Blew stock pistons twice on twin turbo LS2 with low boost-- Please look at my tune!
12-21-2012, 10:26 AM
#23
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I think for now I will leave the tuner anonymous, in respect to give him the opportunity to do something to attempt to resolve the issue. I believe I paid around $850 on this tune if I'm not mistaken, and that alone is a lot of money to spend to end up with a blown engine within weeks after the initial tune.
To give a little more insight on this situation, this tuner has always somewhat bragged about how he spends several days working on a tune, and does a bit of actual street driving after tuning on the dyno to make sure that everything is perfect. The night I picked the car up after he spent several days with it at his shop I immediately noticed on the way home that the transmission would not upshift into ANY gear at full throttle. I surely would have though he would have noticed this, no???
I brought the car back to him roughly a week or two later and had him look over the tune. He made some adjustments to who knows what, I took the car down the street for a drive, and same problem. He adjusted the tune again followed by me taking the car back down the street again several more times over the course of probably 1-1.5 hours, and nothing he adjusted seemed to resolve the issue. He decided that the only thing that could be wrong is the brand new Performabuilt Level II transmission that had just been installed 2k miles ago and was running EXCELLENT at the track and on the street wtih 508 RWHP from his previous dyno he did to the car when it still had the Magnacharger (prior to the twin turbo build). It wasn't until probably almost a year and 2k miles later, after having the turbo setup fabricated that I brought him the car back to do the turbo tune that it suddenly wouldn't upshift.
After the enlisting some friends to help determine the issue we did some testing that involved a few WOT highway runs and that's when the engine blew the first time. I rebuilt the engine, took it to another friend with HP Tuners, and that's when we found that the upshift RPM and RPM limit were both set to 6500. We dialed the upshift RPM down around 6100 or 6200, as I recall, and no more upshift problems. A few weeks later I'm doing probably my 3rd or 4th short highway pull since fixing the upshift problem and that's when it blew for the second time. This time, the transmission issues obviously can't be to blame. There were obviously transmission tuning issues the first time it blew, but from what others have advised me, hitting the rev limit briefly when the transmission did not upshift at 6,500 RPM should not have been the cause of the engine to blow the first time.
What do you guys think? Thanks again!
-Andrew
To give a little more insight on this situation, this tuner has always somewhat bragged about how he spends several days working on a tune, and does a bit of actual street driving after tuning on the dyno to make sure that everything is perfect. The night I picked the car up after he spent several days with it at his shop I immediately noticed on the way home that the transmission would not upshift into ANY gear at full throttle. I surely would have though he would have noticed this, no???
I brought the car back to him roughly a week or two later and had him look over the tune. He made some adjustments to who knows what, I took the car down the street for a drive, and same problem. He adjusted the tune again followed by me taking the car back down the street again several more times over the course of probably 1-1.5 hours, and nothing he adjusted seemed to resolve the issue. He decided that the only thing that could be wrong is the brand new Performabuilt Level II transmission that had just been installed 2k miles ago and was running EXCELLENT at the track and on the street wtih 508 RWHP from his previous dyno he did to the car when it still had the Magnacharger (prior to the twin turbo build). It wasn't until probably almost a year and 2k miles later, after having the turbo setup fabricated that I brought him the car back to do the turbo tune that it suddenly wouldn't upshift.
After the enlisting some friends to help determine the issue we did some testing that involved a few WOT highway runs and that's when the engine blew the first time. I rebuilt the engine, took it to another friend with HP Tuners, and that's when we found that the upshift RPM and RPM limit were both set to 6500. We dialed the upshift RPM down around 6100 or 6200, as I recall, and no more upshift problems. A few weeks later I'm doing probably my 3rd or 4th short highway pull since fixing the upshift problem and that's when it blew for the second time. This time, the transmission issues obviously can't be to blame. There were obviously transmission tuning issues the first time it blew, but from what others have advised me, hitting the rev limit briefly when the transmission did not upshift at 6,500 RPM should not have been the cause of the engine to blow the first time.
What do you guys think? Thanks again!
