Tweety to get a supercharger

[ea81slush]

Been some delays.

I used a red silicone gasket sealant that wrinkled once compressed. Dont know why.

but it caused all sorts of leaks in the manifold.

Just got it all back together after I pulled manifolds off and used a tar type gasket cement called "gasket goo" here in oz. sets hard but parts are easily seperated.

Will start up tomorrow.

[ea81slush]

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.

[ea81slush]

today went for a ride. achieved 4 psi boost but wasnt under much load so more to come maybe. I'd still be happy with 4 anyway if that was its max. seemed to pull nicely. but needs that tune up. will get that Tuesday. readouts to come.

[ea81slush]

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.

Torque last year was 440lb this year 570.

another substantial increase.

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 packe dup 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

[chromedome1964]

Great job Smokey! Thanks for letting us follow along with your install!

[ea81slush]

Its taken a while but am ready to install the new improved manifold each side of the SC12.

This is a pic of the original set up. You can see the grey airbox and how thin it had to be due to the roof frame coming very close to it as the roof was tilted back. The black manifold on the left mounts above the intake. It had an adapter/spacer alloy made by redline under it that had very littel meat to create a good seal- hence a leak.



This is the new set up. I used the spare lynx manifold half to get it shortened.. This allows for the new airbox. And I'll have one centimetre spare. The new manifold to the intake is made out of 4x2" steel tube for the top onto 75mm steel tube under to to the intake the latter being halved for the silicone tube.

Look close enough you might see the Devcon plastic steel lining insdie the lower mount to allow for smoothness for the fuel mix. Good stuff but not cheap.

[ea81slush]

Had a air leak between the custom manifold and the sC. recommend rubberised gaskets with alloy in the middle (dont know the tech term). the faces of the Sc inlet and outlet are not flush perfectly. Save yourself a lot of time if doign this conversion and use the thicker rubber gaskets.

I'm achieving 5psi now. I'm happy with that. throttle off the line is much better, smooth power delivery is not turbo like. I'm happy

[ea81slush]

Note the top mount now. this is due to the manifold now in two peices.



This is Devcon. Amazing plastic putty isnt cheap but great stuff. Use inside manifold for a smooth surface.



This is the rubber gaskets I use.



This is an electrical wire box I used for an airbox



Note the tensioner on the "slack" side of the ribbed belt.

[ea81slush]

With a slight leak in the manifold I've decided to track down some good gasket material for the supercharger especially the seal between the SC and both sides entry and exit.

Clark rubber have a material called Nitrile. Available in black 3mm or white 1.5-6mm (I think white is for food contact) Its 3mm thick and resembles basic black rubber. It is a massive $120 per metre 150mm wide. ouch! So bought 300mm strip for $40. But you dont normally use a lot.

Temp range is about -30 to +90 C. Suitable for petrol and oils.
Furthermore it might be reusable. I'll try it.

Second dyno done. no change in hp. main jets poowered from size 225 to 180.

20mpg...not as economical as hoped but torque is terrific.

[ea81slush]

All leaks fixed with NITRILE 3mm rubber gaskets. Great stuff resistant to gas.

Can now concentrate of cosmetics. Two vW Scat belt guards protect fingers- a legal requirement in Victoria.



There are two belts now and too wide for a single guard.



3 wing nuts with welded bolts make detachement easy and quick.

[ea81slush]

Nitrile rubber 3mm thick was superb and highly recommended to seal manifolds that dont go above 90 degrees C.

Have had delays but ahve compiled most of the parts for water injection.

For those that have followed this project and dont know a alot about superchargers (and I didnt 6 months ago) when the engine gets boost form the blower detonation inside the combustion chambers can easily occur. A few measures can be taken to eliminate this.

Retard the ignition. The ea81 Brat engine runs at about 8 degrees advance at idle and often runs to 32 degrees at full advance, The blown engine doesnt need this amount of advance so I had my electronic distributor recalibrated to alow it to run to 24 degrees at full advance. After a few days running it still detonated (pinged) up hills So I retarded the timing at idle from 8 degrees to 2 degrees and it vanished. However this meant I was not running the engine at its optimum power point.

Water injection. Its been around since Adam was a boy. The concept is to inject water as a vapour into the combustion chamber to stop detonation so it allows you to run the timing at 8 degrees and not have pinging on boost. It will give more lower and 1 or 2 psi extra is common.

How to install it? There are kit available. Autospeed have a DIY system that you make up using a 12volt/220volt inverter. There are some very good ideas on their web site.

Browser Warning .
I decided to not go the inverter route and prchase a 220psi pump from Snow performance.

They were really quick in replying to my emails too.

Snow Performance : Snow Performance Water Methanol Injection Systems. The Best Most Accurate Gas and Diesel Water Methanol Injection Strategies for Fuel Injected Carbureted Turbocharged Supercharged good service. Their 150 psi pump is no longer available. They have kits also. The pump is quiet in operation.

So Tweety has a draw through system with a SC12 Toyota supercharger. Mening gas and air goes through the blower to the engine. There are many debates on the www about the best place to locate an injection nozzle/s for water injections. So I wont bore you with the arguements.

