tweety

They say Supercharging is addictive. So am going to take it easy on upping the boost. think I might see if I'm happy to live with this 5psi. Also the trike only weighs 600kgms so when the engine is under laod it isnt under that much load. Towing my caravan will bring out the best in it, then I'll see if I need more boost. But I dont think so and as you say detonation....dont want that- more trouble eh.

Today was more sweet than bitter but it could have easily turned horrible. Took off at 6:30am bound for Croydon to my friends at VW performance Centre. Got to yea and broke down at the servo when Tweety's engine wouldn't restart. Turned out much later that there was a lot of condensation in the electronic dizzy. Not the first time! Eventually restarted and the engine broke a supercharger belt at Glenburn. Inspection revealed the belt had a tendency to move towards the engine. Later Daniel from VWPC found it was out iof alignment by about 3mm resulting in one of the 5 ribs on the belt to fray, break then the rest of the belt followed. Luckily I had a spare and pushed on from Yea to Ringwood East where the second belt snapped. I heard it go. But pushed on regardless and found that indeed the engine can maintain power without the belt...no boost of course. So Daniel took about 2 hours to make a spacer between the crank pulley and the SC ribbed pulley, plug weld it together etc. Then it was dyno time. I had had 145's as a main jets in the 40 DHLA Dellorto,. In the end we had 225's so you can imagine how lean it was running. Air jets were matched. Accelerator "pump" jets had to go to greater sizes too. Initial runs were disappointing. Last years HP maximum was 60 hp at the wheels. These runs were 58. I asked Daniel to check the throttle. Yep...less that half effective throttle when squeezed tight- my fault. We spent some time remaking a better throttle set up with more throw and a better link. 82.2 hp at the wheels compared to 59.6 last year. a good jump of 32% in hp. I began to raise a smile. At only 5 psi boost. Torque last year was 440lb this year 570. another substantial increase. (Tractive not actual torque) 30% increase there. Here is the graph. The green is last years results after the weber carb was installed. Todays is in red. Power is the humped curve, torque the flatter lines. That was at the wheels. last year the flywheel HP was 75. This year....well we got it way up toward 98 then we had an issue. The engine firstly wouldnt idle under 2500 rpm. Then it wouldnt start. The condensation was blown out with air. Then Daniel found a leak between the custom manifold and the base adapter plate. I recognised that spot. The gasket and hence the gasket goo area was less than 3mm wide between the intake neck and the mounting stud. So we packed up our box of tricks and decided I'd remake the manifold. Daniel supplied me with some 75mm pipe and a leice of 75mm silicome tube. Homewood bound and the difference was- well extraordinary particularly acceleration between 80-110 kph. Truly quick by previous standards. Tackling hills is a breeze where previously I'd drop speed to say 80kph or even drop down to second the trike maintains 100 kph effortlessly. When the trike does hit a slower steeper incline and drop down to second the front of the trike lifts. Not off the ground at that speed say 60kph but you do get that sensation of the machine sitting on its haunches- nice. Boost max indicated was 5psi. I think I'll be happy with that. I wont rule out at a later time changing the SC pulley to a slightly smaller one to get a bit more boost but I'll leave it alone for some time yet. Now to rebuild that manifold and get the manifold between the Sc and the carbie shortened to make way for a wider air box

Went for anther ride today. achieved 4psi boost on the guage. gettign tune next Tuesday. jets arent right.

Thanks for the good advice guys. The BOV now ducted to the cold air intake as it was designed to be. The tensioner- well there isnt many options there I'm afraid. it is on the slack side but closer to the crank pulley. havent had slipping issues though. And it takes a common belt size. update I've allowed for the gasket goo to set. At least I know there are no leaks there now on that custom manifold. Fiddled with jets a bit ended up with 145 mains and 6 degrees timing close to standard timing. But there is still just a little hesitation and as I got rid of most of it then it has to be a tuning issue. Wont know how ridable it will be until the rain stops. Click on the next pic for a video And yet again while fiddling with timing the engine backfired and that BOV worked so well. As for teflon being removed in a draw thru set up. I've had a number of reports here in Oz that that isnt happening. maybe the octane is different?? also the mild level of boost made possible with the Sc running only half its ability eg 6500 rpm might be a factor for longatibity. Here's hoping. and here is the trailer I tow.

