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998 engine rebuild

Trail 8 Michigan UP...many stretches 5 miles plus. Piston or kevlar alley, you pick!

I've ridden every inch of trail 8 from the Soo to Wakefield. Used to do backpack trips in the late 90's early 2000's. It's the only trail that runs through from East to West.
 

Ever try trail 41 down towards Jack pine? That’s know as piston alley, ok back on track. Flash you going with a different tune other that precision?
 
i had same thing happen with my 2020, its now getting stage 6 at TD, .. mine after a long run i shut dwn and was waitiing for group to catch up and i purked out some coolant, then after 10 min looked at tank and level showed ok... went for another long blast and temp showed 174 and then poped gasket... soo they are redoing whole engine just in case it over heated, i agree that the cooling system wont handle long hauls when at the higher tunes. these tend to get AIR locks in them and thats what i think mine did.
 
Nice. Are you going to run the same tune?
Haven't decided yet which tune. The questions in my head are:
1. Was it the tune or was it a combination of me (1-2 mile WOT!) and the other issues (2 of 3 injectors down 3.5%, gas level below 1/2 tank, stock fuel system maxed out, no octane booster, maybe got some bad gas on trail, head temps too hot, etc)?
2. Does anybody's deto protection work 100% of the time? Can it prevent all deto all the time?
3. Are the actions I've taken (ceramic domed pistons, smoothing sharp edges on pistons, upgraded fuel system, clean injectors, adding 10 micron high-flow fuel filter right before injector rail, no more 1-2 mile WOT!) enough to prevent future deto damage?
4. Would closed-loop tune have prevented this?
5. Given the latest TD octane recommendations, was the real issue just too low octane at 17.5 psi boost?

I have the summer to ponder and decide.
I am going to post some info I got from 2 of the major octane booster manufacturers on a separate thread.
 
Soo line in mn has quite a few stretches, but they are patrolling it now around isle.
 
Ever try trail 41 down towards Jack pine? That’s know as piston alley, ok back on track. Flash you going with a different tune other that precision?
Yes, that will take out any weak legged sled! Also I think it is 417 to marquette
 
Haven't decided yet which tune. The questions in my head are:
1. Was it the tune or was it a combination of me (1-2 mile WOT!) and the other issues (2 of 3 injectors down 3.5%, gas level below 1/2 tank, stock fuel system maxed out, no octane booster, maybe got some bad gas on trail, head temps too hot, etc)?
2. Does anybody's deto protection work 100% of the time? Can it prevent all deto all the time?
3. Are the actions I've taken (ceramic domed pistons, smoothing sharp edges on pistons, upgraded fuel system, clean injectors, adding 10 micron high-flow fuel filter right before injector rail, no more 1-2 mile WOT!) enough to prevent future deto damage?
4. Would closed-loop tune have prevented this?
5. Given the latest TD octane recommendations, was the real issue just too low octane at 17.5 psi boost?

I have the summer to ponder and decide.
I am going to post some info I got from 2 of the major octane booster manufacturers on a separate thread.

There has been a pile of Precision Tunes go down down lately. I don't think their knock protection works as well as it should. Would recommend upgrading fuel system as the stock one is really being pushed to the limit with these 17 plus psi tunes .
 
Haven't decided yet which tune. The questions in my head are:
1. Was it the tune or was it a combination of me (1-2 mile WOT!) and the other issues (2 of 3 injectors down 3.5%, gas level below 1/2 tank, stock fuel system maxed out, no octane booster, maybe got some bad gas on trail, head temps too hot, etc)?
2. Does anybody's deto protection work 100% of the time? Can it prevent all deto all the time?
3. Are the actions I've taken (ceramic domed pistons, smoothing sharp edges on pistons, upgraded fuel system, clean injectors, adding 10 micron high-flow fuel filter right before injector rail, no more 1-2 mile WOT!) enough to prevent future deto damage?
4. Would closed-loop tune have prevented this?
5. Given the latest TD octane recommendations, was the real issue just too low octane at 17.5 psi boost?

I have the summer to ponder and decide.
I am going to post some info I got from 2 of the major octane booster manufacturers on a separate thread.
If the tune is correctly mapped on the dyno with proper A/F, timing and fuel octane is followed accordingly, holding it for 5 miles wide open shouldn't be an issue.
 
The issue is the tune/ knock system. It doesnt work. If your going to do long pulls you need octane, theres no way around it. Turbos not that big and gets hot fast and without a huge giant intercooler keeping iat’s down the longer you hold it the bigger your need for high octane to control det. When a knock system works properly it will let you know that your octane isnt adequate for the current condition. A proper working knock system would of recieved feedback from the little listening device(aka knock sensor) that it was detecting very tiny amounts of non damaging knock and had the engine pull timing to control it from becoming damaging knock and when it got to the preset point (max allowable retard)determined by the tuner activated the knock lights to alert the driver. If this didnt occur then the knock protection isnt working. Weak fuel system or poor flowing injectors would make this knock system activate more frequently indicating a problem just like the sled I diagnosed this winter that had a weak fuel pump. The head was off my sled this winter for head studs and shim retainers. My pistons showed zero evidence of det with nearly 5000 miles being tuned from 200 miles with tunes ranging from 17.5-20.6psi. Theres only 1 tuner with a knock system in place thats frequently being questioned.
 
If the tune is correctly mapped on the dyno with proper A/F, timing and fuel octane is followed accordingly, holding it for 5 miles wide open shouldn't be an issue.
The BIG unknown for us guys is what's coming out of that gas pump handle when we pull in for gas. Is it 91 like it says? The tuners tune with gas that has a octane rating and the tune is created around THAT GAS.. If gas coming out of the pump IS the same as the tuners GAS then hold it tight should be doable for 5 miles..
 
The BIG unknown for us guys is what's coming out of that gas pump handle when we pull in for gas. Is it 91 like it says? The tuners tune with gas that has a octane rating and the tune is created around THAT GAS.. If gas coming out of the pump IS the same as the tuners GAS then hold it tight should be doable for 5 miles..
My ma used to say.... If Ifs were horses we’d all ride
 
The BIG unknown for us guys is what's coming out of that gas pump handle when we pull in for gas. Is it 91 like it says? The tuners tune with gas that has a octane rating and the tune is created around THAT GAS.. If gas coming out of the pump IS the same as the tuners GAS then hold it tight should be doable for 5 miles..
There was actually a study/investigation done on this years ago. The result was that there were in fact a few culprits selling premium fuel that was actually 87.
 


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