What will work with the Eaton M90
 

The great debate in the world of the GM cars with the 3.8 supercharged engines.
Some say spray the mix using an adaptor plate between the SC and the intake manifold.
Others say go ahead and spray before the throttle body and the SC.
Which is ok to do?
Is one risky?

I am installing a single stage on my 2000 Regal before the blower. Will it cause problems?

I am about 300 HP and 360 Tq.
Thanks for any input.
-Carl

Anyone?.....Anyone?

Well I installed the alky kit and spray before the TB and it sprays directly on my MAF sensor. While it has reduced KR, I have designed a spacer for between the SC and the engine. A friend of mine is going to CNC it at his machine shop.

Any comments or suggestions are welcome.

-Carl

too busy
 

Sorry was going to reply to this earlier, but work has kept me hopping.

For what its, worth the fuel dragsters injected fuel ahead of the blower for years. It was done to cool the blower, and the thin film of fluid on the walls of the supercharger and rotors, helps improve rotor seal.

If you have no intercooler I would suggest ahead of the blower.

Larry

Larry that makes sense and I have heard it seals the rotors. But What do you think about the theory that all the heat created is after the blower?
The compression of the air is the cooker.

I was wondering if by spraying after the rotors it would be more benificial for air cooling? But as was also concerned that the waterwon't be fully atomized at this spray point.

And hey if top fuel does it then its good enough for my regal :lol:

From what you have said so far I may not make up the plate, but I might move the nozzle a hair farther from the throttle body.

Thanks again for your input.
-Carl

Its mass flow
 

Well the answer to your question depends on what your goal is.

If you trying to control mixture temps, post blower might work slightly better than pre-blower but I doubt the difference would be much.

If your trying to increase the total air flow to the engine without going to an higher overdrive ratio -- the only way to do that is pre-blower injection.

A blower (roots/eaton type) is a positive displacement pump. For each revolution it will move x amount of air. The only way to increase that flow is to spin the blower faster or increase the air density at the inlet. If you cool the inlet air temp the blower will actually act like a slightly larger blower, for each revolution it will move x+y air. The Y depending on how much cooler the intake charge is. If you want to get technical there is also a -z term for the air that leaks back through the blower seals, and pre-blower injection reduces that loss due to leakage.

If you are running the blower at a given rpm, no matter how much post blower cooling takes place, you will still flow only the air the pump can move each revolution. At some point extra cooling post blower only serves to increase charge density by cooling but also drops the boost pressure because its dealing with a fixed flow, based on the rpm of the blower rotors.

IF your detonation limited, cool after the blower, if your flow limited, cool/spray ahead of the blower (or both).

Larry

Injecting before the blower will require a bit more water due to extra cooling needed for your supercharger.

If high consumption is not a problem, go if pre-, hotrod has given you a choice of the two, if you are not sure, do both.

Thanks guys. My plan is to kill detonation/KR. I have plenty more smaller pulley choices to get more boost and airflow.

Looks like for now I am running it before the SC, and this spring I will spray after the SC.

I was almost thinking dual stage and spraying both to get all the benefits.
That would be an experiment.

Thanks again.

I have WI just after the throttle body and just after my M90 supercharger on my car and it works very well. I've got a small yellow jet before the supercharger and a bigger blue jet afterwards. My car is a Ford Sierra, similar to the american XR4Ti but with a V6 engine and 4 wheel drive, with a bored out 2.9l engine (now 3.7l). Take a look at http://www.xr4register.com/profiledavidward.php and click on the supercharger pictures at the bottom of the page.

Dave

Nice setup Dave!
That would be nice to do, but the problem is my M90 is planted directly on top of the engine:
http://www.grandprix.net/multimedia/treals8.jpg

Thanks for the kind words.

I can now see your problem. Does your eaton have a bypass valve fitted to recirclate the air back aroubd the supercharger when the throttle is closed, like the later MK5 eaton chargers do?