Elementary, my dear turbo.

edk

edk

Addicted to Torque
Staff member
In prep for the next turbo upgrade on the YD, I've run some numbers for the compressor. Any insight from anyone with some turbo understanding would be appreciated. Here's what I've got that seems suitable:

Stock:
36.34mm inducer
49mm exducer
Trim = 55

Proposed:
42mm inducer
56mm exducer
Trim = 56

Looking at the housing it won't take any bigger an inducer, but the trim (which I've read relates to flow) is kept to a similar value. Not so bad.

Also schooled up a bit more on A/R and I found this interesting on the Garrett website:

Garrett said:
When deciding between A/R options, be realistic with the intended vehicle use and use the A/R to bias the performance toward the desired powerband characteristic.

Here's a simplistic look at comparing turbine housing geometry with different applications. By comparing different turbine housing A/R, it is often possible to determine the intended use of the system.

Imagine two 3.5L engines both using GT30R turbochargers. The only difference between the two engines is a different turbine housing A/R; otherwise the two engines are identical:
1. Engine #1 has turbine housing with an A/R of 0.63
2. Engine #2 has a turbine housing with an A/R of 1.06.

What can we infer about the intended use and the turbocharger matching for each engine?

Engine#1: This engine is using a smaller A/R turbine housing (0.63) thus biased more towards low-end torque and optimal boost response. Many would describe this as being more "fun" to drive on the street, as normal daily driving habits tend to favor transient response. However, at higher engine speeds, this smaller A/R housing will result in high back pressure, which can result in a loss of top end power. This type of engine performance is desirable for street applications where the low speed boost response and transient conditions are more important than top end power.

Engine #2: This engine is using a larger A/R turbine housing (1.06) and is biased towards peak horsepower, while sacrificing transient response and torque at very low engine speeds. The larger A/R turbine housing will continue to minimize backpressure at high rpm, to the benefit of engine peak power. On the other hand, this will also raise the engine speed at which the turbo can provide boost, increasing time to boost. The performance of Engine #2 is more desirable for racing applications than Engine #1 since Engine #2 will be operating at high engine speeds most of the time.
Click to expand...

Attention then to the two #engine paragraphs.

If I wanted a higher trim I would need to get a larger housing anyway, but as for the top end performance from a higher A/R I wouldn't mind it being a made a little more biased towards it.

There's a 1.9 Vectra lad who is running much higher trims than I could with my current compressor housing, but on the same A/R @ 1.8 Bar and getting 228whp. So although we have the same A/R, my inducer will be a fair bit smaller, and I have my doubts I could reach similar figures with it (also I realise the engines are quite different, but it's a good starting point for comparison).

The same housing with this proposed compressor will give me a performance increase, sure, but will it be enough to get at least 200whp?
 
this should be interesting ed :) i,m running a YD turbo atm and fancy testing some hybrid tweaks.
that little 35mm turbine wheel will be working hard @ 200whp tho eh ! (high exh mani pressures/shaft speed etc)
mine,s the 1549 bn800 post 03 tino/mera one with a/r 43 cast on strangely ? (same compressor specs as yours tho)

1549.JPG
 
Yeah that 1549 is pretty small, was only put on Diesels of around 100-120bhp. Very small turbine housing that!

Here's the turbine specs for the GT1849V

Turbine
43.5 inducer
39.2 exducer
8.2 tip
9 blades
AR .61

I think the turbine side is ok for my needs for now. The hybrid is the same but vanes are cut back to improve top end flow.
.
 
frank said:
ahh, yours is a GT18 then mate :oops: i await your findings :cool:
Click to expand...

edk said:
Here's the turbine specs for the GT1849V
Click to expand...

Err, yes lol. The ph1 110bhp YD22 had the GT1549. They put the VNT GT18 in the DCi 136.



Full specs then of stock turbo that I could measure.

Turbine
43.5 inducer
39.2 exducer
7.5 tip (VNT) 8.2 tip (blade)
9 blades
AR .61

Compressor
36.34 inducer
49 exducer
Trim = 55
4.1 tip
17.66 total height
blades 6/6
AR .43

Not sure what to do with all the info but I need to find a good compressor solution to get that 200whp and with room to spare.
 
So you'll effectively have a GT1856V? Have you looked at the 20 series? The GT2052V is specced for up to 225bhp.
 
It's not an easy case of just throwing on another turbo unfortunately. I need to keep the stock housing so it mounts to my manifold and exhaust ok (if I had the cash I would get something sorted so I could fit any VNT turbo, but alas). The stock housing and 18 turbine should be fine for my wants anyway :).

It's just the compressor side I'm concerned about. Yeah I'm aiming for a GT1856V by the end of it, but I'm learning how many otehr factors there are to turbos and how if affects their performance! Being that '1856' is such a limited description of a turbo. So trudging through that to find the best setup.
 
Very true. You could have 2 1856v turbos and they could be totally different. I was thinking more along the lines of using the compressor housing off the '20 along with the wheel. Kind of the same idea with the T28 (T3 housing on T2 turbo). I bet you could get a cheap compressor housing an genuine 56 trim compressor wheel. Another option worth considering may be to get the outlets ported?
 
I read it all bar that post I think! That should work though. Pretty simple job I would imagine. You taking it on yourself or sending it away for a play?
 
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