Diesel Place banner

Status
Not open for further replies.
1 - 10 of 10 Posts

·
Registered
Joined
·
1,038 Posts
Discussion Starter #1
I've never been on a dyno before, in fact the last vehicle I had that was capable of the Dmax's potential was this 67 RS SS Big Block Camaro that I won the annual "Meals on Wheels" charity drag races in (sorry, couldn't resist an opportunity to brag a bit but felt compelled to compensate for the vulnerability of 1st time dyno admission). I was not expecting this kind of potential when I bought this truck! Everyone would expect it from the Camaro, but not from these trucks!! What fun!!!!





I've seen and heard of some concerns about running on a dyno. Who can comment, and perhaps more importantly, can you give a first time runner any hints about what to expect and what cautions are necessary? I'll only run the lower Quad tunes as I sure wouldn't want to break anything like mt*m*c did!
Does the type of dyno matter? What gear/gears to run the alli? Etc....


If you want to see me make a** of myself (I hope not), come join us at the 1st SE GTG dyno day in McDonough, GA near Atlanta on 11/1. Check it out here; http://www.dieselplace.com/forum/forum_posts.asp?TID=780&PN=1


Thanks!


2DAMAX


PS. I was gonna mention, if you don't understand the vulnerability thing, ask your woman cause they really like it when we do that, but I didn't want them to know that we know!
Edited by: DMAX2DAMAX
 

·
Registered
Joined
·
11,955 Posts
I have one session under my belt but I might catch something other guys have missed.


The place I went to didnt have a tec 2 so I put her in T/H to keep the TC locked and put the OD lock out on to keep her in 4th. The guy running the dyno accelerated moderatly and as soon as he hit 4th gear he jumped on it. He didnt think he could dyno it because it kept downshifting....theres a shocker, an auto that downshifts when you lay into it
I told him to stay on it and it would upshift, theres a thought
Anywho be prepared for a dyno operator that dosnt know about deisels or other stuff.


The main thing I reminded him was DONT SHUT OFF MY TRUCK! I didnt give him the benifit of the doubt or the chance to shut it off after he made a couple of hard dyno runs. That can be real healthy on the turbo



Hopefully they can hook up the little optic eye to the balancer so they can read your torque.


Good luck and have fun!
 

·
Registered
Joined
·
1,685 Posts
Does anyone know the real impact of running in 5th versus 4th (direct) ? I have heard that it will report the numbers lower than running in 4th.


Alan,


When I ran on the dyno the first time I did not have access to a Tech II to lock 4th. David at the shop is very experienced with running the diesels on the dyno so don't worry about the run. We tried some stuff to run in 4th but he also said that running in 5th was generating comparable plots to other runs he has seen for the Duramax.


The run went like this. Ease the truck into drive and start bringing up the speed. Get the truck stable at about 70 Mph. Hammer the throttle and run it up to the redline or speed limiter, whichever comes first depending on your programming.
Ease down and see the results. Using that method the truck only downshifted one time and got a spike on the dyno. All of the other runs had nice curves to them.


All in all I think that the 448 RWHP I put down was pretty accurate. Can anyone tell me if I am off base on this?
 

·
Banned
Joined
·
328 Posts
There is a few hp difference, but I like 5th gear runs because they are easy to duplicate and you get a nice long curve to look at. You get a good curve in 4th gear but 5th is easier for most people to duplicate.
 

·
Registered
Joined
·
3,164 Posts
HEY DMAX2DAMAX ARE YOU FROM THE AMARILLO AREA?? JUST WONDERING I NOTICED THAT THE PIC YOU POSTED WAS TAKEN AT AMRILLO DRAGWAY
 

·
Banned
Joined
·
328 Posts
Ok here is a DO NOT DO tip!


I actually saw this happen, don't ever do it, we were all lucky no one was hurt.


Guy is almost finished with a run and the strap makes a big click sound. Guy in the truck panics and hits the brakes! IT locked them up so fast it wasn't funny and ruined his rear tires. We were lucks it didn't hurt someone or anyone else!


Always use the dyno brakes!
 

·
Registered
Joined
·
12,262 Posts
Roll up slow ,Tech II command forth,once converter lockes "wood" it to rev limiter,if you desire but peak was already accomplised !!!


Forth gear is where you want to be ,one to one ratio .... I want the most accurate not the highest numeral ...


Mac
Edited by: Mackin
 

·
Vendor
Joined
·
9,678 Posts
Mackin said:
Roll up slow ,Tech II command forth,once converter lockes "wood" it to rev limiter,if you desire but peak was already accomplised !!!


Forth gear is where you want to be ,one to one ratio .... I want the most accurate not the highest numeral ...


Mac




Transmission must be in T/H mode as well or the TC will not lock. Just loaf it up to about 30mph and wait for the rpm's to drop. The Tech 2 will beep and kick you out in the middle of the run, but ignore it. Re-enter the menu and go again for next run.





Additionally, I typically do not use the ODLO, rather let it spill into 5th. You just need to ignore any spikes, and set the "test window" to stop at a point before the shift speed.
 

·
Registered
Joined
·
12,262 Posts
Yes John your right I left that out Tow Haul mode for TC lock-up ....

Thanks for the correction ....

Mac
Edited by: Mackin
 
1 - 10 of 10 Posts
Status
Not open for further replies.
Top