Portmatching FC LIM to FD UIM
 

Anybody know someone who can do this ? if so how much would it cost ... i already haveeverything just the them portmatched. So im shopping around seeing how much it would cost. Somebody help me out thanks.

get a little rotary tool ( dremel ) and do it yourself
all u need is a piece of gasket

Not quite that easy if you really want to properly port match them. There is simply not enough casting material to match them up.

You could always just port them to get the runners "close enough" which is what most people do anyways since they are just going for the look. Fwiw, power gains, if any, are minimal.

There are only two proper ways to do this and one is easier than the other though with less desirable results. How much of a difference in terms of power is debatable.

1. Shift the primary ports of the fc lim over closer to those of the fd uim using aluminum filer rod and then port match them perfectly, with minimal ovalizing of the runner. I did it this way and afaik am the only one. It is probably the most effective but also the most complicated. Use the fd lim/uim gasket.

2. Fill in the gap on the outside of the fd uim between the two primary runners. This will give you enough material to hog out enough of the runners to port match them but you signaficantly ovalize the runners in the process in that section. How this affects flow vs. the other method that minimizes the sudden increase and then decrease in volume is the questionable part. This method is far simpler to accomplish though and is how several have done it that have gone through the trouble to port match them. Use the fc luim/uim gasket.

There is (or was) a forum member selling adapters for this swap and that is the simplest solution. I did this to begin with but sold the adapter and port matched them. I saw a ~10-15 hp gain across the board after the change.

3. Fill in the gap on the outside of the fd uim between the two primary runners. This will give you enough material to port out enough of the runners to port match them but you ovalize the runners in the process in that section. Port the FD UIM runner diameter to equal the volume of the ovalized section. Port the FC LIM to the same volume as well down to a tapered section to normal diameter above the bend. Halfshaft/countersink and bevel the primary throttle plate when doing your TB port and clean up the plenum as well. Pin the manifolds so there is no chance of misalignment and you can minimize the port matching volume. FC LIM seconday runners will also need a minor increase in diameter to match the FD UIM. Use the fc luim/uim gasket. This method will probably decrease some low end torque if you are still using the double throttle mechanism, but may or may not increase top end power/flow.

All this help/input is very helpfull thanks alot guys anymore options or ideas would be great pictures would be great too. I just ordered my FD UIM & TB w/ TPS sensor and im talking to a member on here about the spacer he makes to make this all work. I guess my next question is do it myself or use the spacer already made ? :scratch:

wait a second! i know who you are! you work at R/T tuning right?

No ... But i know Vince and Pat (who you thought i was) very well ... known them since they started and pat for years before that. You from the area ?

yeah, i bring my car there all the time

no shit ... what car is yours i might have seen it ... well most likely anyways

adapter would definitely be the easiest route. Also, afterwards you would be able to sell the LIM / UIM's as stock if you decide to go back. But if RX-Heaven says that he noticed a difference in power (to the extent of 15-20 hp) by filling and porting properly, I would do it that way time/skill depending.

can yhou tell me where you found the adapter? i am looking for one