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Author Topic: Compound turbos  (Read 8127 times)

October 01, 2015, 12:57:07 pm

Dieselpower74

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Compound turbos
« on: October 01, 2015, 12:57:07 pm »
Hey guys I have 2 turbos here I'm thinking about doing a little compound turbo system to a m alh tdi. I know there's some people on here that can help see if these turbos will work. The small primary turbo will be a fix open blade gt1749v meaning the vnt will be in the open position. Second low pressure turbo that I have is a Garrett t3 60trim off a 300zx. Looking at both seems to be ok set up but idk if the 60trim is to big for the little system. I will be running stock fueling with 520 injectors just want it to be diffrent looking for 220 hp. And the short block is a pd 100 with ALH pistons.

Link to small turbos compressor map: http://www.turbomaster.info/eng/applications/778445-0001.php

Link to big turbos map: http://www.not2fast.com/turbo/maps/all.html . It's the Garrett t3 60 trim not super 60.




Reply #1October 01, 2015, 01:09:44 pm

libbydiesel

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Re: Compound turbos
« Reply #1 on: October 01, 2015, 01:09:44 pm »
I think you'll find that with vanes full open the 1749v will be quite laggy and not particularly suitable as a 'small turbo'. 

Reply #2October 01, 2015, 01:14:42 pm

Dieselpower74

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Re: Compound turbos
« Reply #2 on: October 01, 2015, 01:14:42 pm »
Really i would never think that. How dose it spool with them open. And I wanted to open them so it dosnt over speed. I would think it should spool fast for how small it is. But only ran one on a 1.6 and it spoold fast but that was the only turbo I had on it. And I live in co

Reply #3October 01, 2015, 01:18:14 pm

libbydiesel

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Re: Compound turbos
« Reply #3 on: October 01, 2015, 01:18:14 pm »
Full open it spools slower than a stock 1.6TD T3 or K24.

Reply #4October 01, 2015, 01:19:07 pm

Dieselpower74

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Re: Compound turbos
« Reply #4 on: October 01, 2015, 01:19:07 pm »
What would be better for a high pressure turbo.

Reply #5October 01, 2015, 01:24:48 pm

Dieselpower74

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Re: Compound turbos
« Reply #5 on: October 01, 2015, 01:24:48 pm »
And sorry when I mean stock fueling I mean stock 11mm pump turned up sorry should have said that.

Reply #6October 01, 2015, 02:21:37 pm

Dieselpower74

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Re: Compound turbos
« Reply #6 on: October 01, 2015, 02:21:37 pm »
Libbydiesel what would you use as a primary turbo. I'm still trying to understand the whole compound turbo systems.

Reply #7October 01, 2015, 04:36:53 pm

libbydiesel

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Re: Compound turbos
« Reply #7 on: October 01, 2015, 04:36:53 pm »
I'm really not the one to ask about compounds.  Other members would give much better advice, e.g Alcaid, Andy2, Rabbit Jockey, etc...
« Last Edit: October 01, 2015, 05:15:04 pm by libbydiesel »

Reply #8October 01, 2015, 05:07:53 pm

Dieselpower74

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Re: Compound turbos
« Reply #8 on: October 01, 2015, 05:07:53 pm »
i understand but thank you for the info much do appreciate it. I have been looking into compound for awhile I just don't have some one here to tell me if I'm wrong or not. When it comes to my math. Hopefully one of those members will help me out. Agin thank you!

Reply #9November 03, 2015, 12:08:29 pm

Dieselpower74

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Re: Compound turbos
« Reply #9 on: November 03, 2015, 12:08:29 pm »
So can anyone help me with this?

Reply #10November 04, 2015, 07:45:13 am

One_punchmachinegun

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Re: Compound turbos
« Reply #10 on: November 04, 2015, 07:45:13 am »
What's the reason for going compound? If 220 is the "goal", there has been people making that out of a single turbo build. Don't get me wrong I like the idea of compounds.

From the reading I've done, it seems to get much more difficult when you run a compound setup, but it could also just be over my head. 
Surprised no one is chiming in on this.

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Reply #11November 06, 2015, 11:14:59 am

vanbcguy

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Re: Compound turbos
« Reply #11 on: November 06, 2015, 11:14:59 am »
A big single turbo that can crank out 220 HP tends to be somewhat laggy giving very little boost in the lower RPM ranges.  A properly set up compound build will have the smaller turbo creating boost much sooner than a big single would while still being able to flow as much if not more than the big single could.  The compounds may produce the same peak power as the big single but the 'area under the curve' on a dyno chart will be wider with compounds.  Peaks aren't everything... ;)
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #12November 07, 2015, 09:23:03 am

One_punchmachinegun

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Re: Compound turbos
« Reply #12 on: November 07, 2015, 09:23:03 am »
Yeah, see I prefer the build up to the peak. 😉
I'm not biggest fan of insta-boost.
I am running a Holset he211w and there really minimal lag, and as of right now I have no tune.  I start to build boost by 2100-2300. And what I've been told these turbos have great potential.
People trying to get to 200ish horsepower usually only run one turbo. The newer vane turbos spool quick and make power. Darkside developments have a bunch of great turbos that will make the power numbers.
Then people looking for 300 seem to lean a little more toward compounds. I don't know, like I said I like the idea of compounds I just depends on the build that is being done, it will take a lot more work to make up a compound setup.


Now this is all my preference.

Please excuse my run on sentences.

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“If anyone hears my words but does not keep them, I do not judge that person. For I did not come to judge the world, but to save the world." Jesus Christ

Reply #13November 09, 2015, 02:51:09 pm

RabbitJockey

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Re: Compound turbos
« Reply #13 on: November 09, 2015, 02:51:09 pm »
you should consider using vane control.  you'll need to change fueling to get your hp goal, but i think with those turbos it is possible.  do lots of reading before you just slap that together tho, you'll want to set it up so both turbos are staying in their efficiency ranges.
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Reply #14November 09, 2015, 05:51:10 pm

Dieselpower74

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Re: Compound turbos
« Reply #14 on: November 09, 2015, 05:51:10 pm »
Hey guys sorry havnt been on for awhile but I know my hp goal is low because I using a stock pd100 bottomend! I'm planning on running forged rods in the future and a 12mm or custom 14mm pump . But I want to do compound because I live in co and everything is over 7000 ft where I live. And it's diffrent and basicly free if these turbos work that is. All piping and lines are done! So I'm just trying to see if these 2 turbos are sized right? Also I have a fully manual adjustable injection pump that I can turn up in the car instead using the screw driver. It's really awesome you guys that love the ve pump or inline pump like a p pump you would love to have this! All adjustment in car on the fly!

I'm trying to get the vnt to work with a wastgate and boost controller instead of a vacume. Still working on it.

 

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