300 promax tuner

**Varmint** · 03-20-2018, 06:03 AM

I dunno,that's why I asked ?

Originally Posted by Chaz

No ... ehh ?

So how often do you think the motors with full liners , go around and wave bye-bye to one's that have been ..... relieved

**Chaz** · 03-20-2018, 08:26 AM

My bad , I thought you made a statement . Theorized from the compilation of your readings ...

"Just" cutting the inner liner will give the exhaust a larger area to expand in before it meets the same "total exit area". There is room on the bottom of the cavitation plate behind the back set of 12mm studs to drill a few .625" holes .
It will be quiet @ idle and move enough air at WOT to be happy .

The tuner leave's a bit to be desired . But if your going to take the time to take the mid all apart you might as well spend a few hours correcting core shift and get rid of the casting (&%&**(()% in the runners .

**One Oldman** · 03-20-2018, 01:33 PM

Originally Posted by Chaz

"Just" cutting the inner liner will give the exhaust a larger area to expand in before it meets the same "total exit area". There is room on the bottom of the cavitation plate behind the back set of 12mm studs to drill a few .625" holes .
It will be quiet @ idle and move enough air at WOT to be happy .

The tuner leave's a bit to be desired . But if your going to take the time to take the mid all apart you might as well spend a few hours correcting core shift and get rid of the casting (&%&**(()% in the runners .

Do you have any pictures of the .625 hole locations? Thanks

**Varmint** · 03-20-2018, 01:51 PM

Originally Posted by Chaz

My bad , I thought you made a statement . Theorized from the compilation of your readings ...

"Just" cutting the inner liner will give the exhaust a larger area to expand in before it meets the same "total exit area". There is room on the bottom of the cavitation plate behind the back set of 12mm studs to drill a few .625" holes .
It will be quiet @ idle and move enough air at WOT to be happy .

The tuner leave's a bit to be desired . But if your going to take the time to take the mid all apart you might as well spend a few hours correcting core shift and get rid of the casting (&%&**(()% in the runners .

thats real nice work, tks. For the reply and info

**Varmint** · 03-20-2018, 01:53 PM

I had to take it apart to cut 5" from the water tube and degrease and paint it, had some salt use at some point, i see where you mean to drill holes in can

**One Oldman** · 03-20-2018, 02:05 PM

Originally Posted by Varmint

I had to take it apart to cut 5" from the water tube and degrease and paint it, had some salt use at some point, i see where you mean to drill holes in can

Dang you have an advantage on me...You have yours apart.