MAC 45 Drilling out the Stinger

[Heartbeat]

I have a MAC 45 with a 45 AB Parabolic Pipe

It just won't turn on, I put another pipe on and the MAC lit up

I read somewhere that you should drill out the stinger to .435

Can somebody confirm that and can anybody give me a starting point for the pipe setting.

Thanks Mike

 

[John Knight]

Mike,

Drill the stinger out. Take a drill bit that is a tiny bit smaller that the ID of the stinger and drill out the internal baffle. I don't remove any of the stinger material. That essentially makes the baffle the same ID as the stinger. Then cut a 1/2" off the end of the stinger. Make very sure that you flush out the metal filings/particles from the pipe.

 

[gil sonsino]

What boat are you running because I've been using the same combo with no problems on my rigger even with the stock baffle.

Gill

 

[gil sonsino]

You can also do what John Knight has described too!

Gill

 

[Eric Gadoury]

What effect does it have when you cut the lenght of the stinger?

Less pressure in the pipe? More RPM???

Thanks

Eric

 

[Tom v.d Brink]

my take on it is this

if you have the first 45parablic with a .300" something dia stinger drill it out to make it work.

if you have the newer pipe with the . 400" something dia. stinger leave it alone it works fine.

 

[Heartbeat]

What does .435" convert into drill bit size?

The baffle hole is way smaller then the stinger. the baffle hole is 5/32

Gill

Roadrunner ultralight pipe set at 9 3/4 it will pull a X452 won't pull a X455

when I changed pipes it pulled a X457.

Thanks for all the Help

Mike

 

[Scooter12195]

Here's a link to a size conversion chart Mike

http://www.evergreen.edu/biophysics/techno.../drill_conv.htm

Nothing exactly .435 that I see but you can get dang close with a 7/16.

Scott Norris

 

[Heartbeat]

Thanks Scott

thats what I needed

WOW thats a big differance

Mike

 

[John Knight]

What effect does it have when you cut the lenght of the stinger?
Less pressure in the pipe? More RPM???

Thanks

Eric

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From what Andy stated before it is a quick release on the pressure coming out of the pipe and it helps to raise the rpm. That is from memory but I believe it is essentially correct. He also told me that the first series had the smaller baffle. The second series has the larger one and did not always need to be drilled. I asked John a couple of years ago, do you drill all of yours for racing and he said yes.

John came to our race this past weekend and both of his 45 and 67 parabolic pipes were drilled and stingers cut off. Looked like the 67 was even more than .5" removed from the stinger. They flew so fast that they looked like they never touched the water. I do not need any more confirmation than that. If THEY do it with those results pay attention to it. The example they set speak volumes.

As for the prop for the Roadrunner Ultralight, the X series had too much lift for me and I use different series props.

 

[ClayGlover]

Like Tom vd Brink said works with mine... for what it's worth, I've tried both parabolice 45 pipes. I've got the old smaller dia stinger pipe's baffle drilled out to the same ID as the stinger, and the newer larger dia stinger pipe's baffle is running stock.

45 rigger

Sounds like you have the newer version pipe there..., but I believe some guys drill them out as well.

 

[ClayGlover]

Are you burning plugs using that ab pipe?

 

[Preston_Hall]

The difference between .435 and .300 is whether or not the pipe is capable of going 110 mph or tearing over a second off the oval IMPBA record.

So which is it? :unsure:

Keep it zipped Don. This should be good for a while. :lol:

 

[Heartbeat]

Clay

Not burning but pulling plugs even when I think I am way rich

Preston

I tried 1455 and a 1450 It likes the X Props, Maybe I have something else set wrong.

maybe I try .300 first

Thanks

Mike

 

[Tom v.d Brink]

I don't know about you guys but i had serious trouble with sound limits when drilling out the first series pipes. made me had to make a muffling system on the back again as it was at and over 92dB and our limit is around 85.

now the current series not only work well stock but also pass the noise test in naviga racing.

quiet pipes save ponds and keep you in a european race...........

 

[Don Ferrette]

The difference between .435 and .300 is whether or not the pipe is capable of going 110 mph or tearing over a second off the oval IMPBA record.
So which is it? :unsure:

Keep it zipped Don. This should be good for a while. :lol:

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[Dan_Cousin]

Heartbeat,

If you are anywhere around sea level and running over 30% nitro you should be able to pull a Octura 1655, 1460, 1457 with cup with that boat and it will run much better. If you get setup well try a 1657 and hold on. Other props to try are ABC h-22 and H-18 spun high or with cup. All of these are heat racing props.

 

[Heartbeat]

Dan

At sea level (SW Florida) 60%

This hull seems to like the X Props After I drill out the stinger I will try X457 or X460

and see where that brings me.

Thanks

Mike

 

[Terry Keeley]

Dan At sea level (SW Florida) 60%

This hull seems to like the X Props After  I drill out the stinger I will try X457 or X460

and see where that brings me.

Thanks

Mike

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Hate to tell you but it'll never go very fast with X series props...

 

[Dan_Cousin]

Thats right,

Make sure the hull is setup according to teh Roadrunner setup instructions. and put on a 1400 with cup or 1600 series prop and it will be a much faster boat.