Borgwarner Twin Scroll 7670 With Dyno Graph
Here's my path of logic.
Dave tunes the engine with the previously damaged turbcharger on the car. It's rubbing on the housing or missing parts of the turbine wheel... or the CHRA has bits of steel in it. SOMETHING is wrong with the turbocharger evident by it's complete lack of response (4th gear spool is worse than the HTA76 in 3rd gear) That's a HUGE WAIVING RED FLAG.
You get the car, run it for 2 laps... turbo eats itself. You go get a new turbo and put it on... The new turbo A) spools up much faster and therefore runs through parts of the map Dave couldn't and didn't tune...and its more efficient and has more mass flow per psi of boost since it's not damaged. This causes the AFR's to go lean... maybe not SUPER lean, but lean enough to run your EGT's through the roof for extended track sessions.
You melt everything in your combustion chamber and send it through your new turbo. New turbo gets a UFO to meet with the TiAL turbine wheel, chips off a huge section of it, causes severe imbalance and bends the shaft.
Tough part about their FMEAs is determining which came first...the engine or the turbo. Pretty easy to follow which one killed what in Leet's case though.
Looks like leet needs a new engine, new turbo, and a tuner who can check your logs and make adjustments to the tune trackside. Since you race in California... RRE or Church seem like great options.
Dave tunes the engine with the previously damaged turbcharger on the car. It's rubbing on the housing or missing parts of the turbine wheel... or the CHRA has bits of steel in it. SOMETHING is wrong with the turbocharger evident by it's complete lack of response (4th gear spool is worse than the HTA76 in 3rd gear) That's a HUGE WAIVING RED FLAG.
You get the car, run it for 2 laps... turbo eats itself. You go get a new turbo and put it on... The new turbo A) spools up much faster and therefore runs through parts of the map Dave couldn't and didn't tune...and its more efficient and has more mass flow per psi of boost since it's not damaged. This causes the AFR's to go lean... maybe not SUPER lean, but lean enough to run your EGT's through the roof for extended track sessions.
You melt everything in your combustion chamber and send it through your new turbo. New turbo gets a UFO to meet with the TiAL turbine wheel, chips off a huge section of it, causes severe imbalance and bends the shaft.
Tough part about their FMEAs is determining which came first...the engine or the turbo. Pretty easy to follow which one killed what in Leet's case though.
Looks like leet needs a new engine, new turbo, and a tuner who can check your logs and make adjustments to the tune trackside. Since you race in California... RRE or Church seem like great options.
First I am fairly certain the video and pics Ben posted are of the first turbo that was damaged. As far as anyone knows right now the new turbo is still on the car and is in good working order. So the engine did not take out the turbo as the engine had the melt down on the new turbo that is still on the car.
Second, I am committing myself to being at his next track event, even if I have to fly to California to do it. I saw the map that was in the car, the car needs me to tune it.
Here's my path of logic.
Dave tunes the engine with the previously damaged turbcharger on the car. It's rubbing on the housing or missing parts of the turbine wheel... or the CHRA has bits of steel in it. SOMETHING is wrong with the turbocharger evident by it's complete lack of response (4th gear spool is worse than the HTA76 in 3rd gear) That's a HUGE WAIVING RED FLAG.
You get the car, run it for 2 laps... turbo eats itself. You go get a new turbo and put it on... The new turbo A) spools up much faster and therefore runs through parts of the map Dave couldn't and didn't tune...and its more efficient and has more mass flow per psi of boost since it's not damaged. This causes the AFR's to go lean... maybe not SUPER lean, but lean enough to run your EGT's through the roof for extended track sessions.
You melt everything in your combustion chamber and send it through your new turbo. New turbo gets a UFO to meet with the TiAL turbine wheel, chips off a huge section of it, causes severe imbalance and bends the shaft.
Tough part about their FMEAs is determining which came first...the engine or the turbo. Pretty easy to follow which one killed what in Leet's case though.
Looks like leet needs a new engine, new turbo, and a tuner who can check your logs and make adjustments to the tune trackside. Since you race in California... RRE or Church seem like great options.
Dave tunes the engine with the previously damaged turbcharger on the car. It's rubbing on the housing or missing parts of the turbine wheel... or the CHRA has bits of steel in it. SOMETHING is wrong with the turbocharger evident by it's complete lack of response (4th gear spool is worse than the HTA76 in 3rd gear) That's a HUGE WAIVING RED FLAG.
