Compound Turbos...

[CamTom12]

Soooo....

My PSD is my first turbo'd vehicle, but I know that the idea in compound turbos is to match them so that when the small turbo is reaching max boost the big turbo starts pressurizing the small turbo inlet, thus keeping it from running out of steam early on.

Well, once I get past the motor issues my truck's been having, I'd like to modify it to make better power around where I drive. I tend to short-shift both in an effort to save fuel and because... I dunno. I guess I always have.

What size turbo would I need to find to act as the small turbo in a compound twins set-up that would utilize the stock turbo as the big one? I don't necessarily want more max boost, I just want a much wider range of boost.

I figure if I can match them correctly I can have a small turbo fully spooled around 1400-1500 when the stocker starts throwing more air downrange. This would match my driving style pretty well since I rarely spin past 2k on a regular day (unless I'm on the highway, haha). In fact, I guess I'm usually shifting right around 1500.

I think this would also prep the truck for an additional overdrive for unloaded highway trips.

I dunno, how reasonable does all this sound?

Also, do ya'll know if our intake port pattern matches close to any type of real intake manifold? I really feel like if I had some runners (like a Victor Jr.) I'd be able to make a lot more torque.

[Marty]

Waste of time honestly...

You can try a smaller housing on the stock housing...

[pipelayerjdh]

With the way a PSD turbo is plumbed, it will be hard to put a smaller turbo where it needs to be. The smaller turbo should be first in the exhaust stream, so you would have to make new headers or move a lot of stuff around. It would be a lot easier to use the factory turbo as the small one, but that doesn't help you out. It will be possible, but very time consuming.

[CamTom12]

I wouldn't be able to move the stocker downstream and just put a smaller turbo in the stock location?

[Marty]

Originally Posted by CamTom12

I wouldn't be able to move the stocker downstream and just put a smaller turbo in the stock location?

It's really pointless for the minimal benefit that could POTENTIALLY be had..

[lilredpowerstroke]

Originally Posted by Maintain

It's really pointless for the minimal benefit that could POTENTIALLY be had..

No offense Marty but comments like this is why the Powerstroke is behind the other two IMO. By trying it you never know what POTENTIALLY may happen. Theres nothing wrong with thinking outta the box. If you want to try and fabricate something to make this work you may be on to something for gettin better gas mileage. If not then you can say you tried. You might even learn something along the way that may help you later.

[Dirk]

Originally Posted by lilredpowerstroke

No offense Marty but comments like this is why the Powerstroke is behind the other two IMO. By trying it you never know what POTENTIALLY may happen. Theres nothing wrong with thinking outta the box. If you want to try and fabricate something to make this work you may be on to something for gettin better gas mileage. If not then you can say you tried. You might even learn something along the way that may help you later.

Heh!

Anyways, I would run the stock turbo feeding into a larger turbo. I don't think a smaller turbo feeding the stock would give you any performance gain. You may have a broader torque/hp range right off the line, but the volume of air moving would overcome a smaller turbo fairly quickly.

Just my opinion.

[jjames25]

There was a guy in diesel world or one of those mags who ran twins on his ford he was from up here in Edmonton area and i think NADP helped him with it. I remember reading he had to clearance his firewall to make space for it and i know he had to run custom tunes and scrapped the egr but i cant remember if it was a 6 or 7.3 maybe look it up on one of their websites you might come up with something

[CamTom12]

Originally Posted by dirk0

I don't think a smaller turbo feeding the stock would give you any performance gain. You may have a broader torque/hp range right off the line, but the volume of air moving would overcome a smaller turbo fairly quickly.

Just my opinion.

You're probably right on this one, but I was thinking a smaller turbo being fed by the stocker. I'm not trying to make more performance in peak numbers but instead to broaden the torque curve...

Does anyone know if there's a runner-type intake that'll fit our heads?

[Fast73Excursion]

CamTom12...I have thought about the same things you have, only I was wanting to go bigger with my charger set-up. I have been thinking on the Intake...I beieve I could make the intake...I have seen it done on the Powerstroke. To my knowledge there is no aftermarket one on the shelves, but feel free to pm me and details can be discussed on the fabricated one.