k24/k26 hybrid

[Mk2Fanatic]

Would a k26(audi 5000 MC turbo) machined to fit the k24 hot side work for a hi-perf street/track diesel?  The k26 is a .6 A/R, vs the stock k24 .36 A/R.  Plans include a giles pump, passenger perf.  2.5" downpipe to 3" from the flex pipe back; 02A diesel trans conversion; lightened flywheel; front mount Mk5 intercooler and 2.5" piping; gasser intake with a G60 tb adapter(2.5" inlet); ARP fasteners.  I have access to a machine shop, and was planning on opening up the k24 turbine housing to fit the k26 wheel.  The k26 could also be mounted with an adapter plate to fit the manifold.  Main reason I'd like to keep the k24 turbine housing, is to keep the turbo close to the same location to use the Passenger Perf downpipe.  Any opinions and thoughts are greatly appreciated.

[Black Smokin' Diesel]

http://vwdiesel.net/phpBB/viewtopic.php?t=7578

[Mk2Fanatic]

seen that post, but no info as to pics or opinions on whether it would be a good setup or not...

[andy2]

The k24 hotside is .3 and the T3 is .36.The T3 is the best old bolt on turbo as it's turbine housing,wheel and wastegate flows much more than the the k24.The T3 will work really well upto 22-23 psi and the k24 would work well to 20-21.For boost pressures above 25 psi you will want to abondon both the k24 and T3 for use as a single turbo as their turbine's simply will not let the engine breathe properly.A T3/k24 can produce over 30 psi boost pressure but in doing so they require about 60+ psi of exhaust drive pressure.This is ok if its just the odd 30 psi run here or there but If you want to hold 30 psi boost you want a bigger turbo.Others have sugested the T3 from the mercedes 3L as it has a .48 A/R trubine will flow well and probably make 30+ psi on the 1.6/1.9 while only taking about 30 psi of exhaust drive pressure to do so.This turbo however will lag very badly for daily driven use and would only work well for street,track use.Basically I don't see the point of making a k24/k26 hybrid for those reasons.

[Mk2Fanatic]

Others have sugested the T3 from the mercedes 3L as it has a .48 A/R trubine will flow well and probably make 30+ psi on the 1.6/1.9 while only taking about 30 psi of exhaust drive pressure to do so.This turbo however will lag very badly for daily driven use and would only work well for street,track use.Basically I don't see the point of making a k24/k26 hybrid for those reasons.

 

What about using the K26  as a whole?

[SMOKEYDUB]

it would probably be similar to the mercedes one , A bit laggy for daily use.

[Mk2Fanatic]

define laggy for daily use.  Right now the car has all the mods from the FAQ except for the exhaust (waiting for my tax return to go full 2.5"+ in SS.)  With a T3 set to dump at 16psi, I feel the onset of boost at about 1500rpm(5+psi) from 1500 to about 3200-3300 she pulls fairly strong.  I'm willing to trade power below 2500rpm for power from 2200 to 5000rpm.  I currently have a bunch of parts sitting for my project (complete 94 passat TD donor car; 11mm auto TDI pump head; rebuilt stock pump(1yr old)with all the FAQ mods; several different boost pins and cam plates; 1z and GTD nozzles).  What else do I need to spin my diesel upto 5-5500 rpm?   I just would like to form a game plan so I can tackle this project the May 24 long weekend.  My ultimate goal is 200whp and 270+ft-lbs...

[andy2]

125-135 whp is all you will get before the headgasket will not seal.If you can seal combustion pressure you will then need to lower the compression ratio to avoid bending rods,need better rings(total seal).You'll need a better intake manifoild as well and if this is still a 1.6 then your cyl head is no good for 125+whp.There seems to be a max safe hp where the stock turbo(t3/k24),engine(1.9 or 1.9) will only handle about double its factory HP :twisted:.Beyond this there is no limits to how much time and money is spent to get an IDI from 125-200whp!

Basically I've been there done that for the past 2 years and still have issues making 150whp.If you want to spend a limited amount of time and money you should run 23-24 psi with the T3 turn up the fueling to match the boost according to EGT's.A good exhaust,intercooler on a 1.9(AAZ) tuned like that will make 110-120 whp and not have major issues.

[Mk2Fanatic]

Things on my shopping list include rebuilding the complete 1.9 from the passat with factory parts(bearings and gaskets), arp fasteners, coated pistons and total seal rings.  What options are there for cams, and can any machine shop handle O-ringing the head and block?  I've got a gas intake and G60 tb adapter for a manifold setup.  My intercooler is a mk5 TDI one with 2.5" ID piping.

[SMOKEYDUB]

O riniging tyhe block doesnt seem to help any....

[Mk2Fanatic]

O riniging tyhe block doesnt seem to help any....

Copper head gasket with the ARP'sor just stock metal and ARP's?