Running a Stage 1 93 Octane Tune on 91 Octane Gas
06-20-2017, 03:27 PM
#1
Pro
Thread Starter
Running a Stage 1 93 Octane Tune on 91 Octane Gas
My 2003 996 TT with ~76.5K miles on it, had a Softronics stage 1 tune put on it two owners and around 10K miles ago. I have the cable and the software, which the owner who did the flash supplied to the guy who sold the car to me. The owner I bought the car from never did anything to the flashed ECU software, never even plugged the Durametric in during his <1.5 years and ~1500 miles of ownership. He ran the car with 91 Octane gas, which is the best that he could buy, also the best that I can buy where I live.
It's unclear whether the tune was based on 93 or 91 Octane; I have called the company supplying it, and they are going to look at my tune file to tell me which level of octane gas the tune was based on. The guy cautioned me that using a 93 octane tune with 91 gas could potentially damage the engine. The default tune would have been 93 unless 91 was requested.
In my own use of the car I have not noticed any pinging or knocking or other problems. The seller of the car never mentioned anything, either, and he was so **** that I have a list of supposed minor problems with the vehicle he told me about, almost none of which have I been able to reproduce. So I'm pretty sure that if he had knocking, or pinging, he would have mentioned it.
I've done a little bit of research on this topic. What I have found is that any engine damage that would potentially occur would be associated with an knocking or pinging in the presence of an aggressive tune, and generally would be present only when driving the car "WOT," or with the accelerator floored, which is not my normal driving style :-)
Other things I've read include that the altitude that a car is operated in has a big effect on this. My cars essentially never go below 2500 feet of elevation, and generally are driven between 2500 and 8000 feet. From what I have read, performance is reduced at elevation, and the risk of getting Pinging and or Knocking is considerably less at altitude because of the reduced performance. In my reading, those fuel additives sold to increase octane generally give only a very minimal octane boost, and are probably not worth using.
If the tune was designed for 93 octane fuel, which is not available where I drive, it would seem that I have several options;
(1) Ignore it, and count on the absence of pinging and knocking, combined with the altitude the car will be driven at, to prevent any theoretical engine damage;
(2) Reflash back to the stock tune;
(3) Purchase a 91 Octane tune.
Has anyone else dealt with this? Any suggestions?
Thanks in advance!
It's unclear whether the tune was based on 93 or 91 Octane; I have called the company supplying it, and they are going to look at my tune file to tell me which level of octane gas the tune was based on. The guy cautioned me that using a 93 octane tune with 91 gas could potentially damage the engine. The default tune would have been 93 unless 91 was requested.
In my own use of the car I have not noticed any pinging or knocking or other problems. The seller of the car never mentioned anything, either, and he was so **** that I have a list of supposed minor problems with the vehicle he told me about, almost none of which have I been able to reproduce. So I'm pretty sure that if he had knocking, or pinging, he would have mentioned it.
I've done a little bit of research on this topic. What I have found is that any engine damage that would potentially occur would be associated with an knocking or pinging in the presence of an aggressive tune, and generally would be present only when driving the car "WOT," or with the accelerator floored, which is not my normal driving style :-)
Other things I've read include that the altitude that a car is operated in has a big effect on this. My cars essentially never go below 2500 feet of elevation, and generally are driven between 2500 and 8000 feet. From what I have read, performance is reduced at elevation, and the risk of getting Pinging and or Knocking is considerably less at altitude because of the reduced performance. In my reading, those fuel additives sold to increase octane generally give only a very minimal octane boost, and are probably not worth using.
If the tune was designed for 93 octane fuel, which is not available where I drive, it would seem that I have several options;
(1) Ignore it, and count on the absence of pinging and knocking, combined with the altitude the car will be driven at, to prevent any theoretical engine damage;
(2) Reflash back to the stock tune;
(3) Purchase a 91 Octane tune.
Has anyone else dealt with this? Any suggestions?
Thanks in advance!
06-20-2017, 03:48 PM
#2
If the tune was designed for 93 octane fuel, which is not available where I drive, it would seem that I have several options;
(1) Ignore it, and count on the absence of pinging and knocking, combined with the altitude the car will be driven at, to prevent any theoretical engine damage No don't do that.
