Supercharging

[XLR8928]

I am somewhat intrigued by the prospect of supercharging my warmed over 4.7us. Has anyone experimented with fabbing up a system, utilizing a used Vortex, Paxton etc.? I know there are pre- engineered systems out there, but the cost is very significant.
-K

[harborman]

There are some charging kits out there for the 928. I saw one here a guy had on a 87, looked real clean install. How much you gain and the worth of it all is the question. I question the resale value when done. The 928 is pretty fast as is unless you intend to go over 150 MPH for extended times on your local roads. It is not a drag car.

[soltino]

Originally Posted by XLR8928

I am somewhat intrigued by the prospect of supercharging my warmed over 4.7us. Has anyone experimented with fabbing up a system, utilizing a used Vortex, Paxton etc.? I know there are pre- engineered systems out there, but the cost is very significant.
-K

Try Advanced Seach with Keyword Turbo or Turbocharged in Titles to start.

Then go to the other Group and repeat and rinse.

tino

[19psi]

Two recent install threads on the other forum. I may eventually install a kit on my '82. For how nice the kits are and everything involved, I'm guessing the kit would be far cheaper by the time you factor in things like parts that didn't quite work out, custom machining and trial and error.

[Danglerb]

I've been looking at turbo or super charging fairly seriously since I bought my old Mustang in 91, and its in many ways comparable to the US 4.7 928. Base motor is about 220 hp at the crank, options for heads and cams bump it to 280 to 300 hp, so do basic boost systems around 6 psi. Cost was also in the same ballpark of $3k to $5k plus install labor which I intended to do myself.

Trouble is, 300 crank hp gets you to the gate of the fun zone, not on any of the good rides. You need one more step of power adder, HCI and boost, more cubes, more boost, and quickly the US 4.7 becomes a poor base block choice.

My choice is the Euro hybrid on a bored block with 104mm pistons and hotter cam grind. I think the combo should hit a sweet spot of around 325 rwhp.

Part of my consideration though is Calif smog, in NV boost might be more practical, but I would not be using a US 4.7 block, and I would not be trying to manage boost with a Ljet brain, and that is not a small factor to change. I would be starting with an S4, more cubes, way better heads and intake, and brain with knock sensors and sharktuning ability.

[Danglerb]

BTW fabbing up something cheap with about 6 psi of boost would not be a major project, getting it to work well might take some time, but technically it should work well enough for you to know what is ahead and want it even more.

[harborman]

I just don't think modifying the 928 for more Hp is worth even considering. Why? It's an old car! If you want all go get it power go by a new Corvette, lots of HP for the money, already, ready to go, tested and you can be one of a million owning such a car. Go buy a new Ferrari, maybe 1,000 HP! What the Hell are you going to do with it?? Kill yourself? Keep the 928 stock as possible and enjoy it for what it was, a really advanced car in it's time!

[XLR8928]

Originally Posted by Danglerb

I've been looking at turbo or super charging fairly seriously since I bought my old Mustang in 91, and its in many ways comparable to the US 4.7 928. Base motor is about 220 hp at the crank, options for heads and cams bump it to 280 to 300 hp, so do basic boost systems around 6 psi. Cost was also in the same ballpark of $3k to $5k plus install labor which I intended to do myself.

Trouble is, 300 crank hp gets you to the gate of the fun zone, not on any of the good rides. You need one more step of power adder, HCI and boost, more cubes, more boost, and quickly the US 4.7 becomes a poor base block choice.

My choice is the Euro hybrid on a bored block with 104mm pistons and hotter cam grind. I think the combo should hit a sweet spot of around 325 rwhp.

Part of my consideration though is Calif smog, in NV boost might be more practical, but I would not be using a US 4.7 block, and I would not be trying to manage boost with a Ljet brain, and that is not a small factor to change. I would be starting with an S4, more cubes, way better heads and intake, and brain with knock sensors and sharktuning ability.

I guess I'm back to my original plan...Get an S4!

[Danglerb]

Originally Posted by XLR8928

I guess I'm back to my original plan...Get an S4!

Solves a lot of issues, and huge torque makes weight not so much an issue.

OTOH for a street car, I think around 450 rwhp I would be looking at something built to give straight line traction.

[SeanR]

Originally Posted by harborman

I just don't think modifying the 928 for more Hp is worth even considering. Why? It's an old car! If you want all go get it power go by a new Corvette, lots of HP for the money, already, ready to go, tested and you can be one of a million owning such a car. Go buy a new Ferrari, maybe 1,000 HP! What the Hell are you going to do with it?? Kill yourself? Keep the 928 stock as possible and enjoy it for what it was, a really advanced car in it's time!

Or you could be one of only a handful of people in the world with a supercharged 928 that will keep up with modern supercars. Do you still wear bell bottoms? Most of us don't like living in the 1970's anymore.

[XLR8928]

Originally Posted by SeanR

Or you could be one of only a handful of people in the world with a supercharged 928 that will keep up with modern supercars. Do you still wear bell bottoms? Most of us don't like living in the 1970's anymore.

Well, my car already has been modified: 4.7L motor, 3 angle valve job, minor cleanup porting, euro cams, MSDS headers with custom 3" exhaust system, I fabbed up. But.... an extra 100hp would be awesome!
BTW- I own a 280zx turbo, and the boost rush is big fun.

[harborman]

Originally Posted by SeanR

Or you could be one of only a handful of people in the world with a supercharged 928 that will keep up with modern supercars. Do you still wear bell bottoms? Most of us don't like living in the 1970's anymore.

The 70's were in many respects better than today! I guess you like a 70's car though! I wish I had kept all the ones I owned, Bell Bottoms too!No, I don't need to be one of a hand full of supercharged 928 owners either. I owned a car with upwards of 550 HP back in 67!

[Hold On]

I happen to have a 928MS stage one supercharger kit in a box in my garage. sell for half price at $3200. Came off my 4.7L 1983 Have 6psi and 9psi pulleys, boost guage and Provent 200 system included. Kevin