4 cylinder twin turbo

[Pimpin_1JZ]

I presume the turbo's are from a Mitsubishi GTO/300ZX? If so they are T25 size from memory. Which would be a little on the bigger side of a twin setup for 2/3T. Some CT12A's from a 1JZ would go sweet and can be had for $300 a pair even cheaper if you look.

[e30-323ti]

The new BMW 123d uses a twin-turbo L4 albeit diesel.
But physically, there is no reason why a TT-L4 won't work or be effective.
As with all turbo's it comes down to sizing them correctly, packaging them and $$$.

[Draven]

it's the whole "just because you can, doesn't mean you should"

as said ^ ^, twin turbos in this case are almost certainly just a more expensive way to achieve the same result that could be had by one properly sized turbo

[wagonist]

I think there's a lot more questions that need to be asked first.

What size 4 cyl? 2.7L out of a Hilux, or 1.3L Suzuki?
Sequential or parallel turbos?
Petrol/diesel?

Twin charging (ie supercharger + turbocharger) on a smaller motor I can understand, where the exhaust flow is small & therefore has trouble creating low rpm boost.

Sequential turbo where the first one is very small to spool up early may be ok, but then you're going to run it right out of its efficiency at the top end, so maybe would have to bypass it at higher rpm.

Toyota's tried both parallel turbos (1JZ-GTE) & sequential (2JZ-GTE). In the end ditched the TT off the 1JZ to be replaced with a more efficient head & single turbo.

Smaller parallel twins will spool up quicker due to smaller rotating mass, therefore creating better response lower down (generally the reason for going parallel), but then suffer at higher rpms . Larger turbos will have more lag.

Personally, I don't think I've ever heard of a parallel twin turbo setup on a 4cylinder, they tend to be 6s or 8s.

[wagonist]

The new BMW 123d uses a twin-turbo L4 albeit diesel.
But physically, there is no reason why a TT-L4 won't work or be effective.
As with all turbo's it comes down to sizing them correctly, packaging them and $$$.

diesel has a higher pressure exhaust flow than petrol, so will spool a turbo up much faster.
My last Dina (TD version) had 13psi at <2000rpm, and I once ran the standard (maybe CT12 size) turbo at something like 25psi & had that by 3000rpm. Fuel couldn't keep up though, so the extra boost was wasted.
Diesel engine also runs much cooler (no introduced heat) so the turbo can be run harder.

[JoJo]

Waste of time and money for lame performance results.....

[LeeRoy]

1g-gte size turbos would fair nicely, or VR4 turbos, they are tiny aswell!!

And they're both shit turbos.

One modern well designed ball bearing turbo will outperform these by a mile.

[metcap]

thanks for all the responds, the reason for thinking about doing this in the first place was because the parts was just available and I was wondering if it could be done with some degree of success. Yeah as some of you said better results could be had with a single efficient ball bearing but that always comes down to how much $$$ you're willing to fork out right?

I presume the turbo's are from a Mitsubishi GTO/300ZX? If so they are T25 size from memory. Which would be a little on the bigger side of a twin setup for 2/3T. Some CT12A's from a 1JZ would go sweet and can be had for $300 a pair even cheaper if you look.

yeah these are garrett t25s off a 300zx, so basically the v6 is running each turbo on 3 cylinders exhaust pulses right? and that would make 1500cc on each turbo pushing 1bar? So my next question would be could it possible work that my 1800cc 4 cylinder make 1bar on 1 of these turbos and not kill it fast?

[RONA]

Piping, manifold etc etc will be far more difficult & expensive then simply doing a reasonably sized single turbo. Hell I hazard a guess then even a CT26 would be more responsive then a budget twin setup.