1978 twin charge saab powered reliant kitten

[froggy]

for cooling, the PWR cores aren't cheap, but blimey they do work very well - plenty of cooling and literally no throttle delay or turbo lag

im using a chargecooler from a focus rs to go between the turbo and supercharger and it looks like il have to make one big enough to cope with flow once the turbo is fully spooled .

plenty of room in front of the engine to fit it all in

[bulletproofbob]

don't the legacy's use charge coolers rather than the impreza intercooler???

[prisspringle]

yes legacys use charge coolers, i think there happy up to 300bhp maybe more. just make sure you've got space for the radiator for it

chris

[froggy]

the focus unit will only have to deal with 1 bar from the holset so wont be working too hard but the unit from the s/c to throttle body needs to be pretty big and i dont thing anything from a production car will be up to the job.

[nige]

cant wait to see this running

as people have said the vw way is going to be the easiest to do but getting it to work correctly will be intresting

[froggy]

the blower i have has a fixed pulley so i need to sort a mechanical bypass valve to unload the s/c under idle and cruise which can be achieved using a cheap chinese ext wastegate with a big diaphram with both ports connected to either side of the throttle body so that the s/c cant make any boost unless the throttle is open and there is no pressure difference between the two signals going to the wastegate . also this method means that you can bypass the s/c by a small amount once the turbo is fully spooled as when the throttle is wide open there is no pressure difference in the wastegate and the mechanical strength of the spring lets say 1 bar would start lifting and allow the turbo to do more of the work at the top end as the superchargers effiiciency drops at higher rpm .

[Relentless Rob]

That's nice but this....

http://cgi.ebay.co.uk/Nissan-Micra-Modi ... 1e6184f760

..has potential and could be built for £999!

[antellis]

Hi, would going through the supercharger first then turbo not work, using the s/c to help spool up the turbo. and i was under the impression that if the s/c could only boosts to say 1 bar and the turbo to 2 bar then then total boost would only be 2 bar.

[froggy]

im still reading up on compund charging and to begin with i thought the same thing ,it makes sense to put the s/c in front of the turbo but the way i read it is that the rootes charger makes boost at very low rpm which increases gas volume through the engine driving the turbine and helping to spool the turbo earlier which in return any flow the turbo compressor make below its normal boost threshold is fed into the s/c which compounds the boost pressure which increases gas flow and drives the turbine harder etc etc.

having the supercharger in front of the turbo would do the same thing low down but you lose the compound effect of having them the other way round and could restrict flow and density of the charge air being heated by the s/c before entering the turbo.

having a big turbo means you can feed a lot of air at fairly low pressure into the s/c without adding lots of heat .

its too late to turn back now anyway

[fha772]

That's looking good!!

[Renrut]

This makes me start to question how much power/torque a kitten chassis can handle before it crumples like a styrofoam cup?

Good to see lots of trying things rather than idle postulating and theorising.

From those pics I'd have thought you'd have a lot of pressure loss in the turbo before it spools up?

If it was pure compound charging I'd put the S/C after the turbo with an I/C inbetween. That way the S/C can be always driven. Not based on any experience just thinking that it would do away with the bypass valve requirement. The otherway round needs the bypass valve.

Makes me think I need a VNT turbo on the Salami...

[froggy]

the s/c is after the turbo with a chargecooler before and after it goes through the supercharger .

no matter how well the vgt turbo ive put on the 9000 it wont be able to match the low down grunt from a supercharger , from my spurious calcs running 10psi from the holset and 7psi from the blower will make around the 400hp mark with full boost at 3400prm and 200lb/ft at 2600prm .

as the supercharger has a fixed volume overall boost is controlled by the wastegate on the turbo so choosing a spring that gives a fixed amount of boost means no need to run a boost control solenoid and go proper old skoool with a bleed valve in the car for dial-a-boost if you need more power

[froggy]

moved the blower lower down to refit the alternator back to its original place and if i can do the maths when i make the blower mount i should be able to use the stock non a/c belt.

turbo manifold done using a cheap 200sx ebay job ,chopped the flange off and tweaked a couple of things and it fits

[bulletproofbob]

i would like to know if a rubber smelting plant would produce liquid rubber faster than you in this.... i can't wait to see it in glorious sideways action!!!!!

[Chairchild]

weirdly enough, planning a similar setup for my scimitar!

Picking up a citroen XM at the end of April, ripping out the 2.1 diesel lump, fitting it upto my 4 speed 'box (in place of the antique 3L v6)with a homebrew adaptor plate, and a clutch from a sierra pinto'd 1600

swapping out the standard turbo, with one from a 3L frontera diesel, and hoping to get an M45 'charger too when the swap's all done, and I've got all the little niggles sorted



got plenty of space, so fitting my HUGE intercooler after the turbo, and another equally HUGE intercooler after the 'charger





see, HOOOOGE engine bay and that's not even including all the wasted space in the nose!