You get the car, run it for 2 laps... turbo eats itself. You go get a new turbo and put it on... The new turbo A) spools up much faster and therefore runs through parts of the map Dave couldn't and didn't tune...and its more efficient and has more mass flow per psi of boost since it's not damaged. This causes the AFR's to go lean... maybe not SUPER lean, but lean enough to run your EGT's through the roof for extended track sessions.
You melt everything in your combustion chamber and send it through your new turbo. New turbo gets a UFO to meet with the TiAL turbine wheel, chips off a huge section of it, causes severe imbalance and bends the shaft.
Tough part about their FMEAs is determining which came first...the engine or the turbo. Pretty easy to follow which one killed what in Leet's case though.
Looks like leet needs a new engine, new turbo, and a tuner who can check your logs and make adjustments to the tune trackside. Since you race in California... RRE or Church seem like great options.
Here's my path of logic.
Dave tunes the engine with the previously damaged turbcharger on the car. It's rubbing on the housing or missing parts of the turbine wheel... or the CHRA has bits of steel in it. SOMETHING is wrong with the turbocharger evident by it's complete lack of response (4th gear spool is worse than the HTA76 in 3rd gear) That's a HUGE WAIVING RED FLAG.
You get the car, run it for 2 laps... turbo eats itself. You go get a new turbo and put it on... The new turbo A) spools up much faster and therefore runs through parts of the map Dave couldn't and didn't tune...and its more efficient and has more mass flow per psi of boost since it's not damaged. This causes the AFR's to go lean... maybe not SUPER lean, but lean enough to run your EGT's through the roof for extended track sessions.
You melt everything in your combustion chamber and send it through your new turbo. New turbo gets a UFO to meet with the TiAL turbine wheel, chips off a huge section of it, causes severe imbalance and bends the shaft.
Tough part about their FMEAs is determining which came first...the engine or the turbo. Pretty easy to follow which one killed what in Leet's case though.
Looks like leet needs a new engine, new turbo, and a tuner who can check your logs and make adjustments to the tune trackside. Since you race in California... RRE or Church seem like great options.
Dave tunes the engine with the previously damaged turbcharger on the car. It's rubbing on the housing or missing parts of the turbine wheel... or the CHRA has bits of steel in it. SOMETHING is wrong with the turbocharger evident by it's complete lack of response (4th gear spool is worse than the HTA76 in 3rd gear) That's a HUGE WAIVING RED FLAG.
You get the car, run it for 2 laps... turbo eats itself. You go get a new turbo and put it on... The new turbo A) spools up much faster and therefore runs through parts of the map Dave couldn't and didn't tune...and its more efficient and has more mass flow per psi of boost since it's not damaged. This causes the AFR's to go lean... maybe not SUPER lean, but lean enough to run your EGT's through the roof for extended track sessions.
You melt everything in your combustion chamber and send it through your new turbo. New turbo gets a UFO to meet with the TiAL turbine wheel, chips off a huge section of it, causes severe imbalance and bends the shaft.
Tough part about their FMEAs is determining which came first...the engine or the turbo. Pretty easy to follow which one killed what in Leet's case though.
Looks like leet needs a new engine, new turbo, and a tuner who can check your logs and make adjustments to the tune trackside. Since you race in California... RRE or Church seem like great options.
It wouldn't surprise me if the chewed up turbine wheel left pieces in the intake track. Causing maybe a sticking valve or the like, taking out the engine. But an even better guess is more simple than that. like something failing in the fuel system causing car to go lean.
Last edited by 94AWDcoupe; Nov 10, 2011 at 03:44 PM.
Sorry I confused the 2nd turbo with the first. The concept stays the same.
First engine failure caused first turbo to fail.
NEW turbo causes new engine to fail.
2nd turbo condition unknown.
New combination should be... BW inspected 2nd turbo or new 3rd turbo... and new 3rd engine. Tuned on a dyno in 3rd, 4th, and 5th. Then when it goes to the track; each log should be pulled and analyzed after each session.
I'm sure Dave didn't measure radial or axial shaft play with a dial indicator...and I'm sure he didn't know what to expect anyway. Dave can't examine the inside of the CHRA.... so your visual inspection only goes so far. (not very far)
First engine failure caused first turbo to fail.
NEW turbo causes new engine to fail.
2nd turbo condition unknown.
New combination should be... BW inspected 2nd turbo or new 3rd turbo... and new 3rd engine. Tuned on a dyno in 3rd, 4th, and 5th. Then when it goes to the track; each log should be pulled and analyzed after each session.
