Jump to content
Ultimate Subaru Message Board

superchargers


crazy D
 Share

Recommended Posts

Kids these days... all about the forced induction:-p

 

Superchargers work off a belt driven system. Also, its a lot easier to put a supercharger (like a turbo) onto an FI setup unless you have some awesome capabilities to get it to work with a carb (is done on old muscle cars). Gotta add more fuel with the added air you're stuffing into the engine. So tuning is another major key and with carbs, you can rejet the carb to add more fuel or go with a bigger carb. Two different styles are a draw through and a blow through. Blow through is pretty self explanitory as far as the air gets "blown through" the carb(s). The draw through draws the fuel/air mixture through the carb and pounds it into the engine. I have seen a couple of Subarus with s/c's on them. One was a '90? Legacy L wagon with the stock EJ22 and a Eaton M30 supercharger on it (I think thats what it was anyways) at WCSS6. I've also seen pics of an STi that some reknob in Colorado did but he left the stock turbo (all disconnected and bypassed it somehow?) and put on a crappy supercharger setup. So yes, it can be done and has been done but tuning comes along the lines of a turbo'd car. More fuel for more air and the a/f ratio has to be pretty spot on or else, lean conditions which equal pre detonation or rich conditions which fouls everything (plugs and 02 sensor), puffs black smoke and gets fuel past the rings and into the oil.

 

If you want a good book (and I advise this for anyone wanting to learn about forced induction) get "Maximum Boost" by Corky Bell. One awesome read but it focuses more on turbos then superchargers.

Link to comment
Share on other sites

Theres no wiring involved to putting the s/c on there. Just belt routing, intake plumbing, and s/c mounting to consider. Look up Matty B's WonderBrumby, the first one. He had a s/c'd, distributed, LPG burnin ej...

Link to comment
Share on other sites

The toyota 4 and 6 cylider SC'ed motors have very good SC's for any Subie motor I reckon.

 

^^^as long as you don't go drawthru carby with them.....petrol kills the seals and lobe coatings in real short order.....the eaton M62 off the buick V6 would be the go in the states.....although i gather that it has the same issues with seals not being petrol proof.....however unlike the SC12 &14 the eaton can be resealed with available seals (SC12&14 used funny size seals).

 

the Merc 230kompressor also had a eaton on it but it had a clutch drive on the front a'la AC compressor style(SC12 has the same type of thing)

Link to comment
Share on other sites

Theres no wiring involved to putting the s/c on there. Just belt routing, intake plumbing, and s/c mounting to consider. Look up Matty B's WonderBrumby, the first one. He had a s/c'd, distributed, LPG burnin ej...

 

do you just plumb the air right into a N/A intake? (FI)

Link to comment
Share on other sites

Dalton, basically, the supercharger sucks outside air into it, compresses it and stuffs it into the intake (or carb if its a blow through). Yes, just plumb it directly into the intake unless you want to put an intercoler on it which would go inbetween the suercharger and the intake.

Link to comment
Share on other sites

What about a supercharger that has a ac compressor clutch on it?Then you could drive around and get something like decent mpg.But then the flick of a switch and you have power for mudding,passing people,etc...

 

However though even if I had something like that I probally would just leave it on...

Link to comment
Share on other sites

What about a supercharger that has a ac compressor clutch on it?Then you could drive around and get something like decent mpg.But then the flick of a switch and you have power for mudding,passing people,etc...

 

However though even if I had something like that I probally would just leave it on...

 

Good idea in theory but if you think about it, the supercharger not spinning will create more of a restrictor for the engine due to the piping and the screws inside the charger.

Link to comment
Share on other sites

Dalton, basically, the supercharger sucks outside air into it, compresses it and stuffs it into the intake (or carb if its a blow through). Yes, just plumb it directly into the intake unless you want to put an intercoler on it which would go inbetween the suercharger and the intake.

 

thanks russ, yes thats is exactly what i was thinking you would do, thanks for clearing that up for me...i was talking to shannon(86bratman) and he was alson talking about a fuel management unit. are these any difficult to fab into the system?

Link to comment
Share on other sites

thanks russ, yes thats is exactly what i was thinking you would do, thanks for clearing that up for me...i was talking to shannon(86bratman) and he was alson talking about a fuel management unit. are these any difficult to fab into the system?

 

depends on if you want to go with a carb or EFI. You'll need it with an EFI setup but with a carbed setup, you'll need to figure out your jetting, how large of a carb you'll need, and how to keep your carb from blowing seals from the boost flowing through it. EFI is a lot easier to build but carb is a lot easier to tune unless you have the knowledge on tuning an EFI boosted car. I would do EFI myself since I've done a lot of reading on turbo'd cars but carb would be fun! I bet you could boost a carbed EA since I've seen it done with a dual carb'd L20B in a Dastun 510.

Link to comment
Share on other sites

EFI is a lot easier to build but carb is a lot easier to tune unless you have the knowledge on tuning an EFI boosted car.

 

I would have thought it would be the other way around.

 

With efi you still have to make similar decisions on the hardware ie size of throttle bodies, injectors etc plus you have to choose and install an ecu.

 

otoh, tuning is often a case of just running a laptop and increasing/decreasing the injector pulse where it's out whereas with carbs you have to pull ************ apart and change fuel and air jets etc.

 

I think that's why forced induction only became common on factory cars with the advent of efi - doing it with carbs is too difficult and not reliable enough.

 

I want to supercharge my ea81 brumby but not until I have megasquirt running cos I don't want to tkeep blowing up my motor.

Link to comment
Share on other sites

What about a supercharger that has a ac compressor clutch on it?Then you could drive around and get something like decent mpg.But then the flick of a switch and you have power for mudding,passing people,etc...

 

However though even if I had something like that I probally would just leave it on...

 

thats how i had the blower on set up last time....i had a bypass round the blower with a homemade oneway valve, as soon as there was pressure downstream of the SC it would shut the valve and force the boost into the motor.

 

i had my supercharger drive-clutch switched on the dash.

 

when i do it again i will run the a 3 way on-off-on switch through a hobbs vacuum switch set to start the SC turning at 9" of vac......switch will also be able to switch blower on all the time

Link to comment
Share on other sites

Thats my wagon pictured a long time ago. Currently it basically looks like this.

 

Drivebyshotwoodburnmay12.jpg

 

 

Under the hood it looks like this....

EngineshotWoodburnmay12.jpg

 

Twin charged!

 

GT30R feeding the Eaton M62.... 30 psi by 3750 rpm!

 

Without the turbocharger, I never did make it over the 200 whp mark. I might be able to on the next motor I am building for another project car though....

 

 

The wagons life/blog is stored here, a kinda long read. :grin:

 

http://forums.nasioc.com/forums/showthread.php?t=605625

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...