Compound turbo setups??

[Craigus]

Just wondering if anyone is running this type of setup?? And what size turbo to use for the second one?

[Jimbo]

Usually something small that spools fast into something bigger that blows hard

[Craigus]

T2 into td04?

[Jimbo]

No something like gt15 into I dunno td05 haha

[Frosty]

Have a read through this Craig

http://306oc.co.uk/forum/thread-261.html

[Poodle]

T2 into td04?

Thinking way too small man. And too old lol.

[strictly_perv]

A VNT into a big blower would be ideal! But the engine will blow up before you could make big power so better off sticking with a mid sized VNT.

[Craigus]

A VNT into a big blower would be ideal! But the engine will blow up before you could make big power so better off sticking with a mid sized VNT.

Vnt's are a headache though hahaha

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T2 into td04?

Thinking way too small man. And too old lol.

How about a gt35 haha

[Piggy]

I think a properly setup compound turbo on a xud with reasonable sized turbos in their optimum efficiency would be ace.

[silverzx]

I think a properly setup compound turbo on a xud with reasonable sized turbos in their optimum efficiency would be ace.

The only ones I know of are Daves and Darrens both of which have used massive turbos that like to destroy engines.

It's mint to see them make silly power and I bet they shift(ed) but I agree it would be interesting to see something slightly less beast that's a bit friendlier on the engine.

I think everyone would love to have a compound setup but no one can be bothered / afford it / figure it out (me included).

[Craigus]

I think a properly setup compound turbo on a xud with reasonable sized turbos in their optimum efficiency would be ace.

The only ones I know of are Daves and Darrens both of which have used massive turbos that like to destroy engines.

It's mint to see them make silly power and I bet they shift(ed) but I agree it would be interesting to see something slightly less beast that's a bit friendlier on the engine.

I think everyone would love to have a compound setup but no one can be bothered / afford it / figure it out (me included).

Yeah that what i was thinking, something a bit smaller but still big if that makes sense lol

[strictly_perv]

IMO just getting one good, well suited turbo will be better than a low powered compound set up. Again going back to VNT. Plus it would much cheaper and easier than designing a compund set-up
The main reason for compounds is to help the big fucker spool up pretty muich.

[Jenkosowls]

I'v always read it as the bigger turbo (low pressure) feeds into the small turbo (high pressure)

http://www.atsdiesel.com/ats2/templates/...22272&c=36

[Tom]

No reason you couldnt get a gt20 wastegated turbo something spooly and a big one like a gt35 or HX35 like Darren or a lorry thing like Dave, then join them together and see what happens. Would be an interesting read anyway!

[Craigus]

I'v always read it as the bigger turbo (low pressure) feeds into the small turbo (high pressure)

http://www.atsdiesel.com/ats2/templates/...22272&c=36

So the bigger turbo feeds the snaller one? I thought the smaller one helped spool up the bigger one?

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No reason you couldnt get a gt20 wastegated turbo something spooly and a big one like a gt35 or HX35 like Darren or a lorry thing like Dave, then join them together and see what happens. Would be an interesting read anyway!

Thats what im thinking of doing, might not be the most efficient way but cant see why it wouldnt work!

[Tom]

[Ruan]

Be warned - there is some actual sciency shit behind all this, I keep meaning to do a post on Pressure Ratio with regards to Compounding etc..

Just wanging two turbos you found together will probably result in things being pretty counter productive a lot of the time...

Don't think of turbos spooling turbos... You have to think of it in terms of the engine increasing in exhaust gas flow, the turbos are basically seperate entities.

The general idea is high pressure turbo (small) feeding into the inlet, low pressure/atmosphere (big) turbo going straight in the inlet of the HP turbo... Then the exhaust side is generally exhaust manifold straight into the HP turbo, then outlet of the HP turbo into the LP turbo... But usually the HP turbo will require to have a significantly uprated wastegate - remember you're going to be using the LP turbos massive airflow - the HP turbos wastegate probably won't cope and you'll end up overspeeding it... Then out the LP turbo into the exhaust.

[samass]

*snigger*


"wang"

[Piggy]

yeah as said..
a twin turbo setup with valves n actuators etc is used to have a small turbo which then a big turbo takes over once spooled but a compound is a totally different ball game.

[darrenjlobb]

Compounds will always be better than one single, even if VNT...you can just make the setup so much more efficiant using a compound setup...theres a reason modern tractors / cars are compounded there just catching up with the times hhaa

[Craigus]

So is the point to have the bigger turbo feeding the smaller turbo to keep the smaller turbo at its peak??

[THE_Liam]

Be warned - there is some actual sciency shit behind all this, I keep meaning to do a post on Pressure Ratio with regards to Compounding etc..

Just wanging two turbos you found together will probably result in things being pretty counter productive a lot of the time...

Don't think of turbos spooling turbos... You have to think of it in terms of the engine increasing in exhaust gas flow, the turbos are basically seperate entities.

The general idea is high pressure turbo (small) feeding into the inlet, low pressure/atmosphere (big) turbo going straight in the inlet of the HP turbo... Then the exhaust side is generally exhaust manifold straight into the HP turbo, then outlet of the HP turbo into the LP turbo... But usually the HP turbo will require to have a significantly uprated wastegate - remember you're going to be using the LP turbos massive airflow - the HP turbos wastegate probably won't cope and you'll end up overspeeding it... Then out the LP turbo into the exhaust.

[Piggy]

So is the point to have the bigger turbo feeding the smaller turbo to keep the smaller turbo at its peak??

not entirely.

they work to be both in their efficiency range all the time.

the small turbo compresses the air already compressed by the bigger turbo.

but both turbos are working happily rather than one poor single turbo working its socks off trying to please you whilst you are working it way out of its efficiency range coz you wana be in the 30psi club

[Poodle]

So is the point to have the bigger turbo feeding the smaller turbo to keep the smaller turbo at its peak??

Do a bit of googling mate, it's no where near as complex as it seems at first. The point is to keep both turbos in their ideal efficiency range while producing decent boost pressures without raping emps.

[darrenjlobb]

It effectively enables you to run the primary in its peak FLOW....IE more total flow because your keeping the PR down, so it can flow more air than if it was trying to maintain a higher PR on its own, which would cause it to become less effeciant / flow less air.... Your still limited by the max flow of the primary, but its increased substantionally by the compound effect

Also makes for WIN exhaust note when boost target it reached as you have more total gate