Rotrex supercharger

[a1rak]

Hi Guys, I know this is a bit off topic being the Cerbera Forum but as I know a lot of you guys on here and always get some interesting replies to my other posts.

I have always been a forced induction fan hence the Supercharged Cerbera.

My other car is a Track based Peugeot 306GTI 6 also running a Rotrex supercharger. It is a lot of fun and has been built for track use but is road legal.

Now Don't laugh !!!!!!!!

If I removed the Alternator, Power steering pump and Rotrex charger from the engine and mounted them in the boot and then drove all 3 of them with a bike engine so that the charger was always boosting to 25PSI irrespective of the main engine RPM do you think it would work and could be successfully mapped.

The engine already produces 370BHP so I'm not interested in more power just a better Throttle response and more torque low down. Its also a bit off fun to try something very different to the norm.

I can easily sort out the mechanical and electrical side but what I'm not sure of is could it be mapped and would I get the results I am hoping for.

I know I'm going to get some witty replies to this but just keep them coming silly or serious.

[spitfire4v8]

I love off the wall thinking like this ..

take a leaf out of nic mann's book .. vid here

https://www.youtube.com/watch?v=Hu_uBuNsT6c


years ago I tried to convince a cerbera owner to supercharge his LS cerb .. but not with an engine driven s/c .. I argued that the last thing needed was more power in traction-limited first and second gears (and even third didn't need much more power) , so I put forward the idea to drive the charger off the nose of the diff .. rising boost with rising road speed .. sadly nothing came of it.

[NMNeil]

Mmmmm.
Upgrade the alternator and have a big electric turbo/supercharger in the boot.
Only need to turn it on when needed, and may be better than all the fuel/exhaust/heat issues with a bike engine in the boot.

[a1rak]

spitfire4v8 said:

I love off the wall thinking like this ..

take a leaf out of nic mann's book .. vid here

https://www.youtube.com/watch?v=Hu_uBuNsT6c


years ago I tried to convince a cerbera owner to supercharge his LS cerb .. but not with an engine driven s/c .. I argued that the last thing needed was more power in traction-limited first and second gears (and even third didn't need much more power) , so I put forward the idea to drive the charger off the nose of the diff .. rising boost with rising road speed .. sadly nothing came of it.

Julian, do you think you could map it successfully if it had an Emerald or similar ECU.

[Imran999]

NMNeil said:

Mmmmm.
Upgrade the alternator and have a big electric turbo/supercharger in the boot.
Only need to turn it on when needed, and may be better than all the fuel/exhaust/heat issues with a bike engine in the boot.

I like that idea!
https://duryeatechnologies.com/duryea-electric-sup...

[FarmyardPants]

I think it would be very difficult to get a stable idle speed with 25psi of pressure trying to leak past the throttles. And assuming enough fuel is supplied for the massive influx of air, the slightest opening of the throttle would buzz the engine past the redline followed by engine destruction. That’s my guess .

[a1rak]

FarmyardPants said:

I think it would be very difficult to get a stable idle speed with 25psi of pressure trying to leak past the throttles. And assuming enough fuel is supplied for the massive influx of air, the slightest opening of the throttle would buzz the engine past the redline followed by engine destruction. That’s my guess .

Well you would need a blow off or dump valve so with the throttles closed the vacuum would operate the dump valve and the would be no boost with the throttles shut as it would be bled off. That's fairly standard stuff on a forced induction set up. It would have to be a good size dump valve though.

[a1rak]

Imran999 said:

I like that idea!
https://duryeatechnologies.com/duryea-electric-sup...

I bet its not cheap, any ideas of the cost.

[a1rak]

NMNeil said:

Mmmmm.
may be better than all the fuel/exhaust/heat issues with a bike engine in the boot.

I think Id prefer all the heat issues in the boot rather than in the engine. It would be good to get some of the necessary parts for the charger, oil cooler , plumbing etc and all the parasitic losses of the alternator power steering pump and supercharger off the engine. I think the weight distribution would be better to. You would not even need a crankshaft pulley so the rotating mass on the engine would be massively reduced.

I know I would have the weight of a small bike engine in the boot but all the fuel, batteries and electrics are already there. I think Id need around 10 or 15hp to drive the set up so maybe a modern 125cc engine would do the job. Could have boost control just by varying the bike engine speed.

[NMNeil]

Another thought bordering on insanity. An air compressor complete with tank in the boot, again electric powered.
Run the compressor to get the tank full and use as needed.

[ridds]

NMNeil said:

Another thought bordering on insanity. An air compressor complete with tank in the boot, again electric powered.
Run the compressor to get the tank full and use as needed.

Look up the USA bumpered Focus rally cars.

[TwinKam]

The volume of air involved at even modest boost pressure makes any form of storage impractical, or the benefit very short lived.
Re the '03 Focus: clever, 45 litres is a biggish tank (which they did well to 'hide'), but I wonder how many seconds it gave them on increased boost, or was the advantage gained more through the increment of air bypassing the restrictor?

[NMNeil]

ridds said:

Look up the USA bumpered Focus rally cars.

I shall, thanks.

[Byker28i]

NMNeil said:

Another thought bordering on insanity. An air compressor complete with tank in the boot, again electric powered.
Run the compressor to get the tank full and use as needed.

Yeah but just use Nitrous if you're going to use compressed gas and plumbing?