2) Reflash back to the stock tune; yes easy solution
3) Purchase a 91 Octane tune.Yes easy cost effective
Has anyone else dealt with this? First if you're concerned flash to stock until Scott from Softronic calls you back with file info or just stay out of boost so not harm engine or other words drive easy especially if hot. I've had Softronic 91 tune for 8 years listen to Scott.
(1) Ignore it, and count on the absence of pinging and knocking, combined with the altitude the car will be driven at, to prevent any theoretical engine damage No don't do that.
2) Reflash back to the stock tune; yes easy solution
3) Purchase a 91 Octane tune.Yes easy cost effective
Has anyone else dealt with this? First if you're concerned flash to stock until Scott from Softronic calls you back with file info or just stay out of boost so not harm engine or other words drive easy especially if hot. I've had Softronic 91 tune for 8 years listen to Scott.
06-20-2017, 04:16 PM
#3
Three Wheelin'
A fuel additive that actually works is Torco Accelerator.
The last thing I would do is drive it hard on a tune that is for a fuel quality that you do not have. Keep in mind with regards to altitude that turbocharged vehicles create their own atmosphere so to speak... 0.7 bar is 0.7 bar regardless of what altitude you are at, the turbos are just having to move more air/spin faster to make the same boost.
The last thing I would do is drive it hard on a tune that is for a fuel quality that you do not have. Keep in mind with regards to altitude that turbocharged vehicles create their own atmosphere so to speak... 0.7 bar is 0.7 bar regardless of what altitude you are at, the turbos are just having to move more air/spin faster to make the same boost.
06-20-2017, 04:19 PM
#4
Race Director
My 2003 996 TT with ~76.5K miles on it, had a Softronics stage 1 tune put on it two owners and around 10K miles ago. I have the cable and the software, which the owner who did the flash supplied to the guy who sold the car to me. The owner I bought the car from never did anything to the flashed ECU software, never even plugged the Durametric in during his <1.5 years and ~1500 miles of ownership. He ran the car with 91 Octane gas, which is the best that he could buy, also the best that I can buy where I live.
It's unclear whether the tune was based on 93 or 91 Octane; I have called the company supplying it, and they are going to look at my tune file to tell me which level of octane gas the tune was based on. The guy cautioned me that using a 93 octane tune with 91 gas could potentially damage the engine. The default tune would have been 93 unless 91 was requested.
In my own use of the car I have not noticed any pinging or knocking or other problems. The seller of the car never mentioned anything, either, and he was so **** that I have a list of supposed minor problems with the vehicle he told me about, almost none of which have I been able to reproduce. So I'm pretty sure that if he had knocking, or pinging, he would have mentioned it.
I've done a little bit of research on this topic. What I have found is that any engine damage that would potentially occur would be associated with an knocking or pinging in the presence of an aggressive tune, and generally would be present only when driving the car "WOT," or with the accelerator floored, which is not my normal driving style :-)
Other things I've read include that the altitude that a car is operated in has a big effect on this. My cars essentially never go below 2500 feet of elevation, and generally are driven between 2500 and 8000 feet. From what I have read, performance is reduced at elevation, and the risk of getting Pinging and or Knocking is considerably less at altitude because of the reduced performance. In my reading, those fuel additives sold to increase octane generally give only a very minimal octane boost, and are probably not worth using.
If the tune was designed for 93 octane fuel, which is not available where I drive, it would seem that I have several options;
(1) Ignore it, and count on the absence of pinging and knocking, combined with the altitude the car will be driven at, to prevent any theoretical engine damage;
(2) Reflash back to the stock tune;
(3) Purchase a 91 Octane tune.
Has anyone else dealt with this? Any suggestions?
Thanks in advance!
It's unclear whether the tune was based on 93 or 91 Octane; I have called the company supplying it, and they are going to look at my tune file to tell me which level of octane gas the tune was based on. The guy cautioned me that using a 93 octane tune with 91 gas could potentially damage the engine. The default tune would have been 93 unless 91 was requested.
