stage 2 dyno #'s

[lukecline]

I posted this over at tds already, but i thought id share it over here too cause it made my day.

Well i finally made it to a dyno today and turned out some very good numbers.

My best in drive was 387 hp and 693 tq with a cf of 1.02 thats 395 hp and 709 tq. My max boost was only 25 psi so a little later i made a few (4) runs in over drive and finally made it up to my usual max of 30 psi.

The results of the od pulls were quite a suprise 424 hp and 818 tq with a 1.03 cf thats 435 hp and 839 tq. This was done with only the mods in my sig and only #2. I have pics posted in my sig of my dyno sheets for all you that are interested. Runs 9-12 were the ones i ran in od. Truck sat and cooled down after runs 1-8 so that might explain why the results ramped up like they did (9-12)


Luke

 

[Max Power]

Very nice. Congratulations. :tu:

 

[bdp]

:ZigBang:

 

[Ford_Forgotton]

The results of the od pulls were quite a suprise 424 hp and 818 tq with a 1.03 cf thats 435 hp and 839 tq. This was done with only the mods in my sig and only #2. I have pics posted in my sig of my dyno sheets for all you that are interested. Runs 9-12 were the ones i ran in od. Truck sat and cooled down after runs 1-8 so that might explain why the results ramped up like they did (9-12)


Luke

Accurate dyno runs should be run in DIRECT DRIVE. I believe thats 5th gear on the 6-speed trucks, and D with OD locked out on the automatics.

What happens is, the dyno can be fooled because of gearing.

The style of dyno, and how the dyno runs were made are also a factor. The way I really dont like is to put the truck in drive, and from a dead stop, run the truck up as high as it will go.

A more accurate way is to put the truck in direct drive, roll up to 45 mph or so (for the TC to lock on an auto) then HAMMER DOWN.

Think about it, your motor only makes X amount of power. If gearing didnt matter, why then, did the HP numbers change? If the dyno really could correct out the gearing changes (such as running in OD), then you should have gotten the same numbers, regardless of what gear you were in.

Also, on my truck, I get better numbers and better track times when the engine is HOT HOT HOT. If I let it cool down, my 1/4 mile times and dyno runs drop. Diesels LIKE heat. A hot diesel is a happy diesel.

I would go by your first set of numbers, and toss the OD numbers.

 

[bdp]

The problem is Forgoten is those little DJ 248's dont load worth a crap, notice only 25psi of boost, OD effectivly in a way loads the engine better, 30psi of boost and therefore better #'s.

I am not saying your wrong by any means, but I do believe that Dynojets are not capable of loading a TD the way its supposed to so the OD runs, although probably not completly accurate due to gearing liek you say but also can be closer to the truth to to a better load on the engine.

 

[lukecline]

The dyno operators claimed that Dynajet told them that running diesels in od got best/ most accurate results. Id always heard to run in drive but when tq looked a bit low compared to hp, and boost was low we decided to try a few runs in od.


luke

 

[Max Power]

I guess you'll have to find a load cell dyno and run it again in D. They you'll know for sure.

 

[95_stroker]

I think either way, both sets of numbers are fantastic.

 

[Renegade]

I think either way, both sets of numbers are fantastic.

I'll second - a big congrats! - from the pics of your run it looks like you have some nice lines with not very many ragged peaks or wild waves.

Cheers

 

[Max Power]

I agree, nothing wrong with either #. Congratulations!