USA vs UK Drag Times / Fuel octane **same car**
Discussion
From this post:
http://www.pistonheads.com/gassing/topic.asp?h=0&f=66&t=143928
Some may recall I left the UK some time ago... Well, I thought I'd give an update on how my mini likes the US spec fuel and the times on the 'strip. Makes for interestign reading - and I'm glad to report that everything - bar maybe the calorific value of the US fuel - all seems to be the same!
Ok a few things to first note:
1) On the UK run I had a basically 'empty' car - no tools or anything. On the USA run I had (at a guess) 40/50kg of 'ballast' (total car weight according to the scales at the US track was 1860lb / 843kg incl driver).
2) The UK time was not my best ever (13.856@101), but a typical time.
3) The car was exactly the same spec as per the time it raced in the UK - the clutch was on its last legs but seemed to 'just' hold up on the track, so is pretty much 'as is'.
4) The car was sipping 93 octane (Ron+Mon/2) fuel on the USA runs, 98 octane fuel (Ron) in England. No noticable difference in 'knock' or detonation noticed, but vehicle doesn't seem to pull quite as hard as it used to (but by a minute amount - will be doing a leakdown test soon).
5) The USA track is approx 1000ft above sea level - not sure about York or AvonPark, but I recall Manchester is something like 100ft above sea level.
6) Air charge temps on the USA runs were typically 5-7 degrees hotter than the runs at Avon Park in 2004.
7) Finally - The USA run was pretty much a 'perfect' run regards traction and launch - the best I did all night at the strip.
Here are some comparitive tickets:
http://www.turbominis.co.uk/iain/up/drag_time.jpg
http://www.pistonheads.com/gassing/topic.asp?h=0&f=66&t=143928
Some may recall I left the UK some time ago... Well, I thought I'd give an update on how my mini likes the US spec fuel and the times on the 'strip. Makes for interestign reading - and I'm glad to report that everything - bar maybe the calorific value of the US fuel - all seems to be the same!
Ok a few things to first note:
1) On the UK run I had a basically 'empty' car - no tools or anything. On the USA run I had (at a guess) 40/50kg of 'ballast' (total car weight according to the scales at the US track was 1860lb / 843kg incl driver).
2) The UK time was not my best ever (13.856@101), but a typical time.
3) The car was exactly the same spec as per the time it raced in the UK - the clutch was on its last legs but seemed to 'just' hold up on the track, so is pretty much 'as is'.
4) The car was sipping 93 octane (Ron+Mon/2) fuel on the USA runs, 98 octane fuel (Ron) in England. No noticable difference in 'knock' or detonation noticed, but vehicle doesn't seem to pull quite as hard as it used to (but by a minute amount - will be doing a leakdown test soon).
5) The USA track is approx 1000ft above sea level - not sure about York or AvonPark, but I recall Manchester is something like 100ft above sea level.
6) Air charge temps on the USA runs were typically 5-7 degrees hotter than the runs at Avon Park in 2004.
7) Finally - The USA run was pretty much a 'perfect' run regards traction and launch - the best I did all night at the strip.
Here are some comparitive tickets:
http://www.turbominis.co.uk/iain/up/drag_time.jpg
A friend had his viper tuned in the states, also using their 93 octane pump fuel.
On returning home, it was detonating on 98 RON fuel.
US fuel is of better quality than our UK crap.
Have you considered adding more timing etc to see if it will run better on the US fuel ?
>> Edited by stevieturbo on Thursday 28th July 00:08
On returning home, it was detonating on 98 RON fuel.
US fuel is of better quality than our UK crap.
Have you considered adding more timing etc to see if it will run better on the US fuel ?
>> Edited by stevieturbo on Thursday 28th July 00:08
I've yet to find a rolling road this side of Detroit who'll let ME do the mapping to see what - if any - more advance it'll take, but I doubt much more really.
It is interesting that 'your friend' had such a bad experience, wheras in my particular verified case with facts supporting for all to see, I've found little or no difference however. Was your friend there when his car was being mapped then - I'd imagine so if he's gone to the expense of exporting, then importing a car just to get it tuned (sounds a little excessive?)
It is interesting that 'your friend' had such a bad experience, wheras in my particular verified case with facts supporting for all to see, I've found little or no difference however. Was your friend there when his car was being mapped then - I'd imagine so if he's gone to the expense of exporting, then importing a car just to get it tuned (sounds a little excessive?)
He was over several times during the build.
I think it basically boiled down to, who in the UK would you trust to work on such a project ?
It made 920rwhp over there, so it was a fairly big project.. The guy who mapped it has been over in the UK since, and re-mapped it for UK. It did lose power, although hard to quantify how much, as it was done on different dynos, and different countries. etc.
Regardless of power made on any dyno, the simple fact was it was detonating on UK fuel, whereas it was safe in the US, on their pump fuel, and warmer climate.
