Twin Charge!!! (the best of both worlds)

[cali yaris]

LOL, so true!! dammit!

[turboecho2005]

Damn Clean Bay!!!...

Looks f'n nice in there. Too bad we never got the Tc in canada :(

[richardholdener]

I recently ran a test on a 2003 supercharged Mustang Cobra equipped with an Eaton supercharger. We ran the 4.6l 4-valve motor first with the supercharger alone, then with a pair of turbos feeding the supercharger and then again with the turbos alone (no blower). The test on this compound system demonstrated that the blower alone was the least effective in terms of power per pound of boost while the turbos alone were the most effective. Having the turbos feed the blower greatly improved the low-speed power production, but reduced the power output per pound of boost (basically the compound system ended up between the blower and turbo). Remember too that this compound system will dramatically increase the boost pressure supplied tot eh motor. Running the blower at 11 psi and the turbos at 7 psi resulted not in a total of 18 psi in the manifold but actually 23 psi (dropping to 20 psi at power peak). The compound system improves average power but reduces the power of turbo alone. I am currently testing a compound turbo system (large turbo feding a small turbo) on my 3-cylinder turbo Sprint motor.

[Sabretooth]

I believe the Twin charge TC made like 350whp or something close.

[cali yaris]

I heard that too -- and could never find a dyno chart, which you would think they would want to show off. When I saw that car, it wasn't running.

[richardholdener]

This car was on display at SEMA but was more of a gee whiz item. The combination of a centrifugal supercharger and turbo is a bad match. Better to combine a positive displacement supercharger and turbo to broaden power curve.

[Tamago]

more trouble then it's worth...

[PHXDEMON]

Good luck cramming all that in the engine bay

[Thej3sta2]

Yeah 'inthemix' just got a turbo scion. Sharp man, sharp

[Tamago]

Originally Posted by richardholdener

This car was on display at SEMA but was more of a gee whiz item. The combination of a centrifugal supercharger and turbo is a bad match. Better to combine a positive displacement supercharger and turbo to broaden power curve.

exactly.. that's like putting two monkeys and one bowl of poo in a room and expectin them not to make a mess ;)

[gboezio]

The idea have been discussed and discussed in the BMW community, we assumed that it's more about the "bling" factor, people will always go wow and want to pop the hood to check that insane setup. But in reality, high performance happens at higher RPM, the RPM should never come short of 4000 RPM on a track or road race, leaving the starting line is at WOT and traction is controlled trough the clutch if you ever want to get ahead of the pack, on a road race you just pop two gears and you are boosting within one second.
If someone would build a dyno queen and need help to spool the monster it could do some good and will need a SC bypass valve or the SC would act as a butt plug for the turbo, for this purpose NO2 is usually used to jump start the turbo, as soon as it's generating enough exhaust gases under boost, it will get to peak efficiency pretty easily.
A Yaris is a bad car for running long stretch races, it's nimble and quick around a short track and will benefit from a smaller turbo that will spool fast and make instant boost from 3000 to 6500, this makes more average horsepower going trough the gears than a fat turbo.
Consider the cost and complexity of a compound setup an overkill for speed purposes.
More rotating mass, higher gravity center from the high placed extra weight.
Two compressor, twice the chance of one failing, not to mention that the first one will kill the second then the engine (ok the IC will hold the bigger debris).
Beside that, the Yaris is a very small engine and pulling horsepower from the crank is worth a thread by itself, using power that have been produced trough the small pistons, rods, crank to spin a SC, while the turbo is there and getting the free exhaust energy is a big no-no to me, I feel that these economically engineered parts are the weak link more than the induction capacity, I'd rather want to have this power available to the wheels.
If one is not afraid of complexity, a SC clutch system could be done to desactivate the SC when the turbo is spooled up, along with the SC bypass valve...and it's not gonna win the race
Why not putting that money on the suspension, tires, brakes where it will definitely gain overall performance.
My two cents

[Split]

i would love to drive a golf GT just to see what its like to make that much power out of a 1.4L motor. that's just unreliable. Germans make the most exciting products, but consequently they're so damn unreliable.

[Tamago]

Originally Posted by gboezio

The idea have been discussed and discussed in the BMW community, we assumed that it's more about the "bling" factor, people will always go wow and want to pop the hood to check that insane setup. But in reality, high performance happens at higher RPM, the RPM should never come short of 4000 RPM on a track or road race, leaving the starting line is at WOT and traction is controlled trough the clutch if you ever want to get ahead of the pack, on a road race you just pop two gears and you are boosting within one second.
If someone would build a dyno queen and need help to spool the monster it could do some good and will need a SC bypass valve or the SC would act as a butt plug for the turbo, for this purpose NO2 is usually used to jump start the turbo, as soon as it's generating enough exhaust gases under boost, it will get to peak efficiency pretty easily.
A Yaris is a bad car for running long stretch races, it's nimble and quick around a short track and will benefit from a smaller turbo that will spool fast and make instant boost from 3000 to 6500, this makes more average horsepower going trough the gears than a fat turbo.
Consider the cost and complexity of a compound setup an overkill for speed purposes.
More rotating mass, higher gravity center from the high placed extra weight.
Two compressor, twice the chance of one failing, not to mention that the first one will kill the second then the engine (ok the IC will hold the bigger debris).
Beside that, the Yaris is a very small engine and pulling horsepower from the crank is worth a thread by itself, using power that have been produced trough the small pistons, rods, crank to spin a SC, while the turbo is there and getting the free exhaust energy is a big no-no to me, I feel that these economically engineered parts are the weak link more than the induction capacity, I'd rather want to have this power available to the wheels.
If one is not afraid of complexity, a SC clutch system could be done to desactivate the SC when the turbo is spooled up, along with the SC bypass valve...and it's not gonna win the race
Why not putting that money on the suspension, tires, brakes where it will definitely gain overall performance.
My two cents

very well put sir.

[Split]

since a ball bearing is still more efficient pound per pound of boost, i really dont see any point of twin charging.. why not just run a twin balling bearing turbo setup? you can make a pretty linear powerband out of them. my buddy's supra is pretty linear. Also, the new 997TT with VTGs is pretty awesome.

[RagnaCaT]

I got a mag at home from a AE92 Twin Charged 4AGE from Australia I think I'll see if I can find it I can remeber that it said that when it went to higher rpms charger is bypassed and turbo takes over.

[Split]

i read jeremy clarkson's review of the twin charged golf gt and he said its one of the worst cars he's ever driven. twin ball bearing turbos ftw!