I was wondering if any of you guys have ported your factory TPI base manifold and had good results. Is there any web sites that that cover exactly what areas to removed material etc. Reason being, I’m a broke college student and can’t afford much more than a cheeseburger and maybe a LT4 hot cam. Lol! (Anybody have an aftermarket base for sale?? Send me an email!!)
I hear a lot about the AS&M Semi-Siamese LTRs. I assume that AS&M is short for Arizona Speed and Marine… Do they have a website?? Where can I find a set of these bad boys? I’ve been looking pretty hard w/ no luck.


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87 IROC 350
13.94@103mph
Stock cam and chip

 

http://www.cis.udel.edu/~davis/z28/buildup/plenum/ http://www.tribal-treasures.com/cars...-port/port.htm http://www.isthq.com/~dan/efi.html

All very good. I'm running a very similar set up to the last link's pictures - see sig. I fully ported the intake from entry to exit. Used a flexible shaft on the grinder to get in the middle,,, just gasket matching will help,, but for the real gains you gotta port it all the way. With my set up,, car pulls really strong to the 5500 shift point ,, just idles rich,,, hope to have that fixed soon though with a new chip!!! I spent well over 14 hours (total)porting every thing

Do a search using "base porting" there's a good thread there. - - Good Luck!!!

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86 IROC - 9.8:1 - 355, TFS twisted wedge heads, 218/228-110, fully ported GM base and plenum, SLP runners, 52mm BBK, 24# SVO, 1 5/8" Headman headers, 3" Dyno-max, TH350, B&M Megashifter, 245/45ZR17s on 212 Eagles

[This message has been edited by BadSS (edited October 14, 2000).]

 

How about 14.21@96mph on a stock 305TPI 5spd in my 92Z28convt with 3:08 rear? Thats the best, she'll run 14.5 all day. I believe there are big gains to be found by porting the intake, plenum and runners. Plus, it's just the cost of some dremel bits

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Rob P
89RSconvtZZ4TPI
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

www.azspeed-marine.com/

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this goies to badss how much power do you think you gained by prorting the intake. were you able to feel. what how much did you gain in the 1/4 mile.

thanks,
Jim

 

Here's a couple pics of my ported stock base:
http://24.1.139.249/images/101500/DCP_0028.JPG http://24.1.139.249/images/101500/DCP_0029.JPG http://24.1.139.249/images/101500/DCP_0030.JPG


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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

firebird87,, I wish I could tell you. I bought the car with the short block fried (dude washed the walls and ran it LOW on oil). I ported the base and plenum and added the SLP runners before I stabbed the new engine. Member "Super Chevy" posted a while back that he fully ported a 86 GM TPI base and got within 2cfm @.400 lift of the TPiS Big Mouth. However, I have the feeling "Super Chevy", since he has access to a flow bench, may have done more than a little porting (like a lot). I would consider myself fairly experienced and not bad at porting. I made plastic templates to use at different points inside the intake ports,, for consistency as well as a micrometer for the entry and exit points. I would think how much power a person got from a home port job would depend on how much they know, have done, and how good they are at minimizing the difference from one port to the next. So,,, power gains would probably vary from one porter to the next.

Saying all that,, as fast as the tach swings to 5500 on my combo, I'd have no reason to doubt if you're willing to put the time and effort into it there is a lot of potential in the stock base.


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86 IROC - 9.8:1 - 355, TFS twisted wedge heads, 218/228-110, fully ported GM base and plenum, SLP runners, 52mm BBK, 24# SVO, 1 5/8" Headman headers, 3" Dyno-max, TH350, B&M Megashifter, 245/45ZR17s on 212 Eagles