I have already started on porting the intake mainifold and siamesing the intake ports on it along with siamesing SLP runners to match (thanks to the ideas by madmax and mateox28). Now I want to go into porting the plenum. If I siamese the plenum ports to the runners and go in a few inches, will this in theory shorten the runner lengths and enlarge the plenum? Also, how should I go about porting the TB and TB entrance on the plenum. Any other upper intake porting suggestions are welcomed.

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"Though I cruise through the valley of Rice I shall fear no turbo, for torque art with me."
--Cullan Hooley
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1985 IROC-Z w/T-tops, 305 out and 350 L98 TPI engine in, Hooker Super Comp Headers, 3" Hooker Super Comp Cat-Back, Dropped Cat, Rebuilt TH700R4 with Shift kit, 2,800RPM Torque Converter, 3.73 Richmond gears, Auburn differential, Accell SuperCoil, Accell 8mm racing wires, BBK AFPR, Homemade Ram-Air (thanks to askulte), MAF screens removed, Dropped A/C, Dropped A.I.R, TB coolant bypass, Hurst Dual-Gate Shifter, SLP Air Foil, K&N filters, Holley performance fuel pump, Spohn Subframe Connectors, Re-located Spohn Lower Control arms, and more to come.

 

Uroc 'n roll,

Check this file:

Plunum Porting.pdf

You'll need Adobe Acrobat reader to view/print the file. (See below)

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Later,
Vader
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"Get UP - Drop the bombshell!"
Adobe Acrobat Reader

 

The TB info was great. Thanks. However I don't plan on doing what he did to the runners and plenum. What do you guys think about my runner shortening idea? Also does anyone have info on porting the head side of the intake manifold and the intake runners on the heads?

 

What engine and what other mods have you done? Is this a stock or aftermarket intake you are working on? Unless you've done a lot of other mods like bigger throttle body, heads, cam, headers, etc., I wouldn't waste too much time doing major porting on the intake. For the intake-heads, gasket matching is probably all you need to do. Just use your intake gasket as a template and open the tracts on both intake and heads to match the gasket. You don't need to go too far inside the tracts, just blend in from the openings an inch or so.

 

http://www.geocities.com/softtailduece01
Heres some pics

[This message has been edited by JucinGTA (edited September 03, 2001).]

 

JucinGTA...nice work. I was looking at that page before I posted. I see you noticed good results as well. What other mods have you done? IROC&ROLL...nice name. All my mods are listed in my sig. Some nitrous, a MSD box, and an LT1 cam are in the near future. I am working with the stock intake. It can use all the porting I can give it. If my theory is sound, about enlarging the plenum and shortening the runners (kinda like a superram), this will be a great (not to mention cheap!) mod. I'll be glad to push torque to higher RPMS. I have more power down low than I need or can use with street tires. Its good to here that good results have been seen with this.