martini

How come I never hear about these things being done to RX-7s? Seems like it would go nicely with a streetport and full exhaust..

or perhaps the stock IM is more that sufficient? Seems to me, even so, that a hone job to smooth the airflow path out would do well..

has anyone looked into it?

Flybye

The next rebuild, I'm certanily going to do it.
I had my upper only Jet-hot coated, and it made a differance enough for my GF to feel. Boost DID come on faster. I'll end up polishing and boring out the lower and upper IMs.

This won't be for a while, so don't wait for results from me

spooledUP7

I matched ported my UIM to the LIM and I noticed a significant result in idle blip responsiveness. I can't tell you if it made a difference in the power because I replaced my turbos and went no-sequential all at the same time. The car is crazy fast now, but I am somewhat sure the match port helped. I did have to adjust my air aduster screw, so something did change.
Extruded hone would be the next step, and then polishing everything before the injectors.

spooledUP7

Flyby, I witnessed your 10 thousandth post.. Whoo Hoo!

spooledUP7

What the hell, it went down one?

Flybye

I ordered another thread to be deleted.

It's ok

duboisr

Garfinkle cleans the insides up and port matches, also all holes that are pluged are blended to the inside surface. He cuts out the area where the double throttle was.

Ring Steel

Does Garfinkle offer this service for a fee?
Sounds like it might be worth having done while my engine is being rebuilt.

fdracer

this is done a lot on ported motors. in fact no one should have a ported motor w/o at least the lim port matched at where it meets the intake port. the im should also be port matched where the uim and lim interface, as casting irregularities make is so that they're slightly unmatched.

however, porting along the entire length of the runners is almost never done, because it's impossible to get a bit all the way in there. the only thing you can do is extrude hone the whole thing, but that is expensive and will give you minimal power gains. plus the super smooth surface will hurt fuel atomization.

RonKMiller

It's worth a 6% increase in flow if done properly. That may seem like a small number, but when you consider how good the flow already is, it's awesome. Worth every minute of labor it takes to do it, and it does take quite a while. Better response, more torque, more horsepower and a smoother running engine to boot.

Takes the place of MANY other mods, and has absolutely NO downside in terms of reliablity or longevity. Deep, quick breathing is good.

That's what RIKKI did - I guarantee it - basic hotrodding.

93blackrx

Do you guys do it your self or send it some where? How do you get the template? After the porting do you coat them with something? I just got a new engine from pineapple and now would be the time to do it. Thanks

regards, Matt

RonKMiller

If you just got a new engine, it's too late. Needs to done while the engine is apart.

I'm sure Pineapple could have done it for you, all of it is grinding and polishing, grinding and polishing, and match porting. But don't try this on your own, it takes alot of expertise and TIME to do it right without ruining expensive parts. Well worth paying a pro who has done it before.

fdracer

it doesn't need to be done while the engine is apart. 93black, just take it to your local rotatary shop and tell them to matchport your lim to your intake ports. you can also have them matchport between the lim and uim.

Ohseyun

flybye,
10,000 posts!!! jesus..

spooledUP7

Again, I did my own LIM to UIM port matching. It was pretty easy to do. I used a die grinder with some cheap bits. I just traced the metal gasket on to the manifolds and went at it. You just need to make sure you index the gasket so that when they go back together you wont have a gasket in the air flow.
There is a sticky in the 2nd gen forum that covers this in more detail, although it applies to pretty much any car.

Erdin

What if we got rid of the lower intake hole as well on the uim to leave one big triangular shap like hole would this work.