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Summit has some SBF forged pistons in stock. Most are 30 over, so you would need to bore. Obviously you will need to check reliefs, compression height, ring lands, etc, but there might be something you can use here.

Friends don't let friends run 5/64 cast rings in a boosted motor.
 

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Well from the looks of the top of the piston and the cracked ring landings. Detonation going on. What is estimated compression on this set up? Pump gas 91-93 octane? Driven all year round? Do they put 10% Ethanol in the pump gas for the winter blend in Phoenix? That's when problems start happening. Tuned good ran good in summer on pump gas with minimal ethanol then driven in winter with 10% Ethanol in the tank and not knowing detonation happened. At least would be my suspicion.
 

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Pimpxs. I'm only running 12° of timing and afr's of 10.8 to 11.0 at WOT. I don't lug the engine as a rule.
Supp man, sorry to hear about this, I've been following your build pretty closely because I have something similar, stock bottom, turbo, PIMPXS, and would like to learn from others (unfortunate) experiences.

I'm dialing in my tune right now and I see you might be a little too rich at WOT. Direct quote from stinger: "Your AFR target under boost should be 12.0:1 or richer, no leaner than 12.5 (low boost) and no richer than 11.5."

Don't want to pass any judgements on your tune, only you know what you're looking at on your tuning software, I just noticed your current parameters for target AFR are not what stinger recommends.

Also, do you run 93? The PIMP map is for 93 but "If you can only purchase 91 octane locally, you should start by pulling 1-2 degrees from the entire timing advance table." That's from stinger as well.
 

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Yeah, next time target 11.9 to 12.1 and read the plugs to get a nice ring at the base.

Sensor could have been off, 12* seems crazy low too, so double check true zero TDC.
 

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Supp man, sorry to hear about this, I've been following your build pretty closely because I have something similar, stock bottom, turbo, PIMPXS, and would like to learn from others (unfortunate) experiences.

I'm dialing in my tune right now and I see you might be a little too rich at WOT. Direct quote from stinger: "Your AFR target under boost should be 12.0:1 or richer, no leaner than 12.5 (low boost) and no richer than 11.5."

Don't want to pass any judgements on your tune, only you know what you're looking at on your tuning software, I just noticed your current parameters for target AFR are not what stinger recommends.

Also, do you run 93? The PIMP map is for 93 but "If you can only purchase 91 octane locally, you should start by pulling 1-2 degrees from the entire timing advance table." That's from stinger as well.
Being over fueled in turbo applications (or most others) alone won’t kill a ring land, just power.

If true wot timing under boost is 12* at less than 12psi, then your chances of killing something are small, even at 91 octane.

I’d double check the timing pointer to make sure the hub on the balancer is where it should be. Besides that, as long as actual timing is synced with the ecu then you’re good.
 

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Discussion Starter · #66 ·
Supp man, sorry to hear about this, I've been following your build pretty closely because I have something similar, stock bottom, turbo, PIMPXS, and would like to learn from others (unfortunate) experiences.

I'm dialing in my tune right now and I see you might be a little too rich at WOT. Direct quote from stinger: "Your AFR target under boost should be 12.0:1 or richer, no leaner than 12.5 (low boost) and no richer than 11.5."

Don't want to pass any judgements on your tune, only you know what you're looking at on your tuning software, I just noticed your current parameters for target AFR are not what stinger recommends.

Also, do you run 93? The PIMP map is for 93 but "If you can only purchase 91 octane locally, you should start by pulling 1-2 degrees from the entire timing advance table." That's from stinger as well.
Please read the whole thread. My tune is not finished. I'm creeping up on the timing and afr. Thanks for the advice just the same. (y)
 

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Discussion Starter · #67 ·
Being over fueled in turbo applications (or most others) alone won’t kill a ring land, just power.

If true wot timing under boost is 12* at less than 12psi, then your chances of killing something are small, even at 91 octane.

I’d double check the timing pointer to make sure the hub on the balancer is where it should be. Besides that, as long as actual timing is synced with the ecu then you’re good.
Timing is all good and synced. As you know; I was experiencing spark blowout at 5000rpm plus. I had just installed a MSD box and was able to finally hit WOT and hold it. Then the piston issue arose. This is why the WOT tune isn't dialed in. I can't wait to get back at it.
 

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I don't want to risk cracking another piston. It sucks pulling the turbo kit off and then the engine.
I made over 500 to the wheels on hyper pistons for years. Hyper pistons can handle a good amount of power as long as your tune is safe.
 

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Discussion Starter · #70 ·
I made over 500 to the wheels on hyper pistons for years. Hyper pistons can handle a good amount of power as long as your tune is safe.
I've had luck with them in the past. I suspect one of the rings butted. Just a guess but it happens. It looks like some kind of stress fracture.
 

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I've had luck with them in the past. I suspect one of the rings butted. Just a guess but it happens. It looks like some kind of stress fracture.
i would say your right.... looked like it to me... and if i were you, I'd be looking at a set of forged ones also. see if you can get a set ordered through mark and cross your fingers that they will come in sometime before next ice age... he def knows about piston and ring packages..
 

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Discussion Starter · #72 ·
i would say your right.... looked like it to me... and if i were you, I'd be looking at a set of forged ones also. see if you can get a set ordered through mark and cross your fingers that they will come in sometime before next ice age... he def knows about piston and ring packages..
I'm currently talking to Mark. I agree.
 

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I've had luck with them in the past. I suspect one of the rings butted. Just a guess but it happens. It looks like some kind of stress fracture.
Yeah that could be the cause but hard to tell for sure. You could put the rings in the bore and check end gap to see where they are gapped. If they are still .016ish that's probably where the problem was. With a stock bore .022 and .026 are where i would feel safe around 500whp.
 

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Discussion Starter · #75 ·
Yeah that could be the cause but hard to tell for sure. You could put the rings in the bore and check end gap to see where they are gapped. If they are still .016ish that's probably where the problem was. With a stock bore .022 and .026 are where i would feel safe around 500whp.
I suspect the rings have little wear at 53k miles. I'm sure the gaps are close to stock.
 

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Discussion Starter · #77 ·

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Yeah I missed that for sure. I know CHP bought Probe out years ago but I have the SRS pistons in both of my cars so I jumped the gun as that was a good price...for the obvious to me now reason.
 

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I'm currently talking to Mark. I agree.
back in the day i had a 1994 mustang that i first ran with a 200 shot... the factory hypers took the abuse.. then i got a good deal on an S trim supercharger.. worked like a champ at around 12 psi...
i then went to a gt40 p headed / intake combo... shorty headers... used the same S trim.. and boy oh boy was it quick.. or so i thought.. haha... i swapped to a tremec 3550 and honestly wasnt much faster than the stock setup with s trim ... but it spun the tires so much more...

then one day i got a deal on a whole lot of parts... trickflow intake.. trickflow heads.. 1 3/4 longtubes.. C4 transmission.. etc etc.. well when i went to put it on, i noticed a cracked ring land.... not horrible but pistons had to be replaced.. so i found a used set of forged foxbody pistons... slapped them in the motor with a crank kit from autozone... and buttoned it all together... on drag radials it was a low 10 second car... couldnt really tune it to it's full potential because the 42lb injectors were maxed out... but boy was it a fun car... i sold it to a guy and told him how to treat it... he didnt listen and blew it up the first weekend he owned it... snapped the crank on the first journal...
 

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I have a set of 8 stock rods/pistons that you can have (for the price of the ride from 55108).
I posted them on here some time ago and forgot about em.
One difference I see is that the "to front' notch is not the same as yours.
Just throwing it out there.

 
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