What CDD DB2 is right for your IDI?

Posted by Wesley Morris on

It's no secret that IDI's make there power from fueling upgrades, but it takes supporting modifications to run many of these performance pumps, this guide will help you determine which injection pump to order, and what engine upgrades to expect to go along with your pump.

  1. What IDI do you have?  We offer injection pumps for 6.9 IDIs, 7.3 IDIs, 7.3 IDITs as well as GM 6.2/6.5 IDIs. If you have a 6.9 or 7.3 IDI, you likely don't have a turbo, if you don't currently have a turbo on your IDI you will not get a significant improvement in performance with increased fueling without adding more air into the mixture. A good upgrade for a non turbo IDI is our factory turbo calibrated DB2, this will give a decent bump in performance but will require an egt gauge and you will expect to see some smoke under heavy throttle. A 90cc can be run without a turbo temporarily, but an egt gauge and a light foot are a necessity. The injection pumps we offer for the GM IDIs all require engine upgrades as we currently offer no stock GM calibrations, so we recommend contacting us per order to make sure you have the right pump for your build.
  2. I've got a turbo on my IDI and want to upgrade my injection pump a bit, what can I do? Our 90cc injection pump is an excellent upgrade for turbocharged IDIs and only requires an egt and boost gauge for supporting modifications, 6.9 IDIs are basically at their reliable limit with a 90cc, and we really like to see 6.9 IDIs head studded to run any turbo reliably, due to their smaller 7/16" head bolt. A 7.3 IDI is also going to require head studs to go larger than a 90cc.
  3. I've got a turbo and head studs in my 6.9 IDI, what the biggest pump I can run? 6.9 IDIs are ultimately limited by the 7/16" head stud, we recommend no larger than a 110cc DB2 on an intercooled, turbocharged 6.9 IDI.
  4. I've got a turbo and head studs in my 7.3 IDI, what the biggest pump I can run? Once head studded, the 7.3 IDIs (with NA rod size) are limited by their connecting rods, which tend to fail under high cylinder pressure, typically around 550-600 ft lbs tq, which is achievable with a responsive turbo and a 130cc injection pump. We have found 110cc pumps to be a reliable size for a studded 7.3, anything larger will eventually cause a rod failure.
  5. I've got a turbo and head studs in my 7.3 IDIT, what the biggest pump I can run? We luckily have not found the failure point of the IDIT connecting rods, (so this section would also work for engines running converted forged PSD rods). These engines with a properly sized turbo and intercooler, have been very reliable up to about 400hp (150cc) which we have found to be the point where an engine girdle and rotating assembly balance is necessary. Above this point, we expect PSD/IDIT factory rods to fail around 550-650hp, at which billet rods and extensive engine machine work is necessary.
We hope this guide helps our customers better understand our range of injection pump offerings, any other questions always feel free to contact us at 830-252-9767 or Sales@classicdieseldesigns.com
Thank You!

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