I've decided to palce it between the carbie and the blower. My reasons?

1/ even though I'm running only 5 psi the blower doesnt get very warm. adding water vapour to the mix will have a cooling effect on the lobes as well as a sealing effect that could add 1 or 2 psi to the boost. 2/ placing it after the carbie wont casue rusting issues to components in the carbie 3/ That manifold has vacuum, the injector wont be battling against boost.

The components.



Nozzle/s. Any smaller than 0.3mm and atomisation wont happen. Neither will it happen with less than about 80psi. Snow also have very small nozzles. I ordered their smallest nozzle that if running continuously will empty the small tank in 25 minutes. So with this revellation only one nozzle is required.

Snow nozzles come with a small filter insode them so you want easy access to it for cleaning.

Water tank

On tweety weight has been creeping up with the roof mod and supercharger and radiator etc. So I'm not wanting to carry the normal quantity of water like you would a car say 1.5 gallons. So I found a 2.5 litre 0.6 US gallon windscreen washer tank in black which will help with algae.

Water injection will only be used on boost. I'm hoping I will use one tank of water to one tank of gas. When towing our trailer (caravan) it will be on boost more often.



Filter

I've taken Autospeeds advice and purchased a caravan fridge filter. They come with quick release hose ends and last 1500 gallons.

great idea.

Pump

220 psi Snow performance pump. A relay is recommended.



Tubing

Common water injection line

Pressure switch

Many pressure switches on the market come on at 5, 10 or 15psi boost. I found one in Oz that turns on at 0.5 psi. To be hooked up to the pump earth wire.

Check valve.

This valve before the nozzle stops the vacuum sucking water when the pump isnt operating.

That's it. I'd also recommend reading up on the web for your application.

I'm hoping to install it in the next week or so.

[ea81slush]

Water injection.

It isnt easy finding a simple boost switch unless you want one to come on at 5 or 10 psi. I wanted one to come on at 0.5 psi to activate the pump.

Found one for $43 plus postage (Oz). This switch is made by a Chinese firm called LEFOO. Item number LF42. Not much info on the web except that its used for remote operation etc.

Hooked it up to a test light and blew into it to find it only came on every second time I blew into it??? So pulled it apart.

This is the switch



Note the two white items on the right.

When I pulled the switch off the diaphram housing it exposed these peices. One is a small rachet shaped like a hole saw and the other shaped like a space station lol. Anyway they were replaced with a small length of tube. reassembly and it works just as I wanted each time I blew into it.



With the tube in place



The discarded internals.



This will be hooked up to the earth lead of the water injection pump and it will be mounted on the manifold with an extension peice. Rated at 80C temp.

dont know the temp a manifold will get up to but play it safe.

[ea81slush]

Some progress after two days working on this trike.

I've taken some advice to make certain there is no impeding of the airflow into the carbie. Used the base of the previous smaller airbox and installed a larger outer case.



But this time air wont just enter from the front but enter at all sides.



This will prevent the foam trumpet filters from getting wet.


Intalled most of the water injection system except the injector and pressure switch.





injector line was purchased from a hose retailer. got the 600psi stuff instead of 250psi.

So now I have to take off the inlet manifold to install the single injector, get an adapter for the pressure switch to be mounted on the ea81 manifold, fit a relay to the pump and wire up the pressure switch, eventually fir a low water warning light, also a no flow light and get that last dyno tune.

[ea81slush]

Final post for this supercharger install.

The last dyno tune was done. No increase in figures regardless of water injection.

I had a lot of blow by. that is fumes in the crankcase fining its way to the pcv or the valve cover breathers. this is more likely in a blown engine. so a one way valve in one said valve cover with mini air filter allowing sucking of air only and on the other side the vent goes to a "catch can" so oil in fumes will be caught before the fumes go into the engine to be burned. works well.



This project I'm happy to declare was a success. Supercharging a flat 4 be it VW or Subaru is not so difficult in my view. A 1800cc 4 cylinder engine can be transformed into 6 cylinder 2400cc powerhouse with great towing ability and low down torque. A good test is a mountain on the way to my residence in Oz.

Whereas the vW 1916cc engine slowed to 40mph in second the Ea81 Subaru engine 50 mph the supercharged engine made 65mph in third gear of the automatic box.



furthermore reliability decreases as boost is increased.

This supercharger has a max of 5psi.

With water injection and calibrated dizzy it is safe to reduce the SC pulley from 5 inches to 4 inches giving about 9psi. It should fly!!

Initially after replacing the VW engine with the not quite so ancient ea81 engine I was disappointed with the performance. Yes the Subaru revved better, was more reliable, was less cost to repair (in Oz) and was much more economical. But I lost 14 hp with the automatic. o a solution was sought. Now I have a powerful engine that is easy to tune/work on and adjust eg valve tappets. I think the only improvement I will consider apart from more boost is a single point fuel injection unit.....one day. I want to ride it for a while first.
The SC install is a good easy cheap and uncomplicated remedy.

If you decide to Sc your vw engine or other engine I'd recommend it. Good luck.