Project: Eaton M90 s/c on '83 944
09-08-2013, 12:55 PM
#1
Rennlist Member
Thread Starter
Project: Eaton M90 s/c on '83 944
This is going to be an attempt at making more power in a NA car without selling it and buying a 951- my project budget is a couple hundred, but I think it can be done. Admiralkhole and Dougs951S are in the mix (and probably doing the majority of the impressive tasks), so metal fab work and sourcing parts probably won't be crazy expensive. My ultimate goal is to make decent power without drastically changing my daily-driver 944. I'm aiming for around 220whp, so I won't need to swap my tranny or internals.
I got an Eaton M90 supercharger out of a 1999 Pontiac GTP for $51. It's in great shape, but I'm going to rebuild it anyway. I might even sell it rebuilt for $400 and buy another one just to fund the rest of the project, but we'll see. It puts down 8lbs of boost, so I won't need to drastically modify my car. 1983 internals were forged, so outside of the usual engine modifications that accompany forced induction, I can keep my car the way it is for the most part.
This is the shopping list as of right now:
- 951 widefire head gasket
- APR studs
- Beefier injectors
- A tune of some sort
- Intake manifold we can cannibalize
- Various piping et al
- Beer?
- I'm probably forgetting a few things
I'm honestly pretty unfamiliar with major work like this. If you have any wise words, please share them!
I got an Eaton M90 supercharger out of a 1999 Pontiac GTP for $51. It's in great shape, but I'm going to rebuild it anyway. I might even sell it rebuilt for $400 and buy another one just to fund the rest of the project, but we'll see. It puts down 8lbs of boost, so I won't need to drastically modify my car. 1983 internals were forged, so outside of the usual engine modifications that accompany forced induction, I can keep my car the way it is for the most part.
This is the shopping list as of right now:
- 951 widefire head gasket
- APR studs
- Beefier injectors
- A tune of some sort
- Intake manifold we can cannibalize
- Various piping et al
- Beer?
- I'm probably forgetting a few things
I'm honestly pretty unfamiliar with major work like this. If you have any wise words, please share them!
09-08-2013, 01:16 PM
#2
Burning Brakes
For tuning maybe you should consider Rogues na-tune ,it will make your life a lot easier.
I'm curious how the mounting bracket will come out , i might be interested in buying one.
I'm curious how the mounting bracket will come out , i might be interested in buying one.
09-08-2013, 01:25 PM
#4
Rennlist Member
Thread Starter
Cale's idea for the mounting was to bolt it to a modified intake manifold. Seems pretty logical to me.
09-08-2013, 03:11 PM
#7
I really like what user blown 944 did as a setup, I'd like to make something close to that, but possibly with a different intercooler setup. Water to air maybe?
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09-08-2013, 03:18 PM
#9
I'll be watching this closely as I am doing the exact same thing. I have an 84 with an 86 motor. I'm running Rogue's N/A tune already. I'm using the Thunderbird Eaton M90 and I've picked up a set of new 951 injectors. My plan is to mount it where the airbox is, running a FMIC and keeping it around 6lbs of boost.
Good luck with yours!
Good luck with yours!
09-08-2013, 04:25 PM
#13
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I owe you an apology Michael 
. One pull through second and 3rd gear in a modded 951 is all it takes to partially ruin the fun of an N/A, it would seem 
Let me update your parts list, and throw some calculations at you. The stock N/A injectors are rated at 22 lb/hr. This is in contrast to the 951 injectors which are rated at 36 lb/hr. These numbers are both at 3 bar fuel pressure, worth noting since that is almost universally what any modded 951 is running while an N/A is running 2.5 bar. Means that at stock fuel pressure, N/A injectors flow 19 lb/hr.
I'm going to make some very general assumptions. At a max injector duty cycle of 80% and an assumed BSFC of .45, you'll need 35 lb/hr of fuel flow to make 250 HP at the crank. You'll really want a set of stock 951 injectors to make this work, and a 3 bar Fuel pressure regulator.
