4000 RPMS on the Dyno

[Bob Wagner]

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This was a very rushed day with no time for ant tuning whatsoever. I want to thank my good buddy Rip Rook for going the extra mile to get the truck on the dyno so late in the day.



Marco is the first to prove that he can do what others can only say.





Let the tuning begin because Marco is yet to see where he can do his magic.























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[Triton]

congrats to Marco, yourself and Rip :-laf

 

[Jim Fulmer]

Nice fat line!



Jim

 

[RobertP]

thats awesome. good work guys. Oo.

 

[Tomeygun]

haha, I would have been shifting into the next gear half wauy through the graph!

 

[AScholting]

Oo. Thats awesome! I cant wait!:-laf

 

[RobertP]

haha, I would have been shifting into the next gear half wauy through the graph!

i think this program is going to the hot ticket for us six speed guys. we can actually use the rpm in more than top gear. i really cant wait to get ahold of it. i should beable to keep it in the power band all the way down the track now. Oo.

 

[JCasper]

Congratulations Marco, Bob, and Rip.



What truck was that Bob?

 

[mattymac]

i think this program is going to the hot ticket for us six speed guys. we can actually use the rpm in more than top gear. i really cant wait to get ahold of it. i should beable to keep it in the power band all the way down the track now. Oo.

Yeah definatley some useful power!

 

[Bob Wagner]

Rip's 2005 at about 1/2 throttle

 

[JCleary]

Jeez...



I kinda wish I hadn't gotten rid of the old '03...



Shifting wouldn't be so bad if I could wait 'til 4k rpm...



OTOH, a 4k shift with an auto should be sick!

 

[JasonCzerak]

i think this program is going to the hot ticket for us six speed guys. we can actually use the rpm in more than top gear. i really cant wait to get ahold of it. i should beable to keep it in the power band all the way down the track now. Oo.

It's going to benfit us HUGELY. we'll be able to make boost in 2nd and 3rd gears and fully utilize them. not to mention getting a breather between gears shifts.



Tho, there's that one thing that is an unknown, how well will the syncro's like 4000rpm?

 

[JCasper]

Rip's 2005 at about 1/2 throttle

Would the dyno not handle full throttle?:-laf

 

[Bob Wagner]

they limited the mph to 120 and the transmission wanted to downshift when Robert went to floor it.



This software is still in the alpha stage.

 

[JasonCzerak]

they limited the mph to 120 and the transmission wanted to downshift when Robert went to floor it.



This software is still in the alpha stage.

What about the the street, does it hold and shift at 4k?

 

[Bob Wagner]

When Rip called me om Sunday he was all Rip says the 0-60 time are

 

[RobertP]

What about the the street, does it hold and shift at 4k?

an automatic trans wont unless it has the valve body modified to hold the pressures longer. it really only benifets the auto guys in the top gear for rpm.

 

[RobertP]

they limited the mph to 120 and the transmission wanted to downshift when Robert went to floor it.



This software is still in the alpha stage.

so that must mean that its ready for us six speed guys, we dont have to worry about our transmissions down shifting on us!!!!

 

[DPeltonen]

That curve begs a lot of questions for me. The first is, how come there is no power below 2150 rpm? Don't most of our trucks put out a bunch of torque down below 1600? What kind of gearing do you have that gives 57mph at 2200 rpm? Also, how did you get the valve float to stop above 3500rpm, I thought that was the reason we couldnt take these engines over red line? In order to get a curve like that (torque and HP peaks way up the rpm range)out of any other engine, you have to change the cam. Did you put a different one in this engine?



I have no dyno experience with diesel engines. Even so, this chart looks really wierd to me. It begs a bunch of questions for the things that I don't understand. I can believe the HP and TQ numbers, and the speeds at which they were attained, it just looks like the tach scale is off by several hundred rpm. If this is a rear wheel dyno, then rpm is measured via a ratio of rear wheel speed for a diesel vehicle. Normally rpm on a dyno is measure via inductive pickup from a spark plug pick up. If the ratio is set incorrectly, then the RPM will be off. Based on the dyno sheet the mph @ 2000 rpm is 52. 6 (that would equal a final drive ratio of approx. 4. 53 in my 6 speed). It appears that the ratio is indicated in the upper right hand corner of this sheet and appears to be around 3. 8?? rpm per 0. 1mph. My truck is turning around 3050rpm at 98 mph, this sheet shows 3800 rpm at 98 mph.



Bottom line, if the chart is accurate, at 2000 rpm the truck does not make enough power to hold 55 mph, much less keep the engine running.

 

[JCleary]

Bob said the run was in 3rd. 3800 at 98 may be just about right. I haven't checked my truck to see how close it would be.



With an auto, it's conceivable that they had to start the run at 2k rpm so the transmission would not downshift on them during the run.



I think the only reason for the run was to prove rpm, not actual performance.



Usually the tach pickup is with an optical sensor on the harmonic balancer. The rollers will pick up the speed.