Thread: Dissapointing fuel pump tweaks...

Originally Posted by Dunnie

What started me off on DIY pump tuning is that I went to a 'diesel specialist' in Osborne Park, Perth. Despite what the sign said, it was obvious that I was talking to someone who knew even less about Bosch VE pumps than I did. I cancelled the booking and did the deed myself with the help of the AULRO links.

Anyone in Perth who wants absolutely honest, genuinely expert help with diesel injection and turbos, I recommend sister companies Turbotech and A1 Diesel Injection in Gt. Eastern Hwy Redcliffe.

Daft thing is I took the same approach, and the guys I used did seem to know what they were talking about, but are still at a loss to explain why I saw no real power gains over peak figures. I've got some things to try suggested by the poeple in this thread, and no doubt I'm going to end up learning a lot more about this than I wanted to...which is why I took it to a specialist in the first place.

my has been on the dyno this morning to confirm the tweak

95bhp at the wheels
16psi boost
670 egt's

has does that compare with yours

does anybody else know what they are getting at the rear wheels

Originally Posted by weeds

95bhp at the wheels
16psi boost
670 egt's

has does that compare with yours

Hmm...you just came in here to depress me further, didn't you?

95bhp at the wheels is very (very) good...to the point I'd be interested in seeing a factory car's figures to make sure their dyno wasn't reading over!

Figures between dynos mean sod all as you have no idea how they're calibrated, but to give you an idea mine was 50kW after the tweaks and 46kW before. Now you can see why I'm so ****ed off.

More interesting was the low end. Here I was picking up the same 3-5kW and 5-7Nm of torque from 1400rpm, which is much more significant and explains why the car is so much better on a light throttle on the road. Above this though, I would regard my results as **** beyond belief.

I fitted a Redline turbo gauge at the same time as the tweaks and I get centre-scale 15psi, or about 1 bar when the foot is hard down, which is what it should be. I have got the wastegate connected directly to the manifold and teed off to the gauge. My son (in Ivan Clark territory, Wodonga) has a Rover V8 powered SII wagon with a single Holley. He hadn't been in my Defender for a long time until last January. His comment was that mine accelerated the same as his.

The biggest single difference (from memory) during the tweaking was turning the fuelling rod 90deg clockwise. The mark on the rod pointed directly towards the engine block as supplied from LR works.