I am going to pick up my car and the shop is going to slap the truck on the dyno. They said they have had problems in the past finding a good RPM pickup spot on some diesel trucks. Could someone please tell me the best spot/wire to use and if possible a picture would be great. Thanks

At the dyno day in Indy they were using some kind of optical sensor that measured the speed at the balancer, I believe. It wasnt working very well because it kept flying off or getting knocked out of place.

I remember reading that there is a sensor somewhere that you can tap in to and make a wire lead that they can use, but I have no idea what/where that is.

they will have to remove the skid plate underneath and put the optical sensor on the balancer as said above. I've seen several duramax dyno's and that is what they did.

Wish it were as simple as clipping it to the number 1 plug..lol

What they said. But.....its pointless to do it if you dont have a way to lock her in a gear since it will downshift on you at a point that is past your torque peak if you go to WOT. Your torque readings will be 100% worthless if you cant comand a gear and start your run in the 1500 rpm range.

On my twin turbo Z I had a switch wired in to lock up the TC and of course wasn't looking for TQ numbers as low. I will see what they can do.

Dosnt matter if they lock the converter or what they do......you need a way to comand a gear

I would say TH mode(this will lock the converter) and put her in 4th gear.

If You Can Get The Tranny To Think Its Cold Enough, It Will Lock Itself Into Second Gear. Also, There Are A Few People That Sell A Clamp That You Clamp To The Fue Line And It Converts That Pulse To A Signal An Inductive Pickup Can Sense. I Know Snap-on Has One.

If they have a low voltage inductive pickup just put it on an injector wire. Works like a charm. The driverside front cylinder is very easy to get to the wires with little to no work.

i was reading about a deal that you put on your injector wire and you can use it for a tack readout dont remimber what it was but was reading about it last night

dousen't gm use the alternater as a tach sig?

Hello my brothers and I own a small shop in Hutchinson KS and we have a 248c dynojet. We have a optical eye that we hook up to diesel's and a piece of reflective tape about an inch long that sticks to the balancer to pick up the rpm signal.