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control the actuator with the ECU use a vacume actuator from something or maybe try looking under the dash of a 2g lude they use electronic actuators for the heating ducts one of those should do the job im thinking of the fresh or recirc actuator should be big enough.

just a thought.

Hey Bigelbo,

I believe Ed @ http://www.fusion-motorsport.co.uk had a bit to do with their March Super Turbo a few years back.

He may be willing to answer any questions if you have them.

Volkswagen more recently did this with their "TSi technology" in the Golf GT Sport.

"Petrol Direct Injection and Twin Charger
The unique feature of TSI technology, which Volkswagen is the first and only manufacturer in the world to offer, is the combination of petrol direct injection and twin chargers. The twincharger, a mechanical supercharger in conjunction with a secondary exhaust turbocharger, boasts one of the best output per litre figures of any production four-cylinder engine, at 90kW per litre of swept volume."

"...best output per litre...90kW per litre" ...easy challange for you there Bigelboe.

Yes, that VW offers one of the best output per litre. Not bad for a forced induction production effort.

However, the engine that has impressed me in recent years is the Honda S2000 NATURALLY ASPIRATED inline-4 1,997 cc engine produced - 247 bhp (184 kW/250 PS) @ 8600 rpm
http://en.wikipedia.org/wiki/Honda_S2000

Does the City engine run anti-clockwise like other honda engines of that era?

If so will the above supercharger have to be rotated 180 degrees or will it be okay?

ProT wrote:Hey Bigelbo,

I believe Ed @ http://www.fusion-motorsport.co.uk had a bit to do with their March Super Turbo a few years back.

He may be willing to answer any questions if you have them.

Cheers I might send him an email

Smithy wrote:Volkswagen more recently did this with their "TSi technology" in the Golf GT Sport.

"Petrol Direct Injection and Twin Charger
The unique feature of TSI technology, which Volkswagen is the first and only manufacturer in the world to offer, is the combination of petrol direct injection and twin chargers. The twincharger, a mechanical supercharger in conjunction with a secondary exhaust turbocharger, boasts one of the best output per litre figures of any production four-cylinder engine, at 90kW per litre of swept volume."

"...best output per litre...90kW per litre" ...easy challange for you there Bigelboe.

I had read that mentioned a few times but wasn't sure if it was in production yet. Interesting to see that superchargers and turbochargers seem to be getting cheap enough to be combined in mass production now. My goal of 200hp is equivalent to 124.16kw/litre heh Pretty pathetic for an aftermarket turbo honda, people make 500hp on stock block 1.8 litre motors.

ProT wrote:Yes, that VW offers one of the best output per litre. Not bad for a forced induction production effort.

However, the engine that has impressed me in recent years is the Honda S2000 NATURALLY ASPIRATED inline-4 1,997 cc engine produced - 247 bhp (184 kW/250 PS) @ 8600 rpm
http://en.wikipedia.org/wiki/Honda_S2000

That s2000 motor is freaking amazing, if you have read any of the data on how it was built, they redesigned so many things, and did so many innovative things in order to get that power reliably.

turbo trevor wrote:Does the City engine run anti-clockwise like other honda engines of that era?

If so will the above supercharger have to be rotated 180 degrees or will it be okay?

It certainly does, and it just happens due to packaging constraints I will be turning it 180deg, but the blower is symetrical and would be fine spun backwards.

Im glad this is provoking so much interest Ill have alittle talk about the drive system.

I am going to use the stock city turbo crank pulley, but it only has a 3-row multi-v belt for the a/c, and ideally I want a 5-row, the same as the stock one on the supercharger. So I am going to stick the pulley in teh lathe, and cut the 3 -row one off. I am then oing to replace it with the 5-row one from a mid 90's honda AC pulley, hopefully at the same time I will be able to space it out a bit, as I wouldnt have too much clearence with the pulleys as close together as stock. As for the supercharger side I am going to use the same A/C pulley, to get 1:1, but this time I will leave all the electromagnetic cluch setup on it. This will allow me to turn the charger on and off with ease. I am yet undecided as to whether to tension the belt by pivoting the entire supercharger, or to have a little tensioning roller like cambelts use. I think I may be forced to use the later to get the belt to bend around the engine mount, as I have to go in front of it, as opposed to around it like the stock city setup.

If you keep the clitch then when you reach boost pressure and the bypass opens, you can turn the clutch off and stop the charger, and reduce load on the engine, would work great!

3GCVC wrote:control the actuator with the ECU use a vacume actuator from something or maybe try looking under the dash of a 2g lude they use electronic actuators for the heating ducts one of those should do the job im thinking of the fresh or recirc actuator should be big enough.

just a thought.

Forgot to reply to this!

What you are talking about is what I am thinking of using, however I have been looking at cruise control actuators. What do the prelude ones look like? A little motor thing with a cable coming out?

mangusta wrote:If you keep the clitch then when you reach boost pressure and the bypass opens, you can turn the clutch off and stop the charger, and reduce load on the engine, would work great!

That was the plan

I thought of one other way to control this system too....

