Race fuel.

[Marti]

Hi guys, I help run a MX race team and just got a deal on Vp race fuel for the motorbikes, silly question but has anybody put race fuel in their Mas?

 

[philw696]

I have only ever put octane boost in mine but to be truthful on the road I can't realy notice any difference so I just use good fuel bp or shell.

 

[Dan!]

I'd imagine you'd need a remap to get the most from it or it'll just run a little hotter.

 

[Marti]

Yes I guess your right we re-map the bikes to suit exhaust, tuning etc . I bet re-mapping a 3200 with twin turbos would pump lots of horses........nearly as many horses as Tesco are selling!!

 

[kodpkd]

If you don't have the compression to take the extra octane,, higher octane will actually lower your HP. High octane is only necessary for high compression.

 

[Grinzzz]

Careful, not familiar with VP but I've seen stuff described as race fuel that's leaded. Unleaded race fuel would probably be fine BUT if you do get an increase in performance there something not quite optimal with your engine. A lot of the race fuel also doesn't contain the quantity/quality of detergent that modern engines appear to thrive on.

 

[Emtee]

If you don't have the compression to take the extra octane,, higher octane will actually lower your HP. High octane is only necessary for high compression.

Hi Kodpkd, I'm no expert at all, but I can't get my head around this?

I understand increasing compression can generally increase HP, but also the risk of knock, so higher octane content allows for this extra compression, but I don't see how there would be a negative of high octane in a low compression engine. Under low compression surely octane content becomes irrelevant in the real world in terms of road car engines. It's an air/fuel mixture that will ignite with the same resulting force as a lower octane air/fuel mixture so long as it's away from the risk of knock?

 

[fcz360]

Grinzzz is right regarding lead. But this depends on what the fuel is race fuel come in all sorts of grades. My concerns would be cats, valves and seats. The detonation rate is higher in line with octane so it will burn out. I think Vp comes in 108-120

Race engines tend to be higher compression 14-18:1 and designed and set up to take the fuel but realistically for the added performance im not sure its a good idea. I would think my 4.7 would be less than 12:1

However we have found the higher the octane the lower the consumption on the beds but with larger engine capacities.

 

[kodpkd]

The down side using higher octane is 2 fold.. You will actually get less power,, and it costs more. Higher octane fuel is less volatile, which is why is doesn't knock in high compression engines. I know this goes against what most people think,, but true. It's kind of like mixture,,, an engine doesn't make more power with richer mixture. The most power is when your mixture is at the point of burn down. Like wise the post power is when your engine is burning the lowest octane without knock. Really true!