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# Thread: The 2LT Diesel Dyno Panga

1. ## The 2LT Diesel Dyno Panga

Well I guess all the hp and ft.lbs talk and no dyno got to me in the end and I finally found myself with the guys at HPR Islamabad requesting some for wheelspin on my lightweight diesel 4x4. And before everyone gets all excited... the pics do look better than the results

2. If I could lay my hands on the jeep at that time.

A little adjustment of the max load and LDA and fuelling governor
checking nozzle pressures
check internal pump pressure
timing the pump

yeehaa twist the diff off

4. ## OBDII needed

5. Originally Posted by VCheng
And how are you going to find out the lb-ft without a dyno on the road?
he already have HP figures against speed, just need rpm against speed.

dont know his gear ratios, otherwise back calculating from there wudnt take much time either, im sure hes already on it.

6. Originally Posted by RedBull_ar
he already have HP figures against speed, just need rpm against speed.

dont know his gear ratios, otherwise back calculating from there wudnt take much time either, im sure hes already on it.
I see what you mean.

However, does not the OP say that the dyno was not capable of assessing diesel engines, so the numbers may not mean much since there's no proper calibration? Please correct me if I understood it wrong.

7. ## Torque at Peak HP back-calculation

@Redbull_ar and VCheng: Just to make sure I have got this right, lets rework the torque number at 4th gear wheel horse peak of 78 hp at around 54mph.

Using my gear ratio calculator I get the following numbers for my 31x10.5x15 rims and 4.1 final drive ratio with 4th gear of 1:1

Engine RPM @54mph: 2389

Using the equation: Torque (lbs-ft) = HP x 5250/RPM
I am getting: 171 lbs/ft @ 2389 RPM

Does this make sense? Please point out if I am missing anything.
Many Thanks again for your interest and guidance.

8. Originally Posted by SuhaibKiani
@Redbull_ar and VCheng: Just to make sure I have got this right, lets rework the torque number at 4th gear wheel horse peak of 78 hp at around 54mph.

Using my gear ratio calculator I get the following numbers for my 31x10.5x15 rims and 4.1 final drive ratio with 4th gear of 1:1

Engine RPM @54mph: 2389

Using the equation: Torque (lbs-ft) = HP x 5250/RPM
I am getting: 171 lbs/ft @ 2389 RPM

Does this make sense? Please point out if I am missing anything.
Many Thanks again for your interest and guidance.

These numbers seem realistic for a 2L-T

9. Originally Posted by SuhaibKiani
@Redbull_ar and VCheng: Just to make sure I have got this right, lets rework the torque number at 4th gear wheel horse peak of 78 hp at around 54mph.

Using my gear ratio calculator I get the following numbers for my 31x10.5x15 rims and 4.1 final drive ratio with 4th gear of 1:1

Engine RPM @54mph: 2389

Using the equation: Torque (lbs-ft) = HP x 5250/RPM
I am getting: 171 lbs/ft @ 2389 RPM

Does this make sense? Please point out if I am missing anything.
Many Thanks again for your interest and guidance.
If the bhp figure is reliable, sounds correct to me!

10. Thanks to Redbull-AR and VCheng for their help in deriving the torque figures. Think this is what it looks like, and the shape of the curve is not very sexy at all. Need to work on the pump, boost setting and turbo to keep the torque flatter.
Would appreciate advice and views as this tuning bit is all completely new to me!

11. Originally Posted by SuhaibKiani
Thanks to Redbull-AR and VCheng for their help in deriving the torque figures. Think this is what it looks like, and the shape of the curve is not very sexy at all. Need to work on the pump, boost setting and turbo to keep the torque flatter.

Would appreciate advice and views as this tuning bit is all completely new to me!
Actually, for a small diesel, that is very good!

12. that is very poor for a 2LT - the pump is way way off - you should be seeing atleast 230 or 240 lb/ft at and keeping it flat till the pump governor starves fuelling. (not that I have dynoed it - but by other peoples experiences with the same settings and same sort of car)

my best experience with a 2LT was in an old cressida with automatic transmission - the revs never dropped from half engine speed - the torque was so much that the engine forced the transmission to keep up.. with the input spin - not the other way round.

You can do it too - just need to get very very miniscule with the settings

13. Originally Posted by SuhaibKiani
Thanks to Redbull-AR and VCheng for their help in deriving the torque figures. Think this is what it looks like, and the shape of the curve is not very sexy at all. Need to work on the pump, boost setting and turbo to keep the torque flatter.

Would appreciate advice and views as this tuning bit is all completely new to me!
Its a huge dip actually.. like if the IP was fuel starved

Are you ready to play with the IP ?? lets tweak it a bit

14. Originally Posted by VCheng
Actually, for a small diesel, that is very good!
Originally Posted by Xulfiqar
that is very poor for a 2LT - the pump is way way off - you should be seeing atleast 230 or 240 lb/ft at and keeping it flat till the pump governor starves fuelling. (not that I have dynoed it - but by other peoples experiences with the same settings and same sort of car)

my best experience with a 2LT was in an old cressida with automatic transmission - the revs never dropped from half engine speed - the torque was so much that the engine forced the transmission to keep up.. with the input spin - not the other way round.

