Project Supracharger

I've discovered that Mercedes used a stepper-motor bypass-valve on the SLK 230 & C230, unearthing one of these may be easier than reinventing the wheel.

Here are some pics I've found, it's a 3 pin stepper motor which the AEM should be happy to manage.

I've sourced the components that I think will do the job and they'll be with me by Tuesday.

Looks like there's to be a few bits of Mercedes added into the Supracharged mix.

This Merc stepper-motor "Air-Flap" is an efficient beast compared to the Jags leaky actuator "Bypass-Valve".

The Merc charger system has an electronic clutch on the supercharger pulley and this "Air Flap", vents post-charger overrun air back to the air filter box and unlike the leaky bypass-valve, when closed this gives an airtight seal.

With the AEM controlling this flap as a bypass, without the boost leakage it'll perform a lot better and will be able to programme a little bypass-leakage at gear-changes to soften this new found wall of torque.

End section of a Jag b-v casting and a flange cut from scrap and one side is ready for welding, but the Merc plug and materials for plumbing the other side of the flap won't arrive until Bah Humbug is over.

David you went to a photoshoot with an unpainted bonnet!!!!

You could have called in at the paint shop on the way!

david you went to a photoshoot with an unpainted bonnet!!!!

 

You could have called in at the paint shop on the way!

I lifted the front and then spent most of a week with frozen fingers getting the Old Girl looking smart, which meant not enough time to install the coil-packs for the Big Day.

I've no shame that the car is a project in progress/development, it is what it is and there were/are more important jobs to do.

I've no shame that the car is a project in progress/development, it is what it is and there were/are more important jobs to do.

That's how I feel about my GMC Typhoon that's been sat engineless for five years in the garage whilst I work on the workshop and garden to re-build it in, (sometimes, when the weather is just right).

Then there's the Supra to de-coke and replace the timing belt and fit the new wheels and tyres and........

That's after the Smart ForTwo suspension and door handles and new right front wing, of course.

Multitasking is so much fun!

I'm right on the cusp of cracking final developments and perfecting this 'mythical' conversion, yet there's more interest in a bonnet that's not shiny.

I'm right on the cusp of cracking final details and perfecting this 'mythical' conversion, yet there's more interest in a bonnet that's not shiny.

Think of it this way David, all this talk of polishing bonnets should attract readers like moths to a flame.

You could also say that your car is like a diamond in the buff, just about to be exposed in all it's glory.

Ooer!

I was planning to have this electronic-flap converted and ready to fit by now, however, it's 10 days since ordering and apparently it'll be another week before I'll receive a piece of aluminium to complete the job.

That'll be 17 days for a section of pipe the size of a shot-glass to travel 45 miles, because of two days National holiday, little wonder our economy is a mess.

"Bah Humbug" is an understatement.

I

I was planning to have this electronic-flap converted and ready to fit by now, however, it's 10 days since ordering and apparently it'll be another week before I'll receive a piece of aluminium to complete the job.

 

That'll be 17 days for a section of pipe the size of a shot-glass to travel 45 miles, because of two days National holiday, little wonder our economy is a mess.

 

"Bah Humbug" is an understatement.

Ho ho ho deer! You should have bucked up your ideers and asked someone deer to you to get you the pipe as a present and Santa would have deer-livered it on Christmas Eve!

You obviously have no-eyed-deer David.

Doh!

My Festive ideers rained on.

My Festive ideers rained on.

You sound totally guttered. Pipe down and don't get your goat up.

That Vixen courier has stopped you Prancer'ing about this Xmas.

Keeping me "Prancer'ing about", more like.

With this increase of torque and without a bypass-valve, controlled normally-aspirated delivery at light throttle is almost nonexistent, this wall of torque is permanently there, on wet roads 2mm of pedal gives a clean launch, 4mm and I'm drifting, the accelerator pedal is an on/off switch.

My eyes sinking into their sockets dynamometer reckons there's a lot more power and it wants to last longer than it's 6.1k rpm rev limit which can be

exceeded exceedingly easily, resulting with a HUGE FLAME & LOUD BANG.

Precise throttle control/feed is essential at any speed, it's a Beast that wants to kill me first chance it gets.

I chose lower exhaust-gas temps over higher supercharger-temp and run the water/meth for good measure until the remap that has been delayed.

So I'm going to have to be sensible and re-plumb the existing bypass-valve to pre-charger vacuum which works properly up to mid-throttle and gives the best of both which will still be plenty enough for winter driving, but before I do, I'll take a video Chris Bailey would be proud of.

You love a good

It's the smiley face thread

This morning the aluminium pieces arrived, an offcut of 64mm O.D. 38mm I.D. pipe and a 38mm O.D. straight hose-connector.

After tinkering on my pals old lathe to make them friends.

Now the two adaptors just need a visit to the TIG welder.

I'm not happy with the muck trap it will create, but don't think there's sufficient space to raise it up enough to prevent without making alterations to both the supercharger-induction elbow and charge-cooler.

The weather's not conducive but now I have the component pieces, I'll have a tinker and see if there's sufficient bonnet clearance to offset the centres of the adaptors and raise it 10mm to give the plumbing a flat self cleaning bottom inside before I have it welded.

I've had a jiggle around with my new alu-jigsaw puzzle and here it is propped into place, in this position the weight of it is slung and it fits nicely alongside oil-breather pipe and around the ICV & loom.

The dogleg needs docking an inch, but you get the idea.

This way up, offsetting the adaptor centres to prevent an oil-trap improves the fit, with plenty of space to insulate the bottom for good measure.

It assimilates sweetly for a plan B.

My camera tells me the cards locked? so here's a phone pic.

After fording floods twice to get my 3D aluminium jigsaw puzzle to the welder and back, I then found there were no lathe tools suitable to finish the job, so have hewn it inside and out by hand and also minimised the length of the adaptors to keep it compact as possible.

The Merc plug & tails have arrived and the unit is now ready for test fitting and final preparations for a pitstop swap.

I left the casting I.D. mark on as I thought "S1" was quite appropriate.

I rammed the dogleg with rag, cut an inch off with a hacksaw and pulled out the rag.

The Merc air-flap now fits a treat with a mm or maybe even two to spare.

Fortunately, after replacing the Toyota ICV with the Audi unit there was an earth and two wires running to the ECU remaining in the loom, which made a simple job of the wiring.

I know that pin 1 is 2v -12v, pin 2 is 12v ign feed and pin 3 is earth, but don't yet know what frequency it needs to operate.

Final fitted and pleased with the result

To late mate, I ate the chicken sandwiches earlier

The AEM gets another job to do

I said "air-flap" not "cat-flap"

Love this build. Really innovative. Is your checklist nearly complete?

I have a question!!!!!.....

Have you painted the bonnet yet?????

Love this build. Really innovative. Is your checklist nearly complete?

Thanks for the build love.

My checklist for the remap is almost there, waiting for arrival of new HT leads, it needs an oil change and a pair of frequency-convertors for the ICV and air-flap.

Both the air-flap and coil-packs will be plug & play ready for a pitstop fit in the car park before mapping.

The checklist for remaining project plans are highlighted in green in "my garage" (Labyrinth).

I'm confident that it'll now produce some 'proper' numbers, yet suspect that assimilating a larger throttle-body will be next on my list.

With this pioneering project of research & development and/or trial & error outside in the elements on my daily drive, innovation is compulsory.

I have a question!!!!!.....

 

Have you painted the bonnet yet?????

I knew your car would attract a lot of pussy!

What's your secret David?