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Engine Specific Info and Questions => IDI Engine => Topic started by: jimbobpolo on September 26, 2012, 04:02:19 pm

Title: Compound turbos on a 1.9td
Post by: jimbobpolo on September 26, 2012, 04:02:19 pm
Hey guys I'm looking to put together my mk2 compound setup, previously I ran a t15 (standard 1z tdi turbo) and a t2 from a landrover 2.5 and had various issues with boost spiking and some high turbine back pressure, the sound of the two turbos was amazing but performance wasn't as I expected, even at 30psi! I put it down to mismatched turbos.
I'm now running a k14 at 18 psi (was running a k24 at 22 psi) and I'm thinking of Plumbing in the k24 after the k14, what you guys reckon? Engine is a 1.9 aaz with 1.6 gtd ip and injectors, 2.5" turbo back exhaust and a huge alloy fmic. Am I correct in thinking 10 psi on the k14 and 10psi on the k24 would give decent total boost?
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on September 26, 2012, 05:09:13 pm
Yes you are right but keep in mind you will still be limited to the amount of air that the larger turbo can flow so I would not expect anymore than 150hp from this setup.  Which is a decent amount especially considering it would probably be quite powerful through put the rev range but nothing outrageous.  Also the boost doesn't just add like 10 and 10 makes 20.  It's a bit more complicated.  If both your wastegates are set to 10psi and referencin their own inlet as the atmospheric side of the wastegate you will actually have nearly 27psi
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on September 27, 2012, 06:45:33 am
Pick a newer, more efficient and more flowing LP turbo, or even better, throw both the K14 and K24 in the bin and change both ;)
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on September 27, 2012, 07:45:05 am
I'm aware of the 10 psi plus 10 psi doesn't equal 20 psi, more like 27 psi, obviously due to the HP turbo pressure ratio...

Ok what turbos would you suggest??
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on September 27, 2012, 07:51:57 am
Depends on your goals, will you keep the pump unmodified?
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on September 27, 2012, 07:54:40 am
I'm looking for 160-180ish whp, I already have done the governor mod, wound in the max fuel screw about 3/4 turn and a custom LDA boost pin, I get a fair amount of smoke but clears when on boost,
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on September 27, 2012, 08:18:33 am
You will be nowhere near your power goals with a pump like that...
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on September 27, 2012, 08:34:21 am
here was andy2's old thread, he eventually ditched the aaz and built an insane compounded tdi with custom cast iron head, i think maybe alot of andys problems were from too small of turbos or simply too old of turbos or maybe too restrictive of manifolds.  who knows since he moved on to another platform

http://www.vwdiesel.net/forum/index.php?topic=2538;
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on September 27, 2012, 10:37:55 am
My gtd pump isn't standard... I had it built up by a Bosch diesel specialist and setup for 20psi with double the amount of stock fuelling..
I think 160 whp is attainable and I'm looking to make it reliable power as its my daily driver.

Shame none of those pics in that thread work :(

I'm trying to use the k14 and k24 as I already have them to hand
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on September 27, 2012, 10:51:11 am
Double of stock fuelling is in the region of 80cc. Not enough for your power goal... But hey, build it and give it a go. Pump can (and needs to) be upgraded later on :)
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on September 27, 2012, 11:17:47 am
I have another gtd pump which I'm planning on sending over to giles at performance diesel, when funds allow!
I'm wondering if I should enlarge the wg on the k14, I'm using a 110hp peugeot k14 not the Vw unit....
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on September 27, 2012, 01:58:08 pm
K24 will not make your goal as the large turbo, I can't say much about your k14 I don't know anything about its size. If you are staying cheap the k24 as the small turbo would do ok, although I'd prefer the vw t3 over it because it has a larger exhaust side.  then for the large turbo you could something like a 60 trim t3 with .48 ar exhausy or basically any medium sized turbo that flows atleast 250 hp worth of air.  That'd be a cheap route can't guarantee it would work well but itd be a good start
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on September 27, 2012, 02:08:36 pm
K24 will not make your goal as the large turbo

True :)

120whp as maximum have I seen in dynos with the K24 or T3 1.6TD turbos. Compounding does not help the LP turbo flow more...
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on September 27, 2012, 02:33:00 pm
Compounding does not help the LP turbo flow more...

As in k24 as the larger turbo will not flow anymore?

I say vw t3 would be a good cheap option but my over al opinion of that turbo is that it was a turd, I believe at the time it was Garrett's smallest turbo they could make but only a few years later they started producing the t2 stuff, smaller and faster spooling more efficient and flowed as much air as most t3 series.  Anyways it has a narrow band of poor efficiency boooo. But it works haha
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on September 27, 2012, 02:42:30 pm
As in k24 as the larger turbo will not flow anymore?

