Supercharger for Subaru?

steptoe · Post by **steptoe** » Fri May 04, 2012 9:00 am

This is how you waste time on the 'net

- coming back later to read it all.

I am yet to see a beetle fly !

Tweety · Post by **Tweety** » Fri May 04, 2012 12:16 pm

In this clip it might not be a beetle but if it was it would fly I'm sure.

PS lets ignor the unsafe work practices....

http://www.youtube.com/watch?v=W0fFS-USoUw

steptoe · Post by **steptoe** » Fri May 04, 2012 9:33 pm

Reminds me of two things - talking to a guy who had a Beetle with EA81, twin carbs and two little turbos and me on a dyno with the op asking me to take it to a hundred - couldn't get proper traction - he forgot I had miles on my dial - I was doing 160 km at about 3400 rpm

I am gonna have to pay even more attention to trikes in the future !

YouTube · Post by **El_Freddo** » Sat May 05, 2012 1:28 am

Very interesting read about that SC12 on the VW engine. It should go well on the EA81. Might want to look into the EA82 inlet manifold upgrade as well - larger diametre inlet = more fuel and air easier

Cheers

Bennie

steptoe · Post by **steptoe** » Sat May 05, 2012 8:08 am

With all the after market performance gear for old Vee Dub engines you gotta wonder why no one has tried turning the tables and shove a 200HP dak dak in a Subaru !

YouTube · Post by **El_Freddo** » Sat May 05, 2012 9:41 am

steptoe wrote:With all the after market performance gear for old Vee Dub engines you gotta wonder why no one has tried turning the tables and shove a 200HP dak dak in a Subaru !

Simple - that would be going backwards!

VW engine with SC is a step up on just the VW engine.

Subi engine in a VW is a big step up. Subi engine with SC in a VW = huge step up!

Cheers

Bennie

Gannon · Post by **Gannon** » Sat May 05, 2012 10:11 am

El_Freddo wrote:Simple - that would be going backwards!

Im not too sure about that, I have a mate that has a 1800cc twin carby VW motor in his beetle that was dyno'd at a touch over 100whp because there are a lot more bolt on options for early VW than early Subaru.

Ive often thought that it would be a cool project to VW an early subaru.

Tweety · Post by **Tweety** » Sat May 05, 2012 10:31 am

I think (for once lol) I can answer this VW into Subaru thing.

Reason could be cost and technology along with maintenance.

I investigate every mod I do for some time before making a move. When I had the 1916 cc VW engine I had had many mechanics and performance expert look at its issues of not running right.

So off wnet the Solex carbs and on went the webers,on went the EI, new valves etc etc.

But to REALLY improve a vW engine I came to the conclusion that its all the way or not at all. VW aircooled engines are no longer the reliable engine the 1200 was in its humble days (my view) and I began to get some prices from the experts.

The most well know expert is a guy named Pobjoy in Sydney. After my lengthy call to him he had convinced me that the only way I was going to go to the effort with my VE engine, to ship it to him was to spend in excess of $10,000. That would include a Pobjoy balanced crank, twin spark heads (he makes them for aircraft), large valves, better exhaust and the list goes on and on.

I pulled the pin on that engine and for 5 grand carried out my conversion. Got 3 grand for the vW donk.

Now? Well I did my tappets on the ea81 for the first time this week. I wont need to touch them for 30,000-50,000 kms (the VW every 3000 kms and beleive me they need it that regular), no overheating issues (yes the VW does overheat when towing) , subie spares are much cheaper and the subie engine- well it feels bulletproof and likely is according to other owners. And finaly economy. The Vw in my auto trike got 22mpg and 19-20 towing. the ea81 26-33mpg and 24-27 towing. an extra 80-120 kms a tank makes a diifference.

yeh, I'm in love.

Tweety · Post by **Tweety** » Sun May 06, 2012 3:52 pm

SC12 purchased.

with clutch pulley.

more details soon. oh yeh!!!

steptoe · Post by **steptoe** » Sun May 06, 2012 7:47 pm

If there were any left after you got yours - DON'T TELL ME - already wondering .....

