I want to get the Holley Aluminum Intake Manifold for my 98 Z28. I read that it can be ported to match cylinder heads. I'm not planning to port my cylinder heads any time soon; however, I was wondering if you can port just the Manifold for increased flow? And if you do port the Manifold, do you have to reprogram the computer for it to work right?

Does anyone know how much it costs to port the Manifold? Or where I can get it done in the Bay Area?

Will getting new fuel rails and injectors help my hp at all? If so, what are some good choices. Does anyone know what the stock injectors flow per hour? I don't want to go to high, but if I'm gonna spend a few hundred on injectors, I want more than a 4-5 lb/hr improvement.

Sorry I've got so many questions. I just need to figure this stuff out BEFORE I buy it. Thanks for all the help.

-Jeff



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1998 NBM Z28, A4 2.73, Chrome 10-spoke SS rims, RK Sport ground effects, QTEC, Flowmaster, CAI, LS1 Motorsports Lid, K&N, MSD wires, custom painted interior.


Best ET: 13.665 @ 103.25
Best 60': 2.114
Best reaction : 0.649

 

OK,I'll help with what I can.The new Holly intake already flows better than stock so you don't really need to have it ported until you get a head/cam package.You shouldn't have to re-program the computer for just the manifold change,it'll be just like putting on the LS6 intake.Also,usd '98s get the larger 28 pound injectors while I think '99 and later get either 24 or 26 pound injectors.I'm not sure what the exact numbers are but I know we got the biggest
Kevin

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1998 Black Z28 A4
-------1/8-------
8.548 @ 83.64 MPH
Pics
Camaro/Firebird Birthday Bash

 

how about consider getting LS1-Edit, and get a shop with a dyno and wideband o2 sensors to tune your car?

Depending on the draw of the straws, you might pick up a good chunk of "free" hp.

 

I plan to that with the dyno and a MAFT.Not real sure if I'll pick up any ponies or not,but it can't hurt,right?
Kevin

 

Ok, so i don't need to port it now. And i don't need to reprogram the computer either. Will I gain any hp from new fuel rails and lets say.....36 lb/hr injectors?

I know you have to change the computer for the increase in fuel, I'm getting the HPP3 for that.

-Jeff



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1998 NBM Z28, A4 2.73, Chrome 10-spoke SS rims, RK Sport ground effects, QTEC, Flowmaster, CAI, LS1 Motorsports Lid, K&N, MSD wires, custom painted interior.


Best ET: 13.665 @ 103.25
Best 60': 2.114
Best reaction : 0.649

 

We gots one of those..

I'm a bit wary of whether its worth $600 or not though, we've made freakin sick power with the ls6 intake.

I guess we'll see eh?

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Slow is Fast.

 

Wouldn't it be fair to say, that if your not going to port match then why not go with the composite LS6 intake, because it should flow better than the cast aluminum, because of the surface finish. The surface finish is much smoother on the composite (SLP) intake vs the aluminum cast piece....???

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99 SS, Dark Metallic Blue, M6
SLP lid, KN, TBB, SLP Y-pipe, SLP loudmouth
ported MAFs, Nitto 315 DRs
Currently: 1/4 13.06@113.8 (gtech runs high in mph by about 4mph), 0-60 4.77 (w/passenger) Gtech'd
12.99@110.2, 2.06 60ft - Tazzo.
Also, 331 rwhp as measured on the Gtech

 

Smooth isnt what you want

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Slow is Fast.

 

Having a slightly rough surface supposidly helps keep fuel is suspension, but our intake manifolds only flow air, since our fuel injectors pretty much fire right next to the intake valve itself, wouldn't smooth be better?

 

your stock fuel injectors and rails are pretty much perfect for a stock engine.

I don't think any new intake manifold is going to yield much added hp to a stock engine, since the stock intake manifold isn't restritive on stock power levels. Money would be better spent elsewhere..

Every little bit helps I guess though.. I guess since some catbacks go for $600, i guess the intake manifold is just another drop in the bucket..

 

the swirl that is being talked about would be for a more efficient way to mix air and fuel, but our manifolds only run air, so smooth=good. I would maybe think that the best flowing set up would be the holley aluminum intake that is extrude honed and port matched. my .02

 

Bigger Fuel Injectors is not a "HP" mod. It is only done to keep up the fuel flow for other mods you have done to up the power. When you need more power...you need more fuel. All bigger injectors are going to do is run at a lower duty cycle anyway, because your engine doesn't need more fuel, so it would be pointless to get them unless you were doing heads/cam.

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1983 Monte Carlo, 307 Stroker, TH350, 3.73 10-Bolt - SOLD 8/19/02

Future F-Body Owner

[This message has been edited by BlackHawk T/A (edited September 10, 2002).]

 

It isnt about mythical swirl or keeping fuel in suspension.. its about aerodynamic drag .

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Slow is Fast.

 

Wow, thanks for all the replies. So, bigger injectors aren't going to net any HP? I saw on Horsepower TV they upgraded the fuel rails and injectors on an LT1 Camaro and gained a few rear wheel hp. I guess I'll just get the Holley Manifold and port the heads and manifold some other year.

-Jeff



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1998 NBM Z28, A4 2.73, Chrome 10-spoke SS rims, RK Sport ground effects, QTEC, Flowmaster, CAI, LS1 Motorsports Lid, K&N, MSD wires, custom painted interior.


Best ET: 13.665 @ 103.25
Best 60': 2.114
Best reaction : 0.649