Captain caveman

So exactly what do I need to do to my intake manifold to work well with a 240sx TB. Do I just need to port match that flange/mount the TB goes to or should I do more?

RubberBerner

just make sure the air has a smooth transition between the T/B and the intake manifold, if its rough-the air will lose velocity, and if the intake manifold is too much bigger (ported too big), the airflow will get a pressure drop after the T/B.

jfairladyz

Take caution as you match them. I've read somewhere that the casting of the manifold is extremely thin somewhere near the TB flange and can very easily be ground right through. Basically just smoothe the edges of the manifold out to meet the TB but don't try to blend it all the way into the manifold or you'll run into said problem. Also, if you plan to keep your air regulator you'll need the TB spacer thats available from a few sources, including ebay. It has the provision for the air regulator to mount. Also without that adapter your stock intake plumbing wont reach your new TB because the 240 TB is considerably shorter than the Z's without that adapter.

NismoPick

I just dug up a couple old pics of my manifold neck when I bored it... you really shouldn't have any probs if you just bore it to 60mm to match the new TB. I used a carbide barbed bit to carve it out. It's really the only thing that worked... everything else just got gummed up w/ aluminum.


You will also need a spacer, so the throttle arm doesn't whack the #1 manifold runner.

RubberBerner

i use a tungston bit @ 25,000rpm's, expensive but good for the first step of porting.

s/cL3.0

Here is some pics of my little project.. Kinda dirty it just got rained on..

Captain caveman

how about porting my runners. Would that be a good idea? will I need to port out the intake on my head to do that?

jfairladyz

Porting the runners is not a great idea as it won't offer much gain in airflow as the intake ports of the head will still present a restriction. If you port both the head and the manifold you will see gains in airflow though. Polishing them up will help airflow though for street use. Also port matching the manifold to the head is a really good idea. That'll also increase airflow. And it's not a difficult procedure at all. Just don't go overboard and use the gasket as a template.

s/cL3.0

I ported and polished my runners.. cant tell if it made a diff or not.. as its not on the car yet..

NismoPick

Pics! We wanna see pics!

s/cL3.0

okay here they are.. There on a diff. forum to but I dont feel like searching..The reason it looks like it stops into the port is it got rained on and it was really dusty today.. and here is a pic of the old N/A one also..

jfairladyz

Did you match the head s/c? That'll make a big difference, especially with your turbo setup.

s/cL3.0

Yeah I machted the head and manifold to the gasket... Did the exhaust ports to of coarse..

jfairladyz

Good deal. Sounds like you're doing one hell of build up. Can't wait to see the end result. Let's get it done man