ISL upgraded

[a johnson]

Has anyone had any experience with heavy diesel tuners? They make an upgrade for the caps Isl.

Heavydieseltuner.com

[D Lindy]

Look at the specs. for the ISL when tuned @ 380, 400, and 425 HP and you'll find that there is very little gain in the torque curve with the increase in HP, which IMO is more important then the HP curve.

[Mr_D]

The ISL is usually paired with the 3000MH. The trans is limited to 450 HP and 1250 ft lbs.
And as was said just above the torque won't increase much and that's what you really need.

[Steve Ownby]

Originally Posted by D Lindy

Look at the specs. for the ISL when tuned @ 380, 400, and 425 HP and you'll find that there is very little gain in the torque curve with the increase in HP, which IMO is more important then the HP curve.

This is partly true but doesn't tell the whole story. It's true that max torque usually doesn't increase but max torque occurs low in the rpm range. The ISL makes max torque at 1400. These devices do flatten the torque curve by increasing torque up at the max HP rpm.

Torque is measured on a chassis dyno and HP is calculated from that. Here is the equation:

HP = torque X rpm divided by 5252.

If the HP goes up and the rpm is the same, then the torque at that rpm had to increase.


Steve Ownby
Full time since '07

[Cat320]

Originally Posted by Steve Ownby

This is partly true but doesn't tell the whole story. It's true that max torque usually doesn't increase but max torque occurs low in the rpm range. The ISL makes max torque at 1400. These devices do flatten the torque curve by increasing torque up at the max HP rpm.

Torque is measured on a chassis dyno and HP is calculated from that. Here is the equation:

HP = torque X rpm divided by 5252.

If the HP goes up and the rpm is the same, then the torque at that rpm had to increase.


Steve Ownby
Full time since '07

Using that formula, what HP is that supposed to equal?

[Steve Ownby]

If the torque at 2100 rpm measures 1000 lb/ft
Then the HP at that rpm would be:

HP = 1000 X 2100 / 5252

HP = 400

Max torque would still be 1250 at 1400 rpm.


Steve Ownby
Full time since '07

[a johnson]

The quesitons is really still there.

If you look at the torque curve on the ISL it drops off as RPM increases.

Has anyone tried one of these:
Cummins CAPS Cas ih chip module power
or
TS Performance Power Play MP8 for 1998-2005 Cummins 8.3L / 8.9L CAPS RV's & Medium Duty Trucks 2110301 - Parleys Diesel Performance
I found lots of info on the TS MP8 module...but i haven't found anything on the Heavy Diesel Tuner module

I tow a trailer with my Alpine and i'm not overly concerned about fuel mileage but would certainly would be nice to have a little more power on tap when i need it.

[MnTom]

A word of advice about those tuners. You NEED to have a way to monitor the EGTs (at a minimum). If your exhaust gas temperature gets to high you will cause major engine damage.

[Mr_D]

Originally Posted by Steve Ownby

This is partly true but doesn't tell the whole story. It's true that max torque usually doesn't increase but max torque occurs low in the rpm range. The ISL makes max torque at 1400. These devices do flatten the torque curve by increasing torque up at the max HP rpm.

Torque is measured on a chassis dyno and HP is calculated from that. Here is the equation:

HP = torque X rpm divided by 5252.

If the HP goes up and the rpm is the same, then the torque at that rpm had to increase.


Steve Ownby
Full time since '07

Then Cummins and others are not being truthful about the figures they show.

[Gordon Dewald]

According to the formula my HP is not even close.

[PDR John]

Here is 1 more maker, just because.

Diesel Power Digi CRTV Power Module for 2005-2015 Cummins 8.3L ISC & 8.9L ISL Diesel Pusher RVs - Parleys Diesel Performance


I have never used any of these, but Dutch Star Don (on this board) used this chip on his Monaco coach. You might want to sen him a PM.

[Koop]

Originally Posted by Steve Ownby

If the torque at 2100 rpm measures 1000 lb/ft
Then the HP at that rpm would be:

HP = 1000 X 2100 / 5252

HP = 400

Max torque would still be 1250 at 1400 rpm.


Steve Ownby
Full time since '07

This is the correct formula for SAE horsepower. Correct notation would be (torque X RPM)/5252. This is how it's calculated.

Torque is derived from a dyno. It is an actual value. Horsepower is a mathematical equation.

[Smitty77]

Originally Posted by Koop

This is the correct formula for SAE horsepower. Correct notation would be (torque X RPM)/5252. This is how it's calculated.

Torque is derived from a dyno. It is an actual value. Horsepower is a mathematical equation.

X's 2 - Concur that this is my understanding too...

On any kind of chipping or upgrading og existing ECM, except those authorized by Cummins and CAT (But never recall can authorizing a reflash upgrade? That having EGT readings is prudent to for monitoring purposes.

Many owners of ISC's/ISL's, both CAPS and VGT generation, have had positive and safe results with DIGI, MP-8, as well as reflashing of stock ECM's.

I did have Cummins reflash my CAPS ISL370 to a ISL400, and so far pleased with no side effect of higher temps or any other problems.

I'm still considering/semi planning, an MP-8 with Cockpit Control as well as adding EGT sensor and gauge. Admit some have reported problems with MP-8, but that may be more of a pin/wiring problem then anything else. (Based on conversations with those that install MP-8, they sometimes need to shuffle pins around in harnesses to ensure proper installs. Many installers don't go far enough to validate that everything is 'syncing' properly. Others, shuffle pins in the harness around as needed and Dyno before and after. You get what you pay for from the install base...).

For those with VGT ISL's under warranty - suggest caution on modifications... That warranty is worth a great deal - so why take a risk... Or if you do, be prepared to self insure if problems occur...

Just my opinion.

Best to all,
Smitty

[Gordon Dewald]

Originally Posted by Koop

This is the correct formula for SAE horsepower. Correct notation would be (torque X RPM)/5252. This is how it's calculated.

Torque is derived from a dyno. It is an actual value. Horsepower is a mathematical equation.

I have an ISL 8.9, 1250 ft lbs @ 1400, 450 @ 2100. I got the numbers talking to Cummins using my serial number. Using the formula:

(1250 X 1400) / 5252 =

1750000 / 5252 =

333

Where am I going wrong?

Thanks for any help.