Can't wait to follow your well researched project

Tweety · Post by **Tweety** » Sun May 06, 2012 8:35 pm

Thanks Steptoe. had to get more decisive about it. Did toss and turn over getting a new Sprintex for $1700. It is compact, advanced, proven and aussie made. but I couldnt justify the total cost.

After I read "Joel's" thread on aussieveedubbers I was convinced the sc12 was the right way to go. Will be shipped shortly from nsw.

I'll do my maths to seek out a boost of around 5-6 psi. I gather from threads that this will enable reliability of the engine to not be compromised.

Its early days. I plan once I get the unit to figure out a way of utilising the cast iron alternator bracket to help mount it.

Also a 2 inch SU. but in that vw thread I read someone used the weber 32/36 so if I can do that?? think SU or holley sidey would be the way to go.

as usual always listening to opinions from subie forumites

and by the way steptoe....you buy one and we could swap notes on the conversion....

stenno · Post by **stenno** » Sun May 06, 2012 11:12 pm

damn it, now youve got me thinking about this too. So this last week, i have done some net surfing to work out how hard this would be.

http://www.theturboforums.com
seems to be the forefront of blown and turbo carby tech on the net. Heaps of DIY but mostly v8 stuff / Holleys / 10 sec quarters etc. Losts of talk on there about extending the fuel bowl vents into the carby hat along with float modification for on boost enrichment rather than the "old school" line of tuning of just massive (methanol sized) jets and pig rich running off boost. This wouldnt really matter with a blower tho. also seems to only be a big issue if your running 12+ psi pressure

www.performanceforums.com and user jmac has been playing around with blow thru carbys for over a decade, He tends to write essays but nothing he types is fluffer. a Google search for the website and terms carby, blow thru, weber, modify will give you a good days reading and a great understanding of what needs to be done. One gem was that the air jet corrector needs to the smallest you can find, like half the cross sectional area (not jet size) of a well tuned NA jetting

http://www.turbogemini.com has a good build up thread of the trials and tribulations of blow through / suck through boosting engines.

So the basic setup to run a sc12/14 blow through weber setup would be:
* Weber (mechanical secondarys) with nitrophyl floats (dont crush under boost pressure) and sealed off choke holes through the body, doesnt boost leak
* Weber type Carby Hat eg K-N Turbo plenum but $200 seems steep, surely something could be made / fabricated cheaper
* Malpassi rising rate carby fuel pressure reg set at around 6psi above boost pressure about $100
* ordinary EFI fuel pump eg Bosch VL commodore pump but anything should do as the highest pressure it will ever see is 6psi above boost pressure. Wrecker hunt should sort this cheaply
* Diahatsu Charade 3cylinder turbo Vacuum advance/retard diaphram for the dizzy for ignition retard on boost. Otherwise locking the advance should work.
* piping from SC12/14 to weber
* Dyno time to tune it

Can you fit wheely bars to a trike?

Tweety · Post by **Tweety** » Sun May 06, 2012 11:58 pm

Wow Stenno...you've been busy haha

onteresting about the diahatsu dizzy diaphram. that'll be the last thing I'll be doing I reckon. I guess I'll be riding it to a palce with the blower switch off and they can reclibrate etc.

I intend to do suck through. there are many examples with a SU 2 inch carb and pressurizing the carbie isnt an issue. I'm hoping my new weber will be used. There have been reports about the SC12 and 14 not liking fuel running through them on the suck through design but many also say the opposite in that fuel helps it seal better.

SC12 has a dip stick. contains 137ml of oil. oil type hottly debated. most say dotn go Toyota as it comes in 50ml bottle so need 3 @ $58 a bottle gulp!. use Holden oil 2x 100ml bottles part number 12345982. bottle has straw syringe you need to fill the SC. SC14 has a sealed oil unit no dip stick.

5 rib crank pulley required and Falcon tensioner also 5 rib of course think of an Ford ea model.

