SX Triple Pipes

power inc centre dumps
147.5 mains
47.5 pilots
raise needles 1/2.
89L weights with 4.5 gram rivet & a 50/44 helix. Pipes need to run at 7900-8150 rpm & absolutely no higher.
 
Thanks Turk!

What temp range is this good for? I thought that they were power inc. Just picked them up on e-bay Should the gearing be changed on the sled, or run stock? How load are these pipes?
 
Your good to -20 at those temps. They are no where near as loud as the end dumps. Stock gearing is fine.
 
Turk said:
power inc centre dumps
Pipes need to run at 7900-8150 rpm & absolutely no higher.
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Wow.. I thought when you triple piped, you'd bump up to like 8900-9100... so I hear. Is that other pipes, or end dumps?? Those rpm are lower than stock... how much extra power do they make? Good pipes?
 
BBlueSRX said:
Why do the PI's make their power at so much RPM's? SLP's max out at 8800?
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So much? Barely 8000 rpm is extremely low, IMO... I was surprised myself.
 
Centre dump pipes by design make hp at a lower rpm. No 2 pipes make hp or are clutched; jetted or run the same. Run em at 8800 & see!
 
wow. I dont understand how you lose RPM's over stock by increasing airflow? I am asking not argueing. I am running the same mains on the SLP's as PI's
 
You don't lose rpms over stock, you just clutch the sled harder to pull the rpms down. The PIPE makes it's power at 8150, so you clutch the sled to run that rpm. If you just added the pipes, you would over-rev
 
If you know you are getting high quality fuel all the time go ahead and run the thin headgasket, you can definately feel a difference. Its just important that when you increase compression you run higher octane fuel to resist detonation. Nobody likes a meltdown.
 
How much more power will you gain? I thought that when you run the triple pipes that they recommend you run the thinner gasket? Will the stock reeds be Ok against the triple pipes? and will the bender spring in the primary be Ok?
 
You will gain a realistic 18-20 hp from pipes. Thinner head gasket is recommended but u gotta run good fuel; u were told 3 times! Stock reeds are fine.What Bender spring? They made 27 of em & they all make your sled run differently. Sounds like u should not do the pipes & keep it stock!
 
Turk said:
You will gain a realistic 18-20 hp from pipes. Thinner head gasket is recommended but u gotta run good fuel; u were told 3 times! Stock reeds are fine.What Bender spring? They made 27 of em & they all make your sled run differently. Sounds like u should not do the pipes & keep it stock!
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I understand the run premium fuel thing. I was looking for an estimated # on the head gasket thing, I have received feed back on this mod on a single pie, and did not now if it has more of an effect with the triple, or is more important to do with the triples. I appreciate the help that you guys give on this sight, I know the Yamaha sleds pretty good as far as maintenance and repairs. I typically do all of my own work. I have torn the motors down, rebuilt the suspensions, and cleaned and measured the clutch parts, but have not done any of the clutching or jetting mods. This is new to me and just wanted some input on various upgrades, so I can decide how much I want to do. Why would you make a comment like that, I am not giving anybody a hard time, just trying to get a better understanding of things. I think your last comment is a little rude, and I am sorry that I have bothered you...

I don't know what bender spring it is, I was hoping that someone could help me figure it out. All I know is that it is the one they use in the power shift clutch kit for the single pipe sleds. It comes in a kit, that came with the sled. Right now it is engaging at about 4,500 rpms, and I didn't know if this engagement rpm would change with the triple pipes.
 
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You would have to change primary weights & helix so engagement would also change. You want to run the stock w-s-w primary spring with the set up i recommended to you.
 
Yep centerdump PI's run at a lower rpm than the end dumps. From what I have heard, all of the pipes that were made for this engine worked pretty good.
 
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