Proper way to set up a Tuned Pipe

[waterbug]

Since it slow in here, what is the proper procedure for setting up a new tuned pipe ????

.21 size engines 8'' seems to be the norm...... How do I know when to cut more off and when to go longer ????? Will it do like a dirt bike and get on the pipe (stage)!!!???

Procedure;?

 

[james irwin]

Since it slow in here, what is the proper procedure for setting up a new tuned pipe ????

.21 size engines 8'' seems to be the norm...... How do I know when to cut more off and when to go longer ????? Will it do like a dirt bike and get on the pipe (stage)!!!???

Procedure;?

hey butch, why didnt you ask me this when i qas down there last week ?????

all i can do is tell you how i do it ? Most all mfgrs like to send there pipes out a little on the long side . as when they are built . hell you never where they are going in the world ? you will NEVER FIND ANY TWO BOAYS THAT WILL DICTATE THE SAME PIPE LENTH .There is always a little detaile some where on the boat that will dictate a differant pipe lenght . now to answer your question . put the pipe on and run it , most allways , it will be too long , (meaning ) all torque and no rpm . welll start cutting my man . i always take off 1/4 inch at a time , on an outboard you will see and hear the rpm commung up . do you stop there ,? hell no man keep on cutting till you get it so short that it will fall off the pipe in the corners , o o sorry andy but themanked andf i will them him . the corners take most all the torque your ol egg beater can generate . i find the rpm will be there if i can keep the ol torque up.( this is for outb. and inboard engines ) i have found that most all are running there pipes way to long . you will ask them why , they will say , i was afraid to cut it ?? then why run the mod class ? why dont you run the stock class? then you dont need to worry abut it . god bless o yes , when you get it to drop off the pipe when you hit a hard corner , then pull it back out that last 1/4 you cut off , then it should be about as good as it can be , be aware , you will need to check this every time you run it .

 

[Tim_Duggan]

Well this will be an interesting thread!

Easiest way is to get a reccomendation for pipe length / prop and go from there, but this isn't always an option. In which case I believe "it's far easier to cut than to add" so I start long, test and then shorten it then test again. When it won't get up on pipe at all regardless of needle or prop - then it's probably too short. Back it out 1/8" at a time until you are happy with it coming on and off pipe.

A sidenote: 3rd channel needle valve makes pipe tuning a lot easier as well as restricting the water so that the engine maintains a good head temperature.

 

[waterbug]

Jim

I wanted to stay and talk but the wife and me to, was dragging our butt's on the ground !!! I wanted to stir things up and talk about something , instead of 35 people being on and saying nothing !!

My purple boat was pulling good off the turns and down the strait's mega rpm's, set at 8''s but am having to run the prop very high ... Anything else and it will not plane off at all.......

 

[Slideblues]

Hey Butchie,

Ya wanna stir it up some Hehehehehe.......

To me it comes down to rigged boat Wt. also.

Like is it 4 lbs wood or 6 lbs fiberglass, reason being more torque needed to pull off tha bouys with a heavy'r hull.

And also driving style, Do ya white knuckle it all the way around or are you a finesse type.

Setup aired out down tha straights and rev'n with enough torque on the exits to hit and get it down the backstraight,

Kinda like shampoo....Wash.... Rinse..... Repeat

There ya go have at it :lol:

Gene

 

[waterbug]

Well the test mule is the Magnum / Mac and I would say med< heavy... I like to whip the mule !!!

Just getting ready for my project Lynx/Mac/SPP/Lawless/ABC just waiting on pipe and paint.....

7.5 Shaman/Rossi/K&B ... All broke-in and ready to race by december.....I hope !!!

Butch

 

[Slideblues]

Yep, Spank dat mule still she whinne's :lol: :lol: :lol:

Got me beat Buddy, I still try'n to deceide on a project <_<

Ahh well back ta reading, Man you guys talked a lot while I was gone

Gene

 

[chunk t]

Hey Gene!

1.) how about the stinger length? I think I recall a thread 3 years back you, tunnle Bill and Olson were talking about both pipe length and stinger length and the mix between the two, to capture the most torque possible while hitting the high RPMs.

2.) if stinger length IS important, how's the best way to capitalize on correct stinger length when you're using an internal stinger to keep the dB's down? or can't you have your cake and eat it too??? :blink:

chunk t

 

[Slideblues]

Hi Chunk!

Yea I tried a bunch of em, But the absolute best stinger mod that I have used was a tip from Terry K.

The internal mod that you insert a piece of tubing inside the stinger back to the widest part of the first cone.

With bout a eighth inch sticking out the stinger.

