twincharger setup

[Lith]

30PSI at 1200 rpm, had to vent the air off back to 20 psi,
made for massive wheelspin, and felt so much faster,
but severe lack of top end power as the SC could just not pass enough air for much more than what was probably around 3-400hp.

Took the SC back off and ran Turbo only again,
made the car much quicker on the circuit, but the Twincharge would be awesome for a road car.

IMHO the turbo would/could have been the reason it fell over top end, I believe people think about this setup wrong. When you put the turbo on, you are turboing the supercharger - not the engine. The supercharger represents the engine X whatever ratio the supercharger is forcing air at.

For example, if I were doing this kind of thing on a 1GGTE, I'd probably try and run the supercharger at around 1.5 (around 7psi if it were just the supercharger) and then treat the turbo choice as though it were going on a 3litre.... given you are feeding a positive displacement supercharger which is mashing another half atmosphere into a 2litre engine, if that makes sense?

Imagine putting a T3 (big or not) onto a 2JZGTE and running any boost through it, it would fall over up high too. On a 1GGTE with a SC14 pushing 8-9psi I would aim for something like a GT3582R pushing say 9psi into the supercharger. The compound effect if my Fridayitis maths are right would result in 20psi at the plenum, and a 2litre 6 making 500+hp with bugger all lag.

[matt dunn]

IMHO the turbo would/could have been the reason it fell over top end, I believe people think about this setup wrong. When you put the turbo on, you are turboing the supercharger - not the engine. The supercharger represents the engine X whatever ratio the supercharger is forcing air at.

possibly but not in this case.

the car was run turbo'd for probably two years and was awesome to drive with good top end, and nothing down low, like most race cars,
before we tried the SC with the same turbo.


Ran it as the ashburton street sprint and was usually in the top 5,
put the SC on it and lucky to make the top 30 or so.
Fitted a piece of uU shaped alloy pipe back in place of the SC overnight on saturday, and jumped back into the top few.

Ask Mr Revhead about driving it home from school in the wet with a locked diff, lol.
I'm sure he'll remember the car.

[AE25]

sounds like you could've changed pulley ratio lower for less low rpm boost.. or some sort of progressive wastegate controller so low rpm traction loss didn't slow you down?

charged v8... me thinks you'd have to do some serious thinking about how much power you want from this thing. even an eaton on top or a twin turbo is some serious mumbo for a ke30. even that is expesive enough. have you considered how much a suitable gearbox, hilux/ford 9" etc will cost.. brake/suspension upgrades.. an ecu to control it.. manifolds, custom intercooler, piping etc etc. 10k would be low balling this triple charger idea me thinks.

how about an eaton on top with one of those sandwiched intercoolers below it sitting on the manifold.. then a twin turbo setup blowing thru a decent sized vertical flow front mount. entering both sides of the intercooler at the bottom tank and exiting with one pipe on the top tank into the supercharger. no bypass valves required. the sc sucks thru the turbos and intercooler. once turbos come on boost its a compound system and use wastegates to control overall boost level.

how much power is enough? this sounds like quite a weapon and capable of blowing std internals apart you might find some ideas in the aussie horsepower hero dyno events

[steve murch]

you dont always benifit from having lots of boost down low infact alot of smaller engines dont like due to the fact they cant cope with the volume and detonation becomes the issue.
me personaly its a more a novelty to run both
a supercharger robs 33% crank power to turn
turbo take 5-7% crank power
there are many ways to make turbos more effecient down low,extra displacement doesnt hurt,if you want low down v8 grunt buy one.
then combine the v8 with the turbo? now your talking from best of both worlds.
i did the turbos on mark chromies world record holding edurance river boat,500cu ford twin turbos,14psi,full boost 2000rpm,2000hp plus
or at the other end a little eng running big boost 40psi plus will make the power but not the torque.
little engines in light cars perform very well,power to weight has a bigger effect than making more power or bring it on sooner.
the old saying you cant have your cake and eat it too,