In my own use of the car I have not noticed any pinging or knocking or other problems. The seller of the car never mentioned anything, either, and he was so **** that I have a list of supposed minor problems with the vehicle he told me about, almost none of which have I been able to reproduce. So I'm pretty sure that if he had knocking, or pinging, he would have mentioned it.
I've done a little bit of research on this topic. What I have found is that any engine damage that would potentially occur would be associated with an knocking or pinging in the presence of an aggressive tune, and generally would be present only when driving the car "WOT," or with the accelerator floored, which is not my normal driving style :-)
Other things I've read include that the altitude that a car is operated in has a big effect on this. My cars essentially never go below 2500 feet of elevation, and generally are driven between 2500 and 8000 feet. From what I have read, performance is reduced at elevation, and the risk of getting Pinging and or Knocking is considerably less at altitude because of the reduced performance. In my reading, those fuel additives sold to increase octane generally give only a very minimal octane boost, and are probably not worth using.
If the tune was designed for 93 octane fuel, which is not available where I drive, it would seem that I have several options;
(1) Ignore it, and count on the absence of pinging and knocking, combined with the altitude the car will be driven at, to prevent any theoretical engine damage;
(2) Reflash back to the stock tune;
(3) Purchase a 91 Octane tune.
Has anyone else dealt with this? Any suggestions?
Thanks in advance!
While detonation can occur under WOT conditions the DME is allowed to run the engine richer and a richer mixture helps prevent detonation.
Besides WOT part throttle/high load operating condition is when detonation can be a problem. This operating condition can occur when one cruises down the boulevard at low engine RPMs and low vehicle speed. Cylinder filling is very good because the throttle valve is open pretty wide due to the load and pumping losses are reduced and cylinder filling is extremely good. Good cylinder filling means the pressure generated in the combustion chamber is high. Ignition advance can be very high too. A real recipe for engine detonation if the wrong grade of octane is used or if the engine is tuned for a higher grade of octane and possibly can't dial back the amount of timing in an attempt to prevent detonation.
(Retarded ignition timing is not without its downsides. Engine efficiency is reduced and exhaust gas temperatures are elevated and all components in the engine exposed to exhaust gases run hotter and heat shortens component life.)
While it is true an engine operating at higher elevations has a lower octane requirement the "tune" of course has changed the engine's octane requirements. This is true regardless of the elevation.
My experience over the years is 2500 feet is nothing. Even at 7700 feet -- around Flagstaff -- my Boxster is only minimally affected by the elevation. (AFAIK the highest octane grade available in Flagstaff is 90 octane. I can't recall ever finding even 91, but I confined my gasoline purchases to a few name brand/top tier stations. I never bothered to exhaustively search for 91 or even higher grades of octane. I was just "passing through". 'course, had I lived there I might have bothered to try to find higher octane gasoline.)
With my Turbo even 7700 feet is nothing. And even at higher elevations to nearly 9K feet the Turbo engine pulls like a freight train. The "secret" is the turbos. (Surprise!) What I found with my Turbo is under hard acceleration at higher elevations instead of the "normal" 0.7 bar boost the engine would develop 0.8 bar even 0.9 bar boost and sustain this boost level.
(My VW Golf TDi (turbo-diesel) would likewise develop scary high boost levels at higher elevations but the engine was fine. It also ran nearly as good a high elevations -- even through the at the highest passes on I-70 in Colorado -- as it did at sea level.)
Back to my Turbo: I can tell you though even at higher elevations -- in Wyoming -- the few times I managed to find 93 octane and filled the Turbo gas tank with this grade of gasoline the engine ran remarkably better. Even at higher elevations the engine was being hampered by a lower grade of octane.
My advice is if you can't (or won't) run the proper grade of octane with the tune you have switch the engine back to the stock tune and run the proper octane grade of gasoline.
06-20-2017, 04:33 PM
#5
Rennlist Member
My 2003 996 TT with ~76.5K miles on it, had a Softronics stage 1 tune put on it two owners and around 10K miles ago. I have the cable and the software, which the owner who did the flash supplied to the guy who sold the car to me. The owner I bought the car from never did anything to the flashed ECU software, never even plugged the Durametric in during his <1.5 years and ~1500 miles of ownership. He ran the car with 91 Octane gas, which is the best that he could buy, also the best that I can buy where I live.
