Driver72

Let me be the first to say, "I was wrong."
I've stated on a few occasions that the average new 5.0 would dyno between 360-370 rwhp SAE on 91 Octane on a Dynojet if calibrated properly.

There were one or two 390-400+ rwhp stock ones and to me without a doubt that's calibration error.

I just dynoed my 5.0 6MT car at the dyno I've used many, many times. It's also the dyno the two premier 335i tuners have used (I have been there with them with too). It's also the dyno Heffner uses to dyno their 1000+ rwhp Ford GT's and they dyno Ferrari's, Saleen Mustangs you name it, it's pretty well established as an accurate and well calibrated dyno.

So because my GT500 axleback exhausts will be going on my car in the coming weeks and I have no other time until then, I needed a baseline dyno on my car. I wish I could of waited a few more weeks however to get more break in miles. I have a feeling I'd see 3-4 rwhp more with 1500+ miles on the odometer.

Here are the details:

75 degrees out
46% humidity
900 feet in elevation

ONLY 438 miles on the odometer!!

We did a couple runs in 4th and then tried 5th. As expected 5th gear produced the higher more accurate number, but we ran into the speed limiter before it could go all the way to 6900-7000 rpms. But it doesn't really matter because it went to about 6600 rpms and it's above the peak hp at that point anyway.

So I'll post the 91 Octane 4th and 5th gear pulls overlayed.

Then I know MANY people wanted to know if the STOCK ECU would adjust up for 93 Octane over 91 Octane. So with about 7 gallons of 91 Octane in the tank I added 2.5 gallons of 100 octane to make a roughly 93ish octane mix.
We ran the car on the dyno rollers for about 2-3 miles varying the rpms and gears to mix the gas and allow the ECU to adapt to the 93 octane.
Then let the car cool for 5-8 minutes and started the runs on 93 Octane.

First two runs the car made essentially NO more power.
Then on the third and final run it made like 3 rwhp more and 0 rwtq more than the two best 91 octane runs.

They probably put in the ability to adjust up to 91.5-92 on the high rpm range which gives it a couple extra hp but no additional torque.
I think we can safely say using 93 octane instead of 91 octane gains you 3-4 hp up in the higher rpms for a bit, but as you can see it's not sustained over a large rpm range. So it just may be an anomaly that it made the additional 3 rwhp at the peak.
So 91 octane state people don't need to feel bad, without a tune, guys in 93 octane states aren't getting really any more power out of their stock 5.0's

Here's the graphs:

Adam

I doubt the ECU makes any sort of change after only 2-3 miles of driving. The increase in HP you see could have been a fluke. It's almost impossible to test, IMO. If you dyno your car on Monday with 91, then drive it two weeks on 93, you now have completely different dyno conditions.

Knight

great numbers man!

DaSFGiants4Life

Fantastic numbers on your stock stang. Once you put all the bolt on mods you'll be in the 400 RWHP EASY!

Driver72

Modern ECU's adapt almost instantly, they have to, to prevent knock.
I've been in the dyno game and octane testing and adapting game for several years.

Once the gas is mixed and driven a short period the ECU will know and adapt pretty instanteously.
Just imagine if what you were saying was the case and somebody put in 87 octane on a car tuned for 93 and it took many many miles of driving (or a couple weeks) for the ECU to detect it and pull back timing. You could do some good damage that way.

The engine adapted no doubt. But the results showed (4 dynos) that the stock ECU is not really capable of adjusting UP much beyond the 91 octane that Ford tuned the car for.
They probably put in a buffer that allows it to go up a bit on the high end, hence the 2.5 rwhp gain in that very small area. But ultimately the point is there is no significant advantage or power gain using 93 octane over 91 octane unless the car is tuned, again, hence the best 91 octane and best 93 octane dynos practically laying on top of each other.

RedCandy5.0

I guess the only thing dyno's are good for is hp increase when adding mods. I can not see this 20rwhp between stock cars. How can some dyno at 360 and others 380? The real test is the track it look like.

Driver72

Here's the best 91 octane run and the best 93 octane run.
Clearly the 93 octane does nothing for the stock 5.0 ecu.

Driver72

That is correct.
Dynos are good for letting you know HOW MUCH power you gained when you mod.
They really can't be compared to other dynos.

But that's just the same with track times.
When someone posts, "look I got a 12.6 @ 114 mph stock at ATCO" and another guy posts, "My best was 13.2 @ 110 mph at xyz track" that does NOT mean the car or driver from ATCO is a faster car or a better driver.
The same guy and car at ATCO could go to xyz track and do a best of 13.3 @ 109 mph.

Unless it's on the same track (and preferably same day or at least different day with pretty much identical conditions) comparing it is pointless.
Same with dynos. That's why Dyno Days are good to.
You get 10-15 cars with similar mods or various mods to all dyno on the same dyno under similar conditions and you see which cars with which mods are making more power than others.

Based on the fact I know this dyno and know what other cars get on it, I'm very happy with my 381 rwhp results.
I was on this same dyno 2 years ago when a relatively new 2008 LS3 C6 Corvette with the 436 hp rating jumped on the dyno. I think he had 1,200 miles on the car and it put down 394-395 rwhp.

So me getting 14 rwhp less makes sense. 436 crank hp vs 412 (416 really) is about 20 hp difference which is about 14-16 rwhp difference.

Ltngdrvr

The PCM in the new Mustang is constantly adjusting the timing as it goes along, always trying to use the most timing it can at any one moment. It's not like it takes one setting and runs for a time and then tries to adjust, it adjusts itself constantly. I don't know what the sample rate is but it is surely thousands of times per second so it adjusts instantly to responses from the knock sensors and the various other inputs.

