Fuel

[anonymous-user]

I've been driving like a granny and my computer tells me I've averaged 19.6 mpg on my 65 mile round trip to and from work. When I check my fuel receipt (59.76 litres) against mileage (224 miles) I find I'm actually averaging 17mpg.

I love my supercharged beastie so much but I don't know how much longer I can justify £400/month in fuel. Perhaps I should buy an old Merc and run it on chip fat? I'm depressed

[crisisjez]

Never really see less then 23 on the computer.

Would the 95 octaine remap have any effect on consumption?

[ringram]

Hey dude, are you running lean cruise? Ask your tuner if you are. On a trip it makes a good difference.
Also some people tune superchargers pretty rich to keep them safe. Dan at chipmaster in Oz actually goes for around 13:1 I wouldn't be surprised if some were as rich as 10:1
I used to get 400 miles to a motorway tank in my heavier VT2 R8 with at least the same power as a VXR500. Safe doesn't often equal efficient.

[anonymous-user]

Thanks, I'll ask Mark when he puts it back on the rollers on Monday to finalise my tune.

I think the biggest problem is my shitty route to work - it's all stop-start and my average speed on the computer never gets above 32mph. On a run, cruising at 90mph I averaged 26mpg, does this sound reasonable?

Luckily I'm changing jobs in 3 weeks and my new route will be much quicker.

I can't sell it as I'm too emotionally attached to it and it owes me to much money!

[V8HSV]

I often fill up around 150 miles, happier when its done 250 but thats only on longer runs, mine offers better return at 100 mph, better than 90, obviously the results were only obtained whilst driving on the continent. Empathise with you taking a car from NA to FI, yes you can get similar fuel consumption, it can actually improve but where is the fun in Granny throttle application.

[stigmundfreud]

ringram said:

Hey dude, are you running lean cruise? Ask your tuner if you are. On a trip it makes a good difference.
Also some people tune superchargers pretty rich to keep them safe. Dan at chipmaster in Oz actually goes for around 13:1 I wouldn't be surprised if some were as rich as 10:1
I used to get 400 miles to a motorway tank in my heavier VT2 R8 with at least the same power as a VXR500. Safe doesn't often equal efficient.

been looking at the leancruise as its a simple enabler but did it really make much difference? I'm now, even in openloop, getting 26mpg on the motorway - thats without pesky stft or ltft messing me about, thats also with dfco = off at the minute! I was hoping it wasnt running lean but all my BENS are 1.0 or +/-1 (using slightly scaled maf too)

[Turbo T]

Do you guys fit AFR gauges in these cars?

If the car is in the 13's on light throttle, there will be substantial fuel savings to be made trimming this back into the high 14's on a long run.

If anyone with a SC car here has an AFR gauge fitted, I would be really interested to hear what the car is tuned too @ WOT.

[anonymous-user]

I will try and get some answers from Mark on Monday. My car is running a 2bar Maffless tune which he built from scratch due to problems with the knock sensors going off all the time due to noise from the SC. He had to obtain a patch for the operating system for them and filter out the frequency that was making them retard the ignition all over the place. It's going on the rolling road for hopefully the last time so I'll ask him then.

Currently 512bhp but 3 degrees of extra advance should see 560bhp. Fingers crossed.

[stevieturbo]

Forget the rolling road, fine tune the fuelling etc on the road, and make it as lean as possible, when using your normal driving style, without actually hindering smoothness etc.

At cruise etc, no reason why you cant run mid 15's

[Turbo T]

wormus said:

I will try and get some answers from Mark on Monday. My car is running a 2bar Maffless tune which he built from scratch due to problems with the knock sensors going off all the time due to noise from the SC. He had to obtain a patch for the operating system for them and filter out the frequency that was making them retard the ignition all over the place. It's going on the rolling road for hopefully the last time so I'll ask him then.

Currently 512bhp but 3 degrees of extra advance should see 560bhp. Fingers crossed.

So the SC was emitting the same frequency as engine knock! Weird. When you say 2bar Mafless, I assume that is 1 bar positive pressure?

