log of 28 pounds of boost.....93 oct
4-wheel: Is your IX stock? If not can you post up your mod list? I am wondering whether other IX´s can/should try to duplicate your high boost feat. I have run 24# boost in my VIII on some very crappy 87-89 octane 3rd world gasoline w/o a trace of ignition retard, even on throttle tip-in. So, I´m not a disbeliever. I was just wonder what your complete modlist is, that´s all.
Last edited by sparky; Mar 24, 2007 at 06:39 PM.
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About boost vs. ignition vs. power and reliability for any application, the only way to prove that a higher boost pressure is advantageous for any given fuel octane is to prove the following:
- The lower boost pressure tuning was brought to knock threshold
- The higher boost pressure tuning is brought to knock threshold in the same parts of the map, AND demonstrates greater power than lesser boost pressure at its knock threshold, all else being equal.
- The EGT does not present a potential reliability issue
If anyone finds fault with any of this logic, feel free to comment.
- The lower boost pressure tuning was brought to knock threshold
- The higher boost pressure tuning is brought to knock threshold in the same parts of the map, AND demonstrates greater power than lesser boost pressure at its knock threshold, all else being equal.
- The EGT does not present a potential reliability issue
If anyone finds fault with any of this logic, feel free to comment.
As you know from a previous thread, I'm just puzzled by the difference in boost run on pump fuel from UK versus USA.
I just found this doc on Shell V-Power (used to be Optimax) here.
According to that it is: MON=87 and RON=99 which would be PON=93
So I think we are safe to say the fuel is equivalent. In terms of dyno differences, the links I've posted to the MLR are on an SuperFlow engine dyno, and also Dyno Dynamics always in Shoot44. Now people would argue you can't compare dynos, but DD themselves would say *I think* that results should be repeatable across diff dynos.
That leaves compression ratio and cams. All I can say here is I know some of the results I've posted to you are on 8.5:1 CR. And the cams in some of the links I can give you are off the shelf items.
So why is 2.2 bar on pump with built engine/head and GT30 upwards common in the UK? I have no idea. Is it possible the tuners there have found they get more out of boost than timing with these types of spec'd cars? I think so! But it is just an opinion and I tend to believe it primarily because I've been watching the MLR closely for about 4 years.
Ted I have a lot of respect for your opinions too. I'm just a Evo enthusiast and not a tuner. As I said just an opinion from an interested observer.
I do have one point of curiousity... what are the problems which can occur due to high EGTs? What type of failures might occur and have you ever seen them?
So why is 2.2 bar on pump with built engine/head and GT30 upwards common in the UK? I have no idea. Is it possible the tuners there have found they get more out of boost than timing with these types of spec'd cars? I think so! But it is just an opinion and I tend to believe it primarily because I've been watching the MLR closely for about 4 years.
Is it possible that a built head due to improved combustion chamber and valve pocket design as well as improved exhaust valve materials could be less detonation prone than the stock cylinder head?
Also, a 30R turbo configured with a higher A.R. turbine housing might run considerably lower EGT´s than a 16G, thus allowing for higher boost levels.
If the off the shelf cams are of the longer duration than stock variety, and are dialed in via cam gears to a more negative setting, then I´ll bet that this would allow for more boost to be run as well.
Finally, we all know that British dynos are strategically located in the chilliest and foggiest crags and grottos on the isle
Ted I agree with the above... I'm not sure how anyone would think otherwise. By the way how are you listening for det? . . . So I think we are safe to say the fuel is equivalent. . . . In terms of dyno differences, the links I've posted to the MLR are on an SuperFlow engine dyno, and also Dyno Dynamics always in Shoot44. Now people would argue you can't compare dynos, but DD themselves would say *I think* that results should be repeatable across diff dynos. . . . Is it possible the tuners there have found they get more out of boost than timing with these types of spec'd cars? I do have one point of curiousity... what are the problems which can occur due to high EGTs? What type of failures might occur and have you ever seen them?
- One doesn't need to get into detonation to test the knock threshold. Just before the onset of detonation, there is a buffer zone (usually a deg or so) where increasing the ignition advance no longer increases power. That is the effective octane limit. Detonation sets in right after that point.
