Turbocharger selection for 1.5 Diesel

[SteveM]

As you may or may not know, I'm working on an H/DT entry.  The machine work on the engine is basically done, I'll be picking it up next weekend.

Specs are 1.5L rotating assembly in a VW 1.6L turbodiesel block.  The head is a 1.9L VW unit (bigger valves, better flow, larger pre-chambers than the 1.5 or 1.5L heads).

The static compression will be around 18:1, as compared to the 23:1 or so for the stock 1.5 or 1.6L engines (due to the larger head).  This should allow me to run more turbo boost, while allowing the engine to live more happily at low rpm & boost conditions.

Anyway - I'm looking for help spec'ing a turbo for this engine.  Ultimately, this engine should make somewhere in the neighborhood of 125-140 HP, and will turn a maximum of 5500 rpm.  My target rpm in top gear will be more like 4500.  If I need to shuffle gear ratios and tire diameters around, I can run more like 5,000 rpm target in top gear.

It will be water-to-air intercooled.

I'm trying to learn about turbo maps, but have only scratched the surface.  Since this will be a race-only engine, streetable characteristics are not needed.  Some of the turbos that look like they might work would be a GT2052, or GT2056. 

Anyone with experience spec'ing turbos is strongly encouraged to weigh in on this topic.

Steve.

[saltwheels262]

there are a lot of links for turbo applications in the build section
under the heading of~~ > wild weasel a true belly tank <   by Sparky.

you can look up his username under members and go to his latest posts.

I'm sure there are plenty of people that will help out.

bf

[Stainless1]

I'd start with the one that comes with the 1.6... My guess is VW knew what they were doing. 

[SteveM]

I'm pretty active on the VW diesel message boards, and I'm looking for suggestions there, also.  There's a whole community of VW diesel guys who are hopping up their Rabbits, Golfs, Jettas, etc.  Most are geared more towards street performance.

The turbos that VW put on the 1.6's and even 1.9's were engineered for low turbo lag and good midrange punch.  They are vastly improved in terms of driveability when compared to the naturally aspirated VW diesel engines in the same vehicles.  The non-turbo VW diesels are notorious for being extremely slow.  The turbos are better for around town acceleration, but are not really set up for higher RPM power like will be needed for an LSR attempt.

I'm trying to talk to as many educated turbo people as possible, to see if I can identify a common approach in terms of turbo sizing for this engine.  I have a few recommendations so far, I'm just hoping that a real identifiable trend will be seen among the recommendations.

Steve.

[kiwi belly tank]

Go here Steve, this will take away the mystery, the guess work & the bull $hit. There's also a gearing calculator in the side bar.
  Sid.
http://www.squirrelpf.com/turbocalc/

[SteveM]

Thanks Kiwi.

    There's good news.  That squirrel perf. calculator matches what the guys on the VW diesel site recommend, which also matches what my local turbo guy recommends, which also matches what someone on the competition diesel forum recommends.

     It looks like I'll be throwing down some duckets on a Garrett GT2056.

Thanks,

Steve

[tauruck]

That's a win right there. You're a fortunate guy to find the right unit. That's a big weight off your shoulders and methinks the pickup is going to go a lot faster than you think. I hope it does because you deserve it Steve. Salt fever???