Eaton M90 Supercharger power query...

Squig

Registered User
Hi people, first time posting in this forum...

Have a question for you, I recently purchased an Eaton M90 from a pontiac 3.8 v6 (not sure of model, I'm in england and not really familar with your cars) with the intention of bolting it to a small block vauxhall/opel/chevrolet GM 3.0 liter 24v v6 injection engine with a 30 degree V... Now with the pulley setup I'm using I get;
1000rpm = 1560rpm
2000rpm = 3120rpm
3000rpm = 4680rpm
4000rpm = 6240rpm
5000rpm = 7800rpm
6000rpm = 9360rpm
7000rpm = 10920rpm
The engine RPM is the first figure and the supercharger RPM is the second...
The GM 3 liter v6 makes 204bhp as stock and I was wondering, with forged pistons, APR head and rod bolts (plus some to hold the supercharger in place), possibly some forged rods, lightened flywheel and standalone engine management combined, with the Eaton M90 what I could expect the v6 to make?
This is going into a car that is a total weight of 1140kg (2513lbs or 1.14 metric tonnes).

Can anyone help me?
oh and how far could I push the supercharger before the RPM's become to high to function correctly, or it and car go seperate ways... via the hood?
 
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Well to give you a comparison the 3.8 made a listed 140Hp (104kW) and the SC made 225Hp (168kW).

Now if you can mount the M90 I'd expect (all other things equal) about 100hp gain. Though the 3.8 is a 90* so you may or may not get it to mount cost effectivly.
 
I think a good start would be to pulley it for about 14-15000rpm. That should get you about 9-13psi depending on engine VE and is about the maximum for a non-intercooled application. If you go intercooled you could up the blower rpm to about 17-18000rpm.
 
Here is link for M90 flow numbers.. http://www.automotive.eaton.com/product/engine_controls/superchargers/M90.asp I don't know for sure but how about looking how much you want to make power -> how many cfm that needs -> M90 rpm's at that flow -> pulley size based on that rpm?
I think you need to add power that m90 takes on top of power you want, start with some estimation, say: 300hp+40hp for M90 = 340 hp -> 510-544cfm -> 12000-13000 rpm (for gen3 M90?) I'm sure it is more complex than that but it s a start :)
 
For comparison's sake, you should look in to the GTP forums, as you said the SC was from a pontiac. As an owner of a GTP and an SC, they aren't really that similar. FYI, a stock l67(GTP motor) makes 240hp and 280tq.
 
If I'm to be brutally honest, I know nothing about superchargers except for the very basics... I'm more after an estimated gain based on the charger I'm using.

Put another way, the below spec with a 12 liter intercooler what kind of RPM's will I need to gain 100bhp on the stock 200bhp so overal total of 300bhp... is this a realistic idea or am I dreaming?


Oh and what do you mean, 4cefed, when you say GTP?
 
GTP is the supercharged version on the Grand Prix (not sure if yall have it across the pond).

Achieving 100Hp is in no way out of the question for a supercharger, assuming have enough fuel. Mike Pucket is making about 420 HP( at the flywheel) on his SC and it is still an M90.
 
go to www.clubgp.com or l67swap.com It may be more realistic for you to swap in a GM supercharged 3.8 than to add it to a 60* motor. For a comparison the supercharged 3.8 makes 240 crank hp stock. It is only a few basic modifications away from 300 hp(intake, exhaust, pulley, etc...). If the car is a rwd vehicle, I would consider looking at the Australian version of the M90 that they used on the older commodore's. It is like a strange hybrid of the GM and Ford M90's. Definitely do lot's of research before attempting anything. It may involve some serious fabrication.
 
4cefed said:
go to www.clubgp.com or l67swap.com It may be more realistic for you to swap in a GM supercharged 3.8 than to add it to a 60* motor. For a comparison the supercharged 3.8 makes 240 crank hp stock. It is only a few basic modifications away from 300 hp(intake, exhaust, pulley, etc...). If the car is a rwd vehicle, I would consider looking at the Australian version of the M90 that they used on the older commodore's. It is like a strange hybrid of the GM and Ford M90's. Definitely do lot's of research before attempting anything. It may involve some serious fabrication.

Not quite that simple I'm afraid... I'm far across the pond and not easily able to get a 3.8 v6 GM engine, supercharged or not, hence I'm using a 3.0 v6 GM engine from another in the GM Europe range converting it to run FWD transfersley mounting in the original engines postition, hence bolting on a big charger, cutting a big hole in the bonnet (hood) and covering that... don't worry mate the only research I haven't done is on the charger, it was a spur of the moment desicion... :D
Hence the thread ;)
 
Squig said:
If I'm to be brutally honest, I know nothing about superchargers except for the very basics... I'm more after an estimated gain based on the charger I'm using.

