Date registered: Aug 2012
Vehicle: 1986 U1300L; 1976 U900 Cabriolet
Location: Sydney, Australia
Mentioned: 0 Post(s)
Quoted: 23 Post(s)
I have a 1986 U1300L ambulance with turbo fitted, but only pushed out to 150hp. Dealer's decision, not mine. I wanted more. I tried 365/85's which are a bit lighter and smaller than your 395/85's and it killed the acceleration and braking. The ambulance is a heavy body and combined with the bigger tyres you will need quite a bit extra from your engine. Atkinson Vos have a kit which adds a turbo, intercooler, uprated radiator, uprated pump and the appropriate injectors and take these NA motors out to about 180hp without sending your EGT's sky high.
I've tinkered with mine over time. Upgraded the turbo to the Garrett used on the U1700L, new injectors and back to 365/80 tyres (biggest difference). I also changed out the portal gearing and bearings to the latest 20% extra gearing from AV. It now cruises at 100kmph (62mph) with ease, but works the engine hard. It's jumped from 22l/100km to 28l/100. The big change I'm making is to replace the ambulance box with a custom camper which will be 2,500lbs lighter. Once that's done I'll try it out to see how well it handles and then decide what to do with the motor.
We removed the camper, 6,600 lbs with all my junk in it, and I took the truck for a drive. I'd expected a bit more neck-wrenching acceleration, but it doesn't seem to pick up speed any quicker, just holds the hills better.