Separate the intake paths for the turbo and supercharger, then have a mechanism to make a 1 way valve in from the turbo, so that when the turbo is not spooled it seals and the supercharger air provides the intake. Then, when the turbo spools up, the door will blow open (Turbo intake pressure higher than supercharger pressure) then cut out the supercharger electrically... might be easier than running the intake through the turbo, then through the supercharger?

Hehe, that was my original plan, great minds think alike

The problem with it, is the way the turbo compressor works.

It needs to flow air in order to generate pressure, so the sir needs somewhere to go at all times, for it to build up enough pressure to open the 1-way valve. You could do this by having the turbo spool against a hole that was controlled by a valve, this is how the sequential turbo system works in the twin turbo RX-7. It has something resembling a blow off valve that the large turbo pumps its air out of, in order for the turbo to spool.

The thing is, you need a bypass for the supercharger setup anyway, so it doesnt make it particularily more complex to pipe the turbo into the supercharger, Ill do a bit of a paint diagram of how I think it will work.

EDIT: It doesn't work how I thought it was going to Supercharger inlet and outlet are on the wrong sides, I guess I could put a twist in the belt...

Ill show you what I was intending anway, don't ask where the turbo intake goes

For the belt, you _might_ be able to get away with a serpentine and just invert the drive with a pair of tensioner pulleys, means it won't be driving on the ribs, but should be ok. see dodgy paint



That also means you could mount the superch. to the body of the car and use the tensioners to keep up any slack from engine vibration (if you need more room etc)...

As for turbo pipng,it might be simpler to reverse the original position of the turbo, have the exhaust go down the gearbox end of the engine bay and then your intake pipes only have to come up past the filter etc, might be easier to fit under the bonnet?

Also, is there a requirement to have the turbo before the supercharger in the circuit?

Could you have the super blowing through the turbo and then once the turbo starts to overpower the super, it can open a bypass to suck air in between turbo and super.

This way the change over can be smooth, as the super can spin, or not spin without restricting or interfering with the turbo?

Also means you can put a pressure switch on the super, just make it turn off when the intake pressure is greater than the super can push (eg, supercharger set to push 6psi, then when intake hits 7psi, disengage the super as the turbo has spooled)

More teh paintshops:

I have been thinking about that system you drew all morning mangusta and I have come to the conclusion it would be essentially the same as the one I drew, with perhaps the disadvantage of adding some resistance to the turbo inlet, which might hurt efficiency. Its muche asier for the turbo to push past a resistance after it than to suck through one.

But I may end up going like that to make the piping more managable. Will still be running a front mount intercooler tho so the air has to get down there somehow.

There is a race car on trademe running a large turbo into the same supercharger i have and making 30+psi of boost into a 1600cc 4age motor . Makes about 400whp on 25psi. I would do that if the city motor would take it

True, though the idea with the intake bypass is that it opens when super to turbo pipe is less than atmos meaning the turbo is trying to suck air through the super...

Only problem I can think of is if the Supercharger pushing through the turbo means that it won't spool properly because the wastegate will be held open by the supercharger right up until it is switched off, meaning it would not be spinning fast.

Otherwise, you could fool the wastegate, by presurising the atmos side of the wastegate with the pre-turbo intake pipe pressure, so technically the turbo will create supercharger pressure + turbo pressure, but you could get around this by bleeding super pressure to keep the manifold absolute pressure at what you want, this way the transition is invisible.

so you would then have to have a bleed on the super to atmos. that is controlled by the manifold pressure, use this to back off the supercharger as the turbo spools, then when the pressure exceeds the super charger pressure, turn off the clutch.

Also means the super will cut back in when the pressure drops...

mangusta wrote:True, though the idea with the intake bypass is that it opens when super to turbo pipe is less than atmos meaning the turbo is trying to suck air through the super...

Only problem I can think of is if the Supercharger pushing through the turbo means that it won't spool properly because the wastegate will be held open by the supercharger right up until it is switched off, meaning it would not be spinning fast.

Otherwise, you could fool the wastegate, by presurising the atmos side of the wastegate with the pre-turbo intake pipe pressure, so technically the turbo will create supercharger pressure + turbo pressure, but you could get around this by bleeding super pressure to keep the manifold absolute pressure at what you want, this way the transition is invisible.

so you would then have to have a bleed on the super to atmos. that is controlled by the manifold pressure, use this to back off the supercharger as the turbo spools, then when the pressure exceeds the super charger pressure, turn off the clutch.

Also means the super will cut back in when the pressure drops...

The wastegate isn't a problem, I will have electronic boost control. I tihnk it might help the turbocharger to spool having the supercharger force the air through it.

Controlling the manifold boost using the bypass, until its maxed then turning off the supercharger was my plan. Everything will be electronically controlled so it will be very easy to change all the variables and constants. I might even be able to get the T2 ECU to control it using the boost control output.

Apparently the electromagnetic clutches on the superchargers don't like being engaged much above 3000-3500rpm, its a bt brutal on them switching in at high revs, so it will have to have a lockout thing that means once its off, you have to drop below 3000rpm to get it back.

Im intrgued by your idea of mounting the supercharger to the body, but I have a feeling that might be asking for belt slippage problems. Its not going to be too difficult to bracket back to the egine, I can probably make alighter affair out of aluminium than the big cast iron beast of a A/C compressor bracket that noramlly sits there.