Page 7 of 15

Re: N13 Turbo - Round 2... Fight!

Posted: Sun Aug 22, 2021 4:15 pm
by BennVenn
What should have been 20min to clock this turbo dragged out to 3hrs... With the housing off, the vnt assembly is keyed so it can't be clocked. Tried pressing it out but turns out it's threaded. Turned down some steel and cut some teeth in it to make a tool. Vnt removed, rotated and locked in.

Just about ready to mount to this manifold and weld it all up. Not sure if I should continue on with this turbo or use the new MPR one coming this week...
IMG20210822150104.jpg
IMG20210822150107.jpg

Re: N13 Turbo - Round 2... Fight!

Posted: Sat May 14, 2022 1:56 pm
by BennVenn
Wow! Almost a year has passed on this!?

A bit has happened since then, I found a chassis dyno for a crazy good price, fitted the yourdyno.com controller, sensors and load cell to it and have spent a few days tuning the controller to get it all dialed in.
Screenshot_20220511-062407.png
I'm onto the 3rd iteration of turbo kit for the pulsar, this time using a Saab 2.0L gt17. It has been ready to install for a little while now. I was waiting to tune the NA engine for a good starting point for the turbo tune. I didn't think there was that much power left on the table in the stock tune, but an extra 20% torque from around 2500rpm up makes it feel a fair bit quicker.
received_686307925963526.jpeg
Next up, tuning the gt17!

Re: N13 Turbo - Round 2... Fight!

Posted: Sat May 14, 2022 2:08 pm
by Charlescrown
Nice gains. Just love the dyno setup. Lucky your neighbours are a distance away.

Re: N13 Turbo - Round 2... Fight!

Posted: Sun May 15, 2022 9:30 am
by BennVenn
Pretty happy with those gains. I would have thought with the 94 e10 I'd get it to knock but any more timing past MBT and it gently rolls off and nothing out of the ordinary from the knock ears. Might be the low compression or the cool weather. That'll probably change with the turbo.

Our town had a 3 day, 24hr bush doof a couple of weeks ago. That pissed off a few neighbours - it was about 4km from us and it carried pretty well. Hopefully a couple of pulls over lunchtime doesn't ruffle too many feathers.

Re: N13 Turbo - Round 2... Fight!

Posted: Sun May 15, 2022 9:47 am
by antus
Thanks for the update. That yourdyno.com kit looks quite cheap and simple and it looks like there is some good info there about low cost and home brew setups. I think i'll have to have a read.

Re: N13 Turbo - Round 2... Fight!

Posted: Sun May 22, 2022 7:09 pm
by BennVenn
The yourdyno gear has been great, really easy to set up and repeatable results run to run. I have a slight issue with strapping a fwd car down, it wants to climb onto the drive roller and off the idle roller which changes inertia and a slight wave in the torque. I'll be setting up a Dyno dynamics style tie down system which should fix that.

A small update on the build, intercooler piping cut, welded and everything fits nicely. Almost ready for tuning!
IMG_20220522_115831327.jpg

Re: N13 Turbo - Round 2... Fight!

Posted: Sun May 29, 2022 8:12 am
by BennVenn
10psi.png
N13 18LE+T dyno day!
Stock: 48kW. Turbocharged: 83kW (at the wheels)
10psi, 85% injector duty (11:1 afr)
Not quite the numbers I was expecting, a healthy boost in torque from around 2000rpm up until 4000rpm where torque begins to take a dive and with it, so does HP. At this torque, if it held steady until 5500rpm, we'd be seeing ~100kW at the wheels.
I know this Saab GT17 can flow 200HP so that's not the bottleneck. Possibly valve float?
I'll pop it back on the dyno today to try find out why the dip. There is a small RPM spike in the ecu log that isn't on the roller log. Maybe clutch slip, maybe it climbed off the back rollers.

Re: N13 Turbo - Round 2... Fight!

Posted: Sun May 29, 2022 9:32 pm
by vlad01
Very likely valve springs. They loose tension with age and Ks. Also the general rule for boost is at a min to increase the spring pressure by the same amount in boost psi x the intake valve area in square inches. So for eg. 10psi boost x 1.5"2 = 15 lb stiffer springs over stock.

Re: N13 Turbo - Round 2... Fight!

Posted: Mon May 30, 2022 11:42 am
by BennVenn
The workshop manual says 300N (67lb) spring force when the valve is closed. I'm not so sure it's valve related now though, before gapping the spark plug the torque dropped off sharply around 3300rpm. After gapping them down to about .8mm it's moved to 4000rpm.

Is there any information on how to adjust the dwell settings in 12p?

What was interesting is with the larger gap at 3000rpm, AFR's never went lean which I assumed misfiring would cause? Likewise at 4k now, ARF still on point.

I'll try find a 5psi wastegate actuator to bring the boost right down to see how that affects torque higher up.

Re: N13 Turbo - Round 2... Fight!

Posted: Mon May 30, 2022 5:54 pm
by antus
dwell is in hardware and cant be changed. the vl400 ignition modules had the smarts to do it but they are no longer available. only option is to change the coil for something with different properties.