DT360 OR Cummins ID, IDI Value, Swap Info ??

[Worstenemy453]

No need to drop the compression ratio without having plans for big fuel and air. With a Moose pump and your standard ATS, Hypermax, or Banks turbo, you will likely loose power by dropping the compression ratio. It has happend before.....

Look at Chris Barber's IDI (diesel4me2). Built like a brick outhouse with a Moose pump, hypermax valve springs, studs, intercooler, lowered compression with shaved pistons, hypermax turbo. He made 148.7HP & 278.8 lb/ft torque on the dyno. Why??? With lowered compression he needs much more fuel and air (more than can be provided by the Moose pump and Hypermax turbo) to make up for lack of compression. That's why he is looking into getting a Super Moose pump from Mel......$2000. Plus, he has a heck of a time starting that rig in the fall/winter.

Heath

So i could actually hurt my performance by dropping the ratio.

 

[hesutton]

So i could actually hurt my performance by dropping the ratio.

Maybe? We don't have much dyno proven info on the subject. The only decompressed truck here that has dyno'ed is Chris'. He made the lowest amount of torque of all the turbo'ed IDI's at the Dyno Day during the 2009 Rally. Everyone else had stock compression. It's not definitive, but the best answer amoung the Rally "think-tank" was the lower compression ratio decreased his torque output and thus lower HP, despite all the other performance mods to his truck.

No one knows (if they do, they haven't shared it yet) the magic fuel/turbo combination for lower compression IDI's. But, it doesn't appear that Chris has enough fuel and air to get the best gain from lowing the compression ratio of his IDI. My guess is that he'll need a heavily mod'ed DB2 and a different turbo, but that is still just a guess.

Heath

 

[Worstenemy453]

Maybe? We don't have much dyno proven info on the subject. The only decompressed truck here that has dyno'ed is Chris'. He made the lowest amount of torque of all the turbo'ed IDI's at the Dyno Day during the 2009 Rally. Everyone else had stock compression. It's not definitive, but the best answer amoung the Rally "think-tank" was the lower compression ratio decreased his torque output and thus lower HP, despite all the other performance mods to his truck.

No one knows (if they do, they haven't shared it yet) the magic fuel/turbo combination for lower compression IDI's. But, it doesn't appear that Chris has enough fuel and air to get the best gain from lowing the compression ratio of his IDI. My guess is that he'll need a heavily mod'ed DB2 and a different turbo, but that is still just a guess.

Heath

an 86 Idi would have a compression of 21.5 to 1 correct. Im wondering if i could down to 19.5 to 1 or so. Im not looking ot go to 12 or anything.

 

[hesutton]

an 86 Idi would have a compression of 21.5 to 1 correct. Im wondering if i could down to 19.5 to 1 or so. Im not looking ot go to 12 or anything.

Chris is no where near 12:1. IIRC, he's in the 18 to 19:1 range.

Heath

 

[Worstenemy453]

Chris is no where near 12:1. IIRC, he's in the 18 to 19:1 range.

Heath

I was just using 12 as an extreme. You would need Tons of fuel and air to use 12 effectively.