It's unclear whether the tune was based on 93 or 91 Octane; I have called the company supplying it, and they are going to look at my tune file to tell me which level of octane gas the tune was based on. The guy cautioned me that using a 93 octane tune with 91 gas could potentially damage the engine. The default tune would have been 93 unless 91 was requested.
In my own use of the car I have not noticed any pinging or knocking or other problems. The seller of the car never mentioned anything, either, and he was so **** that I have a list of supposed minor problems with the vehicle he told me about, almost none of which have I been able to reproduce. So I'm pretty sure that if he had knocking, or pinging, he would have mentioned it.
I've done a little bit of research on this topic. What I have found is that any engine damage that would potentially occur would be associated with an knocking or pinging in the presence of an aggressive tune, and generally would be present only when driving the car "WOT," or with the accelerator floored, which is not my normal driving style :-)
Other things I've read include that the altitude that a car is operated in has a big effect on this. My cars essentially never go below 2500 feet of elevation, and generally are driven between 2500 and 8000 feet. From what I have read, performance is reduced at elevation, and the risk of getting Pinging and or Knocking is considerably less at altitude because of the reduced performance. In my reading, those fuel additives sold to increase octane generally give only a very minimal octane boost, and are probably not worth using.
If the tune was designed for 93 octane fuel, which is not available where I drive, it would seem that I have several options;
(1) Ignore it, and count on the absence of pinging and knocking, combined with the altitude the car will be driven at, to prevent any theoretical engine damage;
(2) Reflash back to the stock tune;
(3) Purchase a 91 Octane tune.
Has anyone else dealt with this? Any suggestions?
Thanks in advance!
It's unclear whether the tune was based on 93 or 91 Octane; I have called the company supplying it, and they are going to look at my tune file to tell me which level of octane gas the tune was based on. The guy cautioned me that using a 93 octane tune with 91 gas could potentially damage the engine. The default tune would have been 93 unless 91 was requested.
In my own use of the car I have not noticed any pinging or knocking or other problems. The seller of the car never mentioned anything, either, and he was so **** that I have a list of supposed minor problems with the vehicle he told me about, almost none of which have I been able to reproduce. So I'm pretty sure that if he had knocking, or pinging, he would have mentioned it.
I've done a little bit of research on this topic. What I have found is that any engine damage that would potentially occur would be associated with an knocking or pinging in the presence of an aggressive tune, and generally would be present only when driving the car "WOT," or with the accelerator floored, which is not my normal driving style :-)
Other things I've read include that the altitude that a car is operated in has a big effect on this. My cars essentially never go below 2500 feet of elevation, and generally are driven between 2500 and 8000 feet. From what I have read, performance is reduced at elevation, and the risk of getting Pinging and or Knocking is considerably less at altitude because of the reduced performance. In my reading, those fuel additives sold to increase octane generally give only a very minimal octane boost, and are probably not worth using.
If the tune was designed for 93 octane fuel, which is not available where I drive, it would seem that I have several options;
(1) Ignore it, and count on the absence of pinging and knocking, combined with the altitude the car will be driven at, to prevent any theoretical engine damage;
(2) Reflash back to the stock tune;
(3) Purchase a 91 Octane tune.
Has anyone else dealt with this? Any suggestions?
Thanks in advance!
06-20-2017, 05:23 PM
#6
Pro
Thread Starter
I do have the Durametric that came with the tune; the first time I ever plugged it in was yesterday, and I just went through the easy testing things in the Durametric program for a few minutes. Since I didn't drive anywhere with the car while it was plugged into the Durametric, I didn't do any datalogging.
It looked like there was an option for datalogging, which I'm assuming would mean that I would have the Durametric plugged into the car's OBD2 port while driving the car. I can certainly do that although having the cable running across my lap would probably not be too much fun.
Scott from Softronics said that there was no way for me to look at the tuning files or to use the Durametric to figure out what octane level the tune was set for, but that he could tell me if I sent him the file, which I have done, and I'm awaiting his response.
What would I learn from datalogging the car that would answer any of the questions posed on this thread?
Thanks.
