98RON or 95RON
Discussion
Hi RED_SLR
Goodness no, when I was running the rally car all you could get was a PECTEL boost control unit. P8 ecu's were the best at the time but with the anti-lag system I had you had no Knock sensor and no Lambda sensor and no Cats. It was open loop
In saying that it was a pig to MOT 9% co was not unusual. The good old days eh...
I had to change injectors & run an ecu more mot compliant. You really did have to know the guy doing the mot in those days, it was always very much at the discretion of the tester.
My last rally car I built form new had to be Q plated because Ford took out an injunction stopping all home built cars from getting a legit RS Cosworth Log Book. The advantage in the mid 1990's was that a Q plate's emissions test was only visual smoke test. Q plates had at that time no pass or fail CO.
Goodness no, when I was running the rally car all you could get was a PECTEL boost control unit. P8 ecu's were the best at the time but with the anti-lag system I had you had no Knock sensor and no Lambda sensor and no Cats. It was open loop
In saying that it was a pig to MOT 9% co was not unusual. The good old days eh...
I had to change injectors & run an ecu more mot compliant. You really did have to know the guy doing the mot in those days, it was always very much at the discretion of the tester.
My last rally car I built form new had to be Q plated because Ford took out an injunction stopping all home built cars from getting a legit RS Cosworth Log Book. The advantage in the mid 1990's was that a Q plate's emissions test was only visual smoke test. Q plates had at that time no pass or fail CO.
When you say "ignition on", do you mean to turn the engine on?? Or just turn the key so that the lights etc go on?
Cheers
Jack
Though, if engine cycles means what I think, at 200rpm, its not gonna take long to go through 100 revsNo, it's actually ignition on for 1 minute - do NOT touch the throttle - then off & start within 10 seconds. I find it best to do this when the engine is already warm & then go for a 20 minute run over mixed road conditions.
Cheers
Jack
nxi20 said:
Tino said:
Sunnysidebb said:
Absolutely.
Your Car is set up for 98 ron from the factory . Use Shell V power its the only one that is 98. ESSO & BP are 97 ron.
Your Ecu will have adapted its self to 95 and will have set the timing accordingly to stop any detonation so you wont notice the difference at first. Eventually the ECU will adapt to the 98 Octane but its going to take a very long time( 100 engine cycles I think corect me if i'm wrong). So long as you know your radio/ PCM code disconnect the battery with the key in position 1 ( stops alarm sounding) and the ECU will re-set the adaption values to the factory setting. You will notice a difference then.
Frank
I thought that you could turn the ignition on for 10 secs, and then off for 3, or something similiar, to reset adaptations.Your Car is set up for 98 ron from the factory . Use Shell V power its the only one that is 98. ESSO & BP are 97 ron.
Your Ecu will have adapted its self to 95 and will have set the timing accordingly to stop any detonation so you wont notice the difference at first. Eventually the ECU will adapt to the 98 Octane but its going to take a very long time( 100 engine cycles I think corect me if i'm wrong). So long as you know your radio/ PCM code disconnect the battery with the key in position 1 ( stops alarm sounding) and the ECU will re-set the adaption values to the factory setting. You will notice a difference then.
Frank
Though, if engine cycles means what I think, at 200rpm, its not gonna take long to go through 100 revs
The ECU is program for 98. That is how it comes out of the factory. If you run less than 98, the program will adjust. If you run 95, and then run 98, it will take 2 tanks of 98 for it to fully adapt. Alternatively you can reset as already mentioned.
You will have the factory power using 98. If you run Vpower (which is actually a true 99, unlike Tescos which is 99 using an toulene I think, you will be guarantee max power (subject to further points below), but still based on the fact that the ECU is tuned for 98. You won't see a remarkable difference between 98 and 99, but all you will do is add a little protection, as has been mentioned.
One thing that has not been mentioned in this thread, which is equally as important, is how the ECU asks for fuel. It uses two parameters STFT (Short Term Fuel Trim) and LTFT ( e.g. Long....). When you first start the car from scratch e.g. the battery is first connected, both paramters are set to zero. The ECU will use the base fueling parameters. The car will then (adapt) read a number of parameters e.g. MAF, O2 etc. So if you drive in a high attitude location where o2 is less, the ECU adjust the fuel, either asking for more or less depending on what it has read.
Those parameters are then stored in STFT. If the ECU continues to see the same levels, it will shift the value to the LTFT, and then set the STFT to zero.
The ECU continues to monitor constantly, and these are then set to STFT. It is sees a trend it updates LTFT.
So how your car can perform is dependant on LTFT. If the LFTF gets out of tolerance, then it will trigger CEL e.g. fault sensor, fuel supply etc. However your car can be close to that tolerance without you knowing it.
For example, if your MAF becomes faulty, the SFTF and LTFT will be adjusted. Remember the MAF tells the ECU how much air, and then requests the fuel.