Thanks CYFUN The radiator at the front is the best way to go especially if you live in cooler climate and like heated legs. I have almost completed the addition of the supercharger, a SC12 in a draw through set up. Best to view that instal at : http://www.ausubaru.com/forum/showthread.php?t=21661 regards Smokey

When my Panther had its VW 1916 engine I didn’t consider a supercharger. Maybe if I did and had read “Joel’s” superbly documented thread at http://forums.aussieveedubbers.com/viewtopic.php?tid=65678&page=5 I might never hav considered superchargers Joel mounted a Toyota SC12 supercharger to his 1776cc aircooled VW engine with fabulous results. The larger SC14 (read longer by 50mm) doesn’t fit in the engine bay as the doghouse gets in the way. Regardless the SC12 fits well. For the novice (as I was 8 weeks ago) let me explain in laymen terms, what this is all about. Turbo chargers run on exhaust gasses, superchargers run off the crank pulley. Superchargers boost is calculated by a formula…I’ve included the formula later. Such formula depends on pulley sizes, the cc of the engine, the size of the SC etc. All basic stuff. Turbos and SC’s have positives and negatives. The supercharger has its boost virtually throughout its rev range. Perfect for towing and enhancing the engines torque, indeed lowering its max torque point a few hundred revs. Superchargers can be expensive. However many people are buying the SC12 or SC14 for less than $400. Total package though is still less than $1500. For around 30% increase in torque and power (say 6-7 psi boost) it is the cheapest bang for buck around. You can buy a sprintex supercharger that have even managed to find their way into new Harleys. These are “twin screw” superchargers meaning the air is compressed internally in the unit unlike the SC12 Toyota units that are called “Roots type” that pressurise the air on the outside of the blower. These are Australian Sc’s and are very efficient. There are centrifugal SC’s also. But I wasn’t prepared to fork out many thousands of dollars on this project. Electric superchargers are on ebay and other places. They, in my view are a waste of time and money. There are two methods in connecting up a SC. First is the method that the blower was originally designed- to compress air only through a carbie and into the engine. This has a few issues with the home built conversion. The carbie has to be built/rebuilt to withstand compressed air for example. This is called “blow through”. But there is a simpler set up. “Draw through” means the carbie works in its conventional manner to inject an air/fuel mixture into the blower. The blower compresses the mixture before it is ingested into the intake. No carbie mods are required though there are good and not so good carbies to select from for this purpose. It is commonly known that SU’s are good as are side draught webers and Dell’orto’s. Some are more efficient than others so there is some homework there to do. So onto Tweety, the Panther trike (Oz). I wont go into why I selected the ea81 Brumby/brat OHV engine in the first place in detail except to say that I wanted simplicity in that I wanted to service and maintain my trike myself. I know my limitations and DOHC’s and wiring looms a ,mile long scared me off. Having said that I also carried out modifications on the standard Panther tow bar to make it run the full length of the trike for it to tow a small caravan weighing some 450kgms wet. I didn’t count on the automatic zapping 15hp out of the engine though. On a dyno the engine, correctly recoed 60,000kms earlier by a Subaru mechanic produced a healthy 75hp. It tows the van well but hills see it die a little too much. A 4 speed manual would have more usable power. So I decided to install an SC12. I purchased one and also purchased a Lynx twin carb manifold suitable for a Datsun 1600-2 litre engine. I cut the manifold in two parts. This was suitable for my needs because the ports, as they meet with the blowers intake, are close together as are the square SC intakes. I made up a small adapter plate. Then I purchased a Dellorto 40mm DHLA carbie fully refurbished for $210 on ebay with a spare carbie for $60. I needed to mount the SC and did so between the alternator and the engine intake by utilising the cast iron mount.. I made a manifold from two 75mm steel pipes welded together sideways, added a blow off valve and I thought this was going to be easy. It wasn’t. I would recommend anyone doing this set up to make two separate mounts one on the SC exit and the other on the engines manifold intake both with 75mm pipes and connect them with a short length of 75mm silicone tube. This allows for imperfections in the joining of them. If the SC is hard mounted like mine you wont need a top mount. If