Let us know how it works out!

 

Curiosity got the better of me and I put the truck on a dyno. It was fun, enlightening, and somewhat disappointing all at the same time!

Data was taken on a Mustang MD500 so no inflated "feel good" numbers here. This was quick and dirty with no forced air cooling and hood closed, no cool down period, and trans locked in 4th gear.

(Run 1) 330 RWHP , 517 TQ
(Run 2) 340 RWHP , 442 TQ
(Run 3) shop screwed up and didn't give it to me

No wonder it has felt like a tire shredder.... Torque is great but I am a little disappointed with the horsepower. Ya, it's just a 91 octane tune but I still expected more power. Basically, I have a FANTASTIC towing tune and that's good to know!

 

Those numbers are intriguing. The run 1 torque seems a bit high to me but not entirely out of range. Thanks for the update.

I've been chatting with Erick at LET over email, mainly about a conservative 87 tune and I think he'll be getting my money in the next couple months. I'll be upsizing tires before June and I want to compensate for the change with a bit of tuning as well as reprogram for the new size.

 

The operator said the converter flashed in Run 1. Maybe converter locked up in runs 2 and 3. And it takes a long time to run through 4th gear so that truck was heating up for sure! Especially with no forced air cooling. Everybody claims the spike anyway.

Just as a reminder, mods are:

LET 91 tune
Solo downpipes
Wagner intercooler
170 degree thermostat

The torque was real... that's why you get on a dyno. The question is why? I feel changes like this in every day driving. Sometimes the truck feels monstrous and wants to light up tires with the flick of throttle. Other times it doesn't. I wish I knew the rhyme or reason.

 

Got it. Makes a bit of sense. Regardless you're making more TQ at the wheels than a stock motor makes at that crank and your HP isn't far behind. I think that's a good increase honestly and I personally wouldn't frown at those numbers especially with a bit of heat sink on 2 and 3.

Did you data log the dyno runs for Erick?

 

Unfortunately I did not data log. This was a spur of the moment decision where I was in the neighborhood of the shop and decided to just drop in unannounced. Better planning and I could have done so.

If I want to feel like a hero I can always find a different dyno.

 

I just noticed the shop screwed up and listed Run 2 twice. I didn't get a print out for Run 3.

 

So I've been looking around the internet tonight as I wonder why my Horsepower numbers are so low compared to so many other people. I'm starting to get a little better understanding how a Mustang dyno works and feeling better about my results.

First, I think the dyno setup was wrong and caused my numbers to be low. Apparently those dynos attempt to simulate driving on-road and the vehicle weight is one of the factors that goes into how much resistance is applied to the wheels by the eddy current load cell, thereby effecting the rate of acceleration and reported Torque and Horsepower figures. I remember the technician used the generic F150 Ecoboost from the drop-down list which happened to be a SuperCab. My truck is quite a bit heavier than that -- a whopping 900 pounds heavier. I don't know how much that effects results but it would only make my numbers better had they used the correct weight.

Now I wouldn't be concerned at all if I didn't already know the "big numbers" reported by other truck owners and tuners. I guess I need to put that out of my mind too because I am learning that comparing my dyno numbers to somebody else is pretty much pointless. Reason why is there is huge variation between dynos, and even settings used on the same dyno. I need to focus on my own improvement since my last baseline (which I don't have), using the same dyno and same settings. The dyno is a tuning tool, nothing more. If I really want to know how much good my mods did then I have to return my truck to stock and measure the improvement. And if I want to know how I compare to other people then I need to run down the 1/4 mile.

Never ran a dyno before so I never had to think about what the numbers meant, outside of being able to read torque vs speed. Looks like it is more complex than just reading a torque curve.

 

I've dyno'ed my diesel a few times, and the HP numbers were identical after the big mods (statistically). 449 the first time, 450 the second. The torque on the first one was over 1000 ft-lbs, the second wasn't giving torque for some reason, so all I got was HP.

But If you're really getting over 500 ft-lbs at the wheels, that's very encouraging! I'm shooting for 400ish HP/500ish ft-lbs at the wheels eventually. If I could better the torque, I'd be extremely pleased.

I've always said these engines feel like diesels, and with numbers like you have, it shows. My first dyno ever was before heavy mods (just tunes, intake, exhaust, etc), and I got something like 310/680. Stock at the crank numbers for my year were listed at 250/510 or something like that.

 

So why the cooler thermostat?

 

Here's some light reading about it. The only thing I DON'T like about the stock setup is that I *think* it runs a little on the hot side in the summer. In other words, my gut tells me it's running a little hotter than I think it should, without any knowledge of what the designers intended. Just normal driving around in the north TX heat, I've seen coolant temps over 210. Even my diesel didn't run that hot. Although, I monitored oil temps, not coolant temps on the diesel.

Low Temp Thermostats: What?s the Advantage? | Tuner University

 

Because it was a cheap mod and LET suggested I try it.

Modern engines run pretty hot to help with emissions (at least I think that is the reason). I think the goal of a T-stat is to run a little more aggressive timing (more power) in the wretched heat of summer. Not sure it helps other time of year. I didn't even bother data logging until it was 90F outside and LET preferred it to be hotter if possible, but last summer didn't cooperate.

It's not just a T-stat change, LET also changes fan strategy. In my case there was no changes to the tune after the T-stat swap so maybe it was of no benefit. Although the AC works better due to the fan strategy so that is a side benefit I will take!

 

I caught up with LET and learned that my numbers are in line with their past experience on a Mustang dyno. And the big torque in Run 1 is an anomaly with the dyno and it happens now and then. Also, my tune will not lock the converter until 5th gear.

So that means my numbers are more characterized by Run 2, which is 340 RWHP and 442 TQ.
And I can't make any more excuses why it should be higher.

 

I wonder how much difference a 93 octane tune would make?

 

I don't have a convenient source of 93 octane where I live. And I can't rely on finding it when I travel places either.
The truck drives really well. I'm now more curious what is my 1/4 mile time than dyno numbers.

I'll be getting my car on the road this year and probably take it to the drag strip at some point. I could just enter the truck at the same time and get a 1/4 mile run in.