Borgwarner Twin Scroll 7670 With Dyno Graph
The engine didn't "blow up", saying that means it failed. Ben says the spark plugs burnt the ends off. That is a "tuning" issue. The problem for me is I tuned it and I know how soft the tune was that it left here with. I can say with complete certainty that it there is no way in hell it could burn the plugs off (detonate) with the tune I had in it, just not happening. 27 psi of boost peak falling to 22 psi, 9 degrees timing going up to 13 degrees on a decent sized turbo, big FMIC, great cams and E85, AFR's in the 11.7:1 range. That is not hurting an engine end of story. Knock control was set up very aggressive allowing the engine to add 15% fuel and pull 10 degrees of timing. I set this car up conservatively to make sure it was going to run a good long time.
Something changed. FPR hose blew off, double pumper somehow didn't trigger, tune was changed, turbo flows more than the last one..........I don't know. I do know the engine stayed together and there is no explanation for the tune to run two 20 minute sessions one week perfectly and then melt the plugs off in less than 10 laps.
I have offered to fix the car out of my pocket if Ben wants to bring it back here. I am beyond pissed off this has happened. I think the next time this car goes to the track I am going to arrange to be there.
Something changed. FPR hose blew off, double pumper somehow didn't trigger, tune was changed, turbo flows more than the last one..........I don't know. I do know the engine stayed together and there is no explanation for the tune to run two 20 minute sessions one week perfectly and then melt the plugs off in less than 10 laps.
I have offered to fix the car out of my pocket if Ben wants to bring it back here. I am beyond pissed off this has happened. I think the next time this car goes to the track I am going to arrange to be there.
Evolving Member
Joined: Apr 2008
Posts: 462
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From: New Zealand
One thing changed since Dave tuned it last... the turbocharger.
It's obvious that the turbocharger was damaged when you tuned it Dave. Explains the difference in the tune, the 2nd engine failure, the lack of response on your dyno (why the EFR spools slower in 4th gear than the HTA3076 did in 3rd gear), etc.
It's a shame eyecrometers don't accurately measure radial and axial shaft play.
I hope to see Ben's car out and running soon.
It's obvious that the turbocharger was damaged when you tuned it Dave. Explains the difference in the tune, the 2nd engine failure, the lack of response on your dyno (why the EFR spools slower in 4th gear than the HTA3076 did in 3rd gear), etc.
It's a shame eyecrometers don't accurately measure radial and axial shaft play.
I hope to see Ben's car out and running soon.
From having 30 years turbo experience, there is no such thing as slightly damaged turbo that would be down on power.
Last edited by R/TErnie; Nov 10, 2011 at 07:30 AM.
Evolving Member
Joined: Aug 2011
Posts: 210
Likes: 0
From: Earth
One thing changed since Dave tuned it last... the turbocharger.
It's obvious that the turbocharger was damaged when you tuned it Dave. Explains the difference in the tune, the 2nd engine failure, the lack of response on your dyno (why the EFR spools slower in 4th gear than the HTA3076 did in 3rd gear), etc.
It's a shame eyecrometers don't accurately measure radial and axial shaft play.
I hope to see Ben's car out and running soon.
It's obvious that the turbocharger was damaged when you tuned it Dave. Explains the difference in the tune, the 2nd engine failure, the lack of response on your dyno (why the EFR spools slower in 4th gear than the HTA3076 did in 3rd gear), etc.
It's a shame eyecrometers don't accurately measure radial and axial shaft play.
I hope to see Ben's car out and running soon.
x2
I feel so sorry for Ben man...
I know exactly how he feels! Ben you will see in the end everything is going to be just fine! Like we say down here in PR, a la tercera la vencida!!!
Good luck!
The car will be heading back to Buschur Racing within the next week or so. Here are some pics of the damaged 7670 for your viewing pleasure.
http://youtu.be/B7XQq5G7VCA
http://youtu.be/B7XQq5G7VCA
Newbie
Joined: Jul 2010
Posts: 27
Likes: 0
From: Europe
Looks like the exhaust wheel has more mechanical damage (broken-out parts of blades) then the compressor wheel.
Would it be logical to assume something went out the exhaust part of the engine, into the turbine, ate some turbine blades and that damage caused the bend shaft?
Something valve train related maybe broke off (valve guide piece or s/th like that?), further causing the engine failure later on with the 'new' turbo?
Would it be logical to assume something went out the exhaust part of the engine, into the turbine, ate some turbine blades and that damage caused the bend shaft?
Something valve train related maybe broke off (valve guide piece or s/th like that?), further causing the engine failure later on with the 'new' turbo?
Looks like the exhaust wheel has more mechanical damage (broken-out parts of blades) then the compressor wheel.
Would it be logical to assume something went out the exhaust part of the engine, into the turbine, ate some turbine blades and that damage caused the bend shaft?
Something valve train related maybe broke off (valve guide piece or s/th like that?), further causing the engine failure later on with the 'new' turbo?
Would it be logical to assume something went out the exhaust part of the engine, into the turbine, ate some turbine blades and that damage caused the bend shaft?
Something valve train related maybe broke off (valve guide piece or s/th like that?), further causing the engine failure later on with the 'new' turbo?