Porsche 944 turbocharger hotside mod?

[20Vcqdriver]

I have slooowly been developing my 20Vt over many years and have the MD357 as Darren but also suffer the same surge issues above 23psi and been advised the 0.6AR hotside is the xause as it will be excessively restrictive with my 2.3 setup with Wagner manifold and ported head. Darren changed his MD357 to 0.82AR with success but I have been informed the parts are no longer available to modify to this now (unless someone knows of a source) but been advised that the Porsche 944 0.8 hotside from the 250bhp engine could be made to fit.... . Be interested in opinions as MD357 in its present form is OK and spools up after 2500rpm it does feel its strangling the engine after 5000rpm. All opinions appreciated.

[Kiku]

https://www.turbosystems.info/produc...ousing-upgrade

Fit and forget!

[20Vcqdriver]

https://www.turbosystems.info/produc...ousing-upgrade

Fit and forget!

Excellent info and looks perfect if it is just the housing change without the need to change hotside impeller too Thanks

[Colesy]

https://www.turbosystems.info/produc...ousing-upgrade

Fit and forget!

Size wise how does that compare to the RS2 and stock S2 hot side?

[Kiku]

Basicaly that hotside is with the same spool up as 8". I have both in my hands.

Compare to rs2 and k24/7000 hotside:
*lower EGT
*no more bottle effect in the manifolds
*you loose in spool up compared to TINY hotside but you gain in mid and top revs, of course you could use a propper setup/tuneup for the ecu

I hope to manage in mid summer to do tuneup in dyno with both hotsides with K27/K26 "3071"

[20Vcqdriver]

Basicaly that hotside is with the same spool up as 8". I have both in my hands.

Compare to rs2 and k24/7000 hotside:
*lower EGT
*no more bottle effect in the manifolds
*you loose in spool up compared to TINY hotside but you gain in mid and top revs, of course you could use a propper setup/tuneup for the ecu

I hope to manage in mid summer to do tuneup in dyno with both hotsides with K27/K26 "3071"

I'd be interested to see those results, Especially when its spool up/ boost point is. Will you be using roller bearing centre section?

[Kiku]

Roller bearing center selection you mean turbo itself? Its oldschool journual bearing, only with 360 degree bearing.

[K Simmonds]

I've been eyeing up those SS Turbine Housings myself to make a mega RS2 hybrid turbo.... Surely it's closer to a (theoretical) #10 housing with it's 10.7 cm2 capacity? I have a couple of good #8 housings in stock but would love to actually get my hands on one of those.

[k.alle]

I'm a bit lost when it comes to this.
Is there any other mod necessary when changing hot side?
Bigger shaft/exhaust wheel needed or is it truly just bolt on?

[Kiku]

For 64/54mm K26 impeller it is a straight fit. Middle part has to be K26 aswell of course.

[k.alle]

So for a RS2 turbo it should be a straight fit?
Or maybe im reading that wrong.

I get that EGT will be lower and spool will be slower du to bigger housing.
But what are the other benefits?
Will the turbo able to produce more pressure up top with this?

Sorry for being an idiot.

[_ShurikeN]

So for a RS2 turbo it should be a straight fit?

Original RS2 KKK24 7400 turbine wheel is smaller than K26 one (50mm vs 54mm), so they are not direct fit.

[Kiku]

As Shuriken told before straight fit it will be for typical k27/26 hybrids and k26 turbos. Im sure that if you write them your turbo exhaust wheel size then they are able to machine it not so big.

Of course you have to map your car for the benefits to achieve the maximum from this hotside!

[Error404]

My MD357 has a modified K26 turbine housing, I also fitted a larger turbine (60mm IIRC) and shaft at the same time. Will dig out my specs:

EDIT:

0.50 A/R GT30 CompCover
7 Blade 53.10mm Ind 73.00mm Exducer Billet Comp Wheel
GT30 60mm 84 trim Turbine Wheel
0.82 A/R Audi Fitment TurbineHousing

[k.alle]

Thanks for the info.
I really need to do some studying on turbos.