Please see the attached pic of the dyno results. On that sheet there are 2 almost identical runs, both within 2 hp of each other. The two runs are superimposed over each other.

This was a hood closed dyno on a "Mustang" dyno. It was calibrated yesterday and the 3 cars that went before me showed normal numbers.

The A/F was 11.7 :1@WOT and a Tac ratio of 2.309

First they ran a baseline to make sure the car was running at normal operating temp, etc, then:

2nd run 352.4 HP @6000rpm 349 torque at 4500
3rd run 350.9 HP @6000rpm 348 torque at 4500

When it hits 6000 RPM, the rev limiter kicks in "With Authoritah" and won't let it go any higher

So if I average these two 352.4+350.9=703.30/2=351.65 RWHP /.83 (to get flywheel hp)= 424 HP, and 419 ft/lbs torque


The car appears stock, but these numbers are way high, and the car does feel strong. The car does a 0-60 in 5.0 flat with a passenger and on slippery tires instead of the stock numbers o 5.3 seconds.

I measured the pulleys. The upper is stock, and the lower looks factory with the largest diameter of 6" even. The cats look stock too. The only change I had made to this car was to put in, what apparently is a "Magic drop in K&N" and to remove the resonators just in front of the rear axles, neither of which should give more than 1 or 2 HP. The car has 52K garage queen pampered miles.

Could it just have a wicked 50 HP tune?? but it still has a 11.7:1 Air Fuel ratio... What is going on here. AVOS, others, I need your knowledge

I am going to buy and install a boost and IAT gauge to see if somehow it is making 52 lbs or whatever of boost instead of the 11.6

I'm confused, but HAPPY

 

Here are photos of what look like stock pulleys.

In the "upper" photo I'm holding a 1.5 or 1.7 pulley from Mina next to what looks like the stock (larger) pulley

Photo of lower too. Looks stock, right?


Why is this thing making so much power?


I'm going next Weds to an official 1/4 mile track and see what it does there, and then do the calculation to verify these dyno numbers.
As promised, I will post all of my findings.

 

Newby right? So why the change in name?


Some questions:
- What was temp/baro pressure
- Did they use a correction for the figures, and if so was it SAE or STD, and what correction factor was it?
- What mustang dyno was it they have several different type of models? Was it a dual drum per wheel?
- Which gear did you do the run?

 

yeah all looks to be normal my friend and the numbers are way nice and strong but from what I have seen this is about 25 to 30 more rwhp than what most get on a strong running stock xjr. Maybe you hve a factory freak haha, but yeah what gear were u in? What were the correction factors, mustangs have a history of being heartbreakers cus their numbers are usually lower than a dynojet but I also know if the user didnt put in all the numbers correctly their easy to screw up. But i am hoping yours is just a killer running beast lol. Congrats on the numbers and even the torque curve looks great, even for a "roots".

By the way posting these things in the x308 section you will get more comments thts where most people post things about their cars. Once again Woot Woot great numbers

 

Yes, I am the artist formerly known as "Newby" heh heh
When I originally signed up, I thought I could change the the name later. Since I couldn't figure out how to do that, I thought Id better change it sooner than later to a permanent one. I changed the name because: A: I have graduated from Newby to novice, but novice isn't a great name, and B: I chose WaterDragon, since I breed Dragonfish (water dragons) and this is the year of not only the Dragon, but also the year of water, hence the year of the Water Dragon, and my 2 XJs are Blue.


The temp was aprox 75-80 degrees F, sunny and dry. I don't know the baro pressure, but is was relatively low and has been for the last few weeks. Also, I think we are at around 200 feet elevation.

Here is the undated info:
It was a Mustang 750 dyno, can hold 1200 hp
Dual drum twin load cell
Corrected SEA

The run was done in 4rth gear per normal protocol of trying to dyno with a 1:1 ratio. They had to slowly accelerate to avoid the kick-down to 3rd and only floored it WOT (in 4rth) after 4500 RPM. They said the test, in 4rth was from 50-150 mph.

 

The numbers are above average, and not by a small margin. The a/f ratio is also relatively lean for your car model, but that wouldn't add so much more power, but certainly has contributed.

My dyno also once wasn't calibrated right, it took them a couple of days to find out, otherwise I had already 560 rwhp 2 years ago ;-). We already noticed that when applying different loads with the eddy current system that the power would go up, which should have been only marginal. This error was caused due a software patch update.

Best to get more data, preferably a dyno slip which shows the environmental and correction standard / ratio being used to understand the figures better.

 

The drag strip won't inflate the numbers.

 

^^^agree, you cannot compare number from 1 dyno 'd car to another on diff dyno/operator. There are many many articles about these issues. Only use same dyno/operator and cal info. To show increase. Dragstrip mph number are what really show the power output acuratly. I run 50 rwhp diff from a dynojet to a mustang/dynodynamics.