As far as airflow is concerned, the AFM can support enough mass flow to support 250 hp, but now you have a tuning issue which lies in the difference between the injector driver circuits of the 951 DME and the N/A DME. You'll have a hard time getting 951 injectors to run off an N/A DME, so you will really want a 951 DME.
Next issue, the 951 DME can not run the N/A AFM as it outputs a totally different signal, so if you go this route you will also need the 951 AFM.
The good thing about all that is those parts are all very commonly swapped out by guys upgrading, making them cheap to obtain. It also gives you headroom and with a nice intercooler (I'd use a stock 951 unit) you could make way more than 220 whp on your stock internals and still be safe.
Of course then you'd need a clutch to hold all that torque, but then again you are going to anyway. No way a stock N/A clutch will hold the ~250 ft-lbs you'll probably end up making. IMHO I think the widefire headgasket and ARP studs are a waste of your time at this power level, especially since the widefire gasket is no better than stock if your block and head are not o ringed. You'd be at stock turbo S power levels, plenty impressive but not really a strain on the stock gasket. Its all in the tune any way.
Bringing me to my next point. converting to true MAF would by far be the most expensive part of this whole project if you did that. I dont recommend it (as awesome as it is) simply due to budget constraints and the spirit of the project. If you use a turbo AFM/injectors/DME, its easy to get a chip burned to tune the thing. Again, I would also go with one of Joshua's solutions and talk to him about what his software is capable of. You would get all the benefits of 3d maps, and I'm pretty sure that his A-tune is capable of supporting the airflow characteristics of a supercharged engine thanks to the beauty of MAP tuning.
Oh, and with forced induction you will probably also (if nothing else, just for verifying the tune initially before beating on it) want a Wideband o2 sensor to make sure you are not rich or lean at any rpm or throttle position. THAT is what will blow a gasket, not the power level or boost pressure.
One last thing You'll need a bypass valve to vent excess pressure when you close the throttle or shift, so I would just use a stock 951 recirculating valve if you are already going to be using an intercooler.
As far as the manifold is concerned and fitting all that crap under your hood, well, I'll leave that mostly to Cale and I'll offer my input if either you or he asks me.
Soooo...
951 DME
951 injectors
3 bar FPR
951 AFM
951 intercooler
951 recirculating valve
intercooler/air intake piping and silicone couplers
more piping to reposition your AFM in the driver side fender well
a cone air filter
hacked up intake manifold
custom plenum
S/C mounting brackets
A belt to run the damn thing
Josh's 951 A-tune
A decent wideband
Beefier clutch disc, or potentially just a stronger clamping Pressure plate with stock disc ( lots of good things to say about my spec PP )
Beer....Lots of Beer
Loots of tires
I would say with a team effort and careful planning/parts sourcing, this can easily be done start to finish for under 1k. The most expensive part of this is definitely going to be tuning it.
Just picture a gaurds red high compression S/C car, a powder blue V8 car, and a metallic charcoal 951 all sitting next to each other.
Its going to be a fun year gentleman.
. One pull through second and 3rd gear in a modded 951 is all it takes to partially ruin the fun of an N/A, it would seem Let me update your parts list, and throw some calculations at you. The stock N/A injectors are rated at 22 lb/hr. This is in contrast to the 951 injectors which are rated at 36 lb/hr. These numbers are both at 3 bar fuel pressure, worth noting since that is almost universally what any modded 951 is running while an N/A is running 2.5 bar. Means that at stock fuel pressure, N/A injectors flow 19 lb/hr.
I'm going to make some very general assumptions. At a max injector duty cycle of 80% and an assumed BSFC of .45, you'll need 35 lb/hr of fuel flow to make 250 HP at the crank. You'll really want a set of stock 951 injectors to make this work, and a 3 bar Fuel pressure regulator.
As far as airflow is concerned, the AFM can support enough mass flow to support 250 hp, but now you have a tuning issue which lies in the difference between the injector driver circuits of the 951 DME and the N/A DME. You'll have a hard time getting 951 injectors to run off an N/A DME, so you will really want a 951 DME.
