[Diehard]

Hennessy Baseline.......... 359.79 WHP / 367.56 WTQ

Livernois Motorsports...... 342 WHP / 345 WTQ (baseline)
Livernois Motorsports...... 368 WHP / 374 WTQ (93 octane perf. tune)

Magnaflow Mufflers......... 365 WHP / 368 WTQ (baseline)
Magnaflow Mufflers......... 377 WHP / 385 WTQ (w/new exhaust)

AIRAID CAI Filter.............336 WHP / 343 WTQ (baseline)
AIRAID CAI Filter.............359 WHP / 356 WTQ (with new CAI)

 

[G8 GT V8]

Where were the details from magnaflow? I assume that the new exhaust was more than just some axle backs swapped out?

Also, I don't get too caught up in dyno numbers. You can put the same car on 5 different dynos and get numbers all over the place. I find them to be more useful when trying to do a baseline and then measuring any gains from modifications tested on the same dyno.

 

[Diehard]

Where were the details from magnaflow? I assume that the new exhaust was more than just some axle backs swapped out?

Also, I don't get too caught up in dyno numbers. You can put the same car on 5 different dynos and get numbers all over the place. I find them to be more useful when trying to do a baseline and then measuring any gains from modifications tested on the same dyno.

Magnaflow Exhaust Updates...
http://www.ssforums.com/forum/engine-technical-discussion/10041-magnaflow-exhaust-update.html

And yes, Maverick Man said pretty much the same on fluctuating dyno results.

 

[GXPaycheck]

Companies should also post the type of dyno used. It can make a big difference.

 

[Headrat]

Hey Diehard, I'm glad I wasn't the only one to see the differences in the dyno baselines, even though they were on different dynos. Thanks for 'charting' it for us.

 

[Maverick Man]

typically mustang dynos read low, Dyna Pac read high and Dyno Jets run in the middle. if you look at the power between base and after tune or whatever you will see the differences and that is all that counts. like someone said even if you use the same dyno it may be different too.

just know that the dyno that read 21 hp may only be 13 on another. don't get caught up in numbers AND DON'T let manufactures fool you to believe their product is better just because their number is higher. the only thing you should compare the number between the base and after on that product only and know there was some kind of increase.

 

[Crisis]

To add to this, I dynoed my SS today.
329hp and 330 tq on a Dyno Jet, nice cool 67F night. The car was running about 10-15 minutes before the run, but I doubt any heat soak affected it too much. I did not have hptuners hooked up to log the run. Stabilitrak and TC were off, and the pulls were probably in 4th gear as they topped at about 125mph. It wasn't a dyno session, just a dyno night so I didn't look into the low numbers too much.

I don't think there was anything wrong with the dyno, a stock 2005 M6 GTO put down 347 just before the SS (like 5 minutes before), all the other cars were putting down numbers just as expected. The numbers for my SS were really low. I don't know if something was screwed up (probably not, 2 pulls and the same numbers). The car has about 700 miles on it, so I really don't know what to think. I think I'll dyno it again after it's broken in a bit more without mods. The only thing I noticed odd about the dynosheet was huge vibration in the torque and hp curves, everyone else were plotting nice smooth pulls (with the same smoothing).

 

[G8 GT V8]

Magnaflow Exhaust Updates...
http://www.ssforums.com/forum/engine-technical-discussion/10041-magnaflow-exhaust-update.html

And yes, Maverick Man said pretty much the same on fluctuating dyno results.

Thanks for the link. Definitely a pretty respectable gain based on the mods.

 

[pigman440]

Give it some break in time Chris and dyno it again.

 

[FSTASNTZ]

The "jitter" in the torque curve can be a number of things, it my experience it has mainly been due the fact the dyno operator did not turn on "smoothing" when plotting the graph.

As for the different dyno numbers, there is also the issue of not everyone going by the SAE reading. Technically they should, as it has a better chance at leveling the field, but I have found sometimes that tuners do not always use SAE (vs. STD or other correction factors) when testing their products. Use to be that the dyno print out told which correction factor they were using.

 

[Crisis]

The "jitter" in the torque curve can be a number of things, it my experience it has mainly been due the fact the dyno operator did not turn on "smoothing" when plotting the graph.

As for the different dyno numbers, there is also the issue of not everyone going by the SAE reading. Technically they should, as it has a better chance at leveling the field, but I have found sometimes that tuners do not always use SAE (vs. STD or other correction factors) when testing their products. Use to be that the dyno print out told which correction factor they were using.

Correction Factor (I'm assuming that is what CF means on the print) SAE, smoothing was 5. They dyno'ed quote a few cars (20?) that day/night (that put down nice smooth curves and about the numbers that was expected). I don't think they got it wrong. That being said, your right, the prints don't reference RPM (which I think should be standard), nor the correction factors, temperature, etc. mentioned. Just SAE and smoothing set at 5, hence why I found the jitted odd. I do intend to dyno the thing just for shits and giggles later to see if anything changes in the coming ~2000 miles.