- In the U.S. some brands of '93' octane tend to work *significantly* better than others (we witnessed this on the dyno just last weekend), so what appears equal on paper isn't always equal in reality, and why I am cautious about making paper comparisons.
- The DD dynos here (at least the ones with which I am familar) give much higher numbers in shootout mode. A stock EVO 8 registers ~270whp in this mode in the U.S. I am told this is different from the ones in the UK, so only DD can provide an explanation. As far as the engine dyno results, given drivetrain losses (or at least what Norris claims), the peak figures for crank hp in the link you provided would not appear to be so unusual when adjusted for expected chassis dyno figures, even for U.S. cars running pump fuel and less boost.
- As far as the effect of high EGTs, one friend recently cooked his GT35R turbine and center section as a result of prolonged high EGT. He was running 30psi on 93 octane on an 8.5:1 motor, with standalone ECU. We found out that when this happens, this turbo (primarily it's expensive BB center) becomes a $1300 door stop - a total loss.
Last edited by Ted B; Mar 24, 2007 at 09:01 PM.
Answers:
- One doesn't need to get into detonation to test the knock threshold. Just before the onset of detonation, there is a buffer zone (usually a deg or so) where increasing the ignition advance no longer increases power. That is the effective octane limit. Detonation sets in right after that point.
- In the U.S. some brands of '93' octane tend to work *significantly* better than others (we witnessed this on the dyno just last weekend), so what appears equal on paper isn't always equal in reality, and why I am cautious about making paper comparisons.
- The DD dynos here (at least the ones with which I am familar) give much higher numbers in shootout mode. A stock EVO 8 registers ~270whp in this mode in the U.S. I am told this is different from the ones in the UK, so only DD can provide an explanation. As far as the engine dyno results, given drivetrain losses (or at least what Norris claims), the peak figures for crank hp in the link you provided would not appear to be so unusual when adjusted for expected chassis dyno figures, even for U.S. cars running pump fuel and less boost.
- As far as the effect of high EGTs, one friend recently cooked his GT35R turbine and center section as a result of prolonged high EGT. He was running 30psi on 93 octane on an 8.5:1 motor, with standalone ECU. We found out that when this happens, this turbo (primarily it's expensive BB center) becomes a $1300 door stop - a total loss.
- One doesn't need to get into detonation to test the knock threshold. Just before the onset of detonation, there is a buffer zone (usually a deg or so) where increasing the ignition advance no longer increases power. That is the effective octane limit. Detonation sets in right after that point.
- In the U.S. some brands of '93' octane tend to work *significantly* better than others (we witnessed this on the dyno just last weekend), so what appears equal on paper isn't always equal in reality, and why I am cautious about making paper comparisons.
- The DD dynos here (at least the ones with which I am familar) give much higher numbers in shootout mode. A stock EVO 8 registers ~270whp in this mode in the U.S. I am told this is different from the ones in the UK, so only DD can provide an explanation. As far as the engine dyno results, given drivetrain losses (or at least what Norris claims), the peak figures for crank hp in the link you provided would not appear to be so unusual when adjusted for expected chassis dyno figures, even for U.S. cars running pump fuel and less boost.
- As far as the effect of high EGTs, one friend recently cooked his GT35R turbine and center section as a result of prolonged high EGT. He was running 30psi on 93 octane on an 8.5:1 motor, with standalone ECU. We found out that when this happens, this turbo (primarily it's expensive BB center) becomes a $1300 door stop - a total loss.
Great post! Would one find a flat spot in power where you wouldn't neccessarilly knock but have a loss in power or a dead spot in the power band before it peaks?
http://en.wikipedia.org/wiki/Detonation
What do you think snaps a rod? Detonation>>smashed bearing>spun bearing>no oil hole>rod seizing to crank journal>rod snapping.
What do you think snaps a rod? Detonation>>smashed bearing>spun bearing>no oil hole>rod seizing to crank journal>rod snapping.
Any more info on your +500whp stock turbo'd EVO??
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One doesn't need to get into detonation to test the knock threshold. Just before the onset of detonation, there is a buffer zone (usually a deg or so) where increasing the ignition advance no longer increases power. That is the effective octane limit. Detonation sets in right after that point.
