parallel turbos?

[nztdi1]

Hi everyone

Looking at installing a 3.0 v6 tdi into a jetboat and just had an idea id appreciate some input on. Would be fabricating jacketed manifolds etc so wanting to future proof to allow for future hp upgrades. only real option i can see to get above what the standard 2260 can offer is a hybrid which starts getting expensive, especially in a marine environment where replacement turbos are likely. Had the idea to instead mount 2x turbos off a newish 1.6/2.0 tdi, which can be picked up fairly cheaply. being in a jetboat packaging is almost preferrable with a turbo each side of the engine, and i'd have to do all the fabrication anyway. what im unsure about is the management, i've only worked with vacuum actuators before, would 2x electronic ones cause any issues? any potential tuning hassles?

any input would be greatly appreciated!

 

[Mongler98]

For the price of 2 of those turbos you could land a used LS that makes the same HP in NA application and probably strand you less often from breakdowns from pushing the limits vs just making fun power that the engine was designed for.
Just saying!

That being said, I would go big laggy turbos for cheap. Thinking like old beefy subuwo turbos like the gt2052 or bigger. There like $600 a pop and with 2 of them.... lol whatever

Keep it simple would be best via boost or vacuum controlled.
But I'm just shooting blindfolded from the hip as I have zero jet boat or marine engine experiance. I just watch Finnegan's garage.

 

[TDIMeister]

Parallel twin turbos can ostensibly work if both use electronic actuators that are compatible with the original. You would twin the single N75 signal for both turbos but the mapping will be completely different. You might need to match the impedance where the signal branches out.

Depending on what RPM your selected prop and gearing will have the engine turning at maximum output (and whatever that target HP will be), you might even just double up 2 stock V6 turbos as you don't really care much about spool up. All this of course depends on how much the WCEM will impact the exhaust gas energy available to drive the turbos.

Given the location of where the stock turbo sits on a pedestal on the back of engine between the Vee and under a cover, a water cooled manifold is not really necessary and you can just jacket the post-turbine downpipe if you're really that scared of things getting hot. I'm other words, don't do twins IMO.

 

[TDIMeister]

Or get an engine with a "hot vee" setup.

 

[Poor King]

 

[Mongler98]

lol all that power just go go 30 knots...

 

[nztdi1]

Mongler- the ls is certainly the engine of choice for jetboats here in NZ, they are nowhere near as cheap as in the states however and petrol is considerably more expensive than diesel. i already have a pd130 in a jetboat which goes great, just getting the new project itch.

tdimeister- spool is still somewhat important for getting on the plane is shallow water, i was thinking something along the lines of 2x gtc1549vk with a target hp around 400, with suitable electronic actuators? i would think 2x manifolds and the crossover pipe in the standard setup would put off considerable heat in an enclosed engine bay so would really want to make jacketed ones even for the standard turbo. i have just changed from a standard manifold to jacketed in my prop boat and the reduction in heat is considerable. still just an idea anyway but good to know in theory twins might be an option!