Rob Edwards

I knew that titling a thread 'aural sex' would be helpful to find it in the future.

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

And the lead-in thread:

https://rennlist.com/forums/928-foru...me-time-2.html

GregBBRD

I quit worrying about dollars, years ago.

The most important thing, for me. is the designing and testing....making improvements.

After I'm happy, I move on to something else. Whatever just got developed gets used in house, of course. As I mentioned above, some pieces are sold to the public, but a lot of pieces never leave here on anything but my own client's cars.

ptuomov

I think that the S4 engine intake and exhaust are reasonably well balanced for the intended purpose from the factory.

To get more normally aspirated power from it with the stock 5.0L bottom end, I think that the main thing to keep in mind is that the stock bottom end doesn’t really want to run well much above the stock redline. If you’re living under 7000 rpms, long tube small diameter headers, higher compression, 16 inch total intake tract length, small and straight intake runners, and (reasonably high overlap, aggressive acceleration and velocity, relatively short duration) cams would probably be the way to go. I’m mostly thinking forced induction, so this is just the hypothetical direction I’d go with a normally aspirated engine.

GregBBRD

Thanks Rob!

I don't see why a GT wouldn't respond just as well.

The Forgotten On

End game for me would be converting my 89 to Miller cycle combustion. But that is a subject for a different time.

I saw a thread years ago where the areas and cavities behind and around the bellmouths in the stock S4 intake were filled with epoxy and netted a 20 HP gain (Dyno tested) IIRC with around $20 in materials.

I'm probably going to do this to the spare S4 manifold I have lying around and see how much it wakes up my stock 200K mile bottom end.

hacker-pschorr

https://rennlist.com/forums/928-foru...o-results.html

merchauser

I would be very interested in "exactly" how and what is done regarding this mod

Erik: have read this post a few times and still don't know "exactly" how and what
was done

https://rennlist.com/forums/928-foru...o-results.html

Carl Fausett

This is the direction I am heading. We are just taking steps towards it - the manifold we just made is our 3rd intake manifold for the 928 (one for 16v, two now for 32v) and we like the results.

The next iteration of this intake will fit under the hood of a 928, and I will test it on a stock 5.0L 928 motor. We now know that a stroked 6.4L 928 is really choked off by the installation of a stock 5.0L intake manifold (154 HP); but what I do NOT know is what the gains might be on a stock 5.0L motor.

We are going to find out.

The end-game for us is an affordable bolt-on aftermarket manifold for the 1987-1995 928. That's what our goal is.

Mongo

For the love of God, one request for these new custom intakes:

Can we please not put the ISV under the manifold?

ptuomov

Another one would be that if possible, make them compatible with the stock MAF housing in its stock location. I understand one could go Sharktuner alpha-N or aftermarket ECU, but the option to retain the stock MAF will expand the market quite a bit and make the whole project more likely to materialize.

Mongo

If keeping the stock system, one can also roll their own chips to tune the changes. Maybe Ken can educate some of us on how to do that.

Carl Fausett

Andy, the IAC was mounted on the throttle body of the brand/and model we purchased, so that moved it out from under neath to the rear.
On the other hand, once wired, the IAC is a never-touch item and has no hoses to or from it like the original does. No service necessary..

Also: if you are installing an after-market engine management at the same time, you may have no need for the IAC at all.
They are no longer needed.

Mongo

Good to know. However, most of us don't want to go aftermarket EFI.

Ex - I live in CA, <The Butt Hole of the USA>. Stock S4 with an S300 EZK chip and x-pipe. If I want to add your intake and take it off every 2 years for smog, I will. However, are you going to offer tuning PROMs with the intake for stock applications? Both EZK and LH chips?

BauerR

Ross Machine Racing is currently manufacturing a full billet manifold as well as a throttle body adapter for stock manifolds to run a Mustang 90mm TB.
I will keep everyone posted.

ptuomov

Interesting. Tell us more about the TB adapter to the stock intake manifold. Will it replicate the zip-tube tuning system?