-Andrew
12-21-2012, 11:00 AM
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Your making 600+ rwhp, on 93 octane pump gas with twins, on a STOCK ls2 shortblock (NON forged pistons obviously) and at wot your tuner has 22 degrees of timing? while you have No meth? no race fuel mix? not even a water 2 air incooler??
Not good at all my friend. I'm pretty sure its a combo of the timing and the amount of heat your building up during those long highway pulls. without some type of cooling of the charge (other then ambient air) that's just, well , "a blown up engine" waiting to happen, again.
Dyno pulls are short and sweet, and depending on the dyno , can actually deceive you into being "able" to run more timing then real life street use. but that's another thread.
Also i curious as to if there might be any cross confusion in some tables, pulling an EFIlive tune of with HPtuners. might not be issues but something to keep in mind.
Not good at all my friend. I'm pretty sure its a combo of the timing and the amount of heat your building up during those long highway pulls. without some type of cooling of the charge (other then ambient air) that's just, well , "a blown up engine" waiting to happen, again.
Dyno pulls are short and sweet, and depending on the dyno , can actually deceive you into being "able" to run more timing then real life street use. but that's another thread.
Also i curious as to if there might be any cross confusion in some tables, pulling an EFIlive tune of with HPtuners. might not be issues but something to keep in mind.
12-21-2012, 11:11 AM
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Your making 600+ rwhp, on 93 octane pump gas with twins, on a STOCK ls2 shortblock (NON forged pistons obviously) and at wot your tuner has 22 degrees of timing? while you have No meth? no race fuel mix? not even a water 2 air incooler??
Not good at all my friend. I'm pretty sure its a combo of the timing and the amount of heat your building up during those long highway pulls. without some type of cooling of the charge (other then ambient air) that's just, well , "a blown up engine" waiting to happen, again.
Dyno pulls are short and sweet, and depending on the dyno , can actually deceive you into being "able" to run more timing then real life street use. but that's another thread.
Also i curious as to if there might be any cross confusion in some tables, pulling an EFIlive tune of with HPtuners. might not be issues but something to keep in mind.
Not good at all my friend. I'm pretty sure its a combo of the timing and the amount of heat your building up during those long highway pulls. without some type of cooling of the charge (other then ambient air) that's just, well , "a blown up engine" waiting to happen, again.
Dyno pulls are short and sweet, and depending on the dyno , can actually deceive you into being "able" to run more timing then real life street use. but that's another thread.
Also i curious as to if there might be any cross confusion in some tables, pulling an EFIlive tune of with HPtuners. might not be issues but something to keep in mind.
12-21-2012, 01:12 PM
#26
Sounds like the tuner didn't know what he was doing.... I recommend methanol on every forced induction street car I touch that still runs 93 in the fuel tank. Cooler charge temps and more octane that is boost referenced and is alot cheaper in the long run compared to buying race gas.
I have some HPT datalogs of a magnacharged LS2 on 8.5-9psi that has one of my camshafts in it running a max of 13* on pump gas alone and dyno pulls and plug checks to prove thats all it liked (dyno dynamics loaded dyno) if that info would help you any. Now I know every car is different and will like different things but seeing as this was a stock LS2 longblock with a cam and a blower on 8.5-9psi it's not gonna be 9* timing different! You'll find out alot of LS2's don't like but ~24* in NA form much less 22* with 8psi.
I have some HPT datalogs of a magnacharged LS2 on 8.5-9psi that has one of my camshafts in it running a max of 13* on pump gas alone and dyno pulls and plug checks to prove thats all it liked (dyno dynamics loaded dyno) if that info would help you any. Now I know every car is different and will like different things but seeing as this was a stock LS2 longblock with a cam and a blower on 8.5-9psi it's not gonna be 9* timing different! You'll find out alot of LS2's don't like but ~24* in NA form much less 22* with 8psi.
12-21-2012, 02:13 PM
#27
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Sounds like the tuner didn't know what he was doing.... I recommend methanol on every forced induction street car I touch that still runs 93 in the fuel tank. Cooler charge temps and more octane that is boost referenced and is alot cheaper in the long run compared to buying race gas.
