Discussion
I'm just curious, planning to run the car on 100ron msa approved 'pump' fuel this year. Will this put my consumption up? As in for the same distance travelled and throttle position on 97 Vpower, will it use the same volume.
As I've read on e85 and other fancy fuels they need to burn more to create the same power, less calorific or something. My only concern is in longer races I run too low with my capacity.
I'm not mapping the car for it to make power, just running it to offer slightly better pick up and protection for the engine.
Thanks
As I've read on e85 and other fancy fuels they need to burn more to create the same power, less calorific or something. My only concern is in longer races I run too low with my capacity.
I'm not mapping the car for it to make power, just running it to offer slightly better pick up and protection for the engine.
Thanks
If you don't change your mapping there will be very little difference. The calorific value of most gasolines is very similar. If you were to remap to take into account the extra knock resistance from the higher octain fuel, you could either make the same power burning less fuel, or make more power burning the same amount as you currently do.
Ok thanks, that makes sense. So it won't reduce my range.
So even without mapping my engine will it be less likely to suffer knock/det by using the higher rated fuel? As that's my main interest for the 45 minute races where things will get a bit hotter.
I'm already at the power limit for my class so don't want more power.
Cheers
So even without mapping my engine will it be less likely to suffer knock/det by using the higher rated fuel? As that's my main interest for the 45 minute races where things will get a bit hotter.
I'm already at the power limit for my class so don't want more power.
Cheers
Edited by Hollowpockets on Saturday 29th March 16:28
Can I ask what "pump fuel" you are using?
Octane doesn't equate to power either. The main benefit of a proper race fuel is it is far better made so that it burns more evenly and completely. It is also consistent (same blend every time, which pump fuel isn't) so it allows for better throttle control/response and removes one more variable.
A faster burn will enhance acceleration more than anything. Often a faster burning fuel allows you to dial back the timing as well.
It is also designed to enhance compression, lower temps and allow you to turn the engine up. Now obviously by doing this you will possibly gain some power, which may lead to slightly high consumption. However if you are using a crap fuel then a potion never gets burnt anyway so this helps off set it.
For me the main reason I would use a race fuel is to protect the engine.
Octane doesn't equate to power either. The main benefit of a proper race fuel is it is far better made so that it burns more evenly and completely. It is also consistent (same blend every time, which pump fuel isn't) so it allows for better throttle control/response and removes one more variable.
A faster burn will enhance acceleration more than anything. Often a faster burning fuel allows you to dial back the timing as well.
It is also designed to enhance compression, lower temps and allow you to turn the engine up. Now obviously by doing this you will possibly gain some power, which may lead to slightly high consumption. However if you are using a crap fuel then a potion never gets burnt anyway so this helps off set it.
For me the main reason I would use a race fuel is to protect the engine.
OK I'm with you. The RSUR, 99 octane. I was called Sunoco69 on here but change my user name for various reasons.
I don't think this will make a massive change to your MPG but you wont know anything for certain until you get out on track and do some running. So your not mapping or altering the engine in any way? So all the fuel will do is as I said above and what they told you. Running cooler engine temps will help later in the summer (if we get one).
Hopefully I will be at some of your events and we can have a proper chat.
I don't think this will make a massive change to your MPG but you wont know anything for certain until you get out on track and do some running. So your not mapping or altering the engine in any way? So all the fuel will do is as I said above and what they told you. Running cooler engine temps will help later in the summer (if we get one).
Hopefully I will be at some of your events and we can have a proper chat.
Ah ok, yeah sounds good.
I'll try the fuel out next weekend at Knockhill so will see how the engine reacts to it.
Nope I won't run any different to how it is now, just hope that because it's turbo'd I'm less likely to melt something or see any drastic drop in power when things do get hot.
I do also run water injection so that should help keep things a tad cooler also.
I'll try the fuel out next weekend at Knockhill so will see how the engine reacts to it.
Nope I won't run any different to how it is now, just hope that because it's turbo'd I'm less likely to melt something or see any drastic drop in power when things do get hot.
I do also run water injection so that should help keep things a tad cooler also.
It won't really make your engine run any "cooler" tbh.
"Cooler" can mean two totally different things, ie Exhaust Gas temperature and internal engine metal temps (cyl head, valves, pistons etc) if you inject the same amount of fuel, and burn it at the same chamber volume (ie with the same ignition angle) then the engine temps, both EGT and component temps will be unaffected.
