280zx stock intake for hot street? Kind find any information

[turbogrill]

Hi,

 

First sorry for the confusing topic, my fingers slipped and I can't seem to change it.

 

There is plenty of information about porting the head but not a lot about the intake manifold. The "How to modify your Nissan OHC" book doesn't mention much either.

(There are some good posts on this forum)

 

What do I do about the stock intake manifold for a mild race engine? 3500 - 7000 RPM. (490 lift, 290 duration cam (ISKY 490), ported head). 

For my RPM range should I port match or just keep as is?

 

Car is fuel injected 280zx with 1980 N47 head and block.

 

Thanks

Edited January 30, 2017 by turbogrill

[HuD 91gt]

Funny you bring this up. Ive been searching the forum for dyno plots of people running a stock manifold or ported one. The only ones I seem to find are turbo charged engines. Big HP NA cars seem to go the way of Weber.

 

I have my L28et manifold cut apart and I'm in the middle of smoothing and polishing. It is the basis of my MS system so I'm curious what kind of power it may be able handle before the so called "restrictions" take over. I have a similar cam as youve posted. Also some headwork to go with it.

Edited January 30, 2017 by HuD 91gt

[NewZed]

BRAAP did some work on intakes in his EFI tips thread.  I have the link in my clipboard - http://forums.hybridz.org/forum/90-l-series/

[skirkland1980]

What type of racing? Turbo?

[turbogrill]

Hi

 

No turbo, endurance racing.

 

There seems to be a lot of conflicting information. Very confusing..

[skirkland1980]

I cut apart an intake and began porting. It wasn't worth the effort in my opinion. Instead I built a custom intake. It was well worth the effort. It runs great, more powerful, and looks cool. I would either keep the stock intake or build a custom one. I only had about $300 in aluminum and a friend welded it for free. A shop had quoted me $600 for welding.

[HuD 91gt]

^ I'm in the middle of porting my turbo manifold. Certainly a lot of hours are going into it. Would be nice to make one but not an option for me.

 

This will have to do. Due to lack of welding capabilities (and for the cost I might as well buy pre made) I'm going to attempt a high temp epoxy, or perhaps try the lab metal product on my shelf.

 

Edited February 1, 2017 by HuD 91gt

[roger280zx]

Look at Monzter's intake thread.

[madkaw]

Not much meat on the stock intake runners to bore out , so more of a matter of cleaning up. Depending on your head dictates what can it should be done with the runners. Again , very limited with stock intake.

after market ECU - or you are just wasting your time.

[Tony D]

JeffP had his L28ET manifold Extrude-Honed. It was about 2mm smaller is diameter than the head ports. 

His head flowed 224 cfm on the intake side, the number dropped roughly 10% when the Extrude-Honed stock manifold was fitted.

 

The stock manifold is VERY well matched to the stock ports flow characteristics.