Raptor Compound Supercharging for ECOTEC

[delcowizzid]

In the late 1930's Mercedes Benz used compound supercharging on there Grand prix cars. In this system one unit pumps into a second smaller unit increasing boost pressures to as high as 38 psi.

even WW2 planes used 2 different sized chargers too

[Raptorsc]

Size of the second stage is no issue at all, they go smaller because they can, we aren't because we don't need to. If you are running rootes type blowers you will take every opportunity to reduce weight and size since the things are heavy and power hungry.

In the case of aircraft, you make everything as light as possible, so if you can get away with smaller on the second stage then you do.

For us we have no such limitations, we will use the same compressor in both stages because we can, enough room etc


Paxton did it with 2 identical units

[Raptorsc]

I have been searching the web the last 30 mins looking for the historical stuff on the paxton twin system ......... nothing. I have somewhere (no idea where) a photocopy of an old magazine article about this system. Judging by the rarity of info about it I might have to dig it up sometime, even the Paxton freaks in the USA will be coming to lap it up

[nermal]

i have been reading up on this forum about the 'css' and i am completely blown away cause as far as i knew at first it was about getting up to 20psi out of an ecotec, and then a couple of days after that i read that it could be producing up 24psi, and on top of that people are thinking of trying to get more psi, i cant help to ask isn't that too much out of and ecotec even if it has been fully worked from the inside out cause as far as i have found i can only find engine components that can only handle up to 20psi, im only new at this and i have that feeling that i might be getting a bit over my head too quickly.

[Raptorsc]

Nermal

Never fear, let us do the testing and see what we have or haven't got and what effect on everything it has.

There will be lower pressure versions of this system for sure however the idea of it in the first place is to run more boost than you can get from the single unit

[eaton v8]

well ive seen a setup on a malloo ute on youtube where a side mount feeds a top mount!!! so i guess this is sorta the same principal... very loud induction noise!!!

i have a feeling if it was a red one that i seen that in a mag and marks workshop in wa put it together

[Raptorsc]

Eaton V8

Yes I have also seen that one, there was some complaint about total noise of the system, goes hard but damn she's a loud one

[Raptorsc]

Supercharger Compounding 101

Theory

By flowing the air through two compressors, the pressure ratio becomes the sum of the two individual centrifugal compression ratios. The result is a much higher total boost pressure available to the engine.

Thats it for today

[nermal]

Nermal

Never fear, let us do the testing and see what we have or haven't got and what effect on everything it has.

There will be lower pressure versions of this system for sure however the idea of it in the first place is to run more boost than you can get from the single unit

i would be more that happy to go over 20psi because if i went any lower like 15-16psi then there would not be any point in getting the 'css' in the first place, i just wouldn't mind knowing if there are engine components out there like forged pistons, conrods, crankshaft ect, that would be able to handle over 20psi because i cant find any, and it would most have to be for a 4.2l stroker kit of some sort cause thats what i am looking at getting.

[Raptorsc]

For sure you can set up to run 20psi, drop the compression to 8.3:1 or thereabouts, go forged pistons and run some decent rods and MLS head gaskets.

COME would be totally comfortable making you a stroker kit for 20psi.

I think everyone needs to take a look at the pressures being applied to stock ECOTEC's now, with 16psi boost seeming to work quite fine if the tune is spot on, therefore for another 4psi the motor can't be needing too much more strenght. Forged pistons and something like an L67 rod are going to be close to a real solution.

Not seeing any huge difficulties yet, we will be running 16psi on the stock motor

[nermal]

For sure you can set up to run 20psi, drop the compression to 8.3:1 or thereabouts, go forged pistons and run some decent rods and MLS head gaskets.

COME would be totally comfortable making you a stroker kit for 20psi.

I think everyone needs to take a look at the pressures being applied to stock ECOTEC's now, with 16psi boost seeming to work quite fine if the tune is spot on, therefore for another 4psi the motor can't be needing too much more strenght. Forged pistons and something like an L67 rod are going to be close to a real solution.

Not seeing any huge difficulties yet, we will be running 16psi on the stock motor

oh ok yeah the 8.3:1 from comeracing is the kind of long stroker kit i was looking at getting anyways mainly because it is the strongest that i have heard of so far, and because i am defiantly going to be strengthening the engine before i supercharge it just incase the worst was to happen and to get even more power out of the engine.

