Yamaha sidewinder falls on face

1nc 2000 said:
Who's tune when your engine went down?
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PEFI. He talks about it in another thread.


SledFreak, if you're referring to PEFI (Precision EFI) IMO the answer is NONE. At the end of this riding season I've seen and heard way too much evidence that the supposed premier PEFI Knock Protection system is non-existent or marginal at best. I'm in the process of doing complete engine rebuilds on 3 TCats (including mine) all w Stage 3 PEFI tunes. Granted sleds have about 6000 miles with this tune but all 3 have serious deto - enough for serious piston damage. Most of the time, these sleds have been run on 93 octane non-ethanol. Why didn't their great knock protection work as they advertise?
Everything possible was done to these 3 sleds to set them up for trouble-free 280HP riding. And I mean EVERYTHING. Every precaution to get best possible gas was taken always.
This is probably a totally different discussion but in some cases, pistons showed no damage from deto but they simply got too hot. The areas around the valve reliefs actually got so hot the aluminum material became "soft" and the relief sagged inward causing the top ring groove to become quite a bit wider (and therefore top ring lost support in that area). As Fleecer stated, multi-mile or extended WOT is most likely the cause (and myself and the 2 other guys who own the TCats are retards LOL). The cooling system in this 998 was designed for 200 HP. That included thickness of head castings, coolant passages, oil sprayers at the bottom of piston, water pump, heat exchangers, etc. At 280+ HP and long multi-mile WOT pulls, IMO the engine is making so much more heat (than at 200HP stock level) the cooling in head (and possibly rest of system) cannot carry away enough heat to keep it cooled properly. The chances of deto goes up and up, the longer the pull is.
 
DMCTurbo said:
PEFI. He talks about it in another thread.


SledFreak, if you're referring to PEFI (Precision EFI) IMO the answer is NONE. At the end of this riding season I've seen and heard way too much evidence that the supposed premier PEFI Knock Protection system is non-existent or marginal at best. I'm in the process of doing complete engine rebuilds on 3 TCats (including mine) all w Stage 3 PEFI tunes. Granted sleds have about 6000 miles with this tune but all 3 have serious deto - enough for serious piston damage. Most of the time, these sleds have been run on 93 octane non-ethanol. Why didn't their great knock protection work as they advertise?
Everything possible was done to these 3 sleds to set them up for trouble-free 280HP riding. And I mean EVERYTHING. Every precaution to get best possible gas was taken always.
This is probably a totally different discussion but in some cases, pistons showed no damage from deto but they simply got too hot. The areas around the valve reliefs actually got so hot the aluminum material became "soft" and the relief sagged inward causing the top ring groove to become quite a bit wider (and therefore top ring lost support in that area). As Fleecer stated, multi-mile or extended WOT is most likely the cause (and myself and the 2 other guys who own the TCats are retards LOL). The cooling system in this 998 was designed for 200 HP. That included thickness of head castings, coolant passages, oil sprayers at the bottom of piston, water pump, heat exchangers, etc. At 280+ HP and long multi-mile WOT pulls, IMO the engine is making so much more heat (than at 200HP stock level) the cooling in head (and possibly rest of system) cannot carry away enough heat to keep it cooled properly. The chances of deto goes up and up, the longer the pull is.
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True in theory that 280HP should require more cooling.
But, when I was recently north, there was a stock Winder along and he was having far more overheating issues than I was. I was running stock muffler 250 power levels TD tuned.
If deto is happening, something is wrong with the mapping(fuel mixture or timing), or not enough octane.
Temperature is displayed on the dash, so if it starts to creep up to the higher end, I back off from those long pulls until conditions permit, which is usually loose snow.
 
We build a lot of engines throughout the year. Upwards of 50 or so. This gives us a certain insight into the market of flashing and how the respective engines are holding up as a result.
While I think that it’s common knowledge of how I feel about Bens character personally, I feel that the TD and Hurricane knock protection system saves a lot of engines. There has never been evidence of detention inside of any of the engines that we’ve serviced. This is why I will not lower the knock light sensitivity when some hurricane customers complain about the knock lights flashing. I will always strongly encourage them to get to the root of the cause rather then taking the easy road and lowering the sensitivity just to make them go away. Their engine is at stake!!
I sat on my dyno with Chris from Gap for days and 4 motors to make sure that we designed the absolute best knock protection system on the planet. That was 4 years ago now and our history provides the confirmation of that
Dave
 
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PEFI Stage 3 280HP. Same tune in the other 2 TCats that are toast.
 
PEFI is hands down JUNK! Anyone running it needs to inspect their engine with a bore scope camera and compression/leak down. The evidence is piling up against them. Most of the operators are well versed at the 'mod sled game' and we know what to look for. Really unfortunate. I am asking for a full refund on PEFI tunes from them, of which I am sure I will be ignored along with 7 others I know that lost motors. DO NOT BUY PEFI!!
 
kinger said:
PEFI is hands down JUNK! Anyone running it needs to inspect their engine with a bore scope camera and compression/leak down. The evidence is piling up against them. Most of the operators are well versed at the 'mod sled game' and we know what to look for. Really unfortunate. I am asking for a full refund on PEFI tunes from them, of which I am sure I will be ignored along with 7 others I know that lost motors. DO NOT BUY PEFI!!
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Do you feel this was the root cause of all your Sidewinder problems?
 
I have two sidewinders and one of them had the falling on its face issue. The other one has been perfect. Both sleds had the same set up from turbo dynamics. Took me two years to solve the issue because it was intermittent. And it usually only acted up at high altitude. After years of troubleshooting I finally purchased the turbo dynamics data log option for my gap flasher and found out my 3 bar map sensor was junk. Logger pointed me right in the direction of the sensor. I swapped it out with the one on my other sled and it worked perfect. Turbo dynamics replaced it for free after told them it was bad. Frustrating as hell trying to figure this issue out.
 
juwalantz said:
I have two sidewinders and one of them had the falling on its face issue. The other one has been perfect. Both sleds had the same set up from turbo dynamics. Took me two years to solve the issue because it was intermittent. And it usually only acted up at high altitude. After years of troubleshooting I finally purchased the turbo dynamics data log option for my gap flasher and found out my 3 bar map sensor was junk. Logger pointed me right in the direction of the sensor. I swapped it out with the one on my other sled and it worked perfect. Turbo dynamics replaced it for free after told them it was bad. Frustrating as hell trying to figure this issue out.
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When Data Logging what specific data indicated that the 3 bar map sensor was the culprit?
 
Well I actually didn’t find out from the logs themselves. There was an alert or an alarm of some sort when I logged into the gap flasher app. It was completely obvious. After I rode the sled with the logger running I connected my phone and if I remember correctly there was an alert on the bottom of the app that said boost sensor failure or no boost sensed it or something like that. Some sort of alarm or code or alert. It was last year so I’m foggy on the details. But It was so obvious that I went straight to my other sled and removed the boost sensor and swapped. I never even looked at my logs after the ride. I was just going to send them to turbo dynamics for analysis because I wouldn’t have a clue what to do with them. But since the map sensor swap worked I never sent them for analysis.
 
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