4x4dually

Well, figures. You know, I have always wanted to invent something and then retire. I though of something totally on my own several years ago. I thought, "man, I could put a GCFI on the end of an extension cord for outdoor use and I'd make millions." Two weeks later, I saw them on TV. I was bumbed. I'm always a few years behind of having brilliant ideas!

So, anyone experiment with "jet assist" on these trucks?

<edit> Never mind. Ol' sig600, MR. OHIO just ruined my idea! Thanks man. You must have posted while I typed my reply.

What about one of those tire seating tanks! That aught to light something off! Maybe the intercooler out the grill!

signature600

Maybe RustyJC can tell you how those systems work...but I think fr the cost vs. benefit, nitrous is cheaper

But I like the way you think! Especially that tire seating tank idea
Chris

RustyJC

Actually, it could work quite well. The secret is that the jet assist nozzles mounted in the turbocharger's compressor housing have orifices in them and have their discharge aimed tangentially to the OD of the compressor impeller. This produces high velocity jets of air that impinge on the tips of the impeller blades - the velocity energy of the air is used to spin up the impeller, and the impeller then provides the additional mass flow for the engine. In other words, the high pressure compressed air is not used to satisfy the mass flow requirements of the engine, but rather to drive the turbocharger.

Rusty

signature600

Yes but how big is the air compressor used to handle this task? Also, at what pressure is the juet operating at?

Chris

4x4dually

By God, now we are getting somewhere!

I too am still laughing about the tire seater tank! Does anyone sell 3/4" head bolts and neoprene gaskets?

RustyJC

Doesn't matter since the air is being drawn from the starting air receiver (a volume tank). The air compressor just recharges the receiver between startups/jet assists, so the compressor size just determines recharge times.
250 PSIG max for air-in-head starting; 175 PSIG max for air motor starting.

Rusty

signature600

So how big of tank would we need to mount to make this work...also, 175psi is getting up there for electri compressors, 250psi is really high.

The bottom line of all these questions is to figure out if this is even possible on the Pickup? Like I said before, I don't think the benefits will outweigh the cost on a HiPo application!

Chris

RustyJC

If you think of the following illustration, the principle is very simple.

Take your shop air compressor out in the garage and fit a "blower" (parts drying, etc.) nozzle to the air hose. Now, take a child's pinwheel toy, aim the air nozzle discharge tangentially at the tip of the pinwheel and watch it spin up. That's exactly how jet assist works.

Oh, and I'm not selling a product. I'm just saying the concept of jet assist is proven and has worked for decades.

Rusty

signature600

I understand the concept...but I fail to see how well it would/can work on a pickup truck application.

Personally, I have a 5 gal air tank on my truck, at 125psi. I can't imagine this tank would be able to run in this manner for more than 1-2 minutes. Add to that a compressor wheel turning at, lets say 75K RPM, and we blow air acrross the BACKSIDE of the fins at 125psi max, diminishing the longer it runs. I can't image this setup making enough extra "boost" to help with engine airflow...not too mention the fact that it will be hard to build and implement/control!

Maybe our shop air compressors at 175psi with 300 gallons of reserve tanks could do it, but anything small enough to be mounted on a truck...I just can't see it.

Maybe I'll do some testing on a charger I have here at the shop
Chris

RustyJC

Actually, I see the following applications for this concept:

1. Building boost while sitting at the staging/starting line at a drag race or truck pull.

2. Assisting in spinning up the turbo under hard acceleration conditions from low boost.

In either case, we're talking about times of a few seconds - maximum. Not much volume is required for these applications.

Control is really pretty simple - an arming switch and a pressure switch to engage/disengage an electric solenoid valve. You could set the pressure switch to disengage at, say, 15 PSIG rising and re-engage at 12 PSIG falling boost pressure.

Rusty

big shifter

the bottom line is its not gonna be fast or drive nice tell you get twins

4x4dually

Gotcha...send me 4 grand and I'll quit thinking about ways around it!