Like what Mke Z used in his pipe shootout, best of Torque and Rpm was with that one for me.

And it was quiet enough to pass tha DB check,

Gene B)

 

[Marty Slater]

I have Irwin stamped on KB 8907 gold carb what size of stinger thank you

Marty

 

[Slideblues]

Hi Marty,

Sorry I dont have one here to measure up for you, Just a piece of brass tubing with a lite interference fit as you slid it in the stock stinger, with a little JB Weld at the end to hold it in place.

Maybe Jim or Mike Z can quote a exact size,

Gene

 

[james irwin]

Hi Marty,

Sorry I dont have one here to measure up for you, Just a piece of brass tubing with a lite interference fit as you slid it in the stock stinger, with a little JB Weld at the end to hold it in place.

Maybe Jim or Mike Z can quote a exact size,

Gene

HMMMM, YOU GUYS ARE TRYING TO PULL CRAP OUT OF MY BRAIN THAT I HAVENT USED FOR YRS.

SCRATCH BUTT , ? THINK , REPEAT . OK / IF MY MEMERY SERV,S ME RIGHT , THE LAST PRESSED PIPES I BUILT HAD A STINGER DIA, ( INTERNAL ) OF 312. / 5/16, THEN WE WOULD SHIM IT DOWN FROM THERE WITH K&S BRASS TUBING . O BOY , WHERE DO WE GO FROM HERE WITHOUT SCREWIN EVERYONE UP? OK , STINGER DIA , & LENTH , WILL DETERMAN TORQUE AND RPM . ( I WOULD NOT RECOMEND ANY ONE TO TRY THIS WITHOUT A GOOD DYNO .) AS I SAID BEFORE , TRY IT FIRST LIKE THE OL GUY SENT IT TO YOU . IF YOU GET LUCKY AND MAKE AN INPROVEMENT . IT WILL BE TO FIT YOUR APPLICATION . SO I WILL SAY THIS , JUST BECAUSE JOE BLOW IS EATIN A HOLE IN YOUR SHORTS , DONOT TRY HIS SET UP ON THE PIPE HE IS USING , AS IT MAY OR MAY NOT WORK FOR YOU . O YEA, THE RESON FOR THE SMALLER DIA STINGER . WAS THE NEWER ENGINES WER MADE TO GO A LOT HIGHER ON RPM THAN THE OL ( K&B ) , NOW FOR THE BIGGY. WHEN SETTING UP A BOAT , THE VERY LAST THING YOU WIL DO IS . IS THE ABOVE , MAKE SHUR TAHT THE ENGINE IS RIGHT , THE BOAT IS RIGHT , ECT, ECT , THEN GO FOR THE PIPE ,

 

[waterbug]

I here you brother Jim !!!!! A total package first, pipe last.......

Butch

 

[Slideblues]

Joe blow eating a hole in yer shorts Yikes!!!! :lol:

Good advice get tha boat dialed in first,

Thanks for tha specs Jim,

Gene

 

[Tim_Duggan]

Stinger diameters also have the effect of changing the fuel pressure and raising the temp in the engine - particularly handy on an O/B engine. It's not uncommon to have to change your needle valve setting to suit the new stinger. What works at one pond might not work at another.

As Jim has said before - there is a certain amount of safety margin built into commercial pipes as the builder has no idea what pond, altitude, fuel etc. etc. the pipe is going to be used at. Also, some engines like more back pressure than others.

 

[Marty Slater]

thanks slideblues for the info and as for james thanks for your pipes they seam to work preaty good the way thay were made but i though i might get a little more out of it and as far as my shorts go the old lady wount even get close thanks all

Marty

 

[Lake S.P.O.R.T.]

Hey Butch! I have recently got my hands on a copy of the two stroke tuners handbook by G. Jennings. Really good info on mods and tuned pipe design and specs. I will get some of the pipe specs and tuning tips out of the book for you. It's really good stuff to know.

Mark

 

[waterbug]

Thanks Mark.... Won't find that at Barnes & Noble

Butch

 

[Lake S.P.O.R.T.]

No you sure won't! Amazing what this guy compiled in this book in 1973. Some of the things that are seen as new an innovative today are covered in great detail in this book, such as inside stingers. Also interesting reading in this book is the fact that the AMA (motorcycle competitions) had a 92 db limit back then.

 

[Slideblues]

Glad to help Marty

Oh Hey one more thang Guy's while yer doin dis pipe yank'n and crank'n :lol:

Put a piece of fishing leader or small lanyard from the pipe to the transom or engine mount!!!

Dat way it wont go Ker Plop and be swim'n with da fishies <_<

Lost my fav Garcia pipe after a flip when dialing,

Gener B)