Is leading timing after trailing timing bad?
10-28-09, 09:20 AM
#26
Also on the EGT, on normal cruising speed when the AFR was between 13.5 and 15, the EGT was around 1500 to 1600 F. And when accelerating some, the AFR went to around 11 and the EGT's could go down to 1300 or 1250. The only thing was that there was most of the time a difference of as much as 150 degrees between the 2 rotors. I know that some difference is normal due to the geometry of the manifolds but I dont know if that was too much?
10-28-09, 02:39 PM
#28
Ok, to arghx, yes I have a wideband and even the Dual EGT gauges. I didnt see any strange readings or hesitation but I didnt drive the car much either. Also on the EGT, on normal cruising speed when the AFR was between 13.5 and 15, the EGT was around 1500 to 1600 F. And when accelerating some, the AFR went to around 11 and the EGT's could go down to 1300 or 1250. The only thing was that there was most of the time a difference of as much as 150 degrees between the 2 rotors. I know that some difference is normal due to the geometry of the manifolds but I dont know if that was too much?
Now for BNA ELLIS, the car has not been tuned after I picked it up. I drove it for less than 2 weeks and I was babying it just to make sure it was ok before I did anything crazy.
So yes, it was only chance that it didnt pop during the tuning session.
Now, the first time it DID pop during the tuning, but the installers said there was nothing wrong in the car and the builder said that it looked like a foreign object hit the apex seal because of the marks that it left inside.
Now I dont know anymore, it could have been just the tuning again
Well thanks for the help so far.
Leo
Now for BNA ELLIS, the car has not been tuned after I picked it up. I drove it for less than 2 weeks and I was babying it just to make sure it was ok before I did anything crazy.
So yes, it was only chance that it didnt pop during the tuning session.
Now, the first time it DID pop during the tuning, but the installers said there was nothing wrong in the car and the builder said that it looked like a foreign object hit the apex seal because of the marks that it left inside.
Now I dont know anymore, it could have been just the tuning again
Well thanks for the help so far.
Leo
"although its impossible to say for sure" you can make a confident bet that the tune caused the blown seal. There are tonnes of factors yes, but always, the most glaring one is the tune. Everything else can be fine, but if the tune isn't the engine won't be. If its a hardware problem, generally, you'll see sypmtoms outside of blown seals. Example - bad fuel pump. Does the pump work after the engine got fragged? If no, chances are it was the pump. See where I'm going with this?
From glancing at that map, it looks hack plain and simple. Nobody has been in there tweaking and adjusting much beyond a few basic items.
Get someone better next time. Best of luck.
Here is the tuning map...
10-29-09, 02:56 PM
#35
Well, its not too bad but there are some interesting spots. Can't really tell much from this but I'll post it anyway. The 3rd line is a little awkward but that would be high boost. At low boost some lines drop off more then others at high RPM. And some random jumps on other spots.
thewird
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10-29-09, 03:33 PM
#36
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The injector compensation map has fuel reduced. The injector base map has injector ms a little longer. The settings tab 3 has injectors reduced by 50 % even with the bigger injectors, on a half bridge single turbo that does not look like it's providing enough fuel. Although I don't know the fuel pressue etc, the fuel settings on that map don't add up.
rgds
Brian
10-30-09, 12:08 AM
#37
Fuel pressure I dont know exactly but originally long agowhen the car was being tuned the firt time, it ran out of fuel at around 17 or 18 PSI of boost so we had to add the second Supra pump.
(kinda strange because I had some known people here telling me that I could use just 1 supra pump for up to 20 PSI and almost 500 whp)
Anyway, so after the second pump they didn't have any more problems with pressure. If I remember correctly they said they were running up to 70 PSI on the fuel? Could that be ok?
But I dont know how stable the pressure was running all the way thru the RPM's. The short period that I drove it I didnt see any strange things on the Fuel pressure gauge but then again I wasnt paying that much attention to it compared to the boost, oil pressure or temperature.
I guess I didnt help much
(kinda strange because I had some known people here telling me that I could use just 1 supra pump for up to 20 PSI and almost 500 whp)
Anyway, so after the second pump they didn't have any more problems with pressure. If I remember correctly they said they were running up to 70 PSI on the fuel? Could that be ok?
