if you have ever gone from a chambered muffler to a straight through muffler, and gained or lost performance, please post up your gains/losses. i'm having a debate on another board and need at least 30 (according to the central limit theorem) scenarios so i can form a proper hypothesis and interval test. depending on where this goes, i may use it as my senior paper, lol.

thanks for the help guys!

please provide DA data for the runs so I can standardize the info. it should be noted that for this test, only n/a cars/trucks will be considered as a turbo or blower might skew the data.

so i'll start, format should be as follows

Muffler type: Moroso spiral mufflers
DA: 2400'
1/4mile mph: 121.8
1/4 et: 11.31
Weight: 3450

Muffler type: Dynomax Bullet
DA: 3200'
1/4 MPH: 122.4
1/4 ET: 11.26
Weight: 3450

i will then take your data, and correct it for DA to sea level using dragtimes da calculator, which is universally accepted as accurate. here's the link: http://www.dragtimes.com/da-density-...calculator.php
i will use the stock/midly modified results across the board for standardizing.

new corrected times:
Muffler type: Moroso Spiral
1/4 MPH: 125.4
1/4 ET: 10.99

Muffler type: Dynomax Bullet
1/4 MPH: 127.4
1/4 ET: 10.83

so the gains seen in this scenario was +2mph and -.16 in ET. once i get 30 scenarios, i can then apply the central limit theorem that says if the mean values of the sample are normally distributed, then the mean values of the population are normally distributed. i can then do some hypothesis testing to see if all mean's are essentially equal, and if i have any outliers