Question About Twins

[whoabeats]

Since ROR is always taking about huge amounts of boost and quick spooling with a VNT, what would you gain with the compound setup that a VNT and a huge intercooler would not give you?

Pretty much it will eventually run out of flow for higher rpm and be outside of its map. You would be hard pressed to find a vgt that could do a better job than a well designed compound set up. I have ridden in a lot of well built trucks and the turbo set ups make you want to cry. The only thing to compare it too is being on a roller coaster because you are being pulled forward so hard. I dont know a lot of roller coasters that go 120mph though. I am very interested in the topic of compounds for my build. But everything has to be budget minded and affordable cuz Im frugal . I also am curious as to how a eaton m45 or larger would work with a stock hx35. My buddy Carl is an innovator for truck performance and was one of the first people to ever do a triple turbo setup and is now running superchargers with large large turbos. I'd like to see how this would work on the vw's. I might enlist him for help.

http://www.youtube.com/watch?v=BAZduIY1aeA&feature=related

http://www.youtube.com/watch?v=9rgs326Ve6Q&feature=autoplay&list=ULOkn7MTZ0OWA&lf=mfu_in_order&playnext=1

[R.O.R-2.0]

Since ROR is always taking about huge amounts of boost and quick spooling with a VNT, what would you gain with the compound setup that a VNT and a huge intercooler would not give you?

Pretty much it will eventually run out of flow for higher rpm and be outside of its map. You would be hard pressed to find a vgt that could do a better job than a well designed compound set up. I have ridden in a lot of well built trucks and the turbo set ups make you want to cry. The only thing to compare it too is being on a roller coaster because you are being pulled forward so hard. I dont know a lot of roller coasters that go 120mph though. I am very interested in the topic of compounds for my build. But everything has to be budget minded and affordable cuz Im frugal . I also am curious as to how a eaton m45 or larger would work with a stock hx35. My buddy Carl is an innovator for truck performance and was one of the first people to ever do a triple turbo setup and is now running superchargers with large large turbos. I'd like to see how this would work on the vw's. I might enlist him for help.

http://www.youtube.com/watch?v=BAZduIY1aeA&feature=related

http://www.youtube.com/watch?v=9rgs326Ve6Q&feature=autoplay&list=ULOkn7MTZ0OWA&lf=mfu_in_order&playnext=1

that right there.. my VNT still runs out of poop up top.

it DOES SPOOL quick. and it does make good boost, but its still a small turbo, no matter how good it flows.. all ive gotten out of it for boost is around 22psi, without having severely retarded timing.. because then you can make 35 psi with it. make her scream..

and the way to get rid of the restriction of the small turbo, is to bypass it with an external wastegate.. internal wastegates are a waste of time with a compound setup.. they dont flow enough volume to be any good..

when the time comes, i will be adding a wastegate to bypass my VNT, and feed a bigger turbo in a compound setup. im thinking either my Audi K26, a Peugeot T3, or a relatively small T4 for a low pressure turbo.. the K26 will probably be the best of those 3 turbos im thinking..

the T3 might not be BIG enough.. i dont know the map for it tho, or the specs or aspect ratios..

[410]

BMW has an inline six diesel with two wastegated turbos that works very well.  I drove an X5 with this 3.0l engine and I was impressed.  I find it interesting that BMW, who has incredible engineering resources chose to go with two wastegated turbos compared to one vnt turbo.

My compound turbo project is moving along well and I'll get some more pictures up soon.  We just ordered the chips from Malone and if we can get up to 26 psi as planned, we'll be in the 300ftlb range with roughly 180 hp.  Should be pretty awesome.    

[RabbitJockey]

No doubt the small hp turbo can still be a restriction but the lp turbo compresses the air before it goes into the small turbo which then conpresses it more the small turbo can then flow more cause the air is compressed going in already they work off of pressure differential not a certain amount of air.

The Porsche set up is called a sequential setup it's not really the same at all toyota and Mazda has used the sequential setup before regardless I think a waste gate is definitely required unless u use a vent that has a huge turbine housing but that'd kind of defeat the whole point

 Ror if u measure the inducer and exducer on that t3 like u did on the t4 then divide the inducer by the exducer and then square that number and multiply by 100 you'll have the trim of the turbo and u can easily find the map unless it's 55 trim they never published that one I think a 60 trim t3 could be a good lp turbo

[R.O.R-2.0]

No doubt the small hp turbo can still be a restriction but the lp turbo compresses the air before it goes into the small turbo which then conpresses it more the small turbo can then flow more cause the air is compressed going in already they work off of pressure differential not a certain amount of air.

The Porsche set up is called a sequential setup it's not really the same at all toyota and Mazda has used the sequential setup before regardless I think a waste gate is definitely required unless u use a vent that has a huge turbine housing but that'd kind of defeat the whole point

 Ror if u measure the inducer and exducer on that t3 like u did on the t4 then divide the inducer by the exducer and then square that number and multiply by 100 you'll have the trim of the turbo and u can easily find the map unless it's 55 trim they never published that one I think a 60 trim t3 could be a good lp turbo

its prolly a 55 trim, lmfao.. i would expect it off a Peugeot..

[RabbitJockey]

U can still get an idea of where the 55 trim will work since its some where between a 50 and 60 trim. Ive actually been working on making a some what accurate compressor map for by combining a 50 and 60 but it's just been during my lunch hour at work. I'll post it when I'm done and satisfied. One of the bigger vnt turbos they use over at tdi Club has the same inducer and exducer size I think it's the 2260 I would imagine the geometry of it is newer and more efficient tho. 55 looks like a good turbo for a vw diesel depending on the exhaust a.r what size of engine is it off of?