I have some HPT datalogs of a magnacharged LS2 on 8.5-9psi that has one of my camshafts in it running a max of 13* on pump gas alone and dyno pulls and plug checks to prove thats all it liked (dyno dynamics loaded dyno) if that info would help you any. Now I know every car is different and will like different things but seeing as this was a stock LS2 longblock with a cam and a blower on 8.5-9psi it's not gonna be 9* timing different! You'll find out alot of LS2's don't like but ~24* in NA form much less 22* with 8psi.
I have some HPT datalogs of a magnacharged LS2 on 8.5-9psi that has one of my camshafts in it running a max of 13* on pump gas alone and dyno pulls and plug checks to prove thats all it liked (dyno dynamics loaded dyno) if that info would help you any. Now I know every car is different and will like different things but seeing as this was a stock LS2 longblock with a cam and a blower on 8.5-9psi it's not gonna be 9* timing different! You'll find out alot of LS2's don't like but ~24* in NA form much less 22* with 8psi.
My opinion is, theres too much timing by about 7-10 degrees and we need a data log showing afr's to go further.
12-22-2012, 10:53 AM
#28
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Is it too late to do datalogging for this now that there are some blown pistons? Like I've said, the engine still runs and is driveable, I just don't know if I can get worthy/useful results at this point or not.
12-22-2012, 12:07 PM
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I wouldn't beat on the thing if it has engine problems. You'll risk grenading the entire motor and won't have as much to salvage from the motor. Post the tune file and I can tell if that's the issue or not.
12-22-2012, 12:37 PM
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Thanks for the info James. The tune file is in the very first post in this thread. I'd definitely appreciate you feedback on it!
Last edited by MEAN GTO; 12-23-2012 at 08:45 AM.
12-26-2012, 10:27 PM
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After looking at the tune I can say that it is the reason why you have went through two motors. The VE table has portions that are stock and being a boosted car should disable below an RPM that boost could actually be built because the stock VE tables do not read above atmouspheric pressure therefor cannot add fuel. The MAF table is stock and for fuel the only thing changed is the injector flow rate. All the other injector constants are stock. PE is an absolute wreck commanding mid 12's or leaner up to 3500rpm. Knock sensor recovery is 15x the stock value, which is basically how fast timing is added back in after knock is detected and timing pulled. Way too much timing especially down low and around peak torque.
Find a new tuner!
Find a new tuner!
12-26-2012, 11:23 PM
#34
After looking at the tune I can say that it is the reason why you have went through two motors. The VE table has portions that are stock and being a boosted car should disable below an RPM that boost could actually be built because the stock VE tables do not read above atmouspheric pressure therefor cannot add fuel. The MAF table is stock and for fuel the only thing changed is the injector flow rate. All the other injector constants are stock. PE is an absolute wreck commanding mid 12's or leaner up to 3500rpm. Knock sensor recovery is 15x the stock value, which is basically how fast timing is added back in after knock is detected and timing pulled. Way too much timing especially down low and around peak torque.
12-27-2012, 06:37 AM
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After looking at the tune I can say that it is the reason why you have went through two motors. The VE table has portions that are stock and being a boosted car should disable below an RPM that boost could actually be built because the stock VE tables do not read above atmouspheric pressure therefor cannot add fuel. The MAF table is stock and for fuel the only thing changed is the injector flow rate. All the other injector constants are stock. PE is an absolute wreck commanding mid 12's or leaner up to 3500rpm. Knock sensor recovery is 15x the stock value, which is basically how fast timing is added back in after knock is detected and timing pulled. Way too much timing especially down low and around peak torque.
Find a new tuner!
Find a new tuner!
12-28-2012, 01:28 PM
#40
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I was convinced by the shop that tuned the vehicle that the transmission was what was causing the engine to not upshift-- the tuner claimed that it wasn't holding to the power. I put the engine back together the less expensive way, so I could go back to determining the actual problem before I spent the money in the wrong area. I could've spent $5,000 on building a new engine, and another $3-4,000 on an even beefier transmission all to find out that the problem has been in the tune all along. Now, you tell me why it would have been smart for me to have gone on any person's gut instinct instead of determining the actual problem first before blowing up a much more expensive, new engine
