HX35 to big for my WBX 1.9L?

[tencentlife]

I think the turbine outlet pipe might be too small. It looks that way in the pic on your site.

[streetvwnorth]

Maybe the hx-35 is to big for my engine and i should try am hx-30 instead. I have to take a look around among my friends and see if the maybe have one.

The turbine outlet pipe is 64mm and that is the same diameter as the original exhaust flange. If it was too small and restrict the flow, shouldn't the exhaust back pressure (before turbo housing) be higher? Because to day the exhaust back pressure follows the boost pressure and never goes over 1 bar.

/M

[DORIGTT]

I just purchased a HX30 for my long over-due project as well. I got it on a recommendation from Marco Mansi and I would have to trust his judgement based on his track record.

[tencentlife]

If it was too small and restrict the flow, shouldn't the exhaust back pressure (before turbo housing) be higher?

I'm no expert on turbines, but I wouldn't think so. Remember that raising pre-turbine pressure is also function of boost. One hand has to wash the other.

But 64mm outlet pipe seems like an adequate size to me, it just looked smaller in your pics.

[streetvwnorth]

Well, the engine i coming apart now anyway. We will see next summer what happens after the upgrade. Thanks anyway for your answers.

/M

[DORIGTT]

If asume your timing is "dialed in" , so 24 degrees is actualy 24 degrees?
if so , you could add a lot more timing here
at 100kpa you could easy have 33-35 degrees with retard down to 26'ish at 200kpa
you should also have lowest timing where the max torque is.
above 4500-5000 you can add a few degrees
not oppsite as you have it

and at lighter load and cruise (below 100kpa) you can add more timing from the base 33-35

Hey fastback,

Would the add-on software tuning packages for Megasquirt do all of this automatically for you?

[Steve Arndt]

DORIGTT,

Timing needs to be tuned manually.

s

[DORIGTT]

Thanks Steve.

[streetvwnorth]

Update!

This summer a saw boost pressure well over 0,9 bar. There is no problem getting 1,5 bar with the Wg locked. The problem was likely too small down pipe and a bad internal WG. This winter i will mount an external WG, change clutch and disc, go trough the gearbox and purchase some slicks. So hopefully next summer i will see some good times down the strip.

Updated engine facts:
Stock WBX 1.9L DG (fully restored with weighed pistons, etc)
Stock intake
Web cam camshaft #118, 286, .402", 112 lobe center
Holset Hx35 twin scroll turbo housings
685cc fuel injectors, Runs on E85
Megasquirt with Edis
Homemade 38mm (inner diameter) exhaust with twin scroll
76mm (inner diameter) down pipe
Small IC



/M

[DORIGTT]

When do will you have time to run it on a dyno to see what the power curve and torque and hp output looks like?

[streetvwnorth]

I live in the north of sweden and i have a long way to the nearest dyno. What i can do is to calculate an app. power from a timeslip next summer.

/M

[fastback]

good
at what RPM do you hit full boost ?

[streetvwnorth]

Still a bit late! App. at 3800-4500 rpm, i don't have my log files here. Hopefully i can fix that with some mapping and the new WG.

/M

[streetvwnorth]

Update!

The summer i soon here and I'm getting prepared for it. This winter i have mounted an external WG, change clutchdisc, gone trough the gearbox, change the downpipe and mounted an modified Garrett turbin housing on my Holset Hx35. Because the mild whether i got the chance to take the car for a ride last week and the car feelt very good. Starting to get pressure around 3500 rpm and full boost at app. 4400 rpm and that with the spark map untested. The external WG performed very good. Stabil boost pressure. I measured the exhaust back pressure and it follows the boost pressure (1:1). And thats ok for now. Get back with more info when i get the car on the street again. But now we have a cold period up here in the north. (-15 degres Celsius, 5 degres Fahrenheit)

Updated engine facts:
Stock WBX 1.9L DG (fully restored with weighed pistons, etc)
Stock intake
Web cam camshaft #118, 286, .402", 112 lobe center
Holset Hx35 with modify garrett T3 .63 turbine housing
Tial F38 (0.8 bar spring for now)
685cc fuel injectors, Runs on E85
Megasquirt with Edis
Homemade 38mm (inner diameter) exhaust with twin scroll
3.5" down pipe
Small IC

[fastback]

cool will we se it at Bugrun?