Trike has enough room no probs likely more than cars. no radiaotr over the transaxle now so a carbie and cold air intake is not an issue.

full throttle on my trike raises the front wheel a foot or so. if the misses is rear seat passenger a bit more, if we attached a sports bag to a detachable carry rack at the back then a SC could prove lethal lol.

back to the SC. Joels thread on aussieveedubbers is a classic and am in touch with him. clever guy. the mounting brackets MUST be at least 6mm thick steel. according the custom rod shop recommendations any boost over 4 psi then you shouldnt use the pulley clutch. also over 2500 engine rpm the same. 3-4 psi (havent worked it our yet) I reckon will give about 20% extra pwoer and torque maybe more.

I will have some issues to deal with. one is the electric fuel pump purchased when the ea81 replaced the vW. it has a rating of 3-5 psi to feed the weber. my trike doesnt have a facility to return fuel. best case seario is the pump will cope with the little boost I seek, if not a bit bigger pump that wont require a return.

Mounting. Using the cast iron alt mount maybe. likely make new ones. vacuum caps on the manifold (all anti pollution gear removed on conversion- trikes dont need them advised my engineer) will be under pressure so gotta secure those. and piping SC to manifold and blow off valve if required which I need to research if I do indeed need one.

Intercooler not required. thats for the big power boys.

if enough ea81 owners do this conversion we might get this thread to be a sticky lol...

I'll read your links now. thanks mate.

and how will she look???

Venom · Post by **Venom** » Mon May 07, 2012 4:14 pm

Found mention of using a EA Falcon CFI throttle body as a bolt on to the weber adapter plate, with some filing. Little bit of info on that in this forum. Lot of other chat is from dato owners and other small capacity 4 cyl car owners adapting it. With some googling there was mention of running the injectors directly of a megasquirt FMU or similar fuel only management unit. Or from factory it just runs itself off 1 02 sensor and a signal from the coil? Couldn't get concrete info on that. Not a very flexible factory management unit though, apparently. No buggering around for a blow through setup though, and a simple almost totally self contained injected throttle body sounds good in theory.

Possible a worthwhile persuit considering you could probably get all the falcon bits out of a bin for practically nothing.

Work filters is making it hard for me to check it out myself...

Tweety · Post by **Tweety** » Mon May 07, 2012 5:04 pm

Thanks Venom.

For me at this time I'll be attaching the SC as simple and cheaply as possible. Certainly want members to keep their enthusiasm for any other ideas particularly injection etc. ea82 intake manifol Bennie said was alrger. another avenue.

Here is a few things I found today.

http://www.youtube.com/watch?v=EYmezE3p ... re=related

also a pic of a corolla witha draw through set up.

Now the weber 32/36 is ok to retain in place of the above 40dcoe side draft. but I've read that the 32/36 is thirsty on fuel. I think a SU or similar single throat 2 inch would be better.

As you can see from the pic there is a long way from th Sc to the intake and I've seen this a lot. I assume guys that distance isnt a concern. or it is that was due to lack of space. If the engine would run better having the oulet of the SC and the inlet of the manifold only a couple of inches then it is quite possible to do this on my trike.

In the old days 1930's engines had carbies many inches vertically above the engine. it apparently helped with smoothness of the engine. So wondering about the benefit of short distance.

The blow off valve (BOV). anyone know anything about these? what can be used or where to get them? looks like I'll be manufacturing my own tubing etc so the process has started.

just took another look at the pic. the exit form the sC is at the rear. meaning tubing from there to the intake manifold would have to be at least 12 inches long.

Also the falcon tensioner should be on the LHS of the SC and crank pulley.

Once I receive the SC12 I'll know the diamter of the clutch pulley and calculate the crank pulley size for 4-5 psi, anyone think this psi is not ok for any reason?

stenno · Post by **stenno** » Mon May 07, 2012 8:28 pm

Looks good. Front wheel 6 foot in the air would make a great photo but could be hazardous ha ha.
The Sc12 may have an internal bypass so that could mean you wouldnt need a bov. Damn an oil change isn't cheap on one either. Running suck through does help the rotors to seal better and can bump up the boost and efficiency of the blower a little. Are the rotors Teflon coated and would fuel "eat" this coating away?
Sounds like it's just a case of you getting it all fitted now and some piping made up.
Would a dead head pump work with your tank setup? Or maybe tap in a fuel return somewhere.

