VVL Head on GTIR block

mreguest

Member
From speaking to a yank in vegas about their petrol being 87RON, he said all his foreign cars are down on power over there compared to the UK/Euro/Jap petrol for 95-100RON.

He had a subaru imprezza which he said probably dealt with things the best (i.e. the least bhp reduction due to RON) he had a maserati convertible which he said was a good 100bhp down on power just because of the RON. And a fooking massive escalade clearly a USA car designed for 87RON... (a yank tank 6.2L V8 beast which he took me for a spin in, very fast considering it's huge, but as they say there's no replacement for displacement...)

He wasn't particularly interested in getting the foreign cars mapped etc. he just liked going round corners well in the subaru, posing in the masi and daily driving in the escalade. He did suggest though that getting them mapped would easily bring them up to spec on low RON fuel, I don't know how true/easy this really is...

As vss says above it would be interesting to know how the yanks claim such big bhps from our small engined foreign cars. I do see the mad yellow gtir claiming 800bhp and maxworks saying similar, but I also saw a picture of them holding a can of race fuel which if I'm not mistaken is 105RON.

At the festival of speed a few years ago I saw BP showcasing some fuel which is 102RON and they used a Porsche 911 turbo. Strapped it down to rolling road ran it through with 95RON, then emptied the fuel tank and put 102RON in it, BOOM 70bhp more there and then, and they did this test over and over all day... why so good?

Same on tv 5th Gear once, they put normal 95RON in a Subaru Turbo and Clio na and Golf Turbo, then swapped it for 99RON and got 20bhp extra subaru, 8bhp extra Golf and 1bhp extra Clio (these values are 'ish' as I can't remember exactly), but they said modern ECUs can reprogram themselves really quickly and efficiently...?

Maybe more RON is the answer?
 

Empty Pockets

New Member
I was led to believe that the yanks rate their petrol different to us, and that their 93ron is the equivalent to our 99, they also have e85 at most pumps iirc so they have better pump fuel than us.... The e85 could be why they claim better figures from 'pump' fuel, but the general opinion is that their whp figures are really flywheel figures...
 

mreguest

Member
It turns out the 87RON I mentioned above was actually 87AKI, so this is about 91-92RON, 82-83MON.

Turns out E85 is 102-105RON, 85-87MON, 94-96AKI. According to wiki - http://en.wikipedia.org/wiki/Octane_rating

Anyway regardless of what RON is what... Has anyone in the UK actually ran a pulsar on E85, or BPs 102RON, or racefuel etc...?

Ed - have you mapped any on 'exotic' fuels, did you get much improvement?

At £3-5 per litre in the UK (http://www.trackstuff.co.uk/) it's a lot ££ compared to the USA, but race fuel might be cheaper per bhp than new turbos etc...?
 

campbellju

Moderators
Staff member
There's been discussions in the past and I looked into it seriously when E85 was being sold by Asda but not sure anyone has made the jump yet.
 

PobodY

Moderators
Staff member
Wasn't there one guy who was building a 500bhp car running on E85? - He gave up, broke, and sold it all didn't he?

The problem to my mind is that when you start talking about fuels other than petrol the octane number becomes a little academic. - Ethanol is a polar fuel, so it doesn't behave the same way as non-polar crude distillates. It flows differently, it has a different potential energy, different latent heat of evaporation... and so on.

You get less detonation from something like ethanol, but you need to burn a lot more of it to get the same energy as petrol. - Burning more fuel means more air in.
You may find that there are other factors like the fuel pressure needs to be changed, and that metal components start to corrode.

I'm not trying to be the prophet of doom. - Ethanol may be the future for many cars like this as fossil fuels get more expensive, and biofuels get cheaper... I just think you need to start from scratch rather than convert an existing (petrol) set up.
 

MarkTurbo

Well-Known Member
There's been discussions in the past and I looked into it seriously when E85 was being sold by Asda but not sure anyone has made the jump yet.
I ran E85 for a while back when Morrisons had it at the pumps. Apart from needing more of it compared to petrol (i was using 700cc injectors with a standard T28 set up :lol:) there are no downsides to it ;-) Shame they binned it off in this country as its a brilliant fuel 8)
 

fubar andy

Moderator & N/W Rep
Staff member
I ran E85 for a while back when Morrisons had it at the pumps. Apart from needing more of it compared to petrol (i was using 700cc injectors with a standard T28 set up :lol:) there are no downsides to it ;-) Shame they binned it off in this country as its a brilliant fuel 8)
How long ago was this?
 
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