[R.O.R-2.0]

U can still get an idea of where the 55 trim will work since its some where between a 50 and 60 trim. Ive actually been working on making a some what accurate compressor map for by combining a 50 and 60 but it's just been during my lunch hour at work. I'll post it when I'm done and satisfied. One of the bigger vnt turbos they use over at tdi Club has the same inducer and exducer size I think it's the 2260 I would imagine the geometry of it is newer and more efficient tho. 55 looks like a good turbo for a vw diesel depending on the exhaust a.r what size of engine is it off of?

from what ive gathered, its a .36 exhaust/.42 intake.. appears to be a clone of a VW turbo.. its off the same engine as my 10mm injection pump, a Pug 2.3L 4 banger diesel, out of a 505TD..

[R.O.R-2.0]

So, does anybody have anything to say about setting up a K24 and a K26 in a compound array?

i have one of each.. a K24 off a 1.6/2.0TD, and a K26 off an Audi quattro 10v.. (wastegateless)

i was told to run them as compounds, with the K26 not running a wastegate at all..

i can make the K24 fit fairly decent, and still have room for the K26..

what do you guys think? kinda would like to know sometime soon.. ive got a boostless diesel that needs new turbos..

[RabbitJockey]

So, does anybody have anything to say about setting up a K24 and a K26 in a compound array?

i have one of each.. a K24 off a 1.6/2.0TD, and a K26 off an Audi quattro 10v.. (wastegateless)

i was told to run them as compounds, with the K26 not running a wastegate at all..

i can make the K24 fit fairly decent, and still have room for the K26..

what do you guys think? kinda would like to know sometime soon.. ive got a boostless diesel that needs new turbos..

k24 i think would be a good smaller turbo, only thing some what bad about it is it has a pretty small exhaust side a/r of .30

k26 i think will be alright, i'd try something bigger personally.  it only flows enough air for maybe a bit more than 200hp and its efficiency range of 70+% isn't that wide and peak efficiency is only 72%.  its worth a try especially since u have it all laying around.

[RabbitJockey]

heres a good thread about the older kkk stuff, pretty interesting especially how the part numbers work.

http://www.924board.org/viewtopic.php?t=15595

[R.O.R-2.0]

So, does anybody have anything to say about setting up a K24 and a K26 in a compound array?

i have one of each.. a K24 off a 1.6/2.0TD, and a K26 off an Audi quattro 10v.. (wastegateless)

i was told to run them as compounds, with the K26 not running a wastegate at all..

i can make the K24 fit fairly decent, and still have room for the K26..

what do you guys think? kinda would like to know sometime soon.. ive got a boostless diesel that needs new turbos..

k24 i think would be a good smaller turbo, only thing some what bad about it is it has a pretty small exhaust side a/r of .30

k26 i think will be alright, i'd try something bigger personally.  it only flows enough air for maybe a bit more than 200hp and its efficiency range of 70+% isn't that wide and peak efficiency is only 72%.  its worth a try especially since u have it all laying around.

the only turbo i have thats bigger than a K26 is a T4.. and a T4 might be a BIT TOO BIG for a 1.6

screw it, just add lots of spray! it will either spool, or go BOOM! hahaha.

honestly, i think im going to play with the K24 first, and see how i like it. i know it spooled pretty early on the 2.0 it was on, so it should be similar on the 1.6

[RabbitJockey]

i had one with a stuck wastegate, i thought spool and power was pretty good at 25psi. just with a turned up pump stock cast down pipe and 2.25 exhaust and a cone filter.  mine even had a knackered compressor wheel.  t4 might be alright, but then u might be better off with one of your t3s i'll look again, i don't know much about the compounding but i figure u want to look at how much the big turbo can actually flow, at 10-20psi which is where most turbos are efficient anyways.  i think even when u do all the math, its still a guessing game and only trial and error will create the best setup. imo for the small turbo u want one that is good for mediocre power(which is why i think k24 is good), and for big turbo you want one capable of flowing a good bit more than your power goal, and that would normally surge and not work on your engine(this isn't necessary but the idea is to move more air than what would normally be possible).  even with the small turbo being mediocre size you're going to get more boost sooner than with just the k24 because of the multiplying effect of the compounds.

[R.O.R-2.0]

holy crap, these K24s take FOREVER to spool.. boost in neutral is out of the question now..

how positive are you guys that the 1.6 and 2.0 K24s are identical? it sure seems like this one spools way late..

it has a 2" inducer on the exhaust side, are the 1.6's the same size?

[R.O.R-2.0]

So, im thinking that a K14, and a K24, or K26 would be a GOOD compound turbo setup.. the K24 is just too big to be the small turbo unless you had an ultra hotrod diesel that spun some SERIOUS RPMs..

someone mentioned using a K24 as a high pressure turbo, and a K26 as a low pressure turbo.. and now having the K24 on the car, i dont think that would be the best plan.. it would be all top end power, and nothing on the bottom end.. i want torque. thats what i loved about my quick spooling VNT turbo, it made boost as soon as you brought it much up past idle..

what do you guys think of the K14? is the hot side too restrictive? i really want a small turbo that boosts fairly instantly.. because this 2.0 K24 is NOT the turbo for me. sure, its cool having a big HIT of boost once it comes on, but my favorite part of my VNT was that it came on way down low..

now im throwing the idea of Nitrous around again.. i have a WHOLE nitrous kit begging to be used. just need to fill and install.. that should be enough to spool my turbo a bit sooner 

[rallydiesel]

I was planning on building a compound set-up with a k14 and a gt2559v. Unfortunately life got in the way and I had to sell the k14. I think the k14 would make a great small turbo in a compound set-up. I think I would use a nice large external wastegate as the k14's is just too small once you start dumping serious fuel.