DuncanR50

Has anyone ever put an S4 Intake manifold on a 85 or 86 928S?

linderpat

I have had this question too. Seems that a remap of the fuel delivery system would be required.

Rick Carter

It's been done, AFAIK no one has ever done a dyno comparison.

Fabio421

It's been done by a few people. Abby is one that comes to mind. As far as I know there hasn't been a side by side dyno done by anyone. Abby's engine isn't stock so even if you got dyno #'s from him they really wouldn't tell you anything. Marcus in CA also did it a long time ago. http://www.marcus3.com/engine1/engine1.html

Rick Carter

I think Marcus did to fit his SC more easily.

Fabio421

I think Abby may have done it to fit the turbo plumbing more easily.

DuncanR50

I was interested more by how open it is with the S4 intake. The engine is less hidden. Looking at PET seems the throttle body is different. Probably more trouble than it's worth.

JHowell37

The level of difficulty is dependent on finding an intact donor to take parts from. This is where you'd get your throttle linkages, throttle body, and all the various pieces to make it all work. I would be curious to see if there's a way to make the flappy work without having to make a lot of changes to the '85/'86 wiring.

Landseer

Discussions here that I've read over the years seemed to conclude, at least strongly speculate, that the organ pipe set up was superior to S4 from airflow / harmonic perspectives.

Tom in Austin

Since you mention it ... why did Porsche only stick with the 'organ pipe' solution for two years? They must have invested a lot of money in developing it and then built what, less than a thousand engines?

Never heard of it having any flaws, but just not like Porsche to make such a significant change so soon. I suppose you could ask the same question about the S4 engine, what motivated such an extensive redesign after only two model years?

mark kibort

Yeah, I heard the same thing that the 85 intakes are superior, but maybe not in the max torque, or the broadness of the max torque area, due to the resonance flap. However, no one has any dynos!

DuncanR50

So the money is better spent on a chip and X pipe.

coast928

From reading on this forum & others, a Porken chip and X-pipe, especially for the '85-'86.5 cars, seems to be a really good, tried and true combination. Check out these threads to see for yourself:

https://rennlist.com/forums/928-foru...ezfr-chip.html

https://rennlist.com/forums/928-foru...by-porken.html

https://rennlist.com/forums/928-foru...s-awesome.html

https://rennlist.com/forums/928-foru...-benefits.html

zoltan944

the power difference in the S3 and S4 isn't the intake its the timing values based on vacuum. on the S4 they added 2 knock sensors to listen and adjust for all 8 cyl so they took the pretty consertative values of the S3 and upped them on the S4. the power is basically matched with a chip although there are torque differnces with the flappy and S4 intake and the organ pipes.

a chip and x-pipe are way better than any intake swap and 8 points easier on the labor.

People who are swapping intakes are because:
-all parts and wiring necessary to want to use the S4 stuff
-need the room for modding.
in fact i believe there may be people going with S3 intakes on S4 motors who went to aftermarket electronics and want the simpler setup?

DuncanR50

The original thought was to get rid of that mess filling up the engine compartment. I don't like the look as much as the S4 or early spider.