But I dont know how stable the pressure was running all the way thru the RPM's. The short period that I drove it I didnt see any strange things on the Fuel pressure gauge but then again I wasnt paying that much attention to it compared to the boost, oil pressure or temperature.
I guess I didnt help much
10-30-09, 10:12 AM
#38
Dual pumps make a big difference in how much fuel the base map needs. Thats why it's important to never use someone else's map even if the setup is similar, too many variables that effect the amount of fuel that's actually delivered. You never know if someone else tuned with a clogged fuel filter or dirty injectors, or any number of other differences.
A single supra pump should be good if it was rewired, but it also depends on the fuel injector setup and the duty cycle they see. A typical rewired supra would flow just enough for 550/1680 at 80% duty and 20 psi of boost pressure with a standard base pressure. (About 430hp) If it was on stock wiring it would flow barely enough for the stock injectors at 80% duty and 20 psi boost. (about 300 HP) If they were running 70 psi base pressure, which I can't imagine why they would, thats pretty ridiculous... but it would quickly max out a single supra pump regardless of injectors, or duty, because the line pressure is so high. They probably were referring to 70 psi total from the pump (IE: 40 psi base, 15 psi pressure drop and 15 psi of boost pressure)
As far as the engine blowing... I would be leery of a tuner that already popped one of my engines, and if it happened again after I left I would pretty much figure it was him that did it the second time. As far as the engine builder saying it was foreign object... I can't imagine he could actually know that considering an apex seal was just bouncing around in there. Unless there was still a pebble in the engine when it was tore down I see no way of knowing for sure. Another thing about dyno's is they don't put as much load as the street does, so a safe tune on the dyno is not always safe on the road.
I didn't look at the map, but if the AFR's are what you say they were, then they sound safe, apparently the timing isn't extremely aggressive from what others are saying. Though the split sounds a little tight, it's not at extremely high boost before the aux injection kicks on. Is it possible the AI system wasn't flowing when it blew? Did you notice any high knock readings after leaving the tuner?
A single supra pump should be good if it was rewired, but it also depends on the fuel injector setup and the duty cycle they see. A typical rewired supra would flow just enough for 550/1680 at 80% duty and 20 psi of boost pressure with a standard base pressure. (About 430hp) If it was on stock wiring it would flow barely enough for the stock injectors at 80% duty and 20 psi boost. (about 300 HP) If they were running 70 psi base pressure, which I can't imagine why they would, thats pretty ridiculous... but it would quickly max out a single supra pump regardless of injectors, or duty, because the line pressure is so high. They probably were referring to 70 psi total from the pump (IE: 40 psi base, 15 psi pressure drop and 15 psi of boost pressure)
As far as the engine blowing... I would be leery of a tuner that already popped one of my engines, and if it happened again after I left I would pretty much figure it was him that did it the second time. As far as the engine builder saying it was foreign object... I can't imagine he could actually know that considering an apex seal was just bouncing around in there. Unless there was still a pebble in the engine when it was tore down I see no way of knowing for sure. Another thing about dyno's is they don't put as much load as the street does, so a safe tune on the dyno is not always safe on the road.
I didn't look at the map, but if the AFR's are what you say they were, then they sound safe, apparently the timing isn't extremely aggressive from what others are saying. Though the split sounds a little tight, it's not at extremely high boost before the aux injection kicks on. Is it possible the AI system wasn't flowing when it blew? Did you notice any high knock readings after leaving the tuner?
10-30-09, 11:34 AM
#39
Hi Dudemaaanownsanrx7, the car was not using the AI when it blew because I was on the low setting that goes up to only 12 PSI max and doesnt use the AI.
As for the 70 PSI pressure, yes it was at max boost when they were tuning. I guess I didnt explained correctly, sorry. Normally while driving, the pressure would be 40 PSI and would go up as soon as I pressed the accelerator, so it looked ok but I couldnt take a very close look since I barely used the car and was paying more attention to other parameters.
Also on the knocking part, this car for some reason always had very high readings on the knocking even since I bought the car before and never had a problem. It could go up to 100% knocking but I think it was a combination of loose parts, high noise from the drivetrain or chassis and an old knock sensor.