[Raptorsc]

You biggest concern at this power level would be the gearbox, you should be looking for a T56 transmission upgrade, unfortunately they aren't so cheap

[LJS-UTE]

Mal Wood do a T56 conversion for the ecotecs... i know of a few that have been done for YT blower set ups. i personally know of a VS and a VX being done, have a chat to find out your options, someone told me ballpark figure is around $5000-6000, dont take that for gospel though, may be totally incorrect!!

[MaN|aC]

oh ok yeah the 8.3:1 from comeracing is the kind of long stroker kit i was looking at getting anyways mainly because it is the strongest that i have heard of so far, and because i am defiantly going to be strengthening the engine before i supercharge it just incase the worst was to happen and to get even more power out of the engine.

Take it from me, I've destroyed two COME Racing engines with 20,000kms apperantly they not too strong mate...
Im currently rebuilding my third stroker atm but this time COME Racing isn't building it.

[Raptorsc]

^^^^ some good advice

There are just a few good ones.


Maniac - is the current build ok for 20psi ?

[MaN|aC]

Once the intercooler goes on then I'll test your smallest pulley available Tim, my current engine still has the same specs as the COME Racing but im using different parts.

When I blow up this engine im going back to my original 3.8 ecotec

[psivyv6]

maniac
u seem 2 no a bit about stroker kits, do u no how much a kit wood b for a vy including labour off the top of ur head?

[MaN|aC]

$10,000 for the long motor

[greenfoam]

Maniac is your car a series 1 :? there was a guy at the easternats with a turbo 304 making 340 rwkw, stock engine!: 2 grand and you would never break another ecotec again

[nermal]

Take it from me, I've destroyed two COME Racing engines with 20,000kms apperantly they not too strong mate...
Im currently rebuilding my third stroker atm but this time COME Racing isn't building it.

was that over there recommended psi rating or under because they are rated at 20 psi at most so they say.

[nermal]

Mal Wood do a T56 conversion for the ecotecs... i know of a few that have been done for YT blower set ups. i personally know of a VS and a VX being done, have a chat to find out your options, someone told me ballpark figure is around $5000-6000, dont take that for gospel though, may be totally incorrect!!

sounds interesting, i was wondering if it was possible to put a t56 on an ecotec a few weeks ago, do you know if its an easy conversion if the ecotec is already a manual or will i have to still change the whole clutch reservoir and pedals ect, to in order to fit the t56

[Raptorsc]

Nermal

was that over there recommended psi rating or under because they are rated at 20 psi at most so they say.

The 10psi rating matters when we are pumping in a single stage, in dual stage we can come back to 8psi per charger (real easy on the chargers) and still make final pressure of 16psi!

[nermal]

Nermal



The 10psi rating matters when we are pumping in a single stage, in dual stage we can come back to 8psi per charger (real easy on the chargers) and still make final pressure of 16psi!

oh ok thanks

[vyls1wa]

sounds interesting, i was wondering if it was possible to put a t56 on an ecotec a few weeks ago, do you know if its an easy conversion if the ecotec is already a manual or will i have to still change the whole clutch reservoir and pedals ect, to in order to fit the t56

Malwoods makes a kit for the ecotech, from memory it was like 6-7 grand.

[HoldenManDan]

my t56 is sitting out the back waiting for my 4.2 L67 to be finished... its going to be fitted to my already manual vs, and all the parts for the conversion plus delivery totalled $8100. It included: (directly from the receipt)

SUPPLY NEW T56 6SPEED GEARBOX. NEW CLUTCH KIT
AND FLYWHEEL, NEW BRAIDED LINE, NEW ENGINE PLATE
AND BELLHOUSING,, NEW GEARSTICK AND KNOB, MOUNT
AND CROSSMEMBER, FRONT HALF OF SHAFT WITH NEW

UNI AND SLIP YOKE

you could bring the price down a bit if you were happy with a reco box instead of a new one, but i'm not cutting any corners with this build.

ummm MaN|aC, my stroker is getting built with parts supplied by C.O.M.E, i'd be interested to know what parts went into your previous builds that failed... a PM detailing what parts were in them would be great if you could!

Cheers