Resetting your SFTF or LTFT can help, so you are either running rich, okay or lean. Therefore Octane may not give the desired results because of this.
In answer to the other question, if your ECU is programmed to adjust for fuel, like mine is, if I put through two tanks of 104 for example, it will work it out, and I get a lot more power. Or I can just reset the values, and it will learn quicker.
Again, IATs play a huge role in how your car performs.
If you put in 98 or above, then you know, that subject to all other things being well, you will get the best results.
So when using different fuel grades, sometimes you may not notice a difference depending on how your car is running anyway.
You will have the factory power using 98. If you run Vpower (which is actually a true 99, unlike Tescos which is 99 using an toulene I think, you will be guarantee max power (subject to further points below), but still based on the fact that the ECU is tuned for 98. You won't see a remarkable difference between 98 and 99, but all you will do is add a little protection, as has been mentioned.
One thing that has not been mentioned in this thread, which is equally as important, is how the ECU asks for fuel. It uses two parameters STFT (Short Term Fuel Trim) and LTFT ( e.g. Long....). When you first start the car from scratch e.g. the battery is first connected, both paramters are set to zero. The ECU will use the base fueling parameters. The car will then (adapt) read a number of parameters e.g. MAF, O2 etc. So if you drive in a high attitude location where o2 is less, the ECU adjust the fuel, either asking for more or less depending on what it has read.
Those parameters are then stored in STFT. If the ECU continues to see the same levels, it will shift the value to the LTFT, and then set the STFT to zero.
The ECU continues to monitor constantly, and these are then set to STFT. It is sees a trend it updates LTFT.
So how your car can perform is dependant on LTFT. If the LFTF gets out of tolerance, then it will trigger CEL e.g. fault sensor, fuel supply etc. However your car can be close to that tolerance without you knowing it.
For example, if your MAF becomes faulty, the SFTF and LTFT will be adjusted. Remember the MAF tells the ECU how much air, and then requests the fuel.
Resetting your SFTF or LTFT can help, so you are either running rich, okay or lean. Therefore Octane may not give the desired results because of this.
In answer to the other question, if your ECU is programmed to adjust for fuel, like mine is, if I put through two tanks of 104 for example, it will work it out, and I get a lot more power. Or I can just reset the values, and it will learn quicker.
Again, IATs play a huge role in how your car performs.
If you put in 98 or above, then you know, that subject to all other things being well, you will get the best results.
So when using different fuel grades, sometimes you may not notice a difference depending on how your car is running anyway.
996ttalot said:
In answer to the other question, if your ECU is programmed to adjust for fuel, like mine is, if I put through two tanks of 104 for example, it will work it out, and I get a lot more power. Or I can just reset the values, and it will learn quicker.
.
What exactly does it work out ? I thought the ECU basically kept advancing timing until knock onset was detected then held it there, just before the onset - so does your programming have a much higher timing advance map which can only be reached when the loopy juice is used (104) ? Or is there other voodoo going on in there ? .
What other readings (other than knock onset) can the ECU read which are a consequence of the 104 (relative to the 99 eg) ? I presumed you manually cranked the boost up when the 104 was in the tank and your proto map had special extra mapping timing advance headroom to go with the boost which all worked nicely with the 104 (subject as you say to IATs being OK)
TB993tt said:
996ttalot said:
In answer to the other question, if your ECU is programmed to adjust for fuel, like mine is, if I put through two tanks of 104 for example, it will work it out, and I get a lot more power. Or I can just reset the values, and it will learn quicker.
.
What exactly does it work out ? I thought the ECU basically kept advancing timing until knock onset was detected then held it there, just before the onset - so does your programming have a much higher timing advance map which can only be reached when the loopy juice is used (104) ? Or is there other voodoo going on in there ? .
What other readings (other than knock onset) can the ECU read which are a consequence of the 104 (relative to the 99 eg) ? I presumed you manually cranked the boost up when the 104 was in the tank and your proto map had special extra mapping timing advance headroom to go with the boost which all worked nicely with the 104 (subject as you say to IATs being OK)
BTW, when I look at my datalogs, or realtime 02 bank1/2 as long as they are not below 0.8, then it is not knocking. When we first tuned, I had some in the low 0.7s and we adjusted the timing since it was running a little rich. Now it is spot on.
Looking forward to seeing how our respective IATs above 150 are. That will be good to have some proper data.
996ttalot said:
. BTW I will only run 99vpower at Brunters just to make it equal
.
Equal .
Unless you are Euro 5 emissions and TUV noise legal then we are far from any "equality"..... run the loopy jiuce and let see some US style mega boost drag madness
Edited by TB993tt on Saturday 5th June 07:18
Sunnysidebb said:
In saying that it was a pig to MOT 9% co was not unusual. The good old days eh...
I had to change injectors & run an ecu more mot compliant. You really did have to know the guy doing the mot in those days
I had to change injectors & run an ecu more mot compliant. You really did have to know the guy doing the mot in those days
One workshop.