I'm sure Dave didn't measure radial or axial shaft play with a dial indicator...and I'm sure he didn't know what to expect anyway. Dave can't examine the inside of the CHRA.... so your visual inspection only goes so far. (not very far)
Last edited by R/TErnie; Nov 10, 2011 at 03:13 PM.
Since you kinda covered it all I quoted you.
First I am fairly certain the video and pics Ben posted are of the first turbo that was damaged. As far as anyone knows right now the new turbo is still on the car and is in good working order. So the engine did not take out the turbo as the engine had the melt down on the new turbo that is still on the car.
Second, I am committing myself to being at his next track event, even if I have to fly to California to do it. I saw the map that was in the car, the car needs me to tune it.
First I am fairly certain the video and pics Ben posted are of the first turbo that was damaged. As far as anyone knows right now the new turbo is still on the car and is in good working order. So the engine did not take out the turbo as the engine had the melt down on the new turbo that is still on the car.
Second, I am committing myself to being at his next track event, even if I have to fly to California to do it. I saw the map that was in the car, the car needs me to tune it.
Aaron
That aside, sorry to hear about yet another failure.
I'm with R/T Ernie though, you can definitely have a mildly damaged turbo that still works for a while. I had a turbo with a half broken thrust bearing. Still made reasonable levels of boost, but made all kinds of bad noises. It was perfectly fine the day before though when the damage actually happened. Friends have chipped compressor wheels and still made 800+ HP on GT42Rs. Not just little chips, 1/4" sections of blades missing... Hell, my old GT2871R ate an EGT probe and it managed to make decent power and never made a noise even with a couple chunks of turbine wheel missing and several others bent to hell.
I would bet there was damage done to the first turbo from the first engine failure and it lead to a tune that didn't work with a good turbo.
Also, the first turbo was an old unit, if I'm not mistaken. Maybe they had some tolerance issues. I've seen a compressor cover that was machined a few thousands off cost a 700HP car 80 HP. A simple compressor cover change (same type) literally picked up 80WHP and had a massive impact on the tune.
Resonance is going to be dependent on the space between the bearings, the length of the shaft, the mass of the wheels, and the materials. These things will change slightly due to manufacturing tolerances, but the turbo is going to reach a resonant speed within a known range.
That aside, sorry to hear about yet another failure.
I'm with R/T Ernie though, you can definitely have a mildly damaged turbo that still works for a while. I had a turbo with a half broken thrust bearing. Still made reasonable levels of boost, but made all kinds of bad noises. It was perfectly fine the day before though when the damage actually happened. Friends have chipped compressor wheels and still made 800+ HP on GT42Rs. Not just little chips, 1/4" sections of blades missing... Hell, my old GT2871R ate an EGT probe and it managed to make decent power and never made a noise even with a couple chunks of turbine wheel missing and several others bent to hell.
I would bet there was damage done to the first turbo from the first engine failure and it lead to a tune that didn't work with a good turbo.
Also, the first turbo was an old unit, if I'm not mistaken. Maybe they had some tolerance issues. I've seen a compressor cover that was machined a few thousands off cost a 700HP car 80 HP. A simple compressor cover change (same type) literally picked up 80WHP and had a massive impact on the tune.
That aside, sorry to hear about yet another failure.
I'm with R/T Ernie though, you can definitely have a mildly damaged turbo that still works for a while. I had a turbo with a half broken thrust bearing. Still made reasonable levels of boost, but made all kinds of bad noises. It was perfectly fine the day before though when the damage actually happened. Friends have chipped compressor wheels and still made 800+ HP on GT42Rs. Not just little chips, 1/4" sections of blades missing... Hell, my old GT2871R ate an EGT probe and it managed to make decent power and never made a noise even with a couple chunks of turbine wheel missing and several others bent to hell.
I would bet there was damage done to the first turbo from the first engine failure and it lead to a tune that didn't work with a good turbo.
Also, the first turbo was an old unit, if I'm not mistaken. Maybe they had some tolerance issues. I've seen a compressor cover that was machined a few thousands off cost a 700HP car 80 HP. A simple compressor cover change (same type) literally picked up 80WHP and had a massive impact on the tune.
Last edited by n2oiroc; Nov 12, 2011 at 06:52 PM.
This is like a Shakespearean tragedy. Road Racing is not for the faint of wallet, it will find the things to break or rattle loose. Hopefully things get better, best of luck.