Now when I picked up the car, the knocking was still high ( around 30 to 60 or 70 % ) but lower than before the engine rebuild.
That is something I wouldn know if it was the sensor or actual knocking.
They always said that the car didnt have any actual knocking when tuning.
I already told them to change the knock sensor for a new one.
As for the duty cycle of the engine, it was much lower this time than when I originally bought the car. I dont think I saw anything above 50 % but I never saw it at full throttle on 3rd or 4th gear. But if I can interpolate from what the difference was before at lower speeds and higher speeds, I would say that it would stay on the 80's at the most now at full throttle.
Hope this helps a little.
Leo
As for the 70 PSI pressure, yes it was at max boost when they were tuning. I guess I didnt explained correctly, sorry. Normally while driving, the pressure would be 40 PSI and would go up as soon as I pressed the accelerator, so it looked ok but I couldnt take a very close look since I barely used the car and was paying more attention to other parameters.
Also on the knocking part, this car for some reason always had very high readings on the knocking even since I bought the car before and never had a problem. It could go up to 100% knocking but I think it was a combination of loose parts, high noise from the drivetrain or chassis and an old knock sensor.
Now when I picked up the car, the knocking was still high ( around 30 to 60 or 70 % ) but lower than before the engine rebuild.
That is something I wouldn know if it was the sensor or actual knocking.
They always said that the car didnt have any actual knocking when tuning.
I already told them to change the knock sensor for a new one.
As for the duty cycle of the engine, it was much lower this time than when I originally bought the car. I dont think I saw anything above 50 % but I never saw it at full throttle on 3rd or 4th gear. But if I can interpolate from what the difference was before at lower speeds and higher speeds, I would say that it would stay on the 80's at the most now at full throttle.
Hope this helps a little.
Leo
11-04-09, 07:37 PM
#41
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You didn't loose a vac line or anything did you? Like the manifold pressure reference to your fuel pressure regulator or maybe your MAP sensor?
It's pretty easy to just say it was the tune, but the timing isn't extreme, and you say your AFR was measured as good... I'd look elsewhere too and not just slam a new engine in there to blow that one too with a different tune.
What about your fuel system? 70 psi sounds screwy like maybe something isn't right, these aren't diesels.
Everything is good there for sure? If you manually bypass the fuel pump to make it run and put some regulated compressed air onto your regulator, do you see the fuel pressure ramp up and down the way it should? What about your pump wiring?
I'm not saying that it's not the tune, just that I haven't seen anything that's conclusive IMO. Haven't pulled up the file yet but initially it doesn't look like the tune is real far out or crazy terrible, like, blow your engine at 10psi crazy terrible. Especially if the AFR's were measured good.
I blew up my own brand new engine from an overboost because of poorly done boost control wiring done by the previous owner but at least there I had an idea of what system caused the problem, the overboost was obvious (I thought I caused it at first)... You really didn't notice anything at all when it went?
What were you doing exactly? Accelerating in a straight line from a stoplight? Were you idling for awhile before the acceleration run? What was the outside air temperature at the time? If you go in and do a Watch are all your temps moving around like they should be? Are your throttle body signals smooth and consistent?
It's pretty easy to just say it was the tune, but the timing isn't extreme, and you say your AFR was measured as good... I'd look elsewhere too and not just slam a new engine in there to blow that one too with a different tune.
What about your fuel system? 70 psi sounds screwy like maybe something isn't right, these aren't diesels.
Everything is good there for sure? If you manually bypass the fuel pump to make it run and put some regulated compressed air onto your regulator, do you see the fuel pressure ramp up and down the way it should? What about your pump wiring? I'm not saying that it's not the tune, just that I haven't seen anything that's conclusive IMO. Haven't pulled up the file yet but initially it doesn't look like the tune is real far out or crazy terrible, like, blow your engine at 10psi crazy terrible. Especially if the AFR's were measured good.
I blew up my own brand new engine from an overboost because of poorly done boost control wiring done by the previous owner but at least there I had an idea of what system caused the problem, the overboost was obvious (I thought I caused it at first)... You really didn't notice anything at all when it went?