The DD dynos here (at least the ones with which I am familar) give much higher numbers in shootout mode. A stock EVO 8 registers ~270whp in this mode in the U.S. I am told this is different from the ones in the UK, so only DD can provide an explanation. As far as the engine dyno results, given drivetrain losses (or at least what Norris claims), the peak figures for crank hp in the link you provided would not appear to be so unusual when adjusted for expected chassis dyno figures, even for U.S. cars running pump fuel and less boost.
As far as the effect of high EGTs, one friend recently cooked his GT35R turbine and center section as a result of prolonged high EGT. He was running 30psi on 93 octane on an 8.5:1 motor, with standalone ECU. We found out that when this happens, this turbo (primarily it's expensive BB center) becomes a $1300 door stop - a total loss.
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From: Ft. Lauderdale, Fl
4-wheel: Is your IX stock? If not can you post up your mod list? I am wondering whether other IX´s can/should try to duplicate your high boost feat. I have run 24# boost in my VIII on some very crappy 87-89 octane 3rd world gasoline w/o a trace of ignition retard, even on throttle tip-in. So, I´m not a disbeliever. I was just wonder what your complete modlist is, that´s all.
i wouldn't reccomend it...
last night i did 10 back to back logs on 28 pounds and looked at the dyno ad noticed that they kept losing significant power.
i waited an hour for the car to cool then did the same on my 24 oct map and the percentage was much less.
so everyones guess of it not being good for the car were correct. but if i were to go to the drag strip for one run every hour... i would probably run the 28 pound map.
cheers!
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Ted I agree with the above... I'm not sure how anyone would think otherwise. By the way how are you listening for det?
As you know from a previous thread, I'm just puzzled by the difference in boost run on pump fuel from UK versus USA.
I just found this doc on Shell V-Power (used to be Optimax) here.
According to that it is: MON=87 and RON=99 which would be PON=93
So I think we are safe to say the fuel is equivalent. In terms of dyno differences, the links I've posted to the MLR are on an SuperFlow engine dyno, and also Dyno Dynamics always in Shoot44. Now people would argue you can't compare dynos, but DD themselves would say *I think* that results should be repeatable across diff dynos.
That leaves compression ratio and cams. All I can say here is I know some of the results I've posted to you are on 8.5:1 CR. And the cams in some of the links I can give you are off the shelf items.
So why is 2.2 bar on pump with built engine/head and GT30 upwards common in the UK? I have no idea. Is it possible the tuners there have found they get more out of boost than timing with these types of spec'd cars? I think so! But it is just an opinion and I tend to believe it primarily because I've been watching the MLR closely for about 4 years.
Ted I have a lot of respect for your opinions too. I'm just a Evo enthusiast and not a tuner. As I said just an opinion from an interested observer.
I do have one point of curiousity... what are the problems which can occur due to high EGTs? What type of failures might occur and have you ever seen them?
As you know from a previous thread, I'm just puzzled by the difference in boost run on pump fuel from UK versus USA.
I just found this doc on Shell V-Power (used to be Optimax) here.
According to that it is: MON=87 and RON=99 which would be PON=93
So I think we are safe to say the fuel is equivalent. In terms of dyno differences, the links I've posted to the MLR are on an SuperFlow engine dyno, and also Dyno Dynamics always in Shoot44. Now people would argue you can't compare dynos, but DD themselves would say *I think* that results should be repeatable across diff dynos.
That leaves compression ratio and cams. All I can say here is I know some of the results I've posted to you are on 8.5:1 CR. And the cams in some of the links I can give you are off the shelf items.
So why is 2.2 bar on pump with built engine/head and GT30 upwards common in the UK? I have no idea. Is it possible the tuners there have found they get more out of boost than timing with these types of spec'd cars? I think so! But it is just an opinion and I tend to believe it primarily because I've been watching the MLR closely for about 4 years.
Ted I have a lot of respect for your opinions too. I'm just a Evo enthusiast and not a tuner. As I said just an opinion from an interested observer.
I do have one point of curiousity... what are the problems which can occur due to high EGTs? What type of failures might occur and have you ever seen them?
comparing different motor's and turbo's is really comparing apple and oranges...
im sure since those are better motors they can take a lot more heat and have better cooling.
cheers!