 

Yes,

I'll use the official 1/4 mile times and actual weight to get the most accurate figures.

This dyno is close to home, so I may continue to use the same one. Since I had a baseline, as I add mods, it may not be accurate as far as total hp, but should be accurate enough as to showing the gains per mod.

All agree with this?

 

Not really, your numbers are to far off, that would require a better understanding of the numbers first imo to explain the deviation.

 

If the dyno is consistent, then you can use it to compare changes. But your baseline might have been a fluke.

 

But the 1/4 mile and weight of the car (with me in it) would give the most accurate real world #s, right?

The way I see it, this dyno sounds like there is at least the potential something fishy as to how it reports the results, and since I'm learning these dynos vary so much, some of the dyno reports may just be mental masturbation for some people.

I'm now thinking (see I change my mind often, but usually because I'm incorporating new and better/more accurate info) that the 1/4 mile times are the most important because that is "actual performance" not a calculated performance....do we all agree on this?

 

Yeah I would agree that your 1/4 mile is going to be the best thing to compare to power to the wheels. You may have a tuned car which would give you 20+ rwhp and this would also explain the much much better 11.7 to 1 afr versus mine which went as far down as 9 to 1 at wot. May try and contact previous owner and have a chat lol none the less it sounds like its running strong good to hear.

 

Previous owner owned a high end mechanic's shop, bought this off his customer, who bought it as a lease return. He claimed it was bone stock. Since I'm no less than the 4rth owner, all bets are off as to knowing what was done to it if it was hidden.

I suspected a tune, given the A/F ratio, but thought I would ask the more experienced people on the board to confirm or share this suspicion.

1/4 mile time it is

 

Well, the 1/4 mile may 'deflate' the true numbers due to poor driving, but it will not inflate them. The trap speed would be the better indicator then ET, since these cars have no lsd and can be tricky to launch.

 

Both have pros and cons, here are some 1/4 mile results with the same car, mod and driver. Difference was mainly weather (so temp/baro/humidity) and weight (ie fuel tank level).



It is not rocket science to get a better understanding of the dyno and the results, so am a bit puzzled that you already give up now.

A leaner mixture doesn't have to be a tune, could have many causes.

 

Adding an additional, and likely better/more accurate system is not giving up, it is progress in getting more accurate results.
I'm still going to get dynos along the way, but rely mostly on actual performances to calculate HP.

1/4 mile times are what they are, actual results in the real world, without any excuses.



I am interested in accuracy, honest accuracy. Non-arguable non-skewable actual performance data. Actual results are far too rare on this board. This is going to change. I will be the change I want to see here. It will be either put up or shut up in the future on this forum.

Dynos are very helpful overall, with tuning, allowing you to visualize performance in another way, etc, but it has been reported in this thread that there is lots of variation and people can and have played games with results. Not pointing fingers here, but just sayin...

As it has been said, the 1/4 mile figures cannot inflate #s on the high side. Sure people can sandbag, or have terrible driving / drag skills I guess, but they can't say they went faster than they went. If someone relies on excuses why actual performances were slow, they will be discounted. What I want to know is how fast my car or your car or his car or his car has actually performed, then can come the explanation and understanding of what mods actually got you there. I'm interested in exposing and sharing actual verified knowledge. I see that most vendors do not give this information, OBVIOUSLY because they cannot back up their claims.

Of course one has to take into account weather conditions/track conditions, etc, obviously. But, If someone claims to have 700 HP but their car has never ran faster than a 13 flat on the 1/4, I am entitled to call Bull.

The HP is a tool to make the car faster, actual performance results totally trumps a sheet of paper or a thread, or a logical sounding argument on an internet forum.

My goal is to get my car to run, on street tires, in street trim, an actual uncorrected 12.5 second or better 1/4 mile time by the end of this year.
Whatever results I get, I will post, WITHOUT excuses.

 

well I think you will do it my friend and it may take some practice but it will be fun along the way

 

I will be using the same dyno to see the changes, and agree that this would still be useful to measure "per mod" changes.

 

The example I gave above of the times already gives a difference of about 40 rwhp, which is with the same driver, strip and car.

As long as one doesn't have actual weight figures, temp/baro information, the time information isn't something you can compare easily. Then the driver skills and the stickiness of the tarmac/tires are another influence.

So even people having mentioned times it still is meaningless without having also the above info. If all is given it is another matter of course.

At least on a dyno your values can be easily corrected to SAE for instance, which will take out the temp/bare/humidity influences, and obviously also the weight factor/driver skills and stickiness of the track. So imho it will help much better when you are tuning, including if you want to compare, as once I know the dyno type I will also know how to interpret the figures.

Of course dyno numbers are not an absolute measure of performance and shouldn’t be used for just that, but its a strong indicator. All my dyno sessions over the years have helped me tremoundously to understand what works and what not, as it is a much better controlled environment.