T-Man Posted 11February, 2014 Report Share Posted 11February, 2014 We didn't know at the time the boxster was carrying 50 kg of additional weight in sausage rolls..... That's a valid point and one I didn't think about, but the 993 was carrying a T-1 & T-2, and still managed better economy. Link to comment Share on other sites More sharing options...
Russ Posted 12February, 2014 Report Share Posted 12February, 2014 Off P car topic, but our LIberty GT specs 98 min, wife accidently put 91 in one day, you would have sworn someone stole the turbo off it! yeah it'll wind all the timing out of it (and some of them change the boost level) to stop detonation I only ever put 98 RON (without ethanol) in my old 911, even if it's wasting it I don't care I'll still put the best fuel in for it. Link to comment Share on other sites More sharing options...
Steiny Posted 12February, 2014 Report Share Posted 12February, 2014 Mine says 96 RON minimum so it's 98 all the way for me. VPower is ok. I like Caltex Vortex too. I prefer BP though only because they're the only supplier that isn't affiliated with shopper dockets (Shell=Coles; Caltex=Woolworths) which I think is a total scam all the way and on principle I don't want to support it. Link to comment Share on other sites More sharing options...
pocketscience Posted 12February, 2014 Report Share Posted 12February, 2014 Mine says 96 RON minimum so it's 98 all the way for me. VPower is ok. I like Caltex Vortex too. I prefer BP though only because they're the only supplier that isn't affiliated with shopper dockets (Shell=Coles; Caltex=Woolworths) which I think is a total scam all the way and on principle I don't want to support it. They are a scam, but if you buy from Coles or Woolies and don't use the dockets to get "cheaper" fuel you're leaving money in the supermarkets pocket. If you shop at IGA then no problems.. Link to comment Share on other sites More sharing options...
tony1 Posted 12February, 2014 Report Share Posted 12February, 2014 at least if we buy from non coles & woolies stores we will have some competition to keep the bastards honest, so much for there so called deal with the ACCC before xmas to stop the 10c discount vouchers lasted 6 weeks, typical corporate ripoff merchants Link to comment Share on other sites More sharing options...
Steiny Posted 14February, 2014 Report Share Posted 14February, 2014 They are a scam, but if you buy from Coles or Woolies and don't use the dockets to get "cheaper" fuel you're leaving money in the supermarkets pocket. If you shop at IGA then no problems.. Coincidentally, I actually shop at Aldi! Link to comment Share on other sites More sharing options...
Kelly Posted 14February, 2014 Report Share Posted 14February, 2014 I would add that most cars are mapped to a particular grade of fuel such as 98 and will retard timing if a lower grade of fuel is used but they will not advance timing to take advantage of a higher grade of fuel. Hence putting 105 Octane race fuel in a car which is mapped for 98 will not deliver any power benefits. Regarding fuel additives - it takes a lot (like 8litres per tank) of extra high octane hydrocarbons such as Xylene or Toluene to raise the overall octane rating of the fuel (I used to do this when I couldn't get race gas conveniently for my 944T). In other words these 500ml containers of fuel additive/octane boosters do next to nothing for boosting octane. With my 996 I went to the trouble of dynoing the car on different grades of fuel whilst datalogging the ignition timing during the dyno pulls so that I could verify for myself how the timing was being adjusted for the different grades of fuel at differing loads. and yes 91 vs 95 vs 98 made a difference. To take advantage of 99 I had to get the car remapped. Link to comment Share on other sites More sharing options...
Mike Posted 14February, 2014 Report Share Posted 14February, 2014 My experience is that BP Ultimate works best with most cars and particularly with MFI and carbies it is well suited to higher compression too. I have also used Caltex Vortex 98 with good results. As far as Venom goes yes it does increase the octane levels, cleans injectors, stops the fuels going off (a good feature for cars that are not often used) and will decarbonize the valves, ports, and combustion chambers! Link to comment Share on other sites More sharing options...
CBR944 Posted 15April, 2014 Report Share Posted 15April, 2014 Slightly OT, but does anyone know if/how early unleaded P-cars were 'detuned' for the only unleaded fuel that was available in 85-86? My 1986 944 turbo specified 95 RON in the owners manual, but that grade of fuel was not available in Australia when the car was new. Did Porsche just expect the knock sensor to take care of it, or did they do something else? Interestingly, the ECU has an 8-position fuel quality switch which could have been used to adjust timing etc to allow for low octane unleaded, but on checking mine recently, it was in the standard position (zero setting) - although I have no way of knowing if the car was delivered that way or if it was subsequently adjusted by a PO or by Porsche themselves. Any suggestions? Link to comment Share on other sites More sharing options...
Peter M Posted 15April, 2014 Report Share Posted 15April, 2014 Don't know about 944's but I understand the '86 MY 911's dropped the compression ratio from 10.3 to 9.5:1, added a catalytic converter and ran a revised ECU to retard the ignition to cope with the 91 RON unleaded which was all that was commonly at the time. With the '87's onwards they revised the ECU again to run more ignition advance to exploit the wider availability of 95 RON unleaded and regained about 8kW of the 18kW that was originally lost.Each of the above changes resulted in a different engine designation - 930.26, 930.21, 930.25 for MY '85, '86 and '87 respectively so it was really more that just a local adjustment of the ECU.Are you sure this era of L Jetronic had a knock sensor? I frankly can't remember but thought that upgrade came later in the eighties.You could have a look at the PET for your model - downloadable from the Porsche Australia website - and look at the changes in the part numbers for the ECU over the period of the introduction of unleaded in Australia.Sorry, that's a bit or ramble and it really doesn't help you...... Link to comment Share on other sites More sharing options...
Pauly Posted 15April, 2014 Report Share Posted 15April, 2014 Interesting. Everyone seems to use v-power. I on the other hand use 7/11 95 ron Link to comment Share on other sites More sharing options...
Pauly Posted 15April, 2014 Report Share Posted 15April, 2014 Only kidding!! I use BP ultimate, well did. United 105 octane e85 I found my car ran better with BP than Shell. Last time i put shell in it, it really didn't like it. felt more lag, less torque. felt crap. Drained the tank and in with BP. Link to comment Share on other sites More sharing options...
JAX57 Posted 15April, 2014 Report Share Posted 15April, 2014 All I know is that 91octane sold in NSW has a compulsory high percentage of ethanol which is a no brainer. I don't believe this is the case in VIC? Link to comment Share on other sites More sharing options...
CBR944 Posted 16April, 2014 Report Share Posted 16April, 2014 Thanks Peter. The 86 944 turbo has a motronic ECU and KLR with knock sensor, so yes, it was capable of on the fly timing adjustments. I have heard that some kind of detuning occurred with early turbos but can find no evidence of this. Fairly sure the ECU was the same part worldwide, but could be wrong. The PET might be worth looking at, thanks for that suggestion. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.