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4wheelslide... sorry to have hi-jacked your thread. I've begun talking about bigger turbos than standard which is sort of off-topic since you are running standard.
My understanding is at 28 PSI the standard turbo is reaching a point where the balance of compressing the intake charge to make it more dense, and heating it becomes skewed so the benefits are small or maybe non-existant. I'm not sure at what point this happens. Somewhere around 28 PSI I suspect but getting out there and mapping your car is the only way to know. I'm not suggesting people do this unless they know how to properly map a car.
Also that much boost should produce a lot of torque so be careful of bending a rod perhaps.
My understanding is at 28 PSI the standard turbo is reaching a point where the balance of compressing the intake charge to make it more dense, and heating it becomes skewed so the benefits are small or maybe non-existant. I'm not sure at what point this happens. Somewhere around 28 PSI I suspect but getting out there and mapping your car is the only way to know. I'm not suggesting people do this unless they know how to properly map a car.
Also that much boost should produce a lot of torque so be careful of bending a rod perhaps.
Last edited by crcain; Mar 25, 2007 at 08:29 AM.
Try again. If you read your link it does not mention anything about bearings. Detonation is more likely to cause the three things I posted. Broken rods are more commonly caused by the direct stresses of detonation rather than seizing to the crank first, then breaking.
Any more info on your +500whp stock turbo'd EVO??
Any more info on your +500whp stock turbo'd EVO??
For info and video on the car, visit www.ttp-engineering.com.
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4wheelslide... sorry to have hi-jacked your thread. I've begun talking about bigger turbos than standard which is sort of off-topic since you are running standard.
My understanding is at 28 PSI the standard turbo is reaching a point where the balance of compressing the intake charge to make it more dense, and heating it becomes skewed so the benefits are small or maybe non-existant. I'm not sure at what point this happens. Somewhere around 28 PSI I suspect but getting out there and mapping your car is the only way to know. I'm not suggesting people do this unless they know how to properly map a car.
Also that much boost should produce a lot of torque so be careful of bending a rod perhaps.
My understanding is at 28 PSI the standard turbo is reaching a point where the balance of compressing the intake charge to make it more dense, and heating it becomes skewed so the benefits are small or maybe non-existant. I'm not sure at what point this happens. Somewhere around 28 PSI I suspect but getting out there and mapping your car is the only way to know. I'm not suggesting people do this unless they know how to properly map a car.
Also that much boost should produce a lot of torque so be careful of bending a rod perhaps.
my torque still sucked..... it spiked high at 4000 then by 7500 it was down by 275-250. i need cams =-p
my hp goes straight up though
cheers!
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I did not even visit the link. Nothing of boosted engines was mentioned. Just trying to set you on the right path.
For info and video on the car, visit www.ttp-engineering.com.
For info and video on the car, visit www.ttp-engineering.com.
so scott, if i drop my car off for a week, ca you make my car 500whp stock turbo on 34 pounds and be completely reliable like urs
cause other than 02 housing, licp and forge w/g. i have every bolt on and a super aggresive tune...
yet i cant trap above 120
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So you don't listen for det? Yikes... I thought that was standard practice (eg headphones etc).
I agree that the fuel comparison is difficult to make.
The link I gave in this thread, an NR Autosport car, is here. So that is 517 bhp and equal torque at the flywheel on pump fuel. Are you saying that is a pretty common result on pump fuel with a GT30 here on Evom? Do you have any links?
If the result of high EGT is turbo failure.. I'm not so concerned about high EGT because I very very rarely read about turbo failures on this board or the MLR.
I agree that the fuel comparison is difficult to make.
The link I gave in this thread, an NR Autosport car, is here. So that is 517 bhp and equal torque at the flywheel on pump fuel. Are you saying that is a pretty common result on pump fuel with a GT30 here on Evom? Do you have any links?
If the result of high EGT is turbo failure.. I'm not so concerned about high EGT because I very very rarely read about turbo failures on this board or the MLR.
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Also I consider DynoJet results to be almost flywheel power. Maybe 10% off. Is that a fair assesment?