DYNO QUESTIONS

[SANCHOBA]

tried to post this in the dyno section:dontknow:



i'm new to dynoing...from the videos i have watched the engine runs up and then shutsdown. what causes it to shut-down? a predetermined rpm setting? rev limiter? does the operator control this? i have the stage 2 flash and the rev-limiter has been "upped" to 6200. i'm a concerned about running the engine up this high after reading what could happen.(sean at roe said "if you want your engine to live a long life,keep it below 5200 and 5000 would be better") do i need to run it up this high(6200) to get the numbers? doesn't hp and torque fall off before 6200?

 

[FlyingLow]

The dyno itself is just a wheel driven treadmill. The guy sitting in the drivers seat controls everything. The run ends when the driver lets off the gas. How high they take the RPM's is up to the driver or you if you tell him don't go over a certain RPM. The problem with QC's is the WOT. The truck will down shift so you need to place the track in Tow/haul mode for the run. You can also disconnect the kick-down cable.

 

[SANCHOBA]

okay....was trying to find on a dyno sheet somewhere,where the torque falls off rpm wise.say..if it falls off at 5800, no need to go to 6200.sound realistic?

 

[FlyingLow]

I think max power is roughly around 5500 rpm just depends on the engine. TRQ usually comes down and HP goes up as the RPM's increase on a NA engine.

 

[SANCHOBA]

any body have a dyno sheet of a stock truck,or a truck with similiar mods to mine? that way i can determine when to shut her down.

 

[TNVIPER]

Dont worry about shutting down...run it to about 6,000 RPM...you will see the power curve telling you when or if your power starts to level off......mine is still climbing at 6K but the general consensus here is you should shift at about 5500-5700.....

 

[SANCHOBA]

am i being to paranoid?

 

[TNVIPER]

am i being to paranoid?

no...well...maybe.....you will be fine once you get to the dyno...the operator will know what to do...if he asks what RPM you want to stop at just say 6K....

 

[moparracing]

any body have a dyno sheet of a stock truck,or a truck with similiar mods to mine? that way i can determine when to shut her down.

i wouldn't be too concerned with lifting @ 6k rpm, i got my best hp by doing just that on my last dyno:

http://www.vtcoa.com/forums/showthread.php?t=20901&highlight=rrev

some dyno's let you run the throttle & some don't - either way they'll have you sign a waiver so they can't be blamed..... me, if it's gonna blow, i'd rather be the one @ the controls rather than someone else..... also, between the dynojet & mustang dyno's, you'll get higher peak numbers from a dynojet.

 

[SANCHOBA]

i wouldn't be too concerned with lifting @ 6k rpm, i got my best hp by doing just that on my last dyno:

so what are your mods with that run?

 

[moparracing]

so what are your mods with that run?

full B&B exhaust, sct tune from marty @ krc performance :rock: , centerforce clutch with viper hydraulics, 170 t-stat........

 

[SANCHOBA]

full B&B exhaust, sct tune from marty @ krc performance , centerforce clutch with viper hydraulics, 170 t-stat........

excellent!:rock: i can only hope i do as well! it is a dynojet by the way.

 

[FSTJACK]

Just beacuse the motor will RPM doesn't make it better to rpm it that much.

On a normally asperated motor the TQ and HP crossover at 5250 rpm.

There is no reason to rev the motor to 6000 rpm unless you want you truck or car to run slower. 6200 rpm on a stock motor is really asking for trouble.

With the oiling issues over 5400-5500 you are shortning the life of the motor and not going any faster.

A boosted motor (forced induction) will make more HP after 5500 rpm but you have the oiling issues still in place. An external oil pump or dry sump oiling system will extend the safe rpm operating range. (An Accusump will help with this issue.) But with the stock camshaft or even a 708 or aftermarket camshaft, you are still going slower by rpming the motor past 5400 rpm.
The hydraulic lifters bleed down too fast to allow the motor to make effective HP at any higer of an rpm.
A soild roller camshaft will take away that limitation, if properly matched to the valve spring package. But solid rollers are noisy and require frequent valve adjustments.

I know of one mamber that sprays, and he shifts at 5000 rpm, with very good results.

 

[NBT]

Here is a dyno from mine. I had CAI, Bellangers, High Flow Cats/Mids, VECII, tuned by Sean Roe, and water/meth.
This was a water/meth pull...dyno.

 

[SANCHOBA]

great info,thats what i was getting at..so limit the dyno rpms to maybe 5400.? and i shall set my raptor to 5000 rpm.

 

[rottenronnie]

any body have a dyno sheet of a stock truck,or a truck with similiar mods to mine? that way i can determine when to shut her down.

This was with a Stage 2, B&B Catback, B&B Hi-Flow Cats and a K&N DROP IN.

 

[FlyingLow]

If you are going to be shifting at 5300-5500 then no need to go higher on the dyno.