Next issue, the 951 DME can not run the N/A AFM as it outputs a totally different signal, so if you go this route you will also need the 951 AFM.
The good thing about all that is those parts are all very commonly swapped out by guys upgrading, making them cheap to obtain. It also gives you headroom and with a nice intercooler (I'd use a stock 951 unit) you could make way more than 220 whp on your stock internals and still be safe.
Of course then you'd need a clutch to hold all that torque, but then again you are going to anyway. No way a stock N/A clutch will hold the ~250 ft-lbs you'll probably end up making. IMHO I think the widefire headgasket and ARP studs are a waste of your time at this power level, especially since the widefire gasket is no better than stock if your block and head are not o ringed. You'd be at stock turbo S power levels, plenty impressive but not really a strain on the stock gasket. Its all in the tune any way.
Bringing me to my next point. converting to true MAF would by far be the most expensive part of this whole project if you did that. I dont recommend it (as awesome as it is) simply due to budget constraints and the spirit of the project. If you use a turbo AFM/injectors/DME, its easy to get a chip burned to tune the thing. Again, I would also go with one of Joshua's solutions and talk to him about what his software is capable of. You would get all the benefits of 3d maps, and I'm pretty sure that his A-tune is capable of supporting the airflow characteristics of a supercharged engine thanks to the beauty of MAP tuning.
Oh, and with forced induction you will probably also (if nothing else, just for verifying the tune initially before beating on it) want a Wideband o2 sensor to make sure you are not rich or lean at any rpm or throttle position. THAT is what will blow a gasket, not the power level or boost pressure.
One last thing You'll need a bypass valve to vent excess pressure when you close the throttle or shift, so I would just use a stock 951 recirculating valve if you are already going to be using an intercooler.
As far as the manifold is concerned and fitting all that crap under your hood, well, I'll leave that mostly to Cale and I'll offer my input if either you or he asks me.
Soooo...
951 DME
951 injectors
3 bar FPR
951 AFM
951 intercooler
951 recirculating valve
intercooler/air intake piping and silicone couplers
more piping to reposition your AFM in the driver side fender well
a cone air filter
hacked up intake manifold
custom plenum
S/C mounting brackets
A belt to run the damn thing
Josh's 951 A-tune
A decent wideband
Beefier clutch disc, or potentially just a stronger clamping Pressure plate with stock disc ( lots of good things to say about my spec PP )
Beer....Lots of Beer
Loots of tires
I would say with a team effort and careful planning/parts sourcing, this can easily be done start to finish for under 1k. The most expensive part of this is definitely going to be tuning it.
Just picture a gaurds red high compression S/C car, a powder blue V8 car, and a metallic charcoal 951 all sitting next to each other.
Its going to be a fun year gentleman.
Last edited by Dougs951S; 09-08-2013 at 05:13 PM.
09-08-2013, 04:56 PM
#14
Rennlist Member
I lived the dream once..... It didn't last very long.
Hats off to you guys if you can make it work, for cheap.
I'm going to redo mine completely and just do everything right this time. No expenses spared, no engines blown.
Hats off to you guys if you can make it work, for cheap.
I'm going to redo mine completely and just do everything right this time. No expenses spared, no engines blown.
09-08-2013, 05:11 PM
#15
Team Owner
Join Date: Oct 2009
Location: one thousand, five hundred miles north of Ft. Lauderdale for the summer.
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huge congratulations in advance. because
1. it's more fun to drive a decent running car than to play automotive pioneer/engineer/astronaut and blow up on the launch pad.
2. by the time he gets done he could have just dropped rebuilt 3.0 Rogue Ant (nothing done to the block, just R-Ant crank hone/rods/pistons/etc and low boost), and still had enough mid-range power to be happy for the next 20 years and *married the prom queen while he was at it.
3. or just had a v8.....
*then again, who the hell am I to say they can't pull it off and enjoy 3 fun 200 hp cars...
I'd just get a 968 engine *(250 hp w/ straight pipes) for $2.5~3 k and swap in that.
hell, they're so bulletproof, mine's prolly good for another 180 k miles.