Has anyone tried parallel turbos. Im curious about trying it with two hx35 turbos or even an hx25. anybody have any input or advice?

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Well no one has said it won't work so I'm going to give it a shot.

 

Here is the issue I see. With two turbos, you essentially have a HUGE turbo. Two HX35's with 12cm turbine housings more or less equate a turbo with a 24cm turbine housing. Equivalent to something in the S400 range. Spooling a turbo, or two turbos half that size, is going to be difficult. You could try to neck down the turbine housings to make them spool better, or run smaller turbos, but then you have restricted exhaust flow. Requiring both to be wastegated, or have an external wastegate.

You would also need two exhaust manifolds to make it work, or a slick adapter to split the flow far enough apart to flow to two turbos.

 

with the smaller housing would there really be that much back pressure, cause your only running exhaust from three cylinders its not like its all six. And the manifolds can be built. Its just getting them to spool that I'm worried about.. thank you for the replay. Its either this or compounds but I want something different.

 

why parrellel's when you could run a big single. i see absolutly no benefit to this unless you were wanting to try triples. i totally agree with the above statement. i aplaud your attempt to be different but i would urge you to spend you $$$ elsewhere. your looking at spending -ALOT- of time and money for something that can easily be had with a single of the appropriate size.

 

OK. So now do you feel about Triple hx35 setup

 

The big problem with parallel turbos is that they can't supply the pressure needed, Asking any turbo to do much over 3:1 pressure ratio is going to be hard on it, and they're going to be making more hot air than anything else... That is why compounding the turbos works so well... if you run both turbos at only a 2:1 pressure ratio, which pretty much any turbo can handle, you've got a total pressure ratio of 4:1, which is 45 PSI, and neither turbo is stressed.

It might be interesting to tune.. but perhaps you could have a parallel exhaust turbo with compounded turbines... don't know if there'd be a benefit to that.....

 

The TRIPLE turbo idea of three HX35s is well doable... i suggest you go for it

It won't give you more than 50-55psi of boost, but that will make your truck fly compared to that single HX35

You would have to close the wastegates on the athmosperic ones, but i think it is a great idea

That way you would be running a 12cm2 wastegated HX35 into 24cm of non-WG...

This should actually spool very well should compare to running a HX52 under that HX35..

Just looks way cooler

Here's a pic of Two HX35s under a HX40:



This should convert to about the same ratios as my setup, just on a smaller scale...

My manifold turbo is a HX40 16cm2, and my primary (athmosperic) is a 32cm2... my setup lights up fluently and has a pretty linear increase in boost over the rpms, i can see where a tripe HX35 setup would do the same...

DO IT

 

It's a good thing I didn't go into engineering. I can look at the front of a photo like that, and make sense of 2 turbos sucking atmospheric air, and sending it directly to that third compressor. But, I can't simultaneously picture the routing of the "hot side" plumbing from the exhaust, thru the 3 different turbines, and then down the tailpipe. Or, I can see the hot-side photo and not imagine the way the front-side relates.

FWIW, that 90* Tee, and the 90* cap look like they would make a LOT of turbulence heading into that other compressor wheel. I'd expect short life on that pinwheel #3, unless you reshape that plumbing. If that setup is just for "proof-of-concept" that's one thing, but, I don't think it'll have longevity.

 

This is how the exhaust gasses would plumb...



And i can see where you would be right on the turbulance thing, i might just suggest that to the owner of that tri-turbo setup...

I just found a thread of this guy on CompD, i think it's a great concept though..

 

that looks cool.. though I think it's a whole lot of trouble, a lot of things to go wrong, for me to endorse it... Good for the guy who built it though if it works!