Will a manifoil form a FD fit on a FC, without any major modifying?

I am thinking of the fitment on the engine.

I know there will be som things i need to think about, but I have all the other stuff sorted out, But dont want to take the manifoil og my FD to see if it fits the FC.

 

not an expert on this, but have searched because i have wanted to do it myself.
came to these answers...

you need to port-match the manifolds, usually done with an adapter plate.
you need the FD throttlebody
you need the FD compression tube
you need the FD TPS sensor
if you have the stock TMIC, you need custom inlet piping from IC to TB

and for what?
looks and slightly better flow...

IMO: not really worth it

 

I have PFC installed in the car, so using the FD tps will only benefite the use of PFC.
I also got FMIC, so piping aint any problem.

My only worry is how a FD manifoil fits on a turbo 2 engine.

Need new secondary fuel anyway, so changing it, I only need to buy a FD secondary fuel rail, insted of a FC fuel rail.

 

you can only use the FD upper manifold from what i've read, then you need to port match the lower TII and upper FD manifold...

 

or get a pre-made spacer/adapter.

 

I have done it.

You need a S5 ('89-91) Turbo lower intake manifold (LIM) as the bolt pattern is close to the 3rd gen upper intake manifold (UIM).

You will need to weld some material onto the 3rd gen UIM between the primary runners as once you port match the UIM to the LIM there is not much flange left there to seal.

Mill the UIM mounting holes to match the LIM studs. IF you do this now it will help line up the gasket as you port match.

Use the S5 gasket and trim it to the 3rd gen UIM primaries. Mark the UIM areas that need to be ported.

Put trimmed gasket onto the LIM and mark what needs to be ported on the LIM.

Port LIM and UIM removing only as much material as needed.

I had to trim a bit off my UIM to fit the aftermarket TII fuel rail for 1600cc inj there.

If your car is S4 you will need to make an adapter for the mechanical OMP.

You will have to shorten the part of the oil filler tube that goes into the center side housing so the oil filler clears.

 

too much bullshit for not enough power-per-dollar/time, FD TPS is not necessary with the PFC either.

 

Looks like a peak of over 20 ft/lbs of torque and about 20 RWHP gain in a broad region between 4,500rpm and 6,500rpm and a smaller ~9 ft/lb and RWHP peak bump between 3,800rpm and 4,500rpm while only losing ~2ft/lb and HP in three very short sections below 3,500rpm on a ~360RWHP 13B.....

Read this back to back dyno thread-
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/conclusive-b2b-dyno-tests-fd-uim-fc-uim-655708/

Probably not from better flow, but from increased dynamic affect supercharging. See how the increase at lower rpm is mirrored in the higher rpm at twice the rpm. That is because of the pressure wave reflection.

 

No.


-Ted

 

god i love it how you always answer with less the 3 words

 

LOL- for some people just washing their car is just too much work.

 

i did it also, takes about 2 hours total time. plenty worth it for 20ft lbs. and 20whp.

 

any pics? ^^

 

my avatar is small, but you can see it there...

 

MINE



Here are the two holes to be milled

 

man thats so nice. can i see more of that plate that separates all the relays and whatnot from the engine? thats a great idea. sorry to jack teh thread though.

 

I'd like to see proof?
Someone did a before-n-after dyno run, and there wasn't really that much of a power difference.
I dunno what your set-up is, but I suspect everything was retuned in between?
The FD set-up did make earlier power, but the FC turbo 13BT set-up made more power later in the RPM band.


-Ted

 

Ted, in that back to back dyno thread (the one I linked) the pink line that makes more power later in the power band was his old turbo set up from a year ago.

The red line was his current set up w/ FC manifold.

The black line was his current set up w/ the FD manifold on it. If you look at the scale it really is like over 20ft/lbs more torque and almost 20hp more.

 

 

https://www.rx7club.com/showthread.php?t=655708


-Ted

 

the red and pink are hard to tell apart, but it clearly shows 20+ torque and WHP in the dyno graph. i havnt done a comparison on mine though.

but if you just think about it, the FD manifold is far greater. have you ever seen the TII UIM cut in half? horible design compared to the FD one. and the FD TB is larger and also better designed. i have never had either on a flow bench. i wish someone would since dyno graphs still are not enough to put this to rest.

i remember seeing something a few years back when this swap was getting popular, and it was something like a 50% flow increase. but since i have no proof of it right now, this statement is useless...

 

i would do it. i believe it is greater, it has to be, its from a fd come on now...
Who makes premade spacers to fit the LIM to the fds UIM?

 

Are you talking about this graph?



Reread the thread description.
You're supposed to be looking at the BLACK versus RED lines.
No wonder everyone is confused.


-Ted

 

I'm glad we're all on the same page

 

And? The FD uim has significantly more area under the curve, to the tune of about 20+ ft lbs. You're a very well regarded and skilled FC tuner but I think its time to get your head out of your ***.