I will be taking my truck to get dyno'd in a week or so, i'm wondering if there's anything I can do while i'm there to check performance wise. My intent is just to get a baseline idea of the horsepower my truck currently has. I'm not into big power performance mods, mostly for financial reasons, but if there's something simple I can do quickly while I'm there, like change to synthetic oil in the rear dif, or air intake heater delete plug, then that would be neat to see the numbers a mod actually did to help performance.

So if you have an idea to try, list it. This is my first time on a dyno, first diesel vehicle, post simple suggestions please.

 

Don't know but I will give you a bump.

 

I would be curious on air filter differences, one run on a dyno w/o a filter wouldn't hurt anything.

Probably the quickest "semi-mod" I can think of now.

Be sure to post your results / mods

 

Check out ...My "unified explanation" for "all types" of dynos... and the graphs at the end of that Post #13 here... http://thedieselgarage.com/forums/sh...p?t=358&page=2 ...and note that if you use an inertial dyno you'll typically get a higher HP reading in your overdrive gear compared to your direct gear. However the resulting MPH in overdrive will exceed the speed rating of LT type tires so it's not the safest thing to do, and if your chip doesn't remove the speed limiter you can't use overdrive anyway!

Ask the dyno operator what atmospheric correction factor and smoothing factor he's using and see if he can explain why he choose the ones he did! I suggest also getting an uncorrected curve with little or no smoothing and no atmospheric correction because the SAE atmospheric correction factor which is commonly used on most dynos is a compromise that's more appropriate for gassers than diesels! Make note of the barometric pressure and ambient temperature and I can provide a more realistic atmospheric correction factor for your diesel. Also some dynos use a temperature probe and it should be positioned so as to get a true reading of the intake air temperature.

Warm the engine and driveline fluids enough to reduce their viscosity but don't over warm the engine because for most dyno setups there's typically either no cooling air or an insufficient supply of it to effectively remove engine heat like when driving down the road and a hot intake manifold due to engine heat leads to hotter than normal air intake temperatures which results in a lower maximum dyno HP reading than you'd normally get when doing a hard acceleration run down the road.

I'm always nervous about EGT and when I've asked to sit in the passenger seat to watch the gauges it's always been ok with the operator, but these were on ground level dynos not the portable drive up elevated types. If you can watch your gauges note the EGT and BP in the 2,600 to 2,800 RPM range for maximum HP.

You can check here... https://www.ford-trucks.com/forums/8...road-test.html ...for my simple road test for getting your RWHP and the following is how to compare the RWHP from my road test with the HP numbers you get from a dyno run.

The way I define terms in my road test the RWHP=Rear Wheel HP is equal to the truck's RAHP=Rear Axel HP because that's the HP which is applied to the truck's rear wheels by the rear axel half shafts, but this isn't the same HP you get from a dyno run! The tires are between the rear wheels and the road and in the process of applying the RWHP to the road the tires flex and this absorbs some of the RWHP as rolling resistance HP so that not all of the RWHP gets applied to the road or to the rollers on a chassis dyno.

To compare a DRHP=Dyno Run HP with the RWHP you get from my road test you need to add the RRHP=Rolling Resistance HP that's dissipated as heat ENERGY due to the flexing of the rear tires to the DRHP so that RWHP=DRHP+RRHP.

For the total truck the RRHP={(GCW)(MPH^1.3)}/{150,000} where the GCW is the total weight supported by all the truck's tires, so for just the rear axel use the RAW=Rear Axel Weight and the MPH for the dyno run which depends on which gear you used.

Say you use your direct gear and that gives 80 MPH at your maximum DRHP reading, and say your RAW is 60% of your 8,000 lb GCW. That gives a rear axel RRHP={(RAW)(MPH^1.3)}/{150,000}={(4,800)(80^1.3)}/{150,000}=9.5 HP and this is the difference between your DRHP and the RWHP you get from my road test. Since RWHP=DRHP+RRHP=DRHP+9.5 you need to add 9.5 HP to your DRHP dyno reading to compare it to my RWHP road test reading.