Two cars.
Two exhausts.
But only one exhaust probe.
End result : One WRC Impreza with MOT pass certificate showing Nissan Micra levels of CO . . .
I noticed a vast amount of difference if I got caught short and had to fill my 996 GT2 up with 95.
If it did happen I'd put the bare minimum in the tank to allow me to get to a petrol station with Shell V power or if possible BP Ultimate (incidentally I note BP have stopped selling BP Ultimate 102 now ?)
Putting 95 into the GT2 felt to pull a large amount of timing (and boost) and blunted its performance considerably.
firstly i was in a shell garage about a year ago when i started talking to a fella who was a delivery driver for bp.he said he would only put shell in his car as bp put too much ethanol in their fuel.i do believe petrol companies can put upto 8% in without telling public(only euro 5 engines run cleanly at this level)please somebody correct me if wrong.also when oil prices were low petrol companies increased the amount of ethanol to improve profit.
secondly i deal with a company that repair/service diesel fuel injection systems and a lot of cars/vans that come in have had problems with supermarket fuel.i was having problems with my daily runner with pinking underload since being advised to switch fuel companies(sainsburys to shell)the problem has cleared up.
finally after reading this thread i decided to try the ecu factory reset(turn on ignition on for 1 minute restart within 10 secs)and i must say the results were impresive(or maybe placebo effect).i have always put in shell v max since new(18 months old)but the pick up seems to be much stronger at mid. to high revs and she is flying at the moment(might be the atmosphere at the moment high moisture content,we shall see).i did wonder is this what porsche do at service time as the car always seemed to run well after a service(and dont tell me changing oil on a low mileage interval would do this).
any techies out there who can spread light on this?
secondly i deal with a company that repair/service diesel fuel injection systems and a lot of cars/vans that come in have had problems with supermarket fuel.i was having problems with my daily runner with pinking underload since being advised to switch fuel companies(sainsburys to shell)the problem has cleared up.
finally after reading this thread i decided to try the ecu factory reset(turn on ignition on for 1 minute restart within 10 secs)and i must say the results were impresive(or maybe placebo effect).i have always put in shell v max since new(18 months old)but the pick up seems to be much stronger at mid. to high revs and she is flying at the moment(might be the atmosphere at the moment high moisture content,we shall see).i did wonder is this what porsche do at service time as the car always seemed to run well after a service(and dont tell me changing oil on a low mileage interval would do this).
any techies out there who can spread light on this?
You need to give it time for the ECU to adapt. There was a thread on here this week that explained how to trick/reset it.
Have to confess I'm a funny bugger about petrol but I see it the same as someone living off Gregg's then complaining they feel a bit sluggish - V-Power is what I use when I have the choice, Total Excellium seemed alright as well, Sainsbury's Super is meant to be BP Ultimate.
Have to confess I'm a funny bugger about petrol but I see it the same as someone living off Gregg's then complaining they feel a bit sluggish - V-Power is what I use when I have the choice, Total Excellium seemed alright as well, Sainsbury's Super is meant to be BP Ultimate.
After finding a Shell station near me (well, a good 12 mile round trip but it's the nearest) I've just put my 3rd tank of V-Power in my 996TT having usually used Esso Super.
The car seems to run far better and smoother but as others have said, my MPG has also gone down a bit.
Still, I didn't buy the car for the economy but it is a wee bit strange.
The car seems to run far better and smoother but as others have said, my MPG has also gone down a bit.
Still, I didn't buy the car for the economy but it is a wee bit strange.
solidstatelogic said:
Did an ECU reset (I think) and now its even worse... 18.4mpg and not much difference in performance.
I might give it one more tank full of Tesco 99RON and see if improves. If not then I don't see any benefit of using higher than 95RON unless you're on a track racing.
Stick V-Power in it, keep sticking V-Power in it for a month.I might give it one more tank full of Tesco 99RON and see if improves. If not then I don't see any benefit of using higher than 95RON unless you're on a track racing.
davek_964 said:
I've been using Tesco 99 since buying the car - but when getting the 964 serviced last month I was told the turbo would prefer Shell v-power and that after a few tanks I'd notice the difference.
I was pretty unconvinced, but did switch to v-power to give it a try. Much to my surprise, there is a noticeable difference - the car seems significant more urgent when I'm in a hurry. MPG is also improved - although I suspect Tesco 99 is still the economical choice.
I didn't expect much difference considering Tesco is 99 anyway - but I won't be going back to Tesco.
my turbo didnt like it funnily enogh thought it was just me!I was pretty unconvinced, but did switch to v-power to give it a try. Much to my surprise, there is a noticeable difference - the car seems significant more urgent when I'm in a hurry. MPG is also improved - although I suspect Tesco 99 is still the economical choice.
I didn't expect much difference considering Tesco is 99 anyway - but I won't be going back to Tesco.
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