Dyno Issues

[FoMoCoBros]

So i put my truck on the dyno. Its an 08 250 with the spartan 250 calibration.

This is the first time i put an vehicle on a dyno and we had nothing but problems from the get go. They couldn't get a strong tach signal so they said they wouldn't be able to get the torque readings. Then the problems began. I couldn't build boost because they said the dyno didn't have enough resistance. Then when i did my runs, it was like the blow off vavle was opening and closing quickly causing an almost chirping sound. Has this happened to anyone? One of the guys said it might be like the new Audi's with the speed sensors on all the wheels where if the front wheels don't turn, it cuts boost.

Anyone ever heard of this happening? Cause i was only able to make 21 pounds of boost and put down a 360hp run....which surely can't be right. Yet on the street i can make about 36 pounds of boost and there is NO chirping. We pretty much ruled out tire spin cause they looked at the graph and there were no spikes where the wheels would be spinning.

Any help would be great cause i want to put it back on and see what it does before i start tearing into it to make power.

[SCUFFY828]

sounds to me like the dyno wasnt a dyno that could be loaded , if nit it wont create boost and you wasted your time, any turbo vehicle has to have load to create boost , that was probably the situation, the nise may have been the engine getting into the rev limiter

[Dirk]

Yep. No real load. 21psi seems awfully low.

AS for the graph, 6.4's are pretty flat due to the twin's. A 7.3, 6.0, and 6.4 will all look different.

Spikes on a 6.4 would tell me that they allowed the truck to downshift.

[FoMoCoBros]

I didn't even keep the graph cause it was all over the place and we had nothing consitant. I was most concerned with the chirping that we got when we layed into it. Seemed really strange. I don't recall if it did it at higher RPM's or if it was all the way through. I am going to check other places out to see if they can load their dyno.

Thanks for the info and hopefully i will be able to post some good news in the near future.

[FoMoCoBros]

Well, i am booked in for 2pm on friday so hopefully i will have some better results at this new place. They told me they could load the dyno down enough to stop my engine so this should be a better run.

Keeping my fingers crossed

[Rudy's diesel performance]

what kind of dyno was this? I am about to take my truck to the dyno but do not want this to happen to me.

[Rudy's diesel performance]

where is a good place that has a dyno? I am in Charlotte, NC.

[SCUFFY828]

Originally Posted by Rudy

where is a good place that has a dyno? I am in Charlotte, NC.

there is a guy in mooresville i think that has one that wil do diesels, i cant think of his name , he does cars too, google dynos and mooresville

[FoMoCoBros]

Originally Posted by FoMoCoBros

Well, i am booked in for 2pm on friday so hopefully i will have some better results at this new place. They told me they could load the dyno down enough to stop my engine so this should be a better run.

Keeping my fingers crossed

Well, i put the truck on this new dyno and it made 385hp and 583tq but they said there is about a 35% loss at the rear wheels...does this sound right to anyone? Like i said, this is the first unit i put on the dyno. If that is correct, would it not be around 520hp and around 790tq ? The only problem i was having was that i wasn't making max boost before my EGT's got too high and we didn't have time to play around witht he load on the dyno.This is the dyno they used:

Performance Plus - turbo and supercharger superstore!

P.S. I don't hae the dyno result sheets because my wife called on the second pull and i was SUPPOSED to be at work. So i will go back next week and see if i can pick them up to post them.