Dyno tune analysis

[Mr Trol]

Greetings all,

Id be most appreciative of some feedback / commentary on the provided dyno sheet.

Background information is as follows:
1998 DX Wagon - New TD42 Nissan crate motor, has done 16000kms. Safari turbo (not sure what boost its running) and intercooler, both overhauled 15000kms ago. Injectors and fuel pump also overhauled 15000kms ago. 2.5” dump pipe and lukey exhaust. 5 speed manual, heavy duty clutch. 275 15 75R BFG All terrain tyres

Originally, I got the dyno tune because it was blowing more black smoke than usual and I’d hoped to squeeze a little more torque out. I started off with 112kw @ 3292rpm and 363Nm @ 2556rpm. The end result was 98kw @ 3222 and 324Nm @ 2333Nm. Based on my assessment of the read out, the kw figures are at the engine, with at the wheel figures of 92kw initially and 80kw now.

I’m told that because the TD42 block does not have the same veins as the td42t block, (or something to this effect) this was the highest output I could achieve. From what Ive heard, these engines can put out 400nm at 11-13psi without unnecessary strain on the internals. Given the new engine and recently overhauled turbo, intercooler, pump and injectors, is 400nm an unreasonable expectation?

Any comments on the overall graph greatly appreciated.

[YNOT]

The only way to get proper engine figures is to take the engine out of the car and run it up on an engine dyno. Your figures were obtained at the rear wheels and a correction figure (usually around 30% to allow for driveline losses) added to get approximate engine figures. You are mainly concerned with before and after figures.

I can't say for sure because I was not there but it looks as though your engine was over fueling causing the black smoke, your exhaust gas temperatures were probably excessive as well. My guess is all they have done is wind the fuel back to get the smoke, mixtures and EGT's back to where they should be. The down side is less fuel equals less power. Ask them if they checked injector pump timing.
The other option (which they may or may not have investigated) was winding up the boost. This would have had the same effect as winding back the fuel but resulted in little to no power loss. 14psi especially with an intercooler is fine for a TD42.
Do you know what the boost is currently set at?

Tony

[MudRunnerTD]

Do you have a Manual Boost Controller fitted to the car? if not then it is likely set at 9 or 10 psi. I agree with Tony mate, they have been reactive the the smoke and the EGT which is the right thing to do during your tune, but to tune it down around 80kw is pretty average to be honest...

I would expect you to be able to get around the 90rwkw with not too much drama with a manual boost controller. The tuner should have sold you one while it was on the dyno and fitted it up for the best possible outcome. This depends on the instructions you gave him though? what was it there for? "It's blowing a heap of smoke? can you sort that out?" will get you what you got. If you rolled off the dyno without knowing how much Boost then i doubt that you have an adjustment and the tune was based solely on the pump screw as the actuator for the boost is preset.

Without a Boost controller you have basically taken your car in for a tune and tied one hand behind the tuners back and said do what you can with this. His whole tune was likely on 1 screw on the back of the pump cause thats all there is.

Fit a manual boost controller that allows them to adjust the boost and get it retuned for peak power EGT balance and you should be able to go to 14psi without too much drama and that should put you back into the low 90's

The 2.5" system may be a little restrictive too for best outcome mate. Also your running slightly oversized tyres i think? this would affect the potential end number your chasing.

The last thing i can add for you mate is dont get too lost in the numbers cause it will do your head in, does the thing do what you need it to do? if it does then its irrelevant, your TD42T will see you do everything you want with it for many years to come.

If your committed to chasing your number then immediately fit a Manual Boost Controller, a Boost gauge that reads to 30 and a EGT Pyro Gauge that reads in Celcius to 900C and then take it back to the tuner for another go. Without the gauges you are risking long term damage to your engine chasing a big number without the monitoring options.

Good luck.

MR

[Mr Trol]

Thank you both for your comments.

It was definitely over fueling when I took it in and likely running pretty high EGTs. I'd hoped the boost would have been increased to match the fuel and not vice versa but without a boost controller this clearly wasn't going to happen.

9 times out of 10 it'll do what I need so I cant complain really and i did manage to average 10l 100km for a 200km stint. That little bit extra would have sure come in handy at Calcup on the weekend though. Boost and EGT guages are next on the cards so I'll fit a boost controller at the same time and see if i cant get it back to previous figures.

Thanks again fellas.

[MudRunnerTD]

No Probs mate, your membership to the forum has been a winner already ;).

Keep us in the loop mate and let us know how you end up.

Good luck with it, rest assured you are not the first person to take their car to get dyno tuned with the same result.

Cheers MR