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Loss of power - dyno test ... not bigger wheels


neels
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Hi

(Previous topic - "Bigger wheels - loss of power ")

I took my dico 2 td5 automatic for a dyno test - results were 248 nm torgue and 73 kw (should be 330 nm and 95 kw) - turbo boost was 1.0 bar (they said it can be adjusted to 1.2bar)

I am now convinced that the bigger tyres (265/75/15) are not the reason for my power loss. I already did the following:

- new diesel pump

- new diesel filter

- cleaned the intercooler etc.

- replaced the turbo boost pipes

- tested another airflow meter - vehicle performed the same.

- Turbo boost test - 1.0 bar (They say it can be turned up to 1.2 bar)

- new fuel regulator

- Airflow too turbo is 212 while driving (hope it make sense)

- New tophead gascet

- computer test - no fault.

- Also found oil in the loom that goes to the computer box. (Land Rover said that this will not have any effect on the performance of the vehicle.)

What is the "EGR" and can this be my problem?

Can I do a compression test on the td5?

Somebody also said that there is a sensor on the transfer box - this tells the vehicle that you are in high range or low range. Sometimes when driving in high range it still registers that you are in low range - result is that you dont get all the power. they say one can bypass this. - Is this true?

What can i do next?

Neels

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There is a sensor and while I have never tried it you should be able to unplug it and either leave it open circuit, or short the connections, to force it to low or high, can't remember which way round forces which mode.

Td5 compression test can be done via the glow plug holes but only on 4 cylinders of course!

Just out of interest where did you find 15" wheels to fit a Discovery 2 and what sort are they?

EGR = exhaust gas recirculation. The problems it causes and means of bypassing it can be found by searching the forum, look in the Defender and International forums plus the Tech Archive, as well as this one, and you'll find tonnes of info.

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You lose a lot through the transmission & tyres. See here and here for dyno losses and how they estimate the flywheel BHP of your engine - a dyno used to cars is going to estimate wrong for a LR.

A TD5 Auto is never going to be a race car, you may be chasing a problem that simply doesn't exist.

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"Bogmonster" - The 15" wheels (steel) are from the BMW 5-series - 6 or 6.5 j - works perfect for 265/75/15 tyres.

"RRX" - I am not sure but i think it is measured from the wheels - test was done in 4wd. Even with a uni-chip they could only manage 271nm torgue. (They had one in stock)

The correct figures are as follows: Speed: 89km/h @ 4192 rpm

Power : 73.0 kw @ 3814 rpm

torgue : 248 nm @ 2213 rpm

"Fridgefreezer" - You may be right that the td5 will never be a race car - but doing 90km/h (full throttle) on a average hill is not right. (Everyone that has test drive the vehicle said that the car was not performing as it should be).

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Corrected means they are probably guestimating the flywheel power so the wheel power is even lower. I would say as they have checked the boost and your running 1 bar then the problem will be fuelling but finding out if its the electrical or mechanical side of the engine playing up isn't that easy. I'm sure the people with td5's can answer this bit i do remember there being issues with oil in the loom causing issues but where and what i'm not sure.

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Just for comparison...

I took my Disco td5 Manual (fully Allisport tuned) for a Dyno test.

Results were 400Nm and 196bhp (flywheel "estimate") - and 130bhp at the wheels.

it really "flies" on the road.

I've got also a Disco 300tdi auto (Allisport tuned as well) that was tested.

The tester would not give me flywheel estimate as they say that auto box cannot be accurately estimated.

However the power at the wheels (Mud 245/75/16) was only 60bhp... even if is goes very well compared to other Disco tdi.

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Somebody also said that there is a sensor on the transfer box - this tells the vehicle that you are in high range or low range. Sometimes when driving in high range it still registers that you are in low range - result is that you dont get all the power. they say one can bypass this. - Is this true?

You can do an easy test to see if this is doing as it should.

Put your main gearbox in neutral. Hold your foot dead still on the throttle at a certain RPM, like 1500 say. Move the transfer lever into low, if it is plugged in and working as per LR intended the revs will drop.

In low range if you do the same as you move back to high range the revs will lift.

Mark

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Hi

MJIBEX - thanks for the advice - did it - mine working perfectly.

nicks90 - good advice - will have it check this week.

I did blocked of the egr valve. Also replaced wastegate and the sensor that located under the aircon. (there is 3 thin pipes - one goes to the wastegate) - Performance is better - but not much.

I am close to the point of accepting the car as it is.

Neels

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