Correct, compounding gives you more boost but not more air mass than what the biggest turbo can flow by itself. Well maybe a small amount more since you can run the big turbo with a lower pressure ratio and the compressor map might give you some extra there instead of running as a single turbo with a higher pressure ratio and being limited by rev limitation or choke.
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on September 28, 2012, 01:53:10 am
So, am I best ditching the k14 and going with the k24 as the HP turbo and using something else as a LP turbo? I have a holset hw1e buried in my garage and a mate that's selling a hx35 with a 9cm exh housing, both maybe too big for it I think.
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on September 28, 2012, 02:02:40 am
K24 spools way too slow to be used as a HP turbo. Better then to use a single turbo that spools quicker and supports your power goals. Those Holsets are way too big period!

A Holset HE211W will give you full boost by 2500rpm and support at least 170whp (dyno proven). A perfect single turbo for your goals!
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on September 28, 2012, 05:08:20 am
I'd prob go that route if I wanted a big single,
I've just been offered a Garrett t04e turbo, it's off a gasser. Not sure if it's any good for my plans?
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on September 30, 2012, 04:25:09 am
(http://i20.photobucket.com/albums/b211/james_g40/4F972F58-5D65-4EDC-8D8F-E0CAA57B795D-12734-00000BCF4AC52735.jpg)

(http://i20.photobucket.com/albums/b211/james_g40/3296DE4F-63EC-4079-A432-831FC81F50D9-12734-00000BCF56AE3F8E.jpg)

(http://i20.photobucket.com/albums/b211/james_g40/E9B46875-5334-406C-8D3D-F0ADED979CE0-12734-00000BCF5FDADD55.jpg)
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on September 30, 2012, 06:35:35 am
Do you know the trim of the compressor and ar of the exhaust side? Probably too big also tho, most to4es are just a hair smaller than holset hx35
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on September 30, 2012, 06:59:35 am
It's .50 a/r comp and .68 a/r turbine. It's quite a lot smaller than the hx35 I've got.
I got the t04e for free so I'd be silly not to give it a go..
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on September 30, 2012, 10:59:39 am
It's .50 a/r comp and .68 a/r turbine. It's quite a lot smaller than the hx35 I've got.
I got the t04e for free so I'd be silly not to give it a go..

.50 ar is not the trim, the physical size of the turbo doesn't really mean all that much, also the exhaust side u sure it's not .63?  It can't hurt to try it tho like u said.  Of its a smaller to4e I think 43 trim it might work alright, but to4es are more geared towards 200+hp. Let us know what u end up with cause compounds are cool!
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on September 30, 2012, 04:08:25 pm
Ah sorry didn't read your reply properly! Comp trim is 48.9 and turbine is 63.9, it's smaller in comp and turbine wheels than my hx35 by quite a long way,
I've got my polo booked in for a power run at my local dyno tomorrow afternoon so it will be interesting to see what it's making currently with the k14 ;) should be good for comparisons
Title: Re: Compound turbos on a 1.9td
Post by: nathantheengineer on October 01, 2012, 12:52:10 am
Keep us posted!! ;D
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on October 01, 2012, 09:17:15 am
Just back from my RR power run, I had guessed around the 110 to 120bhp mark for my 1.9 aaz, I wasn't far off but pleasantly suprised with the figure I got :)

(http://i20.photobucket.com/albums/b211/james_g40/1688FF39-6E60-4042-8A3B-3AD27E786555-13696-00000CC3856C2804.jpg)

(http://i20.photobucket.com/albums/b211/james_g40/7EB6B615-074B-4CA6-9811-347BE2E9AFBC-13696-00000CC376887C26.jpg)

(http://i20.photobucket.com/albums/b211/james_g40/F0C96CD9-FF43-4801-85E8-89DA659C59A0-13696-00000CC37EC80759.jpg)

This run was at 24psi on the pug Kkk k14 turbo I'm running ;)
First run was 127.7 bhp and 185ftlb at the flywheel
Title: Re: Compound turbos on a 1.9td
Post by: R.O.R-2.0 on October 01, 2012, 12:04:00 pm
(http://i20.photobucket.com/albums/b211/james_g40/4F972F58-5D65-4EDC-8D8F-E0CAA57B795D-12734-00000BCF4AC52735.jpg)

(http://i20.photobucket.com/albums/b211/james_g40/3296DE4F-63EC-4079-A432-831FC81F50D9-12734-00000BCF56AE3F8E.jpg)

(http://i20.photobucket.com/albums/b211/james_g40/E9B46875-5334-406C-8D3D-F0ADED979CE0-12734-00000BCF5FDADD55.jpg)

thats not a T4..

