Dyno'd New Engine

[devincox]

Last year I bought a long block from Modular Head Shop for my 97 EB 4wd. The stage 1, 5.4 with ported PI heads. I had a hard time finding someone to tune the engine. Nobody around Oklahoma wanted to purchase the equipment to tune the older fords with the SCT tuner. I finally found a guy, Bo at APS, and he tuned the engine for me this week.

Specs:
Mild-ish bullet cams
24lb inj
K&N cold air
99 stock expedition intake
BBK Ceramic coated 1 5/8" shorty headers
Gibson high flow cats and pipes
Gibson exhaust

It made 228HP / 345TQ to the wheels. Max torque happens at 3250rpms. The HP is a little lower than I expected (I figured it would be around 250HP) but the torque is right where I expected it to be.

I'm taking it get 4.56's next week and then some paint. It should be a decently responsive yet dependable ride once the 4.56 gears are in.

 

[stamp11127]

To quote Smokey Yunick "horsepower sells engines - torque wins races"...

 

[ExplorerTom]

You're putting down 2 less HP and 20 more TQ at the wheels than what the engine was rated for at the crankshaft.

Not bad.

 

[rjdelp7]

Why would you take time and spend money to "dyno" this motor? The 5.4l is not a HiPo motor, it is a work horse. 228hp is pathetic, for that displacement.

 

[devincox]

I guess I should have titled it "Dyno Tuned new engine". You don't have to tune on a dyno but it safer and easier. I don't care about the HP numbers, I wanted some torque to haul a boat and for the truck to move more quickly when merging into traffic. Which with 345TQ to the rear wheels it does just that.

 

[ExplorerTom]

And if you go with 4.56 gears it'll really move.

 

[devincox]

I'm having a hard time deciding on 4.56 or 4.88 for the gears. I like to travel in this and not sure if 4.88's and 31" tires are a good fit for the highway.

 

[ExplorerTom]

4.56s and 31s won't be good on the highway. I had 4.56s and 30s on my Explorer. It would leap away from a stoplight but going over 70 mph seemed like pushing it.

33s and 4.56 are pretty close to an effective ratio of 4.10. Is 4.30 available for your axles?

 

[devincox]

I put some values in an rpm calculator:
3.73 @ 75mph = 2122 RPM
4.30 @ 75mph = 2400 RPM
4.56 @ 75mph = 2595 RPM

2595RPM's @ 75MPH is a little high.

 

[reece146]

3.73s or 4.10s.

Take a look at what the rpms are when the trans is in direct drive for towing. I kinda hate towing with my Cherokee (32s and 4.56).

 

[devincox]

3.73s or 4.10s.

Take a look at what the rpms are when the trans is in direct drive for towing. I kinda hate towing with my Cherokee (32s and 4.56).

By direct drive, do you mean not in overdrive?

 

[drewactual]

why fear the RPM? I've never got that...

the OE's don't test every vehicle for mileage... the EPA uses a calculation on speed/overall gearing/RPM/ displacement and VE.

on paper the taller gear gets better mileage, but rarely in reality- especially for heavier vehicles.

mind a vacuum gauge when operating. higher signal indicates less load... less load indicates the fuel is being trimmed and the PCM/o2 is sniffing 'crossing zero' on the lambda- which is to say it is minutely adding duty cycle to the injectors and minutely pulling duty cycle from the injectors, and the engine is achieving very close to stoichiometric air to fuel ratio's- which is HELLA better for your engine, your transmission, your temperature delta's, and your fuel economy than running the same speed @ 2/3's the RPM and drawing hella less vacuum (increased load).

o/d locked means there is a mechanical connection between the engines crank and the transmission via the torque converter's lock, and no fluid coupling of the torque converter which makes for hotter transmission temperatures... when the o'd is off, the t/c doesn't lock- which allows for torque amplification to take place and less load on the engine (at the expense of higher transmission temperature).

the lower gears (higher numerically) stated above sounds counter intuitive, and there certainly is a point of diminishing returns - you'll only be able to discover (and dial in precisely what you desire by playing with axle ratio and overall tire height) what you're looking for by use of a vacuum gauge and impacting the overall ratio by playing with those two factors. you're kinda stuck with the transmission ratio's, limited in selection with t/c stall ranges, and the camshaft/valve event-displacement-VE is going to determine the RPM range best suited for your application.... Ford tried to hit it in the general area for the widest uses, but it's up to you to dial it in.

 

[reece146]

why fear the RPM? I've never got that...

NVH

Towing a trailer for 8-14 hours a day for several days at highways speeds with the engine spinning at 3k+ RPM sucks. Not recommended if you value comfort at all during your road trips.

2¢

 

[drewactual]

if the OP is driving even 3 hours a day in an expedition towing, he's in the wrong vehicle and gears is the least of his issues... but, i agree... noise vibration and harshness will wear on a man for that kind of period.

 

[ExplorerTom]

Drew, Thats a bit of an exaggeration. It's a 1/2 ton chassis. There are plenty of trailers that are easily towed behind a 1/2 ton. You don't need a 3/4 or full ton to tow an 1800 lb popup.

 

[drewactual]

True... but the post above mine was equally absurd.

 

[reece146]

True... but the post above mine was equally absurd.

Hardly.

Load up a 5k popup and leave the centre of the continent to go to either coast to catch a ferry or meet up with others in your convoy. Oh, and you only get two weeks to get the travelling done AND enjoy the destination(s).

It's not for everyone. Remember that your use case is not the same as everyone else's.

2¢

 

[devincox]

When I travel, it's usually somewhere far away. All the places I like to go are at least 10 hours from me. I also like to travel at least 75mph on the highway so I can spend more time playing and less time driving. That's just me, and I'm not changing now. (c:
I don't care about gas mileage at all, it is what it is but I don't like NVH at all. I'm going to take the interior out and spray on some lizard skin to help with this.

 

[ExplorerTom]

I've also been considering the Lizard Skin treatment.