d24T+T

[lalozf]

Hello, we begin our project of biturbo 760 td, To start I have changed the original alternator (55 amp) to a 80 amp. from 940 d24tic. and the steering pump in order to gain access to fix an exhaust homemade manifold , and 2 turbos, we are thinking of what turbos we are going to screw. What do you think?
Now I have alternator and steering pump in drivers side.
Next will be remove filter and weld two original eshaust manifolds,...
I will post pics when I can
Sorry for my english

[lalozf]

I don´t know, is my friend who is preparing everything, but what would be the advantages between both set ups?

[DWL_Puavo]

I'm building a parallel setup for our VW LT mainly because I happened to score two new garrett 1544's from ebay very cheaply. The main reason however is to do something different than everyone (which usually indicates that it's stupid).

At least it's easy to weld exhaust manifolds as they are only 3-1, not 6-1 as with single turbo. I suppose they also will look cool, if someone wants to open the engine booth under front seat

Parallel setups are said to have better low-end spooling because of smaller components, but I think that can also be achieved easily with VNT turbos.

I'm going to use GT1544's own wastegates (normally open in 0.6bar), maybe modify them a bit to open in lower pressures, and add a simple boostcontroller to control them. This way I can get identical pressure to/from each turbo.

As our LT is used only to carry cars ("Pritschenwagen"), we're not going to try to make as much power as possible. It is registered in special car class allowing it to drive 100km/h (usually vans without airbags are only allowed to drive 80km/h), so we're going to use only as much boost that it goes easily this 100 km/h with 1400kg car "onboard" - supposedly somewhere between 0.4-0.8bar.

[HetLaeN]

if you have 2 smaller turbos that together delivers the same amount as a big one you would get boost much earlier, but not maybe the high boost like you get from a serie connection.

If you put 2 turbos in a serie, (one turbo feeding the second) you could get a pretty high boost.

Just to take it to the extreme. In tractorpulling i heard about one tractor with 4 turbos in 3 stages, that produced a boost to about 25 bars, 362 psi.

[DWL_Puavo]

Originally Posted by ForcedInduction

No. It doesn't spool up any faster, slower actually because you have the friction and pumping losses of TWO turbos instead of one.

Two turbos identical to only one spool up slower of course. However if the parallel turbos are much smaller than the single turbocharger, they'll spool up faster just because of their lower rotational mass and smaller turbines. Not sure about if that's worth of anything at all.

Comparision in size those gt1544's I have are physically about 2/3 of the size of normal T03 in d24t's.

[DWL_Puavo]

This is good enough and easy-to-understad explanation for me, thanks! Efficiency is quite clearly better with one turbo.

So it seems that only good reason to do parallels to in-line 6-cyl engine is that it's quite stupid ("Two is more than one! It has to be faster!") and that is a plus itself ...well headers are simpler but double the amount, so no gain there also.

Stop the press! Having more letters to the badges! Imagine "VOLVO 244 GLE DL6BT INTERCOOLER" !

[HetLaeN]

buy one more turbo, a bigger one, and build it in 2 stages then you surely get enough air to the engine

Parallel twins on an inline engine have no other use than to brag about having two turbos.

[VolvoForLife!]

Agreed with the above.