block, place the bottom 2 pieces of the intake on the heads and bolt it into place. The lower section just gets matched 1/2" up to the cylinder heads. Once all 8 are done than I remove the lower 2 pieces and bolt the manifold together. We use sanding rolls about 2" long to blend the port matched section up into the runner.

 

The majority of the work I do is reshaping the exits of the intake going back about 4-5" or so. Its more extensive than a "port match" implies. Most of the final shapes and contours I arrived at were proven on the flowbench running thru an actual TB and cylinder head during the testing. Alot of this R&D was done almost two years ago when I was trying to optimize the first AFR 205 combo with the 224/228 cam on my stock GM short that we featured in various articles and you guys read a good deal about on the various LS boards. Subsequently, a few other people wanted to copy that package to the letter so I decided to port a few intakes similar to my own. It is worth reasonable gains in TQ and HP. The few I have gotten dyno results from have performed well....similar to the gains I witnessed on the flywheel dyno during our initial testing of the new (then) AFR 205 product.

Bottom line guys, pouring more money into an already expensive intake isn't for everyone....in fact its for a very small segment of the market that doesn't want to leave anything under the table and is willing to put either more time, more money, or both into trying to coax as much power as they can out of their particular combination.

Here is some dyno results from a few months ago that Patrick G. conducted, a regular on the "other" board (and a very sharp guy technically), who spends countless hours tuning, tweaking, and just looking for more....

http://www1.ls1tech.com/forums/showthread.php?t=361298

Note the gains immediatly in TQ and HP (as low as 2500 RPM's)....not a common situation when comparing a stock FAST to an LS6...in fact most people comment that a stock FAST will be weaker down low. My experience on the dyno shows a stock FAST coming in real close in the lower RPM's....but down a few ft/lbs here and there depending on RPM.

PM me if you guys need more info etc....

Happy Holidays...

Tony M.

 

Shane,
We did it to see what we could do. 4 horsepower at some level is important, but in most cases it's not. We got bored one night so we attacked it. Would we do it again, maybe if we need a little bit more. But most likey not.

Randy

 

For those who don't want to click to the other thread, here are the dyno gains from running an LS6 intake with epoxy ported TB to a Mamo ported FAST 90 with a Nick Williams 90mm TB. Very impressive gains.

 

Just because one thing is only 4 and another is only 9 and another is only two doesnt mean that there isnt a substantial gain when used in concert. For all the non-believers, the UD pulley (9), the ported TB (2-3), the ported FAST (8), the air box (?), ....you get the point...may make the difference in good gains and great gains.

I want to point out the nmber of people who dyno their cars and whine from the 'missing' 10-15 hp that so and so got. Often you see the mods they didnt do are the ones that the rare high HP cars did.

Patrick's car is and example of a lot of these little things adding up to 487rwhp using a cam that isnt as big as you think. In addition all those that bashed Tony Mamo's set-up by saying they only got 440 to the wheels, failed to see the UD puleey, 1.7 rockers, ported intake manifold, ect were all dismissed as useless mods yet the pulley, FAST Intake and port, and rockers accounted for at least 40rwhp. So maybe his 480 isn't such a mystery and the ported manifold isn't just a dyno error and ported TB's do make a difference when added to 5 other 'useless' mods that aren't worth the time as the non-believers say.

 

Thank you. That's a great explanation!



Patrick G - Hey! Welcome to this Forum! Nothing like a little testing for sound results. Thanks!!