you use the silicone tube then you’ll need a top mount which isn’t hard to make. When making up the manifolds/adapter plates I finished the joins both externally and internally with Devcon plastic steel. A more common material is JB weld. This epoxy can line the inside with little chance of breaking off, is sandable etc. There is usually a pulley on the SC12 that has an electric clutch. This is not suitable for a draw through set up. You need the blower operating all the time with draw through. So I got my engineer to fix it with 3 bolts through it. At the same time he fixed a 5 ribbed pulley to the crank pulley. Then I purchased a Ford tensioner pulley and mount. I used a 5 ribbed belt 5pk-0965 which is a common size. The specs of the set up are: cranks pulley 135mm, SC pulley 120mm. Calculated boost around 6-8psi. Below is a calculation using my Ea81 engine. Simply calculate your own by replacing my figures with yours. When fitting a supercharger, you should match the swept volume of the supercharger to the size of the engine. If the choice is made carefully, problems from overboosting and the required paraphenalia to solve these problems will be minimised. The supercharger will also be kept in its safe operating speed with correct selection. To choose a setup you need to know :- 1. Engine capacity 1.8 2. Maximum engine speed you will be using. 5500rpm 3. Boost level desired 6-8 psi I am setting out the calcs needed for a 1800cc engine in the steps below. FIRST CALCULATION (Engine Litres/min @ 0 Psi ) Multiply engine capacity (in litres) times maximum engine Rpm. E.g. 1.8 litres x 5500 rpm = 9900 litres/minute. Divide this figure by two as engine only fills every second stroke. 9900/2 = 4950 litres/min. This is the engines air requirements in litres/minute at 0 Psi boost. SECOND CALCULATION (boost ratio) Add the boost pressure desired (8 Psi) for the engine to 14.7 Psi (atmospheric pressure). (8 psi boost desired +14.7 =22.7 psi) Divide this answer by 14.7 and this gives the boost pressure ratio. (22.7/14.7=1.544) This is the boost pressure ratio above atmospheric pressure. THIRD CALCULATION (Actual air requirements @ desired boost) Multiply the boost ratio by the litres/minute obtained for 0 Psi and you get the actual air requirements in Litres/min for the engine at that boost. In our example this is 4950 litres/min X 1.544 = 7642.8 litres/min for 8Psi boost. To decide on the correct size of supercharger you need to know :- 1. The swept volume per revolution of the supercharger. ( SC12- 1.2 L/rev) 2. The maximum continuous safe operating speed for the supercharger. (Toyota SC12 11000 rpm??) 3. The maximum pressure that can be safely produced by the supercharger continuously. (Eaton M62 12 psi, SC14 10-12Psi) CALCULATION (Supercharger rotor speed) Divide the desired air flow (7643 L/min) by the swept volume of the supercharger (SC12 from the is 1.2 litres per revolution). This will tell you the maximum speed the supercharger rotors must be run at to produce the volume required. 7643/1.2 litres = 6369 rpm for the SC12 well within its capabilities. CALCULATION (Pulley size ratio) Divide the rotor Rpm by maximum desired engine rpm to get the drive ratio of the pulleys. For an SC12 on a 1800cc @ 8psi boost the desired supercharger pulley ratio is 6369 /5500 rpm = say 1.1:1 My Crank pulley is 135mm diameter and SC pulley is 120mm. About 1.1:1 =spot on. Ignition and Fuel. Commonly and especially with aircooled engines the ignition should be retarded or the advanced limited. As you are forcing air into the combustion chamber more fuel is needed to balance the mix. Hence larger jets. In both cases a dyno should sort this out. Be warned however that a rich or lean mixture can cause harm to your internals. Intercoolers. Read up on them. They are not however suitable for draw through set ups. Test ride. Tweety’s Dellorto was rich and the engine bogged down a lot. Eventually I feathered the throttle to enable him to pick up speed. Then going up a small hill I let him kickdown from 3rd to 2nd and the front wheel lifted. The trike has more kick in the back and I’m impressed. Tuning will result in a better response. Supercharging is addictive and some say eventually I’ll want more boost. Trouble is when you go over about 6psi reliability becomes an issue. The SC12 in my case is spinning at around half its capability. I am happy enough and don’t want a screamer. Lining up the belt correctly is critical. Finally, tuning is critical. get it right sooner than later.

Tweety the trike is getting very close to having his supercharger fitted to its ea81. Almost completed the adapter plate from carbie manifold to supercharger inlet. Blow off valve in position. had to get a collar lathed up in steel to get it braised onto the steel tube.