It looked like there was an option for datalogging, which I'm assuming would mean that I would have the Durametric plugged into the car's OBD2 port while driving the car. I can certainly do that although having the cable running across my lap would probably not be too much fun.
Scott from Softronics said that there was no way for me to look at the tuning files or to use the Durametric to figure out what octane level the tune was set for, but that he could tell me if I sent him the file, which I have done, and I'm awaiting his response.
What would I learn from datalogging the car that would answer any of the questions posed on this thread?
Thanks.
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06-20-2017, 08:37 PM
#10
Rennlist Member
I do have the Durametric that came with the tune; the first time I ever plugged it in was yesterday, and I just went through the easy testing things in the Durametric program for a few minutes. Since I didn't drive anywhere with the car while it was plugged into the Durametric, I didn't do any datalogging.
It looked like there was an option for datalogging, which I'm assuming would mean that I would have the Durametric plugged into the car's OBD2 port while driving the car. I can certainly do that although having the cable running across my lap would probably not be too much fun.
Scott from Softronics said that there was no way for me to look at the tuning files or to use the Durametric to figure out what octane level the tune was set for, but that he could tell me if I sent him the file, which I have done, and I'm awaiting his response.
What would I learn from datalogging the car that would answer any of the questions posed on this thread?
Thanks.
It looked like there was an option for datalogging, which I'm assuming would mean that I would have the Durametric plugged into the car's OBD2 port while driving the car. I can certainly do that although having the cable running across my lap would probably not be too much fun.
Scott from Softronics said that there was no way for me to look at the tuning files or to use the Durametric to figure out what octane level the tune was set for, but that he could tell me if I sent him the file, which I have done, and I'm awaiting his response.
What would I learn from datalogging the car that would answer any of the questions posed on this thread?
Thanks.
Kevin also has a nice data logger that plugs in to your obd port and you don't have to deal with a tablet & cord plugged in while you do full 3rd and 4th gear pulls. Just put it somewhere it won't smack you when you hit the brakes for the popo. Kevin's logger pulls more info at a much faster sample rate than the Durametric too, fyi.
06-21-2017, 05:43 PM
#11
Pro
Thread Starter
I have heard back from Scott that the tune was for 93 Octane gas, which you can't buy, period, where my cars and I live. You can buy ethanol-free fuel with some difficulty, however, no 93, only 91.
I will have to pay $500 to get a 91 tune "upgrade." I'm going to think about this tonight and decide whether to do that or to reflash back to stock.
My original plan was to drive the car 150 miles to my home tomorrow, however it turns out that the audio install that was done for me on Tuesday needs to be slightly revised, and that can't happen until my next trip here the end of next week. So, I'm just going to leave the 996TT in the garage here and drive another car home, a convertible, that will be fun to have at home the next week and a half anyway. Then I'll flash whatever I decide onto the turbo, when I get back next week.
Thanks for all the information given in this thread, I do appreciate it.
I will have to pay $500 to get a 91 tune "upgrade." I'm going to think about this tonight and decide whether to do that or to reflash back to stock.
My original plan was to drive the car 150 miles to my home tomorrow, however it turns out that the audio install that was done for me on Tuesday needs to be slightly revised, and that can't happen until my next trip here the end of next week. So, I'm just going to leave the 996TT in the garage here and drive another car home, a convertible, that will be fun to have at home the next week and a half anyway. Then I'll flash whatever I decide onto the turbo, when I get back next week.
Thanks for all the information given in this thread, I do appreciate it.
06-21-2017, 11:02 PM
#12
Race Car
I wouldn't drive a 93 octane-tuned car on 91 octane gas. One time when was creating custom tunes for my old supercharged 928, there was a gas shortage due to an issue with a refinery in Texas. Most gas stations were out of gas, but I managed to find one that had some 87 octane gas left. My tune was for 93 octane, and that was the first time I actually heard pinging/detonation. I easily changed the tune to globally scale back ignition timing and made it more rich, but was curious to momentarily run a test. When I could hear it, the pinging/detonation was already really bad. Even when I scaled back the throttle to not be able to hear it, I could see the knock sensors going crazy on the monitor.
Dan
Dan
06-22-2017, 12:45 AM
#13
Pro
Thread Starter
I haven't decided what to do, so I'm still thinking.