Put another way, the below spec with a 12 liter intercooler what kind of RPM's will I need to gain 100bhp on the stock 200bhp so overal total of 300bhp... is this a realistic idea or am I dreaming?


Oh and what do you mean, 4cefed, when you say GTP?

OK, I'm giving you some figures that will answer your question.

To achieve 200bhp @ 6000rpm from 3.0L requires an engine VE of about 90%. This is not unusual for a 4 valve/cylinder motor.

To increase this to 300bhp requires positive manifold pressure of about 12-13psi. With an intercooler this boost level should be easy to maintain with decent air charge temps. However, one thing we haven't considered is compression ratio of your motor. If it has a compression ratio of 10.0:1 or higher, then you may have some issues with running that much boost on pump gas.

According to my data I would expect a drive ratio of about 2.25:1 to achieve the 12-13psi necessary for the power you want to achieve. This drive ratio will give you a blower rpm of about 16,000rpm at your engine redline of 7000rpm. This is within the design parameters of the blower.

So yes, I think it is reasonable to expect to make 300bhp from the motor using the blower you are refering to. Proper tuning will be important.
 
bowez said:
GTP is the supercharged version on the Grand Prix (not sure if yall have it across the pond).

Achieving 100Hp is in no way out of the question for a supercharger, assuming have enough fuel. Mike Pucket is making about 420 HP( at the flywheel) on his SC and it is still an M90.

cheers fella
 
XR7 Dave said:
OK, I'm giving you some figures that will answer your question.

To achieve 200bhp @ 6000rpm from 3.0L requires an engine VE of about 90%. This is not unusual for a 4 valve/cylinder motor.

To increase this to 300bhp requires positive manifold pressure of about 12-13psi. With an intercooler this boost level should be easy to maintain with decent air charge temps. However, one thing we haven't considered is compression ratio of your motor. If it has a compression ratio of 10.0:1 or higher, then you may have some issues with running that much boost on pump gas.

According to my data I would expect a drive ratio of about 2.25:1 to achieve the 12-13psi necessary for the power you want to achieve. This drive ratio will give you a blower rpm of about 16,000rpm at your engine redline of 7000rpm. This is within the design parameters of the blower.

So yes, I think it is reasonable to expect to make 300bhp from the motor using the blower you are refering to. Proper tuning will be important.

Forged pistons, APR head and rod bolts (plus some to hold the supercharger in place), possibly some forged rods, lightened flywheel and standalone engine management... that's along the line. Now the compression ratio is aprox 10:1, I was hoping to use forged rods from the straight 4 turbo in the opel range which, if I'm not mistaken, should lower the comp ratio... for other options on that I know a guy who is building a RWD mk2 astra (same as mine) with a 3 liter with twin turbos. Out of intrest what would you use, that would work in general principes?

the bank angle is only 54%... very compact powerful engine

My Project...check it out
 
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you might be better off using a ford charger on an application like that. A friend of mine is going to be starting a project to mount a ford M90 to the side of a taurus SHO. It is going to be very difficult to fabricate something to bolt an M90 to the lower intake. A ford M90 would allow you to mount the SC to the side of the motor, and use some turbo tubing to connect it to the stock manifold/ throttle body. If I can find the thread to the SHO, I'll post a link later.

Off Topic, Dave what would a 14.26@ 98.5 with a 2.05 60' equate to as far as HP and TQ numbers go?
 
will be casting my own manifold and using the existing fuel rail and injectors... and mounting on the side of the block is physically impossible due to serious space constraints
 
Squig said:
Forged pistons, APR head and rod bolts (plus some to hold the supercharger in place), possibly some forged rods, lightened flywheel and standalone engine management... that's along the line. Now the compression ratio is aprox 10:1, I was hoping to use forged rods from the straight 4 turbo in the opel range which, if I'm not mistaken, should lower the comp ratio... for other options on that I know a guy who is building a RWD mk2 astra (same as mine) with a 3 liter with twin turbos. Out of intrest what would you use, that would work in general principes?

the bank angle is only 54%... very compact powerful engine

My Project...check it out

There should be no need to replace all that internal stuff at 300bhp. I'd just get the motor running with the supercharger on it first and then decide what issues need to be addressed from there.
 
XR7 Dave said:
There should be no need to replace all that internal stuff at 300bhp. I'd just get the motor running with the supercharger on it first and then decide what issues need to be addressed from there.

the pistons are notoriously rubbish when boost is involved... plus if I can squeeze more ponies out with the charger, I will. Then there's the issue of NOS in the future...
 
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