And next time you ride Tweety I'll be insisting you twist that throttle more Bennie. lol But yeh the engineering issues in Australa keep them in a job. I'm getting a lot of replies on various forums about "should have gone EJ". It really is putting the ea series engine down I think. I'm so impressed with the ea81, its longativity, realibility and simplicity. And Bennie, one day when you are settled and secure I'm intending to help you build a trike dream machine. The supercharger instal plan has started. Will look nice above the engine. started building the first manifold

see my latest posts that I posted today on http://www.ultimatesubaru.org/forum/showthread.php?t=60231&page=2 My Panther (Oz) trike has an ea81 mated to a vW automatic. Many people urge for the eJ series engines. I went to ea81 for old school simplicity. that's my choice and although I am about to fit a Toyota sc12 supercharger to my engine I still prefer to do this than go EJ. I'm just in a time warp lol The Subie ea81 revs easier than the VW, more torque, simple, reliable etc. You can read the above thread but also see my ea81 auto trike at

continued Forget the radiator at the back. I moved it later. A supercharger set up like this is planned. Might get a intake off an ea82 which is larger. I'd like a little more power for towing see it perform at

Well done. Nice and neat. I have an ea81 Brat/Brumby engine in my PANTHER (Aust)trike. With VW automatic. I have an electronic distributor, weber 32/36 carb, iridium spark plugs, 8.8mm plug leads etc. Am about to fabricate mounts to install a Toyota SC12 supercharger. I had a MR2 Toyota radiator mounted above the transaxle. It had 2 thermatic fans. It also had air vents carved into the body to get air in there. No matter what the fans would still come on at speed as there is a vacuum at the rear of the trike. Recently I changed radiators to a smaller one from an Alfasud 1984-1990 model. It fitted better up the front. 32mm stainless steel tubes to carry the coolant and a larger than common thermostat 180 degrees so the coolant circulates better. A Hyundau expansion tank also. I also fitted a Husdsons instrument temperature switch in the usual temp sedner location and this has a truck reversing alarm on it so it goes off at 95 degrees C or 200F. The large brake pedal required extensions and made them adjustable for my wife's short legs. The Subie engine performs overall better than the 1916 VW, revs easier, much more economical and remains compact and simple. Simplicity was a need of mine. The supercharger will be a draw through set up with Dellorto or SU carb. Will plan for 6 psi boost. Should end up with 25% more power up from 75hp to 100 and up the torque by 30% at 2000 rpm instead of 2400rpm. Smokey from Victoria Australia more to come

thanks Davebugs. The "ladder bars" as they call them here in Oz are an option. Normally they just have a single bar. I wouldnt do without them. They do add a little strength but nothing substantial. The roof is my own design. Yes have seen the bug roof trikes on the net and a few are ok but some not so. Most improtant I think to get the design right. It is a head turner. Stop at a town and the cameras come from all over...

Thanks Subeefun This trike is my hobby and is an ongoing project. Upcoming additions are: Single marine windscreen wiper Custom dashboard to incorporate trailer brake controller, digital thermatic fan switch and reverse camera. twin heater radiators. It has a single one now and a second one will eb a bonus. and vanes to direct air from heaters. Windscreen demister is required also for cold weather. thanks again

The engine, regardless of two thermatic fans, gets too hot. So I purchased a kz250 Kawasaki radiator. Its onlt 14"x5" and is mounted a tthe front brake pedal. keep the engine much cooler. and the bonus is the hot air keeps my legs warm.

fuel usage. Australian gallons = 4.5 litres. 220kms 20 litres = 9.1 L/100kms or 31 mpg. very good. 98 octane

