Lund Racing to announce their tune results today at noon!

[GTBOB]

Is that AG?? Thought it was white


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Definitely not white. Look on the 1st page as you can see a "white" car behind the Shelby for reference.

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[Trackaholic]

I see that not much was changed down low (there is still a big jump @ 3200-3800 RPM). I wonder if the tuners will be able to determine why there is such a big dip in torque at the low end and if they can find a way around it.

-T

 

[wproctor411]

You guys need to learn a little about Ford's modern fuel systems and ECUs before you get sucked in by the old anti-E85 rhetoric.

If you run it out or refill regularly E85 is great, or drain it that is fine but many will go several months without driving these cars. Have you seen 6 month old E85? Chem separation and breakdown starts to be noticed and gums up much worse than regular fuels.. Aircraft are required to use leaded fuel, the main reasons are lubricating, cooling, cleaning and burn stability which contributes to life safety of pilot and passenger.

 

[Nataphen]

I've already mentioned that you shouldn't store the car with E85 in the tank.

 

[DrumReaper]

So... Can we get back to the tune in general? I wasn't aware that E85 could be the nay in the dirt that keeps getting beat over n over...


Moderator Edit: Posts regarding Lund/Evo's 1/4 mile run have been moved here.

 

[[email protected]]

Great news for all us GT350 owners thanks Lund and can we gain from a K&N air filter or is fords sufficient. 2015 shelby cobra GT350 Mustang deep impact blue with black stripes technology package Vin number 0088 can not wait to get it here in portland oregon Donny Hulstrom

 

[tuckermaclain]

Pretty good numbers. If it were to come standard with a turbo or a SC, imagine what you could do with relatively few bucks.

 

[Mikeiscoo2]

figure out if the intake manifold from the 350 can work on the 5.0... as for you people wondering why their is a power dip down low that is because of the flat crank. its a different type of motor. as well as the intake manifold could have some part in that as well

 

[mustang_guy]

figure out if the intake manifold from the 350 can work on the 5.0... as for you people wondering why their is a power dip down low that is because of the flat crank. its a different type of motor. as well as the intake manifold could have some part in that as well

Its already known that it won't work.

 

[Grimace427]

... as for you people wondering why their is a power dip down low that is because of the flat crank.

Why do people say this? What evidence points to the crankshaft as the reason for the low rpm bump and not something as simple as the tune or camshaft design?

 

[krt22]

Why do people say this? What evidence points to the crankshaft as the reason for the low rpm bump and not something as simple as the tune or camshaft design?

Because people like to point fingers at things for whatever reason

I dont think there is anything inherent with the FPC design that would preclude it from making power down low. The motor was just designed to put out a lot of HP relative to its displacement, which means designing it around moving air at high RPM. The more air it can move at the high end, the harder it is to build cylinder pressures on the low end.

Same principle as making turbo power, you can make big power without sacrificing low end torque and lag.

 

[Nataphen]

Why do people say this? What evidence points to the crankshaft as the reason for the low rpm bump and not something as simple as the tune or camshaft design?

Here's my hypothesis. I believe it's a combination of several things, including the crankshaft design.

Starting with the FPC, the lower weight and firing order actually generates less low end torque than the heaviness and smoother firing order of a CPC V8. After the crank gets spinning, the lightness and the more even exhaust pulses start to be more efficient than the CPC.

Next, the larger valves and cams. We haven't seen full cam specs yet, but I'd bet that not only are they larger (14mm or .550") lift, but higher in duration for high RPM power. Variable cam timing is a fantastic help for curing the low end losses of high duration cams and high flowing heads, but they can only adjust so far. On Lund's tune, the torque is significantly smoothed and bolstered in the low end, but we still see the engine having to climb into its efficiency range. Smaller cams, like in the Coyote, would likely make more low end torque in the Voodoo, but then the top end suffers.

Then, there's the 12:1 static compression. I think this could likely be the biggest reason for the torque jump in the stock tune. At low RPM during full throttle, the engine experiences its highest loads. As the RPM gets higher, loads are lower, and timing and cam tuning can start to get more aggressive without detonation. I believe that the stock tune, and even Lund's 93 octane tune seen above, are having to back off on ignition timing and bleed off dynamic compression through cam detuning to keep this engine from detonating. That's why they're able to make 23whp/22wtq more and spread the usable torque out with E85. With an NA Coyote, you're lucky to gain 10whp/10wtq over good 93 octane fuel, and your curves don't change at all.

 

[Grimace427]

Here's my hypothesis. I believe it's a combination of several things, including the crankshaft design.

Starting with the FPC, the lower weight and firing order actually generates less low end torque than the heaviness and smoother firing order of a CPC V8. After the crank gets spinning, the lightness and the more even exhaust pulses start to be more efficient than the CPC.

Let's not confuse torque with inertia. A heavy rotating assembly has a lot of inertia and stores a lot of potential energy that can be release at launch. This makes the engine feel 'torquey', however once in gear that heavy rotating assembly will actually inhibit acceleration. This potential energy does not show up on a dyno as torque because the clutch is already engaged when the pull starts.

I haven't seen any evidence that the firing order of the Voodoo negatively affects torque production. Perhaps it's there, but it hasn't been proven by anything. The Coyote isn't exactly a torque monster and when built to run to 8,000 rpm it definitely isn't a torque monster.

Then, there's the 12:1 static compression. I think this could likely be the biggest reason for the torque jump in the stock tune. At low RPM during full throttle, the engine experiences its highest loads. As the RPM gets higher, loads are lower, and timing and cam tuning can start to get more aggressive without detonation.

This is what I feel is the actual reason. The high static comp means Ford had to tune the engine very conservatively to run on pump gas and is the reason for the jump at 3,500rpm. Further tuning will show if this is the case.

 

[Nataphen]

You're correct about the inertia comment. I just sort of lump that together when talking about the crank and torque because people don't want to accept that the car IS going to be more difficult to launch because of this. Just as a lightened flywheel isn't always better, neither is a lightened crank.

However, the losses on the low end because of more efficient exhaust flow is a valid line of thought. I'm not saying I'm correct, but it makes sense. It's like comparing headers with larger primaries to ones with smaller primaries. On the low end, you will give up a little with larger primaries, but you gain in the top end.

Couple that with very large valves, high flowing CNC heads, and high RPM cams, and there may just not be enough adjustment in VCT to keep the airflow velocity up at lower RPM. Like you said, we'll see if some more tuning can help this out. Looking at the tune graphs though, you can see that Lund lowered the usable RPM by about 500RPM on E85. That may be about all she wrote. Small displacement, high-RPM setups have their limitations.

 

[cjgt350]

Same here I have a Speedway down the road with 115 and airport nearby with 100LL.

Do NOT use 100LL or Avgas in your modern vehicle. The lead package in the fuel will foul or ruin every associated sensor and run like crap.

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