mark kibort

I was thinking more along the lines of just adapting the intake to the heads and loose the ITBs. just put the MAF out in front of it all.
we have already seen how well andersons intake runs (and Joe fans, when they are not leaking air or crack)..... so why not stay with something dirt simple that is fairly easy to tune and get the big gains too??

John Speake

If you use the Sharktuner Alpha-N you don't need to worry about a MAF...

IcemanG17

Is your stroker 16V or 32V? If it is a 32V then I would just get the intake from Doc Brown...it performed great on a mild stroker in Dr Rob's street stroker.....

Ducman82

^^^ pic?

terry gt

32V , pics I am having trouble loading from my I phone the docs seem too big . If I get some time I will list the details of the motor . But it is a scat crank / 968 piston style motor .

Strosek Ultra

The IDA style twin throttle bodies have a C-C of 120mm very close to the 928 cylinder C-C of 122mm. IDA style twin bodies can be had from several suppliers like Jenvey, At Power, Extrudabody, Borla Induction, Kinsler. AT Power has the most advanced shaftless design having up to 7% improved air flow. Manufacturing runners between throttle bodies and cylinder head is not a big deal. Whoever who is a bit handy can do it.
http://www.jenvey.co.uk/home/twin-th...dies-ida-style
http://atpowerthrottles.com/catalog/...ion-p-181.html
http://www.extrudabody.com/servlet/t...m-Taper/Detail
http://www.borlainduction.com/other-...body-kits.html
http://www.kinsler.com/Kinsler-Handbook/HTML/#48

hans14914

I could whip up a S4-to-IDA adapter in a couple minutes. I already have all the data here from my lower manifold development. It would be easy to design, but machining costs would be high for a single set. That is one reason the lower manifolds I designed don't exist yet, not enough demand to justify production.

If someone wanted a set of these, its something I could do if they wanted to pay for the first set.

123quattro

It's not nearly that simple. 928s have weird port locations compared to modern V8s. The ports face straight up vs a 45* angle on new engines. To make a modern intake manifold fit you would want to mill off the cylinder head ports and weld on flanges at a different angle. It's a ton of work. That, and the bore spacing is pretty wide so you really need a big block sized intake manifold. However, there are new good factory efi/ITB big block manifolds.

GregBBRD

Whatever one does, it is not simple.

The ITB pieces that I've used are not simple to install and get working. It especially gets crowded and complex if one is trying to address the oiling issues and breather issues that these engines are known for. Add in an aftermarket injection that has to be programed and has a "learning curve"....and you can be fussing around for many months....if not years.

My goals are pretty simple. Give people an alternative to stock, which bolts on and uses most of the stock injection system (sans air flow meter). Turns out that this is not all that simple....for a tiny shop that has to also pay the bills on a day to day basis. The time investment for development is very dramatic, moving from a prototype to a working "customer purchasable unit" is difficult, and any the "pay back" in this tiny market is virtually a dream.

After my last "time investment " in finishing my test manifold and then bolting it onto two separate engines (with tremendous results), for testing, my patient wife said, "Well, that might be fun and you might be learning tons....but could you stop and go back to work, for awhile, so I can pay our bills?"

As much as we complain about the stock intake system, it is a very compact, well engineered chunk of magnesium that does what it was intended to do, very nicely.

And when push comes to shove, most of the "race engines" out there are not limited by the intake system, but are limited by durability. It really doesn't matter if the engine makes 400, 550, or 750 horsepower, if it only runs for a very short period of time. The errors in part selection and in assembling these engines "kill" the large majority of these engines, long before the ignition system is energized, for the first time.

hans14914

Greg is absolutely correct. The rest of the ITB system is a pain, expecially getting the vacuum plumbing, throttle sync, opening rates (ramp angles very finicky on the throttle cam to get a good street drivable setup). ST-Alpha would help, but it would still be a large learning curve over the standard ST2 methodology. ITB would be the last thing I would personally want for a street car.

The GB style manifold, something like the current Cayenne model, with a single properly sized throttle, and runner length tuned for the intended application (cam and driving style) is going to be the best option... but that would also mean you would need to have a version for strokers, track driving, street driving, big cams, stock cams... list is infinite. That is why I really would like to get a modular intake structure started with a "universal" lower block that could be used for most (not all) applications.

I am considering launching the "928 Lower Intake" project for crowdfunding on Indiegogo next week, with a fixed funding goal for the castings. If it gets funded, anyone would have access to lowers for whatever design they envision at a reasonable price. If not, no one loses any more money on the project (no pledges actually charged) and we know the concept was a non-starter to begin with. I am still mulling it over. Its a lot of work, and I just dont see the interest to support it.

As GB says, the stock intake isnt that bad. It could be a lot worse.

GregBBRD

Truthfully, the lower intake stubs were the easy part and took the least amount of time....even though I made mine from billet pieces.....and they took quite a few hours to fabricate.

The difficulty level went up, like a space shuttle, after that.

I'm a pretty "handy guy" around visualizing, drawing, machining, and fabrication and I literally "ran out of talent" on the center plenum and intake manifolds.

My "box-o-scrap" pieces for this project is pretty full.

Because of this, I can see 99% of these stubs sitting on people's shelves until the cows come home....

mark kibort

too bad you just cant send the original finished product to china to have it made out of plastic and masss produced for the 10 guys that really want it.

dr bob

Fixed that for ya...


There is no single perfect solution for every car, driver, and driving style. Greg will build one for you, for your engine, for your duty. No 'mass produced' here at all, since yours is a unique situation. Need one with or without provision for driving in fifth gear? Just make a note of that on your build request.

Or maybe you could adapt an intake from a big AMG V8. Taper some gaskets, a few offset bolts, and you should be good to go!

GregBBRD

In my youth, I had a VW engine with 48's on it....nothing can duplicate the sound of those things sucking air and fuel.

Imagine the sound from a big hot rod 928 engine sucking through four of those things. What a symphony that would be!

andy-gts

Greg
uh!! no more ITB like the set you did for me!!! It runs and drives great and I thought after mine, others would want to jump for it…..it only took a couple tuning sessions and with your help it is a good daily driver and a monster with my foot to the floor….

happy as could be!!!

I just thought you made kits like all the pieces you crafted together for mine….I will send the car back if you would like if there are any pieces you would need to copy….just say the word!


andy