The differences in volatility at high loads and speeds are irrelevant really, and the tiny burn rate improvement over normal "pump" grade unleaded fuel will be immeasurable.
"Cooler" can mean two totally different things, ie Exhaust Gas temperature and internal engine metal temps (cyl head, valves, pistons etc) if you inject the same amount of fuel, and burn it at the same chamber volume (ie with the same ignition angle) then the engine temps, both EGT and component temps will be unaffected.
The differences in volatility at high loads and speeds are irrelevant really, and the tiny burn rate improvement over normal "pump" grade unleaded fuel will be immeasurable.
Max_Torque said:
It won't really make your engine run any "cooler" tbh.
"Cooler" can mean two totally different things, ie Exhaust Gas temperature and internal engine metal temps (cyl head, valves, pistons etc) if you inject the same amount of fuel, and burn it at the same chamber volume (ie with the same ignition angle) then the engine temps, both EGT and component temps will be unaffected.
The differences in volatility at high loads and speeds are irrelevant really, and the tiny burn rate improvement over normal "pump" grade unleaded fuel will be immeasurable.
Sorry but that is incorrect. Race fuel burns more completely and evenly than pump fuel so it will effect temps. "Cooler" can mean two totally different things, ie Exhaust Gas temperature and internal engine metal temps (cyl head, valves, pistons etc) if you inject the same amount of fuel, and burn it at the same chamber volume (ie with the same ignition angle) then the engine temps, both EGT and component temps will be unaffected.
The differences in volatility at high loads and speeds are irrelevant really, and the tiny burn rate improvement over normal "pump" grade unleaded fuel will be immeasurable.
For example a couple of years ago I was at Snetterton on a really hot weekend for the HRDC and the support races were all the old boys in MG's. They were really struggling with engine overheats until 3 of them put our race fuel in. End result was they solve the problem, word went out and I was busy as hell as the whole bloody paddock of the blue rinse brigade wanted fuel.
Edited by Grumfutock on Sunday 30th March 09:43
Grumfutock said:
Max_Torque said:
It won't really make your engine run any "cooler" tbh.
"Cooler" can mean two totally different things, ie Exhaust Gas temperature and internal engine metal temps (cyl head, valves, pistons etc) if you inject the same amount of fuel, and burn it at the same chamber volume (ie with the same ignition angle) then the engine temps, both EGT and component temps will be unaffected.
The differences in volatility at high loads and speeds are irrelevant really, and the tiny burn rate improvement over normal "pump" grade unleaded fuel will be immeasurable.
Sorry but that is incorrect. Race fuel burns more completely and evenly than pump fuel so it will effect temps. "Cooler" can mean two totally different things, ie Exhaust Gas temperature and internal engine metal temps (cyl head, valves, pistons etc) if you inject the same amount of fuel, and burn it at the same chamber volume (ie with the same ignition angle) then the engine temps, both EGT and component temps will be unaffected.
The differences in volatility at high loads and speeds are irrelevant really, and the tiny burn rate improvement over normal "pump" grade unleaded fuel will be immeasurable.
For example a couple of years ago I was at Snetterton on a really hot weekend for the HRDC and the support races were all the old boys in MG's. They were really struggling with engine overheats until 3 of them put our race fuel in. End result was they solve the problem, word went out and I was busy as hell as the whole bloody paddock of the blue rinse brigade wanted fuel.
Edited by Grumfutock on Sunday 30th March 09:43
From my experience with race fuel, unless you map the car, the only difference you will get, is a better throttle response,ie, smoother, as the higher octane fuel will detonate more consistently compared to standard pump fuel, which in a race car will get you out the corners smoother.
Temps are unlikely to be affected.
If you map the car the differences will be greater, but temps may still not be affected,
In short Graham, you are better running with race fuel, but get the car mapped. IMO of course
Temps are unlikely to be affected.
If you map the car the differences will be greater, but temps may still not be affected,
In short Graham, you are better running with race fuel, but get the car mapped. IMO of course
Grumfutock said:
OK if a fuel burns faster and more completely then it will lower cylinder temps as the burn is more even and faster. Normal fuel is all over the place.
Except that it's just the opposite...If it burns faster, then the cylinder pressure (and therefore temperature) will be higher for the same ignition angle - i.e. changing nothing else. Exhaust gas temperature will be lower.
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