ok, maybe I am missing something-


How the heck are they getting 289 rwhp on a STOCK 05 GT?

 

Uncorrected non SAE numbers maybe?

 

BTW...I am dissapointed they didn't use the regular bassani mufflers. Oh well....sounds like (no pun intended) all the exhuast systems are basically the same power wise.

Bassani's still have my vote...or straight pipes.

 

The airbox was modified, maybe a few more HP over stock.

 

I've read through this entire thread and it sounds like the only way to get more horsepower and torque from the aftermarket exhausts is to add the x pipe and headers, and the only difference between all of them is sound? Maybe I misunderstood.

 

Thanks.....OK quick pitch...

Yes, due to the break in time for our exhaust, it will initially be quieter then stock- then when the rockwool expands and hardens, it becomes much more dense and does not bsorb sound as well-

It takes 2-4 weeks to harden completely-

The Magnaflows were designed however to not be alot louder then stock- the Magnapacks however were designed to be much louder then stock and after several weeks they will be much much louder then stock

I posted the link to the 5.0 magazne article several posts ago where they gained 9rwhp with our catback-

If you live in Southern CA and would like to come over and get a tour of Magnaflow- and witness first hand our R&D facility and see cars getting tested first hand and be able to see actual internal dyno charts

call 1-800-990-0905 and ask for Brent- I will be in the office next week-

Again, according to our R&D- all of the systems tested made more power then what the magazine reported- I guess thats all Ican really say when it comes to the hp numbers

Thanks again
Brent

 

Actually you can get power from just adding axle backs but

1. You will not gt the same gains as you would on a 99-04GT
2. You need to give the computer time to go through a complete drive cycle so that it can adjust to the new exhaust
3. If you just bolt on an axle back and immediately dyno test you will not see any power gains
4. The 05 GT is one of the hardest car we have ever seen to do R&D on
5. An axle back is only good for 5-7rwhp depending on brand- you can get up to 10rwhp with a catback depending on brand


Its up to you to decide which brand will give you the most- Im just telling the gains- I dont want this to turn into a this brand is better then this brand right now-

I am trying to just share facts that I have- so I will not say how they all compared to each other- just that is the range of the gains we saw

 

Brent,

Is there anyway to post some of those dyno runs here? I'm not sure about the legalities of posting the other brands. The Magnaflow site only shows the Tru-X and cat back results. Can you post just an axle back dyno?

Greg

 

Thanks man. I appreciate your input and honesty. I am new to this modification thing. I am just trying to soak up as much knowledge as possible.

 

Greg- I will see what I can do-


There is nothing illegal about posting dynos from other systems, however our company believes that by posting dyno results of other systems, it could be taken as negative advertising as our exhaust system will be making more power then others and our owner does not believe in negative advertising- so I can't do that-

I will see what I can do about getting dyno sheets to post- should not be a problem- however I am on a business trip in Sioux Falls South Dakota right now- so it will have to wait until I return to Southern CA next week-

Of course if anyone in Southern CA would like to stop by and see for themselves as well- I will leave it as an open invitation as at Magnaflow, we are all car lovers- we all modify our vehicles- and when it comes to other parts- like intakes, superchargers, and brakes- we are all in your shoes- we just try to remember that when we talk about our own product-

I was afterall a Mustang enthusiast long before I worked for Magnaflow, and if I ever change directions in my career (although I dont forsee it happening ever) I will be a Mustang enthusiast long after-

I just love talking about MUstangs- and if there is information I have to share- I will always share what information I am allowed to share-





Side note- if anyone is interested in a Steeda cold air intake and Diablo- let me know- my buddy just got called to duty and we removed all of the performance parts off the car since he has to sell it- and I told him I would try and sell them for him- He also has Steeda wheels and tires but they should be sold- it did have exhaust- but that is sold-

I am basically open to offers as I have no idea what they would be worth used- about 400 miles on them- PM me

sorry- just found out so I thought I would add that in-

 

Picked up the magazine and read the article. All of the after market mufflers have higher torque and horsepower numbers below 3000 RPM, in some cases as much as 10-15hp and 20 ft-lbs pf torque. As RPM approaches 3000-3500, the stock mufflers start to hold their own pretty well, and in some cases are better at higher RPM than the aftermatket versions. The article doesn't quote average numbers, but actually the peak observed during the test. So it appears that whatever exhaust tuning Ford did to get a mellow cruise but good sound/perfromance under load appears have worked. You will see an improvement in around town driveability, but not much top end improvment. So really, it comes down to the sound you like.

 

In addition to the significant gains at lower RPM mentioned by Juice, I noticed a couple of interesting things about the article. For one, you can't really compare the averages they published. The average for the stock exhaust is calculated between 2400 and 6200 RPM while the unmuffled and aftermarket system averages are calculated beginning anywhere from 2000-2200 RPM. This skews the aftermarket averages to be lower. Calculated across the same RPM ranges, the after market systems show more significant gains and if you sum the differences across the power band (say 3000-6200 RPM) for example, the cummulative gains of the Bassani and Flowmaster seem to be quite significant over the stock exhaust. I'm basically a newbie to this stuff but does my analysis make sense? Opinions welcome.

 

After going through and doing my own graph, (I wanted to see what "Un-Muffled numbers looked like) I see what you're saying.

At 2,400 RPM all except JBA gained at least 20hp and 40 ft-lbs. After that they all start to drop off. That's fine with me since that's where I wanted more power and torque anyway.

They definitely screwed up the way they did the numbers. I'd love to see what the readings are BELOW 2400 RPM!