Hey all, it looks like i'll be yakking and porting my plenum next week. while i have that off, i was thinking, maybe i'll go nuts and decide to port match the runners to the plenum/base as well. And if i'm going that far, why not yank the base and port/port match that too.
Now i doubt i'd go too nuts on the base at this point, so the odds of me pulling it now are slim, more of a summer project. But would it be worth it to do the runners for now. Or should i take the easy way out, do the plenum, and live to grind another day?
...ed

 

I don't think you'll gain much grinding on the stock runners, as there isn't that much there to grind. Do the plenum for now.

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Bob '89 Ram Air Formula 350
Last(lost)Member of the Elusive Great Lakes Crew
My car's homepage

 

Wait to grind, do the plenum. Plenum is a must IMO. The base on the other hand is also a great restriction and in the summer I say go for it. A fully ported stock base will flow more than an aftermarket base. It's when the aftermarket bases are further ported is when they start to flow more, like the TPIS base.
Best of luck Ed


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-Bill

-=ICON Motorsports=-

Modertor TPI board

Looking for 86/87 Turbo regal
1991 Z28 SOLD

 

I dont have much data to offer, but I went from stock iron heads and a 198/210 cam, with a stock TPI intake, to ported iron heads, ported stock TPI intake, and an LT1 201/207 cam, and gained 40 HP and 0 TQ at the wheels.

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West Coast GM Shootout 2001!
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=-

 

You are going to spend a lot of time porting the intake and you will be unhappy with the results. That is unless you have something to put underneith the intake, ie. cam, heads. Plus you run the risk of grinding too far, and the price of a new or used TPI is not cheap.

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92 Camaro Z28
350 TPI
Dart Iron Eagle heads
10.5:1 cr
Lunati L54779 cam
52mm throttle body
Ported plenum
Home made AFPR ($2)
1 5/8 shorty headers
Ram air
255 lph Holley fuel pump
2.5 inch TRUE DUAL exhaust (no cats)
Flowmaster mufflers
4.10 gears
700R4 w/2000 stall
100HP nitrous
Best time before any of these mods:
15.1 @ 91.9
Best time after mods:
12.60 @ 108.3
That is at high alt.
5600 feet Morrison, Colorado Bandimere Speedway

 

I ported everything on my two stock TPI systems. You'd be suprised how much you can get out of the runners, especially where the tubes connect to the flanges. I believe in the every little bit helps adage.
You'd have to get very agressive on the intake to ruin it. I used a dremel and a wand and cleaned mine up nicely.
My stock 92Z28convt5spd 3:08 posi rear put 220hp to the rear wheels on the Dyno at SuperChevy last year. I've also run a best of 14.21@96mph on stock Eagle GAs. Otherwise 14.5's all day. Not bad for a motor rated at 205hp at the flywheel. I have a hollow cat, Dynomax cat back, alum drive shaft, coolant bypass, K&N filters and nothing else. Stock ignition, stock wires, stock FPR. If you are gonna run the stock TPI for awhile, you might as well clean it up as much as possible. My friend over on SETHIRDGEN is selling my old stock intake for what I sold it to him for, $50. It's machined for both style heads (the intake came off a 92Z28). I upgraded my other stock TPI with an Edelbrock Hi-Flow and SLP runners. I cleaned those up also before installing.

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Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/relocated MAT/ 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!

 

Yeah, i'm leaning towards leaving the base alone for now and concentrating on the plenum, and maybe the runners if i'm bored enough. If i'm gonna dive into the base i'd like to have a lot of time to really play with it, i don't wan tto go through the **** of taking it off just to do a once over. Seems like a waste. If anybody else has input, drop in and speak though.
...ed

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Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper
-=ICON Motorsports=-

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

 

If that's the case, check this file:

Plenum Porting.pdf

You'll get an idea of just how much port opening mismatch there can be on stock, mass-produced components.

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
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