650 hp from a 3.5L
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JExpedition07
That One Member
Probably not.....most likely would predetonate and throw a rod through the side of the block....
It only says 91/93 is recommended which leads me to believe that it will run just fine on 87 like the Expeditions do
HP per liter has gone up significantly over the years.
https://www.roadandtrack.com/new-cars/g6482/10-cars-with-the-highest-specific-outputs/
The volvo xC90 is impressive:
The XC90's turbocharged and supercharged 2.0-liter engine makes 316 horsepower, giving it a specific output of 158 horsepower per liter.
...and folks are worried about 400HP on a 3.5L?
https://www.roadandtrack.com/new-cars/g6482/10-cars-with-the-highest-specific-outputs/
The volvo xC90 is impressive:
The XC90's turbocharged and supercharged 2.0-liter engine makes 316 horsepower, giving it a specific output of 158 horsepower per liter.
...and folks are worried about 400HP on a 3.5L?
JExpedition07
That One Member
They May be able to retard the timing and sense it with knock sensors but it will run like crap. High performance motors like the 5.2L Voodoo V8 and 3.5 HO have to compress more atmosphere and fuel to create more power so compression must be raised. At higher compression low octane fuel will predetonate and destroy the engine, you need a fuel more restistent to detonation to contend with higher compression. So it may run on it but it’s going to run like crap and put out a fraction of power it’s capable of on a high compression engine. Way different ball game than an expy. To create more power you must burn more fuel, which leads to this fun fact- The 3.5 GT gets worse gas mileage than the 8.1L Dodge Viper.
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Yeah their little thread they have going on this forum about hp numbers with 91 octane and ppl moaning and complaining about fuel octanes and summer/winter blends. It’s just comical along with MPG worries. Folks these are 5000 lb trucks in the shape of a cinder block (4th gens more of a squared off minivan) you aren’t gonna get impressive numbers unless you own a SWB 2WD and drive like a grandpa
So true. The way I see it is you break down a vehicle in 3 basic areas, size, mpg, HP. You get 2 out of those 3, the one you don’t choose is the big loser. Getting a Navi or expy you are choosing size and HP.
jeff kushner
Full Access Members
I've learned over the years that any "given engine" will make X amount of total power......I can move it in the rpm band, or I can concentrate ALL POWER at a very specific RPM such as the more explosive engines, be it a 70's two stroke or the Ducati 1299 engine which was also a bit of a handful BUT the overriding fact it, unless I change parameters, the engine power is finite.
All this talk on power/detonation....EVERYTHING in engine design is a compromise. I run 165PSI of static compression on this engine(remember that primary compression in a two stroke occurs UNDER the piston) ....dynamic combustion compression ratio is calc'ed to be OVER 16:1.....yet because of other porting features I incorporated when building, it makes 77HP , 17 more than optimistically advertised by Kaw...yet still does not detonate when run on 93ron. There are no electronics on this 40 + year design, no rider aids, nothing........and it runs perfectly!
jeff
All this talk on power/detonation....EVERYTHING in engine design is a compromise. I run 165PSI of static compression on this engine(remember that primary compression in a two stroke occurs UNDER the piston) ....dynamic combustion compression ratio is calc'ed to be OVER 16:1.....yet because of other porting features I incorporated when building, it makes 77HP , 17 more than optimistically advertised by Kaw...yet still does not detonate when run on 93ron. There are no electronics on this 40 + year design, no rider aids, nothing........and it runs perfectly!
jeff
NO ONE is using 87 in the Ford GT (not GT40) it is a $400,000-500,000 flawlessly designed, masterfully crafted, street legal race car. i can guarantee you that there is a program, switch, or setting to run high octane race gas from the factory. they sound amazing!!!!!
aggiegrad05
Full Access Members
From the Ford GT manual:
Choosing the Right Fuel
Use only premium unleaded gasoline with a minimum pump (R+M)/2 octane rating of 91. For optimal performance, use premium unleaded gasoline with an octane rating of 93 or higher.
The use of the correct fuel is an important part of the proper maintenance of your vehicle, and a condition of the vehicle Warranty. For this vehicle, the use of gasoline with an octane level of 91 or higher is required. The use of gasoline with an octane rating lower than 91 will invalidate the vehicle Warranty. It can degrade vehicle performance and lead to severe mechanical damage.
Note: Use of any fuel other than those recommended can impair the emission control system and cause a loss of vehicle performance.
Do not use:
Do not be concerned if the engine sometimes knocks lightly. However, if it knocks heavily under most driving conditions while you are using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.
Choosing the Right Fuel
Use only premium unleaded gasoline with a minimum pump (R+M)/2 octane rating of 91. For optimal performance, use premium unleaded gasoline with an octane rating of 93 or higher.
The use of the correct fuel is an important part of the proper maintenance of your vehicle, and a condition of the vehicle Warranty. For this vehicle, the use of gasoline with an octane level of 91 or higher is required. The use of gasoline with an octane rating lower than 91 will invalidate the vehicle Warranty. It can degrade vehicle performance and lead to severe mechanical damage.
Note: Use of any fuel other than those recommended can impair the emission control system and cause a loss of vehicle performance.
Do not use:
- Diesel fuel.
- Fuels containing kerosene or paraffin.
- Fuel containing more than 15% ethanol or E85 fuel.
- Fuels containing methanol.
- Fuels containing metallic-based additives, including manganese-based compounds.
- Fuels containing the octane booster additive, methylcyclopentadienyl manganese tricarbonyl (MMT).
- Leaded fuel (using leaded fuel is prohibited by law).
Do not be concerned if the engine sometimes knocks lightly. However, if it knocks heavily under most driving conditions while you are using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.
Seems to be called both Ford GT and GT40. Thanks for trying to correct me though!
JExpedition07
That One Member
I was a bit confused too..... but the manual posted clearly states NO 87 octane for the GT which is what I suspected. 91 Octane minimum.
jeff kushner
Full Access Members
"Do not be concerned if the engine sometimes knocks lightly. "
Ford really published this? Be VERY concerned if you suffer ANY "engine knock"? Over time, it's effects are devastating.
Picture the piston rising at over 4,000 feet per second, and just before it gets to the top of it's rotation, a sledge hammer slams into the crown of the piston.................this is as accurate a description of what actually happens as can be.......
Knowing this, are you really going to "not be concerned" if this is happening in your engine?
jeff
Ford really published this? Be VERY concerned if you suffer ANY "engine knock"? Over time, it's effects are devastating.
Picture the piston rising at over 4,000 feet per second, and just before it gets to the top of it's rotation, a sledge hammer slams into the crown of the piston.................this is as accurate a description of what actually happens as can be.......
Knowing this, are you really going to "not be concerned" if this is happening in your engine?
jeff
IT IS THE FORD GT. Whoever calls it differently, is wrong. Thats a fact Jack. Its heritage is of the GT40 family, but it is the Ford GT. Period. You're welcome!!!
I like GT40, there are a lot of wrong ppl then. And my name is not Jack, it’s jdizzleforshizzlemynizzle
Flexpedition
Full Access Members
Ford GT doesn't have a 3.5L under the hood.
aggiegrad05
Full Access Members
Yeah it does look it up brah
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