I've since rebuilt the turbo kit using a GT2860 which was pretty much useless, no boost until 4800rpm but it did want to make power out past 6500 which was new. That confirms there are no valve train issues / float etc and it was just the gt17 choking the exhaust flow.
After looking around for some forged turbo rods I ended up on the UK Vauxhal C20LET facebook groups to see if they had any stock rods they'd part with. Found a few but it turns out the part number and casting numbers are identical to the rods used in the aussie 18LE motors. The bearings and rod bolts are also identical. The C20LET guys run their stock motors reliably around 350HP and up to 7000rpm with only ARP rod bolts so that's a little reassuring for the old pulsar motors. They also use cast pistons and they say the rods fail before the pistons, if the tune is good. I've got a set of ARP bolts on their way.
The current build is now using a TD04l-13t subaru turbo. I finished it yesterday and ran it up on the dyno. It's making a safe 97kw atw at 0.5bar of boost. Full boost by 3100RPM, 4psi at 2100rpm. Peak power at 5000rpm
I figure if I raise boost to keep torque level, it should raise power to around 110kw at 5k with theoretically no more stress on the rods than I'm seeing now at peak torque.
I'm using ford XR6t injectors at 3bar which top out at 75% duty cycle at 5500rpm. Still a bit of room there if I run them at their rated 4bar but I'll need a new pump for that.
So next up will be an electronic boost controller to keep that torque curve flat out to 5500 and when the bolts arrive, maybe up the boost a touch.
Right now its making more power at the wheels than my VP and is 400kgs lighter. Pretty happy with that! I think we're approaching the limit of the drive train. I've already fractured the spring cage out of the exedy clutch plate and now the passenger side CV is clunky.
- td04_log.PNG (19.04 KiB) Viewed 2533 times
