found out the hard way that my new to me 07 MC with G56 only has a top speed of 85mph while trying to pass some one on the hwy even with the smarty ....

i was thinking of downloading the tnt tune for the smarty to turn 4k, but im really not to enthused about the $4-500 valve springs and the hassel of changing them.... what is the "safe" rpm limit of the stock valve springs? i know its said it's 3k, but is anyone running higher?

 

Are you pushing 3000 rpm + at 85mph or just cut out like it is governed?

The Smarty has a built in speed limiter / delimiter so it could be set for 85 in which case it would defuel at 85. You would just need to reset it.

My estimated top speed with 48re and 3.73's with the tires I have is around 120ish, but haven't done it as I don't know the egts pushing it that long. With the tires I have and the Smarty it jumps from 75-90+ in a hurry, for me that is 2000-2700 ish.

 

With the Smarty Revo and TNT program the max RPM should be 3500 and is valve train safe. TNT-R is 4k.

Just need to adjust the speed limiter to a higher setting with the Smarty. I have mine set to 130 MPH.

MikeyB

 

I have speed limiter turned up to 125, it just absolutely will not go past 85 mph and roughly 2700 rpm's

a little more looking this mornin... im about 62 mph @2000 rpm's and have a free rev of 3200....

 

You have other problems. Check fuel and air filters first.

 

Filters are new

 

The typicla speed limiter on these trucks is 110 mph, if everything works right. Even with a G56 it should easily top 120 mph.

Considering how wonky the speedo's on the CAN systems can be are you sure it is 85 mph and not 110 mph?

Its either a misreport by the speedo or you have a hosed ECU\other electronic doodad.

 

Dodge trucks are limited to 106mph, ford and chevy's to 96mph. I have personally proved this many times with the trucks I rent for a certain event held in the desert every year
Have you checked to see if you have any DTC's showing? (key on/ off 3 times will bring them up in your odometer display) I have seen just over 120mph in my 03, though the Egt's got up there, so I had to back down.

 

I'm sure It's 85, gps confirmes that, I wish I knew what gears it has in it, but basically its defuling about 2500, and by 2700 in 6 gear it just doesn't have any more, lower gears will spin 3000 but its slow goin past 2600, I do have the smarty revo in it, should it be spinning more rpms than that

 

First off unload the Smarty and put it back to stock to see if that changes anything. You should be able to get to around 110 stock.

There were intermittent problems with Smarty defueling about 2500-2600 rpms and not sure if they ever tracked the issues down.

 

A stock size tire g56 truck should be gear bound right at about 110. Sounds to me like you are running out of fuel. It only shows up in 6th because of the increased load. Check lift pump operation and volume.

 

Ok.... Definatly got a fuel issue, it does the same thing in stock setting, I also loaded the tnt-r and turned on the high rpm, it free reved to 3500 (would've gone more but I didn't push it) but with the tnt it became evev more appearent, with little power over 2000 rpm when using a lot of pedal.... Lift pump seems ok with good flow but no means of checking pressure, guess I'll order LP & rail pressure gauges and a coloum pod and go from there.... Any ideas?

 

Could be LP, IP, PRV, FCA, etc, etc, etc. Without gauges its hard to tell where to start looking.

 

Yup, that's my thoughts too, I wish smarty did data logging.... Hmm, I do have a dodge superchip 3865 with data logging, wonder if it could tell me anything?

 

Yup it worked!!! But now it gets strange.... I monitered tps, boost, rail press, and engine load %.....tps/apps shows perfect, boost matches my gauge an maxing out about 37 psi, rail pressure shows about 7252 psi at idle, and about 20,000 at full throttle, and is holding there even while its loosing power, but below 2000 rpm I could only get to 75% load, but over 2000 rpm the load % started dropping and was down in the 40's by 2500 rpm, and this is with the tnt-r tune, I'm lost....