I will be porting my intake soon and would like to know if i should touch the area around the injector.

 

I have a spare base i've touched a bit and have big plans for here. IMO the entire port area around the head is the ugliest part of the TPI intake, maybe worse than the ridiculously long runners. Let's see if i can make an ASCII rendition of why the TPI base sucks:
intake _//\ head
~~~~~~\
OK, if that looks reasonable, the point is, the intake runner comes in low and straight. The // is the intake/head junction, and the head is pulling down through the \ \ part. You can see that the head port is pointing straight at the roof of the intake, which reduces the effective cross section that the head port sees. In short, air coming down the intake runs straight into the roof of the intake port in the head.

I'm going to open up the whole injector area, removing as much meat as possible / reasonable to help air make the transition from the intake to the head.

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Ed Maher - Moderator @ The TPI & Carb Boards
92 Z28 Convertible - Quasar blue / Tan top
305 TPI A4 2.73 - 14.8 @ 93.1
Stock except ported plenum and dual cats
-=ICON Motorsports=-

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

[This message has been edited by Ed Maher (edited October 04, 2001).]

[This message has been edited by Ed Maher (edited October 04, 2001).]

 

I unshrouded the injectors on mine to the point that they do not interfere with flow into the heads (ie matched to the head). I was told by some people that this area is not that important due to the fuel injector protruding into the intake runner and the fuel itself being sprayed in at that point, messing up flow. Some people even said that this material should aid in the atomization of the fuel! Ahhhhhh.....???? I did not agree, and the way that I look at it, the injector nozzle itself doesn't interfere with flow very much and if the injectors are in good shape, they should be atomizing the fuel perfectly to the point that it isn't an issue with airflow through the intake port.

I basically port matched the intake to the TFS 23* heads, working on keeping the transition areas the best I could and the short side radius of the port where it turns to the side and than down into the head (I also worked on the runner-ends of the manifold in the same manner). By removing all of the injector "shroud" material, the air should make a much more uninterrupted flow down through the intake runner and port. I think the results of my work are pretty good as my car is pretty close to a 12 second pass and still has a stock, ported base on it.

Good Luck


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1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

WOW, and i thought i was going to be yelled at. If this is such a good idea, how come i havn't seen this mentioned before?

Does anyone have some pics of waht they have done?

 

You haven't seen this metioned before cuz you haven't looked hard enough. I actually noticed the same thing when i picked up my base, that i coulnd't find any real mention of 'specifics' of porting the base to help it out. The best picture/concept i have seen comes from dan burk's website (sorry i forget his user id off hand) where he had pictures of his ported set ups that kind of showed what i was thinking. With creative searching you can find a little more info.