5.0 Performance parts
10-08-2012, 09:36 AM
#51
Senior Member
I'd have to say roughly around there, my Supercharged Thunderbird gains about 30hp/30tq to the rear wheels just through timing advance with E-85 over straight 91 BUT I don't run my E-85 tune in it as my 42# injectors are RIGHT at 100% duty cycle at the rev limiter 
, they only see ~70% on 91.
, they only see ~70% on 91.
10-08-2012, 01:31 PM
#52
The 5.0 is pretty nice as is. A good tune like the 5 Star is good bang for the buck as far as performance gains.
Too many have found little or no gain for the dollar chasing other options. Several methods change the sound of the truck without doing much for performance. And in some cases the owners have not been pleased with the "new" sound.
If you really need more than a tuned 5.0 has to offer, you might have bought the wrong truck.
Too many have found little or no gain for the dollar chasing other options. Several methods change the sound of the truck without doing much for performance. And in some cases the owners have not been pleased with the "new" sound.
If you really need more than a tuned 5.0 has to offer, you might have bought the wrong truck.
10-08-2012, 09:52 PM
#53
I'd have to say roughly around there, my Supercharged Thunderbird gains about 30hp/30tq to the rear wheels just through timing advance with E-85 over straight 91 BUT I don't run my E-85 tune in it as my 42# injectors are RIGHT at 100% duty cycle at the rev limiter , they only see ~70% on 91.
, they only see ~70% on 91.There are several reasons why there are a lot of different numbers thrown out there for E85's octane rating, generally ranging between 95 and 115.
1. The "octane rating" we see is a average of two numbers- research octane rating (RON) and motor octane rating (MON.) The research octane number is determined by running an engine at lower loads and motor octane is determined at high loads. The RON is always higher (light loads = less pinging) and is what the rest of the world uses as their "octane rating." That's why Europeans seem to have much higher octane gas. However we Americans do actual work and use an average between the low-load RON and the lugged-engine MON called the Anti-Knock Index (AKI) as our "octane rating." That's where the (R+M)/2 on the octane sticker comes from. E85's RON is 102 and the MON is 90. Regular unleaded 87 AKI has an RON of 91 and a MON of 83. Premium 91 AKI has a RON of 95 and a MON of 87.
2. Federal law does not mandate posting the AKI on the pump for E85 or for that matter any fuel with more than 10% ethanol. Since it is not mandated to be posted most places don't post it and the average guy who doesn't search for research papers online doesn't know the actual AKI octane rating of the fuel. The AKI must always be posted for gasoline fuels and everybody who pumps their own fuel knows that regular in most areas is 87 octane and premium is 91-93.
3. Ethanol is much more volatile than gasoline. This increased volatility leads to a cooler charge air compared to gasoline and increases the CR you can run on 96 AKI E85 vs. 96 AKI gasoline. That's where the 105 octane figure comes from- E85 allows roughly the same CRs as 105 AKI racing gasoline.
4. Ethanol has a very nonlinear octane-increasing ability when mixed with gasoline. Mixing 10% ethanol with 90% 87 AKI gasoline yields a fuel with a 91 AKI. 30% ethanol and 87 octane has an AKI around 94. Going up to 50% ethanol has an AKI of 96- the same as E85. The ability of ethanol to increase gasoline AKI at low concentrations is called the blending octane and is usually quoted at around 115, because mixing 10-20% ethanol with regular gasoline increases the octane as if you had mixed in that quantity of ~115 octane gasoline. Some people, especially ethanol supporters, like to use the blending octane number when referring to the octane of ethanol.
Hope that clears stuff up.
