It's Dyno day!

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Originally Posted by Rick122

Dyno tests should be done in 4th as it is a 1:1 ratio. Your power would be slightly higher if done in 4th. There are reasons the dyno operator will do the runs in 3rd, usually due to the tyres not being rated to do the high speeds. The has been cases where tyres have delaminated during a dyno run.
Oh, and torque reading on a chassis dyno should be ignored as the figure is multiplied by gearing, the size etc. It'd only useful to gauge before and after readings.

Sent from my XT1033 using AULRO mobile app

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Fourth in a 300tdi ain't breaking the sound barrier......and I assume the trees would handle it.

I can't remember what gear he did mine in.........I trusted he knew what was best as its his daily job.

Good to hear all went well.........Good thing you were not standing next to your car while its being driven on a dyno......sounds scary.

Hi Mud, that dyno graph is worth a thousand words, very informative thanks for sharing, it reinforces what I was thinking.
i) best torque is between 2200 -3200 rpm, but still good up to 3500.
ii) The power curve is flattening out at 3500 rpm.
iii) the sweet spot for cruising is between 2200 and 3000.

Your tires are 275/85, about 3.5% taller than mine, my 235/85, will bump the revs up a little compared to yours.

I have the Madaman VNT, APT inter cooler, some tuning of the fuel pump on the boost compensator only, No exhaust mods, but considering removing the center muffler (seems a popular thing to do).

My impression driving the car is much improved low down torque, and more power at highway speeds, able to keep up with the traffic on the highway and maintain speed up most hills in top gear. Generally a much more relaxed drive. EGTs are similar to yours, and boost pressure maybe little higher. I need a new boost gauge, tidy up my intercooler pipes, and make some adjustment s to the maximum fuel screw, then I'll definitely be going to BT&T for a run after I have.

I used the Dave Ashcroft ratio calculator, and if I fit the disco trans- case, it will put me at 2200 rpm at 100 kph, 2400 rpm at 110 kph, 2630 rpm at 120 kph. My engine feels like it can use the taller gears, but it's only my seat of the pants feel. ( But I don't tow anything) Thanks for the info, I'll share mine when I do next year. cheers simmo.:)

Hi Simo

Yes, it's a great improvement. I don't have any mufflers and I also have the the metal intercooler pipe (between intercooler and turbo) modified with the squashed/flat section removed.