panchosouth

Am I mistaken, or has someone here on RL developed a VS system to retrofit the S 4?
Thanks
Frank

John Speake

Depends what you mean by Velocity Stack - this is one form:
http://s287999742.e-shop.info/shop/p...Rc&shop_param=

Ducman82

Simard has a Individual Throttle body kit.
http://www.simardracing.com/InductionSystems.html

WallyP

Of course, the standard S4 intake has velocity stacks...

panchosouth

Guys-

Thanks for the feedback and putting up with questions. Yes, the ITB is what I'm speaking of. I love this look, and want to incorperate it with my 87.
Is there a work around to the airbox? This is far to beautiful to have it tucked under a box-
I want to produce about 400+HP from the upcoming rebuild, a ground up re-build, but I don't want a race set-up. Feel free to chime in.
Thanks
Frank

Mike Simard

The airbox is a dilema. I'm on my third design now. That's because I want the best power and good overall design for the real world.
The first box was aluminum and I had an alternate Lexan lid for that one. Since the throttles are at the head ports, the box doesn't see full vacuum and this is practical.

The second design was carbon fiber and I also started making the trumpets out of CF too. The flat snout goes to a giant oval filter inside the bumper.

For the 3rd design I'm moving away from front inlets and have modeled a CF box that is a little wider and has a lid. The lid is a formed CF part but I suppose you could use clear Lexan for it. I'm waiting for the first new design boxes to come in, any day now....

Your 400hp target is very practical and easy to obtain with good driveability. The ITBs transform and engine in more ways than you would think. Intake charge reversion is no longer an issue so you can run bigger cams with no awkward street manners but still get the big power. I also make cams.

The first ITB conversion I did (Ford V8) amazed me with very noticable improvements at all ranges and no downsides at all. The ones I make for the 928 are not common units bolted to an adapter but designed from a clean sheet for a 928 and have had substantial design effort put into them.

Who's building your engine?

Hilton

Seriously, before you change the intake setup completely, there are better places to modify for more power (I'll exclude suspension/brakes/wheels for now).

In order of increasing cost:

Making sure the car is running like factory (no broken sensors, ECU faults logged etc.)
Exhaust (normal X-pipe, up to headers with a custom X)
Cams (either modified S3 cams, or something custom)
Boost
More "cubic inches" (Stroker, bigger bore, custom pistons, or combination of them)

Changing to an ITB setup will be expensive - between the parts, custom fitting, and then designing and making the manifold to sit on top. Expensive enough that its only really worth it once the stock intake is struggling to keep up with the airflow needs of the engine (which IIRC seems to be around 450rwhp).

edit: Mike's stuff is very droolworthy. On second thought, get the intake now, on an otherwise stock S4.. then take it to a couple of reputable dyno shops after sharktuning.. the community desires that data greatly

John Speake

You would have to arrange some kind of cold, filtered air feed to the bellmouths. The picture in my avatar was taken at a very early stage of tuning the race car. It has MAF screens over each bellmouth but of course that is not adequate, except for stopping large objects dropping into the ports...

The racer has now an airbox with filter incorporated in the lid, with a forward facing scoop on the hood.

This picture shows the airbox, the hood is resting on the roof of the car, you can see the scoop.

Mike Simard produces an ITB kit, and Louie Ott still has a system available based on the ITW ITB's. The other option is Jenvey ITBs for which I sell adaptors to ther heads. With any of these you can use the stock LH and EZK ECUs, with the SharkTuner-Alpha system recently announced here in Rennlist and demonstrated at SITM

You may be able to work out a system that puts the "velocity sstack" more on display - maybe some form of high temperature clear plastic for the airbox ?

Mike Simard

There's also no reason you can't cut a big hole in the hood.

I've thought of doing that and then making a formed clear llid that protrudes outside of the hood slightly. I've been on the verge of doing that for some time but it's been a big enough job to get a basic box to base that mod on.

John Speake

There is already a project underway to put ITBs on a 5litre GT with ST-Alpha...

panchosouth

I was chewing over the hood idea....like a functional shaker hood set up...but more a la Maranello 550....something subtle but mechanically sound. Who would be able to handle modifying a hood like that?
Engine work- Haven’t decided on that as of yet (who/what) so open to suggestions. I figure a budget of 8-10K should get it done…optimistic? I would like the engine bay to be spit and polish, even if I can’t see it, it gives me the warm fuzzy knowing everything is well sorted and nice and shiny. That being said, I want something I can drive hard and fast and not worry about spending hours re-detailing it. Shiny and durable.
Cams, suspension et al. I would like end up with a capable (as in honking fast) driving beasty, but also one that I can strap on and drive cross country and not step out feeling like I was in a cement mixer. Nor do I want people cringing as I drive by, yet still want to enjoy the melodic pleasure of a bunch of angry ponies.
I suppose while the engine is out, and I have sent the interior off to be re-done (lobster red is feeling pretty funky right now) I should have the gear box sorted. At what point does HP start making an issue for the factory specs?

rad_951

Would the short intake runners of the ITB kill low end torque on a 5.0L motor? Is anyone running a 5.0L motor with the ITB?
Thanks.

OBehave

On the Hanson car I decided to go the cowl induction route with factory air filter and clear plastic cover.Of course I don't need the heater box etc. so it's not really applicable to a street car.

Ducman82

i would love this set up for a 16v....

panchosouth

Mike, forgot to mention that your CF set-up looks chub-o-rific. Engine art!
I have a picture somewhere of a ITB set-up with individual foam covers and a screen for each ITB...it is a race set-up so not sure if it is street suitable....? Way past my skill set with this stuff so if the questions appear ...non-educated please forgive....