I think it basically boiled down to, who in the UK would you trust to work on such a project ?
It made 920rwhp over there, so it was a fairly big project.. The guy who mapped it has been over in the UK since, and re-mapped it for UK. It did lose power, although hard to quantify how much, as it was done on different dynos, and different countries. etc.
Regardless of power made on any dyno, the simple fact was it was detonating on UK fuel, whereas it was safe in the US, on their pump fuel, and warmer climate.
More will be revealled once the leakdown proves all is ok, and the next track run that'll be done with an empty car!
The times are ok for a heavy (by mini standards) mini... Weight loss would see them improve, as would more boost, but I suspect my turbine housing is cracked as it simply won't boost over 16psi. All seems well, and I don't want to push it further until I've gained confidence with the fuel over here...
www.turbominis.co.uk/iain/up/frnt.jpg is a pic of the engine being fitted the last time.
I might put 'regular' in it next 'gas-stop' to see how it feels with that stuff. Again - I'll see how the knock resistance is first - I know how close it was when I ran on 95Ron in England. If ok, I'll open it up on the strip - the times will tell the truth.
Stevie - Shame your friend didn't do something like a few drag-strip runs before returning to the USA to give evidence as to if it's just the 'knock resistance' of the fuel that's different, or the calorific value aswell.
>> Edited by turbodave on Thursday 28th July 19:57
The times are ok for a heavy (by mini standards) mini... Weight loss would see them improve, as would more boost, but I suspect my turbine housing is cracked as it simply won't boost over 16psi. All seems well, and I don't want to push it further until I've gained confidence with the fuel over here...
www.turbominis.co.uk/iain/up/frnt.jpg is a pic of the engine being fitted the last time.
I might put 'regular' in it next 'gas-stop' to see how it feels with that stuff. Again - I'll see how the knock resistance is first - I know how close it was when I ran on 95Ron in England. If ok, I'll open it up on the strip - the times will tell the truth.
Stevie - Shame your friend didn't do something like a few drag-strip runs before returning to the USA to give evidence as to if it's just the 'knock resistance' of the fuel that's different, or the calorific value aswell.
>> Edited by turbodave on Thursday 28th July 19:57
HarryW said:
I would have thought that the increase altitude and temp alone would easily accounted for the time, let alone the different grip levels between the strip surfaces.
Mighty fine times IMHO for a mini, what rwhp does it have btw, I assume standard not.
Harry
I believe it has zero rwhp lol, might have a few horseys at the front wheels though...
He only entered one event while over in the US, which was the Silverstate mile in Nevada ( circa 6000ft, so down on boost being supercharged )
It was supposed to be a mile run, but was reduced to 1/2mile due to high sidewinds. He won that event, beating the JUN twin turbo 350z.
He did get a couple of mile runs, and was close, or maybe even achieved the magic 200 from viewing datalogs.
Must actually ask what his 1/2 mile times were....
He'll be running this weekend and TOTB in Elvington, and will be using US spec fuel that he bought, so be interesting to see what times it manages, as long as it stays dry.
Perhaps later in the year he may run on regular pump fuel too if he gets the chance.
Must admit, my mini always ran on 4 star. Its never been on the road much since its demise.
Our times are quite different, although terminals are pretty much the same. I suspect you are getting better traction maybe ? Mine never really fully gripped until about 70mph, although with its gearing, I was crossing the line still in 3rd.
I was running about 20psi at most on 4 star. Maybe some day I'll sort the rust out, and get it back for some further development.
I just stopped driving it, as I moved onto bigger cars. The mini was quite dangerous really when I look back.
Dave,
If you plot the burn/pressure characteristics of the fuel against T, the plots will vary from fuel to fuel. When I say that, I mean the components, whether the fuel is aromatic (lots of cyclic hydrocarbons like xylene/toluene/benzene) or paraffinic (di-methyl octane, etc-branched chains) The leaded in the UK has quite a high benzene load which is good for octane but crap for lead response. If you can find out if the fuel you're using is paraffinic, you should be able to throw buckets of tetraethyl lead in there and get about 130 octane. Should see some good results.
I'd be interested in finding out about your fuel. Keep us posted.
Stu
If you plot the burn/pressure characteristics of the fuel against T, the plots will vary from fuel to fuel. When I say that, I mean the components, whether the fuel is aromatic (lots of cyclic hydrocarbons like xylene/toluene/benzene) or paraffinic (di-methyl octane, etc-branched chains) The leaded in the UK has quite a high benzene load which is good for octane but crap for lead response. If you can find out if the fuel you're using is paraffinic, you should be able to throw buckets of tetraethyl lead in there and get about 130 octane. Should see some good results.
I'd be interested in finding out about your fuel. Keep us posted.
Stu
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