Cajun Dyno Day Results?

[CUMINNTSTRKN]

jqram



go find out what rpm is 29mph and use the formula.

 

[BIG BOB]

I think I may have been misunderstood. The torque number 1912. 4 that jgram35 has on his dyno sheet is actually the RPM's that maximum torque was acheived. Not torque at peak HP.



Here is an example of my Dyno run at Diesel Thunder in Spokane;



Diesel Thunder Dyno Run



Notice that my maximum torque was acheived around 2780 rpm. If we use the formula as stated previously we have;



(5250 x 460. 1)/2780 = 868. 9 ft/lbs of torque. The 2780 being the rpm's where maximum torque was acheived.



That is real close to what my dyno sheet reads at 857 ft/lbs of torque. It may not be exact but it is alot closer than the numbers you are assuming are torque numbers (which are not).



My maximum HP was acheived just over 3000 rpm's. So Jim's numbers of 400 to 800 rpm's less are real close.



Jim, you have plenty of dyno sheets, try working them with the formula and see how it works for you.

 

[BIG BOB]

Cummntstrkn,



Jim, I took your dyno numbers from Diesel Thunder and plug them into the formula and this is how it looks;



(5250 x 492. 1 HP) /2880(rpm's at max torque) = 897. 06 ft/lbs of torque. I'd say that is pretty close compared to what your dyno sheet says, 890. 8 ft/lbs of torque.

 

[jqram35]

I went out and ran the truck to 29 mph and the rpm was somewhere around 2700 rpm. That works out to 414ft/lbs, which is not right I hope. It occured to me that accerating on the street and on the Dyno are 2 completely different things and I don't believe the truck will give the same mph/rpm readings as the load is different??? I'd say the torque figures are worthless accept to compare figures if I run again under simular circumstances. You can't get away from needing accurate rpm readings from the dyno. But, I do know where I stand in the HP department and after transmission upgrades down the road there will be more BOMBING

 

[CUMINNTSTRKN]

jqram



lol. sorry you need to be in third gear since that's what gear your truck should have been in on the dyno.





big bob



on the dynojet trq is tuff to get becuase of the lack of boost at lower rpm's. on the mustangs i've run on they very between 400 and 800rpm. between max hp and max trq.



jim

 

[jqram35]

I'm pretty sure they ran the truck in drive thru all the gears to 85 mph. The graph I got from them shows all 3 shift points between the 4 gears. By the way my ETC does not drool at all, I do all the drooling every time I drive it! LOL

 

[Gerhardt Diesel Performance]

Horsepower Only

I notice everyone is trying to figure the proper torque value from our DynoDay event last Saturday. Because of the number of trucks in attendance vs. the limited number of hours available, we chose to utilize only the dyno rollers for information. We did not probe the engine for RPM signal; if we had the dyno would have provided exact horsepower and torque figures in numbers everyone would agree with. Without probing the engine, we have no rpm signal which is necessary to produce true torque. However, roller speed MPH will give accurate horsepower at the rear wheel. We debated this decision up to the last minute, but decided it would far better to run everyone in the parking lot rather than risk disappointing some people who had higher registration numbers. Sorry for the confusion, but afterall, we were trying to find the "Baddest Truck in the Parking Lot," and did!

Tim

 

[jqram35]

I am not complaining after all you all did it for free. I was just trying to make sense of it all.

 

[Gerhardt Diesel Performance]

We enjoyed seeing you there

and I didn't think you were complaining, rather confused like the rest of us about those high torque figures. Maybe we can probe a few vehicles next time to show the real torque values. Hope to see all of you in 2002 at our next DynoDay event. We will announce the date within several weeks on our website www.dynoday.com. Keep an eye out for it!

Tim

 

[BIG BOB]

Cummnntstrkn,

Jim, If I'm not mistaken this formula is the formula that Brian at BD gave everyone to calculate their torque on the Mustang Dyno while at BD Dyno Days. Just trying to help people get realistic numbers for torque. It is sure alot closer than 1917. 4 ft/lbs of torque!



jgram35,



I still think that the 1917. 4 is the rpm you reached your maximum torque. Being you have an automatic, it is really hard to know what gear you were in when you acheived this number. Anyone who has a stick will usually use the 1:1 gear for their dyno run. I know that Jim (Cummnntstrkn) has obtained higher readings running in a different gear. Not sure how accurate that is.

 

[CUMINNTSTRKN]

Re: We enjoyed seeing you there

Originally posted by Gerhardt Diesel Performance

and I didn't think you were complaining, rather confused like the rest of us about those high torque figures. Maybe we can probe a few vehicles next time to show the real torque values. Hope to see all of you in 2002 at our next DynoDay event. We will announce the date within several weeks on our website www.dynoday.com. Keep an eye out for it!

Tim

tim



you have a mustang dyno right? you do not have to probe the motor to get a tach signal. you can choose tach calibration by roller speed. you hold the truck in direct at 2000rpm and hit the set button. now your ready to go and it's fast.



jim