What were you doing exactly? Accelerating in a straight line from a stoplight? Were you idling for awhile before the acceleration run? What was the outside air temperature at the time? If you go in and do a Watch are all your temps moving around like they should be? Are your throttle body signals smooth and consistent?
11-05-09, 01:27 AM
#43
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Actually, the map is way off if you take into the consideration of 50% fuel out of the PIM map. I suspect the base fuel pressure is around 55-60psi since there were fuel taking out in the vacuum area on the map.
You didn't loose a vac line or anything did you? Like the manifold pressure reference to your fuel pressure regulator or maybe your MAP sensor?
It's pretty easy to just say it was the tune, but the timing isn't extreme, and you say your AFR was measured as good... I'd look elsewhere too and not just slam a new engine in there to blow that one too with a different tune.
What about your fuel system? 70 psi sounds screwy like maybe something isn't right, these aren't diesels. Everything is good there for sure? If you manually bypass the fuel pump to make it run and put some regulated compressed air onto your regulator, do you see the fuel pressure ramp up and down the way it should? What about your pump wiring?
I'm not saying that it's not the tune, just that I haven't seen anything that's conclusive IMO. Haven't pulled up the file yet but initially it doesn't look like the tune is real far out or crazy terrible, like, blow your engine at 10psi crazy terrible. Especially if the AFR's were measured good.
I blew up my own brand new engine from an overboost because of poorly done boost control wiring done by the previous owner but at least there I had an idea of what system caused the problem, the overboost was obvious (I thought I caused it at first)... You really didn't notice anything at all when it went?
What were you doing exactly? Accelerating in a straight line from a stoplight? Were you idling for awhile before the acceleration run? What was the outside air temperature at the time? If you go in and do a Watch are all your temps moving around like they should be? Are your throttle body signals smooth and consistent?
It's pretty easy to just say it was the tune, but the timing isn't extreme, and you say your AFR was measured as good... I'd look elsewhere too and not just slam a new engine in there to blow that one too with a different tune.
What about your fuel system? 70 psi sounds screwy like maybe something isn't right, these aren't diesels.
Everything is good there for sure? If you manually bypass the fuel pump to make it run and put some regulated compressed air onto your regulator, do you see the fuel pressure ramp up and down the way it should? What about your pump wiring? I'm not saying that it's not the tune, just that I haven't seen anything that's conclusive IMO. Haven't pulled up the file yet but initially it doesn't look like the tune is real far out or crazy terrible, like, blow your engine at 10psi crazy terrible. Especially if the AFR's were measured good.
I blew up my own brand new engine from an overboost because of poorly done boost control wiring done by the previous owner but at least there I had an idea of what system caused the problem, the overboost was obvious (I thought I caused it at first)... You really didn't notice anything at all when it went?
What were you doing exactly? Accelerating in a straight line from a stoplight? Were you idling for awhile before the acceleration run? What was the outside air temperature at the time? If you go in and do a Watch are all your temps moving around like they should be? Are your throttle body signals smooth and consistent?
11-05-09, 10:34 PM
#44
I am sorry if I mislead you guys. I said that I remember them saying something about running out of fuel when tuning originally with the single pump at close to 70 PSI but don't know the exact amount ( that was at around 18 PSI ). And what I can remember when I was driving was a starting point of around 40 PSI but could have been close to 50 PSI since I didn't pay as much attention to that as to the other parts of the car.
Anyway, I checked the engine after that and I didn't see any disconnected vacuum lines, specially because I have read about them getting blown if they are not tight enough.
As for what was I doing at the moment, I was coming back from a 20 minute drive at a steady 65 MPH and driving very cautious since I had my daughter in the car. So then I wanted to see how fast was the car would generate full boost so I told my little girl to pay attention to the boost gauge and tell me when it reached 12 PSI (Low setting on the boost controller-No AI ). I started accelerating in 3rd gear from around 2000 RPM and as soon as she told me that I reached 12 PSI, I let go slightly and then tried to accelerate again but the car was already in 1 rotor.
The temperature outside was around 75 degrees so it was slightly warm. The engine temperature every time I checked was very close to 185.
As for the throttle signals, they felt as smooth as a Half bridge can feel, little harsh on low RPM and smooth after 2500 to 3000 RPM.
