Ok my buddy in town that has a dyno just got the stuff to dyno diesels. So my questions are for those that have dynoed alot.... on standard trucks what gear do they normally pull in and at what rpm do they start? An on autos do they leave it in drive and what gear do they pull in, rpm? Last, how far is it safe to take it too rpm wise? Thanks for the time.

p.s. for those of you around the Killeen, Fort-Hood, Cove, Harker Heights, etc. area. They will be dynoing as soon as we get used to it and figure out how to get the smoke out for all exhaust types. Ill keep ya posted on a dyno day or whatever!

 

depends....5th or 6th(4th, depending on year model) bring it up to 1500 and hold for the start of the pull. I usually try 6th first, then do a pull in 5th to see if there is any difference.

 

See if you can find out what kind of dyno it is. That is important. For example if it is a "Mustang" Dyno.....you would want to dyno in 5th gear (1 to 1 ratio) or in the case of automatics.....you would want to dyno in 3rd gear with o/d locked out.


If the dyno is a "Dynojet" you want to be in the highest gear possible (6th for you). Autos use o/d...but need to get the rpms and speed up high enough so that it doesn't shift down to 3rd. I try to dyno from about 70mph on up since I have an automatic and definately prefer dynojets.


It has something to do with "load" dynos vs. "inertia" type dynos. I am sorry I can't explain the "why" part more........I just know that for dynojets you want to be in the highest gear.

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it is a dynojet

 

Every truck is different so it is important for this shop too understand that and allow an extra pull for baselineing......My truck can dyno 5th or 6th and usually are within 1-2 hp of eachother on a dynojet.....however I know of another 6 speed truck that gains 25hp from moving upto 6th gear from 5th. Alot of factors play into this....turbo size, tire size, nitrous.....that is why I say they should doo a proper baseline before actually letting her rip.