Cure for lack of low-down power?

[Ovets]

I am extremely happy with my Challenger both on-road and off, but there is one thing that I'd like to rectify and that is the lack of power low in the rev range.

When off road, I would prefer to tackle hills in second gear to reduce wheelspin but find that the car bogs down badly when the revs drop. For example, slowing for an erosion mound going uphill sees me lose momentum and more often than not requires a change back to first gear (mine is manual).

Two possible solutions I've thought of are a more free-flowing exhaust and/or a performance chip.

Can anyone shed any light on which of these options (or possibly others) might be worth looking at?

[skinnee]

i assume you are running correct tyre pressures or tried lowering them a bit more to aid in traction? And also the stability control turned off

Having just come back from a professional Sand Dune/Beach driving course which included driving sideways on a dune i cannot fault the power except when the nut at the wheel (being me) forgets to turn off the ASC.

I wouldn't be spending the money on exhausts/chips, they are better off being spent elsewhere.

[Ovets]

My problem has nothing to do with traction (or lack of it) - it has to do with the fact that the car really bogs down until the engine revs get above 1750rpm or so (when the turbo kicks in). I'm getting wheelspin because I have to keep attacking hills in first gear because the car will stall out in second.

I recently did a 4WD course and there were some vehicles that could just about climb hills in second gear at walking pace - there's no way my Challenger could do that.

What I want is to get some more power from the engine lower in the rev range.

[Bennys]

Switch ya lock on if u have one as that helps. But it's just about balancing the throttle, small adjustments here and there as u assess the terrain in front of u. U get a feel for it eventually.

Saying that I run a chip and 3 inch exhaust in the triton, makes a world of difference.

Another avenue is a sprint booster, which adjusts the voltage being sent to the ecu from ur accelerator, seemingly makes u accelerate harder/faster without changing anything to do with power.

[fuelconsumption]

Yes, the lack of torque from idle to 1500 RPM is very noticible in the manual. I was on a trail last weekend which my old '93 manual 3 liter petrol Pajero walked up effortlessy, whereas in the Challenger the revs had to be kept above 1800RPM, resulting in a higher-than-ideal vehicle speed. This is not a serious issue for me, as I prefer to be gentle on the environment and walk or mountain-bike if the going is seriously tough, but I still can't help but notice the lack of torque just off idle.

The options that would make a real difference are an auto, a petrol engine, or a (much) larger capacity diesel.

None of those options suit, so I think you will need to put up with the nature of the beast. This is a small capacity (2.5L) diesel, which will always be essentially naturally aspirated at idle because turbos do little at idle, and a 2.5L naturally aspirated diesel won't pull the skin off a rice pudding. Get used to it.

I doubt that a larger exhaust will make much difference, because at these low RPMs there will be little exhaust flow anyway. Tinkering at the edges.

I not sure how much a 'chip' could help, because at these low RPMs there just ain't enough exhaust to get the turbo on song, and I don't see how the chip can alter that, though it could mildly overfuel and gain a bit more torque that way. Claims and hand waving are easy, though I would believe a dyno plot.

Despite the low down torque being less than I'm used to, mine takes me anywhere I want to go, just takes a bit more anticipation, a few more revs, and often a gear lower than I'm used to.

[skinnee]

My problem has nothing to do with traction (or lack of it) - it has to do with the fact that the car really bogs down until the engine revs get above 1750rpm or so (when the turbo kicks in). I'm getting wheelspin because I have to keep attacking hills in first gear because the car will stall out in second.

I recently did a 4WD course and there were some vehicles that could just about climb hills in second gear at walking pace - there's no way my Challenger could do that.

What I want is to get some more power from the engine lower in the rev range.

What is wrong with using 1st gear then? I dont understand spending all that money if 1st gear will do the job, each vehicle is different so I wouldn't be concerned what gears others do it in. Their gear ratio and tyre sizes are probably different for starters.

Wheel spin results from loss of traction due to momentum and tyres pressures, what tyre pressures were you running out of interest? I run 22psi on rocky climbs , 12-16 psi on sand using LT AT tyres. For rocky climbs depending on steepness 1st or 2nd gear low revs around 1800-2000 , sand climbs i use high range 1800-2000 revs mostly , really steep i use low range 1st on both and adjust revs accordingly

[AndrewF]

G'day,

While I'm really happy with the Challenger, the only issue I have is the desire for more low rev torque.

I've also sometimes felt I'd rather use low second for a little more momentum than using low first but when the revs go below about 1800 or so find myself changing back to first, sometimes at an awkward moment...

I've always been a bit apprehensive about "chipping" and while looking around came across this which has sparked my interest... You might find it interesting... It seems to have a more thorough approach than "chipping"... I have no desire for extra "power" but would love more low down torque...

I assume it would void the driveline warranty though... I also assume it may have implications towards the clutch (perhaps requiring a heavy-duty clutch?).