Hope this helps a little.
Leo
Anyway, I checked the engine after that and I didn't see any disconnected vacuum lines, specially because I have read about them getting blown if they are not tight enough.
As for what was I doing at the moment, I was coming back from a 20 minute drive at a steady 65 MPH and driving very cautious since I had my daughter in the car. So then I wanted to see how fast was the car would generate full boost so I told my little girl to pay attention to the boost gauge and tell me when it reached 12 PSI (Low setting on the boost controller-No AI ). I started accelerating in 3rd gear from around 2000 RPM and as soon as she told me that I reached 12 PSI, I let go slightly and then tried to accelerate again but the car was already in 1 rotor.
The temperature outside was around 75 degrees so it was slightly warm. The engine temperature every time I checked was very close to 185.
As for the throttle signals, they felt as smooth as a Half bridge can feel, little harsh on low RPM and smooth after 2500 to 3000 RPM.
Hope this helps a little.
Leo
11-06-09, 01:24 AM
#45
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I run negative split only for the idle area of the map becaase I run a full manual controlled idle without any ISC. This allows me to run leaner at idle which keeps my plugs clean.
11-06-09, 09:18 PM
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OP said wide band was reading good..and we don't know the base fuel pressure. Pump gas is pretty stable at 10psi and low 9's CR even on a rotary. But, you're probably right. Would make total sense if it was a first shot through the 10psi higher load/rpm calibration areas. I was putting too much weight on the fact that the OP said a/f looked good and looked at the shape of things, not hot, but not bad. Didn't look at the magnitudes.
Would be interesting to see what the base fuel pressure actually is.
11-07-09, 01:40 AM
#47
I will find out the base fuel pressure and get back to you guys. But it will have to wait until Monday unfortunately since they don't open on weekends.
Is there anything else ( besides the base fuel pressure and max fuel pressure at certain boost) that I can ask that could help here on this little investigation?
Thanks again for all you help.
Leo
Is there anything else ( besides the base fuel pressure and max fuel pressure at certain boost) that I can ask that could help here on this little investigation?
Thanks again for all you help.
Leo
11-08-09, 12:28 AM
#49
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I will find out the base fuel pressure and get back to you guys. But it will have to wait until Monday unfortunately since they don't open on weekends.
Is there anything else ( besides the base fuel pressure and max fuel pressure at certain boost) that I can ask that could help here on this little investigation?
Thanks again for all you help.
Leo
Is there anything else ( besides the base fuel pressure and max fuel pressure at certain boost) that I can ask that could help here on this little investigation?
Thanks again for all you help.
Leo
Standard fuel pressure regulators (FPR) add equal fuel pressure to manifold pressure increase. So if your base fuel is at say 40 psi, and you add 1 psi of boost, your FPR would be 41psi. If you go to 15 psi boost, you would expect to see:
40 base + 15 manifold = 55psi <---at your fuel rail
Basically the only thing the FPR is doing is keeping the pressure differential (Δ)
across the fuel injectors equal as you add/subtract pressure in the intake. Add 1 psi positive manifold pressure, add 1 psi fuel pressure, and so on.
11-08-09, 01:08 AM
#50
Unfortunately I don't have the car with me since it is at the shop and it is pretty far from me. But I am pretty sure I can get the information on Monday.
Yes I have the basic idea of how the FPR works but thanks for the info anyway. I am always happy to learn something new and there is always something interesting in every thread here.
Even though I know lots about Piston engines ( I used to work as a race car mechanic in my country) there is still so much to learn about Rotaries that it gets overwhelming sometimes, specially because since I haven't had my car for a year now so I can not practice anything in it.
Well hopefully someday soon I will finally have it back.
Thanks again for all the help guys.
Leo
Yes I have the basic idea of how the FPR works but thanks for the info anyway. I am always happy to learn something new
and there is always something interesting in every thread here.Even though I know lots about Piston engines ( I used to work as a race car mechanic in my country) there is still so much to learn about Rotaries that it gets overwhelming sometimes, specially because since I haven't had my car for a year now
so I can not practice anything in it.Well hopefully someday soon I will finally have it back.
Thanks again for all the help guys.
Leo