I'm not reading to much into it. It was just a couple of pulls, not like a dyno/tuning session. The place is also very reputable.

Here's the print.

 

[ChevySS]

To add to this, I dynoed my SS today.
329hp and 330 tq on a Dyno Jet, nice cool 67F night. The car was running about 10-15 minutes before the run, but I doubt any heat soak affected it too much. I did not have hptuners hooked up to log the run. Stabilitrak and TC were off, and the pulls were probably in 4th gear as they topped at about 125mph. It wasn't a dyno session, just a dyno night so I didn't look into the low numbers too much.

I don't think there was anything wrong with the dyno, a stock 2005 M6 GTO put down 347 just before the SS (like 5 minutes before), all the other cars were putting down numbers just as expected. The numbers for my SS were really low. I don't know if something was screwed up (probably not, 2 pulls and the same numbers). The car has about 700 miles on it, so I really don't know what to think. I think I'll dyno it again after it's broken in a bit more without mods. The only thing I noticed odd about the dynosheet was huge vibration in the torque and hp curves, everyone else were plotting nice smooth pulls (with the same smoothing).

Crisis, what kind of fuel (octane) did you have in your car? The stock numbers are with 92 octane. It's what the LS3 calls for. Our manual calls for 91. Next time you go, try 93 octane if available, if not, get your fuel from either Chevron or Exxon.

 

[GXPaycheck]

Brand can make a difference too. Make sure it is a Top Tier brand.

 

[z51vett]

How many miles on car are you running mobil 1 and of course 93 octane.
z51vett
Doug

 

[Crisis]

Crisis, what kind of fuel (octane) did you have in your car? The stock numbers are with 92 octane. It's what the LS3 calls for. Our manual calls for 91. Next time you go, try 93 octane if available, if not, get your fuel from either Chevron or Exxon.

Shell V-power.
I'm pretty much used to just using it since a while back that was the only premium fuel in the area with 5% or less ethanol content.

There's another dyno day coming up end of March. I'll have it dynoed again.

 

[Crisis]

How many miles on car are you running mobil 1 and of course 93 octane.
z51vett
Doug

Factory fill oil and 93 octane Shell V-power.
I'll have the oil changed Friday. About 700 miles on the car.

 

[Crisis]

Factory fill oil and 93 octane Shell V-power.
I'll have the oil changed Friday. About 700 miles on the car.

Just thought I'd update this.

Dynoed the car again on 3/29 (well the wife did as I had a work related trip).
This time I think the car had about 1700 miles on it.
The ambient temperatures were about the same between this pull and the last one, about ~65f

Of course not at the same place (type of dyno / dyno calibrations) or same day etc. so it's worth nothing as a comparison.

Put down 344 hp / 343 ft-lb on a Mustang dyno.
The results for others that night were "normal-ish".
Probably nothing wrong with the car.
Simulated 1/4 mile (just for kicks) was a 12.506 @ 110mph, which I think is way optimistic, maybe by 0.5 seconds and 3-4mph.

 

[BGB0AR]

Here is another way to look at this and it takes the variables of the dyno completely out of the picture. I had my SS (still factory stock) at the Atlanta Dragway last Friday night. I was only able to make two runs but the ET and MPH were very close for both. I weighed the car on the track scale and with me in the car and a quarter tank of gas it weighed in at 4110 pounds. Using the finish line speed of 103.69 mph and 4110 pounds this calculates to be 357.606 whp. This matches very closely to the Hennessey baseline number in Diehard's chart. I used the online formula at TCIauto.com but I am sure it doesn't matter which one you use. The only value that could be questionable in this calculation is the weight. It was a digital scale but who knows about its calibration. Anyway, just thought I'd throw this in the mix to possibly validate one of the dyno data points.

 

[topo444]

BGBOAR
Your baseline number is exactly the same as mine was( 357RWHP ). Again I agree it's just a tool to judge changes . My pull was done in Jan. with cool weather and low Humidity. Recent pulls have been in the mid 70's with higher Humidity but again you can only really compare same car and changes and maybe see trends.

 

[Drew888]

Perfectly normal, it looks fine to me as Mustangs read a little low.

Just thought I'd update this.

Dynoed the car again on 3/29 (well the wife did as I had a work related trip).
This time I think the car had about 1700 miles on it.
The ambient temperatures were about the same between this pull and the last one, about ~65f

Of course not at the same place (type of dyno / dyno calibrations) or same day etc. so it's worth nothing as a comparison.

Put down 344 hp / 343 ft-lb on a Mustang dyno.
The results for others that night were "normal-ish".
Probably nothing wrong with the car.
Simulated 1/4 mile (just for kicks) was a 12.506 @ 110mph, which I think is way optimistic, maybe by 0.5 seconds and 3-4mph.