Just because it made a few more HP between 91 and 93 on one dyno run doesn't mean that at some other time it might not make even more or possibly even less, just depends on all the sensor inputs.

Knight

In regards to the hp difference between 91 and 93, I don't think you are getting acurate results with your gas mixing, doesn't sound like you are getting 93 gas.

Try running straight 100. I beleive i saw somewhere the stock ecu can keep adjusting quite high, further then even 93. I highly doubt that 91 maxes out the timing adjustment.

I wish I owned a 5.0, all the stations near me are 93 or 94. I wouldn't be able to get 91 to test against though, lol.

Adam

They have knock sensors for a reason. Obviously it will retard the timing instantly if it detects knock. However, I fail to believe it immediately (within 3 miles) advances timing when going from 91 to 93. Using that logic, the ECU is constantly trying to advance the timing until knock is present, then it retards it? I find that hard to believe. On that note, I would still agree with you that 93 doesn't produce any extra power. I have no proof though. Are these dynos sufficient evidence? Maybe. Maybe not. I think it's safe to assume Ford programmed the stock tune for best performance at 91 octane since 93 isn't available everywhere. As always, just my 2 cents..

Driver72

Adam, it does so almost immediately.
I've done this test on many cars before and have seen pretty instant improvements of 5-6 rwhp on cars that will adjust up to 93 octane over 91.
If anything my mixture was closer to 93.5 octane.
I had straight 91 in the tank and my gas tank needle was a bit below (about the width of the needle) 1/2 tank. If the gauge is remotely accurate at 1/2 tank (which often they are) I'd of had about 7 gallons in.
The actual amount of 100 I put in was 2.57 gallons.
That would make around a 93.5 octane mix.

Again, on other cars that were 3-4 years older than this one, I have done this test from 91 octane to 93 octane and even to about 97 octane and just running the car on the rollers for a mile or so, then dynoing saw 4-5 rwhp instantly and then up a couple more on subsequent runs as it adapted even more. Once it levels off and gains no more power (usually after the 3rd pull) I do one more. If it gains no more power, it's maxed.

But again, trust me here, I've done this personally myself on my own cars, and have been with tuners that have done this while tuning and you get nearly instant results once the gas has mixed (which rocking the car to shake up the tank and running it on the dyno, or street, for a bit does the trick).

I've seen 91 octane dynos with 2 gallons in the tank then add 10 gallons 100+ octane and dynoing shortly thereafter add 20 rwhp on cars.

The sole reason I did this 91 vs 93 octane test is because I know many have wondered IF the stock 5.0 gets more than what Ford rates the car at with 91 octane when 93 is used.
You could go out and test it yourself if you want, but again, I've done this enough to know that IF it was going to advance the timing further it would have done it and I'd of seen a measurable gain.
I did not, the dynos lay over top each other.
Maybe someone could test a 91 vs 100 octane dyno, but I could tell you right now, on a stock tune and ECU it's probably going to do no good.
It would be very easy for Ford to program into the ECU a max timing advancement based on 91 or say 92 octane.
I, tuners, and even the shop owner I was talking to about this today have actually seen DECREASES in power on stock cars when higher than recommended octane is used.
A magazine did that test many years ago too.

There is no doubt with a tune we'd probably see 4-5 rwhp more on the 5.0, but on the stock ECU it's doing essentially nothing more for the rated power than what 91 octane gives.

Lastly if you don't believe me and my test results, go into a dyno with 87 octane in your stock 5.0
get the dyno numbers. Dump in enough 100 octane to give yourself 91+ octane. Rock the car a bit and run it for a mile or two on the dyno rollers at various rpms and gears. Then let the car sit for 5 minutes to cool.
Then do 3 dyno pulls with 1-2 minutes in between.
I'll put money on it that even the first pull will show a measurable power increase over the 87 octane baseline.

zilla8

those are some really stout numbers for a stock 2011 GT.I think it shows just how much conditions and dyno operator/calibration play in the numbers you see.

IMO there should not be this much differance in numbers on cars with the same gears and transmission.In this artical from 5.0 their car made 368rwhp in stock trim with 3.73 in 5th gear pull.

Driver72

That was a Mustang dyno though.
They read lower than Dynojet's.
Actually 368 rwhp on a Mustang Dyno is probably 385ish on most Dynojets, so I'd say their car is similar to mine (and probably most) in the dyno results.

eric n

WOW great numbers. Congrats, I'm probably going to wait a few more miles before I get mine dyno'd. I'd like to do a before and after cai and tune. I had a couple of BS check engine lights and I want to get another thousand or so miles before I start f'ing with warrantee issues.

Bert

yeah, that's the way I thought it worked

This is interesting though, I don't know if the 2011 5.0 is different, but I thought that the 2010 4.6 would make the same peak HP regardless of octane, but would beef up the low-mid range torque a bit on higher octane.

zilla8

thats good info 72,I did'nt realize there was that kind of difference 12-13% these coyote 5.0 motors are sweet

KonaBlue5.0

Since no one else did it, I'd like to extend a big:



But yeah, congrats on the nice output. Try to do a hotswap before/after dyno if you choose to tune it, though!

Driver72

Thanks and yeah I know you did.

Of for sure.
I will be doing several dynos in the coming weeks.
I want to do another when I put my axleback on.
The problem is I'm hoping the weather will be similar, we'll see.

I will also then do one after I put on the intake and tune.
I will do another run just before the intake and tune goes on, so I see the immediate same day advantage of the intake and tune.
I will also run the intake and tune on the dyno rollers for a few miles with varied rpms and gears to let the ECU adapt too (but again it's really almost immediate anyway, but that's just for reinforcement sake).