No, we didn't measure anything with a dial indicator. We glanced into the turbo, checked out what it looked like, sprayed cleaner through the top and out the bottom to try to wash any possible bearing debris in the turbo out the bottom (this is what we do to all turbo's that come in with an engine with bearing problems-and it works). Could we have missed a slight wobble in the shaft? I suppose so. I think it's all pretty moot.
The car is being shipped back here, I am going to fix it all out of my pocket. We will decide what is going to happen to the turbo/turbo kit when it is here and I will tune the car again. Then when it goes to the track again I will fly/drive there to tune it at the track to make sure all is good.
I agree, something in the fuel system could have caused this, I asked Ben to check the vacuum line on the FPR and the relay/double pumper but I didn't hear anything back.
The car is being shipped back here, I am going to fix it all out of my pocket. We will decide what is going to happen to the turbo/turbo kit when it is here and I will tune the car again. Then when it goes to the track again I will fly/drive there to tune it at the track to make sure all is good.
I agree, something in the fuel system could have caused this, I asked Ben to check the vacuum line on the FPR and the relay/double pumper but I didn't hear anything back.
No, we didn't measure anything with a dial indicator. We glanced into the turbo, checked out what it looked like, sprayed cleaner through the top and out the bottom to try to wash any possible bearing debris in the turbo out the bottom (this is what we do to all turbo's that come in with an engine with bearing problems-and it works). Could we have missed a slight wobble in the shaft? I suppose so. I think it's all pretty moot.
The car is being shipped back here, I am going to fix it all out of my pocket. We will decide what is going to happen to the turbo/turbo kit when it is here and I will tune the car again. Then when it goes to the track again I will fly/drive there to tune it at the track to make sure all is good.
I agree, something in the fuel system could have caused this, I asked Ben to check the vacuum line on the FPR and the relay/double pumper but I didn't hear anything back.
The car is being shipped back here, I am going to fix it all out of my pocket. We will decide what is going to happen to the turbo/turbo kit when it is here and I will tune the car again. Then when it goes to the track again I will fly/drive there to tune it at the track to make sure all is good.
I agree, something in the fuel system could have caused this, I asked Ben to check the vacuum line on the FPR and the relay/double pumper but I didn't hear anything back.
Evolved Member
Joined: Jun 2004
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From: KL,Malaysia
No, we didn't measure anything with a dial indicator. We glanced into the turbo, checked out what it looked like, sprayed cleaner through the top and out the bottom to try to wash any possible bearing debris in the turbo out the bottom (this is what we do to all turbo's that come in with an engine with bearing problems-and it works). Could we have missed a slight wobble in the shaft? I suppose so. I think it's all pretty moot.
The car is being shipped back here, I am going to fix it all out of my pocket. We will decide what is going to happen to the turbo/turbo kit when it is here and I will tune the car again. Then when it goes to the track again I will fly/drive there to tune it at the track to make sure all is good.
I agree, something in the fuel system could have caused this, I asked Ben to check the vacuum line on the FPR and the relay/double pumper but I didn't hear anything back.
The car is being shipped back here, I am going to fix it all out of my pocket. We will decide what is going to happen to the turbo/turbo kit when it is here and I will tune the car again. Then when it goes to the track again I will fly/drive there to tune it at the track to make sure all is good.
I agree, something in the fuel system could have caused this, I asked Ben to check the vacuum line on the FPR and the relay/double pumper but I didn't hear anything back.
Here's a
to you
Evolving Member
Joined: Aug 2011
Posts: 210
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From: Earth
No, we didn't measure anything with a dial indicator. We glanced into the turbo, checked out what it looked like, sprayed cleaner through the top and out the bottom to try to wash any possible bearing debris in the turbo out the bottom (this is what we do to all turbo's that come in with an engine with bearing problems-and it works). Could we have missed a slight wobble in the shaft? I suppose so. I think it's all pretty moot.
The car is being shipped back here, I am going to fix it all out of my pocket. We will decide what is going to happen to the turbo/turbo kit when it is here and I will tune the car again. Then when it goes to the track again I will fly/drive there to tune it at the track to make sure all is good.
I agree, something in the fuel system could have caused this, I asked Ben to check the vacuum line on the FPR and the relay/double pumper but I didn't hear anything back.
The car is being shipped back here, I am going to fix it all out of my pocket. We will decide what is going to happen to the turbo/turbo kit when it is here and I will tune the car again. Then when it goes to the track again I will fly/drive there to tune it at the track to make sure all is good.
I agree, something in the fuel system could have caused this, I asked Ben to check the vacuum line on the FPR and the relay/double pumper but I didn't hear anything back.
Adios amigo! lol! I see it coming...