ISX Horsepower/Torque setting

[marek4792]

I run a 3.36 and I believe a couple other members here run 3.42/3.36 gears (which are nearly identical) of course with 13/18 speed manuals. We don't split the top gear to the high side when running 65 mph or less to keep the rpms up when cruising. It works out OK, but prepare a budget to eventually regear it for your purpose if you can't find a truck with the right rears.

[TBraun]

I decided to buy this truck today. Engine sounds like it stumbles and possibly miss out at idle when cold. It did this when started the first time of the day. It's sounds much smoother when warm, but still might studder every once in awhile. Previous owner says it's bone this for a very long time. He recently had overhead run and made no difference. Any idea what could cause this? I haven't had a computer hooked to it yet, no engine warning light. Engine runs very smooth running down interstate. Put about 600 miles on it today just bobtailing, I can't complain how it runs down the road. Just don't know what to think about the low idle. It does sound better if you bump the idle up to 1000 or so. Don't hear anything abnormal out the exhaust. Engine has zero blowby, or next to zero. Appreciate any thoughts. Thanks.

[Bengy88]

Probably metering and timing solenoids getting worn. Common problem with an isx.
http://rawze.com/forums/showthread.php?t...619#pid619
This should help you out…. Don’t just stop at the video.

[TBraun]

Are pyrometer probes all the same? Or are they different resistance's? This truck I bought has a functional pyrometer but not a boost gauge. I definitely want a boost gauge. I have a multi function Tel-Tek gauge that shows boost and pyro but I don't have the probe that came with the gauge. Can I use the probe for the factory gauge?

[Nostalgic]

(09-13-2022 )TBraun Wrote:  Are pyrometer probes all the same? Or are they different resistance's? This truck I bought has a functional pyrometer but not a boost gauge. I definitely want a boost gauge. I have a multi function Tel-Tek gauge that shows boost and pyro but I don't have the probe that came with the gauge. Can I use the probe for the factory gauge?

Probably not. Depends on if your probe is isolated or non-isolated, and which type your gauge requires. My digital smart gauge teltek requires a isolated probe.

[TBraun]

Got a couple questions. I bought this 2000 International 9900ix truck with the ISX engine in it. Obviously all pre-emissions. The data sticker on the engine shows it a ISX600/1850. The previous owner said he thinks the engine was de-rated at one time because the engine was running rough, they told him it was set at 565. This would have been many years ago. He said he had it on a dyno afterwards and it had 450 at the wheels, he couldn't remember the torque reading. He asked why it was so low and they told him because you loose that much to the wheels. That seems like a lot of loss, but maybe that's right. If I get Insight hooked to the engine, with it show me what the HP and Torque settings are? Or does it just show the program numbers? Also, what kind of boost pressure would/should the engine run if it was around 550 hp and full load? The truck doesn't have a boost gauge, but I'm adding one. It has a waste-gate turbo, so obviously it's not going to be above what it's set to, I'm just wondering where they should run.

[Rawze]

(09-19-2022 )TBraun Wrote:  Got a couple questions. I bought this 2000 International 9900ix truck with the ISX engine in it. Obviously all pre-emissions. The data sticker on the engine shows it a ISX600/1850. The previous owner said he thinks the engine was de-rated at one time because the engine was running rough, they told him it was set at 565. This would have been many years ago. He said he had it on a dyno afterwards and it had 450 at the wheels, he couldn't remember the torque reading. He asked why it was so low and they told him because you loose that much to the wheels. That seems like a lot of loss, but maybe that's right. If I get Insight hooked to the engine, with it show me what the HP and Torque settings are? Or does it just show the program numbers? Also, what kind of boost pressure would/should the engine run if it was around 550 hp and full load? The truck doesn't have a boost gauge, but I'm adding one. It has a waste-gate turbo, so obviously it's not going to be above what it's set to, I'm just wondering where they should run.

It will show the HP/torque. If it is a CM570 ISX engine then it should have about 36-psi boost under full operating load. And by the way, in regards to the ISX, more boost does not make more power .. it only causes accelerated wear and increased friction in the engine.

If you are not sure what program belongs in it then sign up to cummins.quickserv and look it up. Its free.

As far as a dyno goes.. it depends on the gearing of the truck. If it has a tall set of rear end gears than it can loose up to about 18% or so of the flywheel power at the wheels. If you want to improve it then a better set of rears is always a far cheaper solution with much better performance results than trying to turn up the engine and wearing it out faster.

[TBraun]

I agree with you on the better set of rear gears. This truck has 1.9 million on it and still has original diffs in it. To me that's a good sign the truck has been driven with sense. If I end up having to replace one of the differentials, I'll replace them both. The engine made 1.5 million before it was overhauled by it was a one owner, owner/operator truck. I think that makes a big difference. Thanks.