Technical VL36 Vs VL38 differences

[Ben D]

Just got a very cheap VL36 that needs some work. Compressor housing is fine, turbine housing is cracked and although core seems ok, it will be replaced.

Ordered a new turbine housing from Italy for peanuts so that just leaves the CHRA which confuses me a little.......

All built and balanced cores I can find are listed as for VL36/38, or just VL38. If they're interchangeable then then logic says the compressor housings of the two should be identical also. If this is the case, how is the difference in performance between the boost / RPM / torque / BHP explained between A500 and AGP?
Is it in the cams or mapping or, is it the number of or attitude of the fins on the compressor wheel? Or possibly a difference in diameter inside the two compressor housings on the outflow to the intercooler, maybe larger bore on VL36 allowing later onset of boost and higher peak output?

I know the hot side of VL36/37/38 are identical so I'm struggling to work out where the physical differences lie between the VL36 and VL38 units.

Having spent ages tracking down a 36, I don't want to go and throw a 38 core in it.

Any clarification appreciated.


Cheers

Ben

 

[Ben D]

Anyone got any thoughts on this or even any idea of where to look? I've asked a few people I thought would know but can't get a firm answer.


Cheers

Ben

 

[aurick86]

I've never been able to find a definite answer.. but to my knowledge the vl37~vl38.
Just get a vl36 CHRA based on the part number; the one I've used is 55212916 (definitely the turbo on the T-jet 150)

And yes.. a different compressor housing that uses the same compressor wheel can make some differences... but more in lag... not so much in max power.

 

[Ben D]

One source told me the 36, 37, 38 are all identical in every way and the difference in performance would be in the software which I'm not too convinced about. A reputable tuner told me what we all believe, 36 and 38 have differences in how they boost.
I know the hot side is the same on all three.

Number on my VL36 is 55222014 although I've been searching 55212916 too. Only CHRA I've found listed for VL36 rather than 36/38 is from Nerings in Latvia. All the UK rebuild / refurb places only list for both.

Latvia it is then!


Cheers

Ben

 

[aurick86]

I've had both vl36 and vl37 side by side. they are definitely not the same. the vl37 is smaller.

Ben, the one I got was the one from this seller on ebay.

With this the car got 194hp... so i'd say it's good enough.

Keep in mind the only difference between vl36 and vl38 might be ... different production technique/ production location...
It could also be that the compressor housing is slightly different ... Boost would be moved up/down on the rpm range.. but max power should be about the same. (but you already have the vl36 housing)


When i got mine the one from Nerings was about 175 euro... so yah.. get it from them!
Remember to post 100 pics when it arrives.

 

[Ben D]

I'll whack some pictures in a new thread. Stripping a turbo may be of use to someone else in future.

Cheers

Ben

 

[Ben D]

Having done some more digging on this, it seems that the only difference between the VL36/VL38 is the wastegate actuator. The spring fitted inside the factory VL36 actuator is apparently stiffer than that fitted to the VL38 and this accounts for the difference in boost characteristics.

Cheers

Ben

 

[Gribouilly]

Hello !
Small UP (more than 4 years yet lol) about this question I have on my head.
I have 2 complete TJET engines for my Seicento racetrack car : first coming from GP 155 equiped VL38 , second coming from A500 135 equiped VL36.
On the GP155 engin, the exhaust manifold and the turbo exhaust housing were cracked , so only now I saw the name VL38 and the VL36.
Of course I have now answer about the difference because it appears completely identical.
Anyone have other comments about ?
Thanks.