In my road test I start with the RWHP and then subtract the full RRHP using the truck's total GCW on all its tires, then I subtract the ADHP=Aerodynamic Drag HP to determine the RWHPa that's available to accelerate the truck. So the bottom line is that in this example you need to add 9.5 HP to your dyno numbers when comparing them to my road test RWHP numbers. Of course the numbers 8,000 lb GCW and 80 MPH at your maximum DRHP reading were just an example and you've got to use your actual numbers here.

If you do the road test on the same day as your dyno run then you'll have a "calibrated" road test result and you can then use future road tests to compare your RWHP improvements with different mods without the need to go back to the dyno each time. I'll be glad to help with the details if you want to try this approach.

 

thanks for keeping it simple eugene, j/k. sounds like you've done this before. thanks for the reply though. i'll re-read your post later when I'm not on the clock.

I'm still open for other suggestions, if ne1 wants to chime in.

 

gene, your first link didn't work for me. is the page still there?

 

With just the K&N (think about getting rid of it, BTW) and an opened up muffler, I'd think you'd be around 215-220 RWHP.

Maybe the wiper mod will get you a few more though....

BTW, the rear diff should have syn in it already. It's supposed to be 75W-140 syn per the manual....

 

I copied and pasted it again, it's post #13 here....

My "unified explanation" for "all types" of dynos...
HP, TQ, Dynos, a new beginning... - Page 2 - TheDieselGarage.com

Yesterday I towed the eastbound stretch of I-40 from Kingman to Holbrook AZ which is a towing version of a very long session on a load dyno.

 

thanks gene, I got it now.

I will not be getting rid of the K&N air filter anytime soon. I know the 6637 is a popular mod, but I've checked my intake, it is clean. Only very fine light dusting on the inside of the tube. And if ne1 thinks I don't live in a dusty environment, guess again.

Synthetic already in the difs, good to know. I'll not worry about changing that.

Razzin a newbie about his mods? Ok, smart guy, I'll remember you, Izz351.

 

Is your K&N a flat filter in the stock air box or a cone? I've used both types and on the flat version I sealed around the perimeter with petroleum jelly and on the cone I added a K&N pre-cover. Even if you keep both versions well serviced they still pass too much small particle dust. See my post #17 here and the pic of my new compressor wheel... https://www.ford-trucks.com/forums/8...ml#post7108078

 

I call 214hp and 449tq to the wheels!

 

I will say that hes just trying to help you out and not razz on you in any way, shape or form. Joe is a good guy and Ill vouche for him here on this one, There just have been a few people who have dusted a motor because of those filters, Im not saying your filter isnt working well, Im just saying its happens more with k&n filters.

 

Yeah, Joe's a reall *******

 

Since DRHP=RWHP-RRHP=214-9.5=204.5 HP that means you're predicting about 204.5 HP applied to the dyno rollers! The reason I used... "RAW is 60% of your 8,000 lb GCW" in the above calculation is because the rear axel is strapped tightly to the dyno rollers.

If the RAW is 40% of your 8,000 lb GCW and the MPH at your maximum DRHP reading is 70 MPH then the rear axel RRHP={(RAW)(MPH^1.3)}/{150,000}={(3,200)(70^1.3)}/{150,000}=5.3 HP and RWHP=DRHP+5.3 HP.

According to the Banks dyno a DRHP=212 HP is typical for a bone stock truck and using the above estimate for the HP absorbed by the rear tires this gives a RWHP=DRHP+RRHP=212+5.3=217.3 and this in turn corresponds to a FWHP of about 255 HP depending on your exact driveline loss between the flywheel and the rear wheels.

The DRHP itself depends on the atmospheric correction factor and smoothing factor used during the run so be sure and report those factors as well as your results.

 

Or, you could just skip all that headache BS stuff, and use prior knowledge and make an educated guess ???