Made a dyno run with and without the Magnaflow catback. Test was done on Danny's dyno at Swanson Performance. Temperature inside shop was the same on both days and truck was allowed to cool for about 2 hours after the drive to Danny's. Numbers with Magnaflow were 417.8 HP and 490.7 Torque. Stock exhaust numbers were 425.6 HP and 498.1 Torque. The Magnaflow lost 7.8 HP and 7.4 lbs of Torque. Needless to say, I have one slightly used Magnaflow catback for sale. The truck seemed to run better with the stock muffler and now I know for sure that it does. The A/F was the same and the mid 90 degree inside shop temp was the same. The truck is much more enjoyable on long drives without all of the noise. It is unreal how quiet the stock exhaust is. Sorry guys, but like all the tuners have said, there is zero power to be made with a catback. I did not expect to loose power with one. I know that I will probably get flamed, but these numbers are true and correct. Gas Milage is even slightly better with the stock setup. The Magnaflow sounds kind of cool and the tips look great, but performance is down from stock. Skip

 

interesting...

 

So let me get this straight, you dyno'd the truck 2 days apart?

Skewed results. You need to test back to back, same day and same methodology strategy.

System tested on my truck is done this way and shows results every single time. Off the street Lightning came in last week and also showed results.

 

Everything was the same, including boost levels. These results are correct. I wanted it to work, or else I would not have bought it. The truck felt a bit slower since I put the Magnaflow on. That is why I spent my time, money and energy doing this test. I am not knocking the product, just posting my results. Skip

 

"Showed results"? WTF does that mean?

 

what about the humidity?

 

Great Unbias Post ~~~~~~~~~
Thanks Skip..................I'm sure w/your $$ invested in the Magna
Flow you were looking for equal or better performance..............

 

I for one believe it without any doubt. I have always said that there are no gains to be had with a cat-back only system, whether it be a 650$ bassani or a 350$ Maggy setup. All you can do is choose a well made stainless kit with nice tips, that you like the sound of.

How exactly is the dyno result going to be different because there was a 2 day wait? As long as ALL the conditions are the same I fail to see how it could effect the results.

 

You can only get so scientific with comparisons. The data is as good as it gets. Even if you ran the two runs the same day, conditions always change. Maybe the engine temp is slightly different, the fan isn't in the same position, barometric, humidity, temp, etc. How in the heck could you ever compare track times if that were the case. At least the numbers show there isn't a performance advantage at all.

 

Welp, as you may know, we arent exactly far apart. We have had very crazy weather here in LA and OC areas with High Humity that has changed drastically up and down over the past week. That alone will kill power. I know Torrance isnt the coolest spot in LA either. This why im saying your dyno results are skewed.

This reminds me of guy who posted about a CAI on an 03 Cobra. He dyno'd his car 2 days apart. First day was stock, then second day was with his new CAI and picked up 40 hp. So, make your own conclusions.

As far the claims that the Magnaflow doesnt make power... They wouldnt sell it if it didnt. Thats their guidelines.

 

Somebody must have farted in the dyno bay and changed the atmospheric conditions, thats why the #'s are off.

 

Originally posted by Flying ****
As far the claims that the Magnaflow doesnt make power... They wouldnt sell it if it didnt.
__________________________________________________ _

 

What mods do you have on your Lightning??????

 

7 HP out of 425 is about 1.6%. I could sneeze in the vicinity of my truck and change the horsepower output by 1.6%. No flame intended, but 1 dyno pass on 2 separate days isn't that precise to draw hard conclusions from.

As **** said, humidity makes a huge difference in power with these blower engines. Secondly, was the truck chipped or not. Was the computer reset at any time between the dyno runs. This can make a huge difference.

I've now seen claims of everything from -7 HP to 17HP peak gains depending on who you ask. I'm thinking it is probably somewhere in between, but I just can't believe that you LOSE power with an open cat-back exhaust.

 

I could see losing some lowe end because you might lose some back pressure, but that should be made up by upper end horsepower. Thats what I have seen. Less backpressure = loss of low end torque and gain in mid to upper horsepower (unless you have a v8 exhaling through a straw, then you could make both with a bigger exhaust). I dont know about blower motors, but thats the case on N/A motors. see it 1000 times and witnessed it a few myself.

Chris