Exhaust headers

[Betterbuell]

Anyone done any dyno runs with U4 or MR12?

What are U4 & MR12 ?

[Doosh]

Fuel.

[Betterbuell]

Ok , like 91 or 98 in OZ

[d_adams]

http://www.vpracingfuels.com/motoroadracing.html

U4 looks to be 103 octane, MR12 is 87.

[Doosh]

Ok , like 91 or 98 in OZ

Not really. Both are oxygenated racing fuels.

[GJB]

Yes, oxygenated. Gives a 5% or so HP increase and much crisper throttle response.