So, for interests sake...

http://www.supercarperformance.com.au

Cheers,
Andrew

[Pickle]

Ovets I know where your coming from with this. I have driven enough of them to know how they suffer in a good climb. The auto is no where near as bad as the manual with the lag. Not much you can really do about it as it's pretty much how Fuelconsumption has described it. Really need that turbo to kick in a tad earlier.
Dave

[AJC]

2.5; 2.75 or 3" pipe, depending what is out there for a 2.5 four potter (and what you want ... i'm told smaller for offroad / low down torque; larger for highway towing torque); all would give quicker turbo spool , less lag

[Ballfyboy]

Check out MRT. They will have a dyno chart of the Trition/Challenger on their site. I have posted a dyno chart of my car on here already, you could probably find it if you searched. Keep in mind that I have an auto.

MRT retune pros:
Power baby, power.
significant lowering of turbo lag
did I mention the power.

cons.
If you factory service, and they reflash your tune you will loose it. it is a major PITA to get it put back on.
I seem to blow a lot of smoke.
after you get used to the power, you want more.

[DaveXT]

G'day,

While I'm really happy with the Challenger, the only issue I have is the desire for more low rev torque.

I've also sometimes felt I'd rather use low second for a little more momentum than using low first but when the revs go below about 1800 or so find myself changing back to first, sometimes at an awkward moment...

I've always been a bit apprehensive about "chipping" and while looking around came across this which has sparked my interest... You might find it interesting... It seems to have a more thorough approach than "chipping"... I have no desire for extra "power" but would love more low down torque...

I assume it would void the driveline warranty though... I also assume it may have implications towards the clutch (perhaps requiring a heavy-duty clutch?).

So, for interests sake...

http://www.supercarperformance.com.au

Cheers,
Andrew

Im with you, low down torque is disappointing and I have learned to select a lower gear as it can become dangerous changing gears on a steep incline. It can also be very hard on the driveline, not to mention having to reverse back and make another attempt.
I believe fitting a 3" dump pipe and possibly and chip will certainly help to gain torque as the turbo will spin up a little quicker.( by how much is unknown)
For me I don't do enough offroad to justify the expense and I would also be concerned about warranty.
If you would like to investigate further I suggest have a look at www.newtriton.net

[RMX]

#11 posts and no one has covered it?


The EGR valve closes at 2,000 RPM.

The hole you feel is because while the EGR is open, a portion of the exhaust gas used to make boost is being diverted back into the engine.

This has two knock on effects, First the turbo is not getting all of the exhaust gas and secondly when the EGR is open it is recirculating hot exhaust gas directly into the intake.

Higher intake temp = less power.
less exhaust gas to spool turbo = less bost down low = less power.


The reason you feel at bang on 2,000 rpm the motor pickup and a decent hit of boost for the first time is the EGR closing.


You can block the EGR valve with a blanking plate but be warned this is illegal as it alters the factory emissions (Not detectable - No roadside emissions test for diesel), It 'may' throw ECU fault codes (*if* an ECU fault code is thrown and check engine comes on, Triton owners are know to drill a small hole anywhere up to 6mm in the blanking plate) and it could potentially void your warranty if found during a service at Mitsubishi (although takes 5 mintes to remove, apparently).


Now the positives: Much more down low power, Add an exhaust/more boost/tune if you wish .. But an EGR blank will cost you next to nothing and provide a substantial difference.. It will also ensure that the carbon buildup in the intake is greatly reduced.

Left to its own devices, the EGR valve will fill the intake manifold with carbon deposits..

Pic taken from link below from a Triton intake:




refer here for more info: http://www.chipit.com.au/support/sup...lanking_plate/

[AndrewF]

#11 posts and no one has covered it? The EGR valve closes at 2,000 RPM......

Thanks for the info... This is really interesting... Appears to be a mod that's cheap and easily reversed, so it would be worth a try...

My only concern is the possibility of throwing an engine fault code...

If a fault code is thrown, does that invoke going into any form of limp-home mode or anything? I'm just a bit anxious if it could happen at an awkward moment going up a steep climb or anything, or does it just throw the code for reference?

Also, can the code be cleared using one of those ODB scan tools?

Thanks for the info, this is really interesting (and cheap to try!)

Have you tried it? I'd be keen as mustard to understand the degree of improvements from anyone that's done it...

Cheers,
Andrew

[JGB1491]

Hi Andrew, Re Blanking EGR valve I Bought a blank from Chipit in WA and they E mailed instructions for fitting. I had mine fitted at one of their dealers locally. Their method is to drill a 12 mm hole in the throttle valve which allows correct pressures in manifold and sensors read correctly thus no fault will be shown. EGR tests OK at service too. Definitely worth fitting one.

[j3st3r]

Hi Andrew, Re Blanking EGR valve I Bought a blank from Chipit in WA and they E mailed instructions for fitting. I had mine fitted at one of their dealers locally. Their method is to drill a 12 mm hole in the throttle valve which allows correct pressures in manifold and sensors read correctly thus no fault will be shown. EGR tests OK at service too. Definitely worth fitting one.

Did you notice a marked increase in low down torque after doing this mod