[stigmundfreud]

Turbo T said:

Do you guys fit AFR gauges in these cars?

If the car is in the 13's on light throttle, there will be substantial fuel savings to be made trimming this back into the high 14's on a long run.

If anyone with a SC car here has an AFR gauge fitted, I would be really interested to hear what the car is tuned too @ WOT.

I've tuned NA to 12.95 wot and in OL command 14.63 at present. With Lean cruise I'd like to know what it will run at - I might enable it this weekend and log to see what its at.

Without searching Richard, is there a way to test if the LC enabler is on?

[Turbo T]

stevieturbo said:

Forget the rolling road, fine tune the fuelling etc on the road, and make it as lean as possible, when using your normal driving style, without actually hindering smoothness etc.

At cruise etc, no reason why you cant run mid 15's

Steve, I regularly ran 15.2 cruise on my Supra with no ill effects, and have heard of people going as lean a 16 but that scares me a little.

Agree with the on the road fuel tuning as the load is always different. Love your Granada by the way, nearly lined up against you a few years ago @ TOTB.

[Island boy HSV]

Before ringram says anything could you get the dyno sheet at the wheels with no correction's

[anonymous-user]

stevieturbo said:

Forget the rolling road, fine tune the fuelling etc on the road, and make it as lean as possible, when using your normal driving style, without actually hindering smoothness etc.

At cruise etc, no reason why you cant run mid 15's

The ignition curve was built up on the roads and Mark has done an excellent job, much smoother than standard or the crappy Wortec tune I originally had. The rolling road is to do the power runs.

Apparently it's not that unusual for a SC or and after market exhaust to interfere with the knock sensors, all they do is detect vibration afterall. Mine is a 2005 model with the electric throttle and it's given Mark all sorts of headaches although I think we're almost there now.

Edited by anonymous-user on Friday 23 November 15:45

[wortec2]

I will give time to consider your post before I reply.

[Turbo T]

wormus said:

Apparently it's not that unusual for a SC or and after market exhaust to interfere with the knock sensors, all they do is detect vibration afterall. Mine is a 2005 model with the electric throttle and it's given Mark all sorts of headaches although I think we're almost there now.

Edited by wormus on Friday 23 November 15:45

I am going to take mine to Mark after Christmas for a health check. I will be very interested to see what he finds as it is nearly 7 years since LSV did the conversion, and I am sure he has found a lot out since then.

Edited by Turbo T on Friday 23 November 16:33

Edited by Turbo T on Friday 23 November 16:56

[stigmundfreud]

wortec2 said:

I will give time to consider your post before I reply.

[S600VXR]

If you love the car that much buy a shit box for commuting and save the Ro for fun or the occasional blast to work. Might work out about the same in total but your saving wear on what is an expensive car. OMHO mind.

[stigmundfreud]

S600VXR said:

If you love the car that much buy a shit box for commuting and save the Ro for fun or the occasional blast to work. Might work out about the same in total but your saving wear on what is an expensive car. OMHO mind.

400 p/m x 12 = 4800 quid

buy a astra diesel, pay about 120 month in fuel (if that) = 12x120+1k= 2440 = car paid for and in pocket

Edited by stigmundfreud on Friday 23 November 17:03

[monkfish1]

wormus said:

stevieturbo said:

Forget the rolling road, fine tune the fuelling etc on the road, and make it as lean as possible, when using your normal driving style, without actually hindering smoothness etc.

At cruise etc, no reason why you cant run mid 15's

The ignition curve was built up on the roads and Mark has done an excellent job, much smoother than standard or the crappy Wortec tune I originally had. The rolling road is to do the power runs.

Apparently it's not that unusual for a SC or and after market exhaust to interfere with the knock sensors, all they do is detect vibration afterall. Mine is a 2005 model with the electric throttle and it's given Mark all sorts of headaches although I think we're almost there now.

Edited by wormus on Friday 23 November 15:45

As this tune was carried out at our premises, could you enlighten me as to how it was "crappy". After we had replaced your o2 sensor that was defective it was functioning correctly when we handed the car back. At no time after this did you suggest there was a problem?