You can do it too - just need to get very very miniscule with the settings

Originally Posted by akifjanjua
Its a huge dip actually.. like if the IP was fuel starved

Are you ready to play with the IP ?? lets tweak it a bit

Please correct me if I am wrong, but the 2.4l 2LT engine was rated at 96 bhp at 4000 RPM with 139 lb-ft of torque at 2200 RPM.

Isn't 171 lbs/ft @ 2389 RPM pretty good for this engine already? Considering at 20% loss for a 4WD drivetrain, horsepower at the wheels should be around 77 bhp, and he is getting about that., although at a much lower rpm.

Considering that it is a non-standard drivetrain and the dyno may not be correctly calibrated, what am I missing here?

15. @Suhaib Bhai.
Thank YOU for such an amazing opportunity to see the first diesel 4X4 dyno in Pakistan.
It was a pleasure.

16. @Mir: Thank you for making it possible to test on short notice. It was a pleasure to have you there.

@Janj: Thanks and Nice....but I think i'll go with the iPhone application :

@Xulfiqar: VCheng is right, if you ignore the area beyond 2400rpms (just for now) the performance is off the charts for a 2400cc 2LT and once you take into account drivetrain losses of 15-20%, the performance is actually comparable to 3000cc 5L and 1KZ-TE engines How is that possible??? Well that was my question too....details soon

@Akif: We figured out the reason for the torque drop... it was a poor calibration on the boost compensator...the metering rod was set at the wrong face as it was kicking in too early and letting go too soon. Details to follow....

17. ## Janj: This one is better!

18. Originally Posted by SuhaibKiani
@Mir: Thank you for making it possible to test on short notice. It was a pleasure to have you there.

@Janj: Thanks and Nice....but I think i'll go with the iPhone application :

@Xulfiqar: VCheng is right, if you ignore the area beyond 2400rpms (just for now) the performance is off the charts for a 2400cc 2LT and once you take into account drivetrain losses of 15-20%, the performance is actually comparable to 3000cc 5L and 1KZ-TE engines How is that possible??? Well that was my question too....details soon

@Akif: We figured out the reason for the torque drop... it was a poor calibration on the boost compensator...the metering rod was set at the wrong face as it was kicking in too early and letting go too soon. Details to follow....
SK lets check XJ at Dyno, which model of Dyno they have? To check Full time 4wd vehicles they might need different model. Regarding your Jeep performance it seems pretty good, why don't you change your pump to electronic to get more out of 2LT?

19. ## How is possible?

To cut the long story short, for the last run the HPR guys had recommended shutting off the waste gate (or something) on the turbo to increase boost as they thought it was not running more than 4psi originally. This was done for the last 4th gear run, which sounded pretty scary to me

Anyways, many thanks to to Ali aka Charged and Mechanic Farooq we were able to measure the pressure on the turbo using a meter Ali had in his car. After restoring the waste gate to standard settings, we hooked the meter near the boost compensator via a t-joint. Ali read off a max reading of 1.4 kg/cm2 in a small run. Later I hooked another PKR 160/- desi meter to the pipe and got a max reading of around 18psi. Hence on normal settings, the 2LT turbo appears to be currently running around 18-20 psi of max boost. With the waste gate mod, we were probably running 20+psi of boost whereas I understand OEM pressure is around 10-12 psi max.

So in simple english we were over boosting the engine with the turbo, while the pump was overfueling it at least upto 2400rpms where the boost compensator moved to he off-boost setting thankfully cutting back on the extra fuel. We were lucky, not to have fried the engine....

20. Originally Posted by Janj
SK lets check XJ at Dyno, which model of Dyno they have? To check Full time 4wd vehicles they might need different model. Regarding your Jeep performance it seems pretty good, why don't you change your pump to electronic to get more out of 2LT?
@Janj: I think we will have to have a 4x4 dyno day where we pitch all the big boys against each other Let me just negotiate my cut with the HPR guys

I would think an electronic pump is ruled out after this. Once we know what we are doing (slowly getting there hopefully ) manual pump allows a lot of settings, and at full gusto appears to be capable of producing better equivalent or results. To play around the same way with an electronic pump we would also need to get a reprogrammable chip along with a programmer.....

21. point noted - but the factory adjusted 2LT is just so wheezing it seems like its mom used to smoke crack while pregnant..

Your engine is pumping out some good numbers but you can squeeze much much much more juice from the 2LT if you want, but you would need to get creative with the pump - I would suggest an 11mm pump head and a stupid cam plate in it. Some metering sleeve calibrations - just be sure your turbocharger has enough lungs - The pump is capable of double the stock fuelling and the engine is tough as bricks to take it.

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