its a T3..
Title: Re: Compound turbos on a 1.9td
Post by: Blocksmith on October 01, 2012, 08:01:33 pm
Not to sound like a jerk or anything--I'm just wondering how you knew that it's a T3 vs a T4, just looking at it? How does one know based on just the outward appearance?
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on October 01, 2012, 08:24:57 pm
I would agree with him it's probably a t3 just by how the housing looks and the size of it compared to the keys, and the size of the compressor housing vs the size of the turbine housing makes it look more t3 sized.  And it's a 50a/r housing which I think was a Saab part but I'm not 100% on that.  Depending on which t3 it is it could work for you
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on October 01, 2012, 10:40:46 pm
What was the numbers at the wheels?
Title: Re: Compound turbos on a 1.9td
Post by: R.O.R-2.0 on October 02, 2012, 09:46:30 am
Not to sound like a jerk or anything--I'm just wondering how you knew that it's a T3 vs a T4, just looking at it? How does one know based on just the outward appearance?

because ive owned that EXACT TURBO.. its a T3.. the exhaust outlet flange is the DEAD GIVEAWAY..

a T4 is HUGE compared to a T3.. and i dont know of a .50 aspect ratio T4 either..

lemme snap you a pic of the size difference..

brb..

OMFG.. is that an EBAY TURBO?!?! it sure looks like one..

its going to EXPLODE if you try and run it!

sure looks like it says "TURBOCHARGER" on the number pad on the intake scroll...
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on October 02, 2012, 11:59:31 pm
It's 104.8 at the wheels,

R.O.R, your correct, after a quick call to the guy that gave it to me it turns out it is an eBay special! Haha it's gonna take pride of place on the top of my pile of scrap turbos! I don't fancy putting it anywhere near my aaz! I don't fancy bits of compressor wheel potentially finding their way into my engine!

On the subject of size, it is huge compared to my k24 and massive compared to my mates t3 on his type25 camper, so it's got t3 flanges but the compressor is about 20% bigger than a genuine t3.

Back to square one then! What's peoples suggestions for a LP turbo?
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on October 03, 2012, 12:03:37 am
104.8whp --> 130bhp on a FWD car? Only in the UK ;)
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on October 03, 2012, 04:58:23 am
It looks larger because it's a 50 a/r housing
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on October 03, 2012, 05:09:07 am
104.8whp --> 130bhp on a FWD car? Only in the UK ;)

I do not understand why so many euro people correct the numbers to flywheel hp.  It's like all the muscle car guys here they always want to compare their Guestimated fly wheel to everyone else's whp.  Especially when they compare old factory numbers to newer cars,  before 1972 the hp was measured on an engine dyno with no accessories installed and completely different exhaust manifolds.  So that 500 claimed hp is probably closer to the 3-400
Title: Re: Compound turbos on a 1.9td
Post by: MJF on October 03, 2012, 11:03:49 am
Becouse we are intrested how much power engine makes. Not how much power you lose to drivetrain. For example, transmission fluids will affect drivetrain losses. That has nothing to do with engine power.
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on October 03, 2012, 01:03:03 pm
But UK dynos tend to add more "drivetrain losses" than others to get happier customers ;)
Title: Re: Compound turbos on a 1.9td
Post by: RabbitJockey on October 03, 2012, 02:45:49 pm
Yes but it is still a guess rather than actual power at the wheels.  And it also goes under the assumption that the drivetrain always takes he same percentage; and that the amount of power you lose increases equally with how much power you make, I know there's a thousand ways to skin a cat but to me my personal preference is I want the most realistic numbers possible
Title: Re: Compound turbos on a 1.9td
Post by: Blocksmith on October 03, 2012, 06:00:02 pm
Just the difference between how the car as a whole will perform based on the engine, as opposed to how just the motor as an isolated system is performing, I suppose.
Title: Re: Compound turbos on a 1.9td
Post by: MJF on October 04, 2012, 03:03:53 am
Drivetrain losses are measured in dyno everytime. It's not just estimated value.
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on October 07, 2012, 03:08:46 am
Anyways the power run was done just so I had a before and after comparison,
I still need some suggestions for a good LP turbo to use..
Title: Re: Compound turbos on a 1.9td
Post by: Alcaid on October 07, 2012, 04:16:38 am
Your 160-180whp 1.9TD goal is easily reached with a single turbo with early spool and good efficiency. No need for compounds, compounds will only give you higher intake air temperatures, complicate the build and add lots of weight. Why bother?
Title: Re: Compound turbos on a 1.9td
Post by: jimbobpolo on October 07, 2012, 05:21:39 am
Ive had a big single turbo but I want a compound setup, i already have a huge alloy fmic and I've never had problems with intake temps and I don't see a major issue with space or the weight of another turbo? It's easy for me to plumb in too as I still have parts left over from my previous setup.
I think I'm gonna use my k24 for the LP turbo as its to hand and I already have flanges made for it.