My personal opinion is that we are talking about what I would call a "defective" product here.
Why do I say that?
As someone who owns a number of out-of-production cars, I know and everyone reading this here knows that cars like a 996 TT changes hands with surprising regularity. I have no data on this particular car (13 to 17 year old 996 TT cars), but I do know some other cars with similar or even more rarity, of similar age, and I'd estimate the average ownership period to be 1-3 years in most cases. Now you guys who have owned your cars for 10 years, I know you exist, but you are not the norm.
So you set up a business to sell tunes for cars that you know, in all honesty, in all reasonableness, are likely to change hands in a year or two or three. But nonetheless, you sell them (preferentially--e.g. you recommend this) with a tune for gas available only in certain parts of the country. And you say that this tune can damage the car's engine if the car is run on lower octane gas, as is only available in a large percentage of the country. And you have no control over what the person you sell the tune to tells subsequent buyers of the car when sold to someone else not knowing these issues, and you know that you will have no control over such persons once they pay for your tune, and ultimately resell the car.
And then, when the car changes hands, you tell the new buyer to cough up $500 so that their engine won't be damaged. Would you run a business like this?
I would not.
So I'm thinking about it, do I want to encourage this.
For years I have told people on forums, "do not buy modded cars, and do not mod your car." It is for experiences such as this one, that I gave that advice, and that I would give this same advice to others in the future.
My personal opinion is that we are talking about what I would call a "defective" product here.
Why do I say that?
As someone who owns a number of out-of-production cars, I know and everyone reading this here knows that cars like a 996 TT changes hands with surprising regularity. I have no data on this particular car (13 to 17 year old 996 TT cars), but I do know some other cars with similar or even more rarity, of similar age, and I'd estimate the average ownership period to be 1-3 years in most cases. Now you guys who have owned your cars for 10 years, I know you exist, but you are not the norm.
So you set up a business to sell tunes for cars that you know, in all honesty, in all reasonableness, are likely to change hands in a year or two or three. But nonetheless, you sell them (preferentially--e.g. you recommend this) with a tune for gas available only in certain parts of the country. And you say that this tune can damage the car's engine if the car is run on lower octane gas, as is only available in a large percentage of the country. And you have no control over what the person you sell the tune to tells subsequent buyers of the car when sold to someone else not knowing these issues, and you know that you will have no control over such persons once they pay for your tune, and ultimately resell the car.
And then, when the car changes hands, you tell the new buyer to cough up $500 so that their engine won't be damaged. Would you run a business like this?
I would not.
So I'm thinking about it, do I want to encourage this.
For years I have told people on forums, "do not buy modded cars, and do not mod your car." It is for experiences such as this one, that I gave that advice, and that I would give this same advice to others in the future.
06-22-2017, 10:58 AM
#14
Race Car
IMO there is absolutely no responsibility by a tuner to support the car if it is sold by the owner that bought the tune. It is solely the responsibility of the buyer to negotiate the terms of the sale with the seller. If the car has a tune that is not compatible with the potential buyer's area, this needs to be part of the negotiations. If the seller purposely does not mention that the car has a tune that may cause problems, that is fraudulent.
Dan
Dan
06-22-2017, 11:39 AM
#15
Three Wheelin'
Yeah there is really no liability or responsibility on the tuner or seller of the car. You knew it had a 93 oct tune when you bought the car I am presuming. Blend in some race gas, run Torco Accelerator or a similar product, or cough it up as part of your necessary maintenance.
You'll be fine driving it calmly with a 93 oct tune on 91 oct... Don't push the car.
Side bar: I wouldn't go out of your way to find ethanol-free gas on forced induction car. The cooling effect given by even 10% ethanol presence is beneficial to turbo cars enough to negate any perceived gains by running ethanol free fuel. Naturally aspirated engines are a different story.
You'll be fine driving it calmly with a 93 oct tune on 91 oct... Don't push the car.
Side bar: I wouldn't go out of your way to find ethanol-free gas on forced induction car. The cooling effect given by even 10% ethanol presence is beneficial to turbo cars enough to negate any perceived gains by running ethanol free fuel. Naturally aspirated engines are a different story.