Tweety · Post by **Tweety** » Mon May 07, 2012 9:22 pm

Dead head pump??? me no kabish? maybe that means a one way pump?

there is no location to return fuel back into the alloy monocogue type fuel tank. the motorcycle fuel tank is actually where the electrics are and the 50 litre tank is the black box section under it.

you can see it here:

Suffering info overload with this aTM. BOV's, etc. but am absorbing some of it. my coming SC12 has had the oil drained so will get Holden Sc oil.

All I know is suck through is my way. Single throat SU or similar seeking 5psi unless someone thinks a bit more. But reliability is priority and towing up hills using my 3 speed auto to seek improvement. The ea81 has its modest max torque at 2400 rpm lower than any motor I've seen of 1800cc. so for a SC to enhance that will be most interesting.

stenno · Post by **stenno** » Mon May 07, 2012 10:22 pm

Ah, drilling a hole in the "tank" for a return would cause structural issues then.
Yeh a deadhead pump is just that, return less. But I think they may have to be mounted "in tank".
If the blower has an internal bypass essentially the blow off valve is internal to the blower.

Tweety · Post by **Tweety** » Mon May 07, 2012 10:41 pm

Not structural issues. just something I'd get someone else to do I suppsoe- not confident in some areas. But that could be one hurdle to overcome (overcme many with my engine conversion in these pages)

itneresting for me is: non supercharged

Name: 4A-GEU
Type: 1587cc EFI DOHC 16-valve 4-cyl
Power: 88kW @ 6600rpm(1988), 100kW @ 7200 (1990)
Torque: 142Nm @ 5200 (1988), 147Nm @ 6000 (1990)
Sources: FWD GT Corollas, mid mount in early MR2, RWD sprinter, 1988 version had 9.4:1 CR, 1990 had 10.3:1 CR and different intake.

Supercharged

Name: 4A-GZE
Type: 1587cc EFI DOHC 16-valve 4-cyl supercharged
Power: 108kW @ 6400 ('90 123kW @ 6400)
Torque: 186Nm @ 4400 ('90 206Nm @ 4400)
Sources: 88-89 Levin GT-Z and MR2 GT, uprated in '90 Trueno GT-Z

the supercharged (using SC12) has about 24% more power at 200 rpm's less and about 30% more torque at 1200 rpm lower. They run the SC12 at max 8psi boost.

ea81 specs suggest 54kw@4800rpm and 127 nm@2400 rpm

I've dynoed my ea81 and made all the common improvements but for the sake of it say my engine has standard outputs.

24% increase in power would equal 67kw ( 91 hp)@ say 4600 rpm and 30% increase in torque would mean [email][email protected][/email] with me now!! thats a very rough guess with 10psi.

If 6psi boost is sort max instead of 10psi (standard boost for MR2) then according to Joel of the aussieveedubbers forum site already previously listed on a link

"So it was off to the wreckers to find a 5 rib pulley
i knew what size roughly i needed as size detemines boost levels
the standard 1600 toyota runs a 150mm drive pulley which boosts to 10PSI
but that was more than i wanted to run and also the 4AGZE motors rev out to 7500rpm
and my bug motor only revs to 6000rpm.
i figured about a 130mm pulley would give my desired boost level of 6-7Psi
so i came home with the crank pulley off a mazda 626"

Hence a ribbed pulley around 120-130mm will be sort.

So what will 5-6 psi increase of power and torque be with 6psi? and at what revs.

Dyno showed 74hp at the crank of my ea81. I'm hoping for an increase from 60hp at the wheels (the auto zaps 14 hp according to dyno) to 70-75hp maybe 85hp at the crank. But I think the real benefit will be the torque. I love low revvign engines with pull. Hoping for a 20% increase at even lower rpm say 2000. I'm rambling...I wont sleep now lol

But we are dealing with unknowns and they are unknown unknowns etc as Donald Rumsfeld told us once.

A supercharger and 6 inch lift kit and Mt Cole here we come haha

stenno · Post by **stenno** » Tue May 08, 2012 10:24 am

4agze only ran 8 or 8.5 compression compared to 10.5 too. They do mad front wheel skids too in my mates converted corolla.
Years ago I remember my mechanic saying 1 bar boost would roughly double power all else the same so 6 psi should give you the extra 20% your after