Update: I had thought the second throat of the new Weber was flooding the engine or too much air or had a blockage. This morning I attended VW performance Centre in Croydon Victoria Australia. Within 20 minutes they had assessed: -that the weber was operating correctly but might need jetting -that the fault was electrical. -that they had rang an ignition specialist 5 kms away to ask them to look at the distributer which was also new. Something about "phasing". I rode to the sparkies and it took them 3 minutes to ask me why a red wire was connected to the negative side of the coil. I told them it was the kick down switch, the only wire I didnt label when the VW donk came out- reason? because it didnt come from the engine- it came from the gearbox. But I should have labelled it positive!!! because it was on negative The result was that everytime I throttled on to a point whereby the kickdown switch went on, the engine cut out. Charge? no charge. Returned to vW performance Centre and dyno tune, carbie jetted correctly etc. Dyno power output result was 76hp at the flywheel (74hp when new in a brumby) and 60hp at the wheels. Daniel told me the auto zaps a lot of power out of the engine. Would I be happy? Well I had been putting 91 unleaded in the tank and wanted it tuned to that fuel. On the way down I achieved 24 mpg (VW engine 21-22mpg) and that was with the wiring fault and a bit of towing the van for testing. I refuelled to return home, rode through the city then up the freeway to Euroa. I found that the trike now wants to sit on 120kph so I have to watch it, also in traffic when the transmission kicks down the front wheel wants to go airborne - nice 'wants to boogie' feeling. Above 4000 rpm the engine has a howling note through that exhaust, really pleasant sound. Acceleration is very satisfactory for me. And the economy on the way home? 29mpg. 190 kms 18.4 litres 9.7L/100kms VW 22 mpg 13L/100kms (range for 50 litre tank) 384 kms EA81 29mpg 9.7L/100kms (range for 50 litre tank) 515 kms or 30% more economical. or $20-24 a tank savings. By selling the vW engine and the cost of this conversion ($2000 out of pocket overall) it will take, at the rate of my current kms/year around 4 years to recoup the difference. The towbar now has an added support from the front of the trike ladder bars for peice of mind. Ready for a holiday (vacation in US).

My VW trike to Subaru conversion is located in "Meet and Greet" section. The project just got completed and this is a video of the trike with its unique roof and the ea81 mated to a full VW automatic.

thanks Bill. its been a long conversion for me as was in a wheel chair for 8 weeks then blood clots. so this is my therepy!!

Here is my video Cant drift it as too much grip and second throat on weber 32/26 isnt operating.

Thanks mate. Video in a short time. bit busy but WILL be done! It is quiet with a nice rumble and ohhh so smooth... Exhaust is now finished. Got it home. Engine got hpt today and it is a cool day so an issue there. But riding up the small mountain near home....usually at 70kph flat out in 2nd gear in the VW 1916 I cruised up there without using the second throat on the weber carb at 90 kph. says it all? <a href="http://s804.photobucket.com/albums/yy330/eaglefree/?action=view&current=exhaustfinished1.jpg" target="_blank"><img src="http://i804.photobucket.com/albums/yy330/eaglefree/exhaustfinished1.jpg" border="0" alt="Photobucket"></a>

exhaust nearly done

Being Australian up until 1976 we also were in miles and gallons (oz gallons which is I think a little more than US gallons). Then we went metric. Trouble has been since then that some organisations use litres per 100 kilometres, others kilometres per litre. So if you find it confusing now consider us! This was at a time when speed limits changed also. 35 mph went to 60 kph on town speed limit signs. For two decades after that I was still in my head multiplying that 60 by 6 to result in an approximate mph speed eg 36mph. Celcius temperature reading came in too. So to get an approximate Fhareinheit reading (cant be bothered with the spell check) you doubled it and added 30. eg if the forecast was for 30 degrees celcius then x2 = 60 and add 30 eg 90 degrees Far.... But some things never changed. Peoples height is suppose to me in millimetres eg 182mm but most palces still say 6foot. tyres pressures most are in psi but slowly we are getting to metric. Pity the world isnt uniform. I mean when are you guys going right hand drive anyway?

Thanks guys. I rode it with two motorcycle riders two eyars ago up the Snowy mountains here in Oz. The bikes were a HS springer and a Yamaha FJ1200 tourer. Both scraped their pegs and braked through corners jsut as I wanted to put the gas on. These trikes have some F1 pedigree in them I think. The roof adds a little body roll but still hands on. The sunroof is out of a Mazda 121 what we call a funtop here, two electric motors poewer the roof forward and back (not connected yet!) I have other improvements to come. A single wiper, a heater (why not, its damn cold here) and demister. Exhaust next week and more pics or a short video

The project is now complete except for the exhaust. I will post pictures once the "blow you away" exhaust is installed. The second throat of the weber carby, when it wants to cut in, causes the engine to die. but I can ride it to an exhaust place at least and get it fixed a litle later.