Stock Rod Limit

[EcoSwag1990]

While I do appreciate you coming out and providing your findings, it does seem like it was a crappy tune where boost was just cranked way up

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[Juben]

Guys, I'm not saying that what they were doing was a good idea, but Brad has been pretty clear in that they were trying to push it to it's limits. Although I think the engine will hold more hp/tq than that reliably on a good tune, it did kind of give us a rough starting point of what to look at and gave us a dang good idea of what NOT to do lol.

 

[BGolden]

I am considering closing this thread as I have asked repeatedly to discuss the motor and the limits. Not opinions of the tune.

I started this thread to help the community. Its the only reason.

 

[EcoSwag1990]

True but it doesn't seem like you've found the limits in a reasonable manner. What we are saying is that given a different tune this same power/torque could be made more reliably

 

[BGolden]

Pull your motor apart and take a real good look at those rods. Then get back with me about how much torque you wanna push through them. Do you know that Ford does not machine the rod end caps? They break them off. Ford did not build this motor to make that kinda of torque, and I know that now.

No one has come in and had a discussion about making 450+ ft/lbs of torque on the stock bottom end. I haven't seen anyone else push over 450 Ft/lbs either. I put my engine at jeopardy not a customers and I did this so we would know, and it held up for several days abused and finally let go when I had free time on my dyno to see what it was pushing. I was headed to the track with it the next day to find out if I could meet my goal.

I was pushing it stupid hard for a reason. If you read through my posts you will see why.

 

[Brent302]

I'd say you would be fine. There are tuners who are beyond 400 wheel tq without grenaded motors.However you'll probably be a decent amount less I'd guess, which is pretty safe IMO.

Yet

 

[dragonacc]

Pull your motor apart and take a real good look at those rods. Then get back with me about how much torque you wanna push through them. Do you know that Ford does not machine the rod end caps? They break them off. Ford did not build this motor to make that kinda of torque, and I know that now.

No one has come in and had a discussion about making 450+ ft/lbs of torque on the stock bottom end. I haven't seen anyone else push over 450 Ft/lbs either. I put my engine at jeopardy not a customers and I did this so we would know, and it held up for several days abused and finally let go when I had free time on my dyno to see what it was pushing. I was headed to the track with it the next day to find out if I could meet my goal.

I was pushing it stupid hard for a reason. If you read through my posts you will see why.

I personally think people are being overly rough and blaming your tune as an easy way for them to feel better about what their own engine will hopefully be able to handle some day.

I imagine when MAP blows up their stock bottom end (on purpose or not doesn't matter) if it's close to the same wtq as yours when it goes the critics won't have much to say anymore.

 

[EcoSwag1990]

I personally think people are being overly rough and blaming your tune as an easy way for them to feel better about what their own engine will hopefully be able to handle some day.

I imagine when MAP blows up their stock bottom end (on purpose or not doesn't matter) if it's close to the same wtq as yours when it goes the critics won't have much to say anymore.

I don't plan on doing anything else but intercooler under the hood. Most of us, myself included have no intention of taking the engine that far. Im just observing the fact that this test was done at very low rpm with like 29psi of boost

 

[Impulsed7]

Umm, forged one piece rods that are cracked at the end cap are stronger than most machined pieces... unsubscribed...

 

[Herr_Poopschitz]

Umm, forged one piece rods that are cracked at the end cap are stronger than most machined pieces... unsubscribed...

Gotta give the guy the benefit of the doubt.

Stock rods simply don't have enough meat through the beam to account for the crippling stresses that are seen at these higher than 'design-to' loads. Increase cross section height, increase flange thicknesses, change to a good material (powder 'forged'...c'mon) can all increase the strength in compression.

Basic solution would seem to be to keep cylinder pressures at a safe level, but spin the little guy faster...then see what new part breaks...lotta factors in this however, most blatant is the mass flow capability of the compressor used.

Tension in the rod? Lose valve stability due to weak springs? Hell...oil pump? Kaboom.

Fun times ahead for sure...and sure glad it's not on my dime. There's a lot of $ to be made on this platform. The first to work out the bugs will probably be greatly rewarded.

:clap2: you guys.

 

[MAPerformance]

Just so everyone has an idea what the stock rods look like:

I've seen worse.

 

[arghx7]

If you don't have some kind of detailed metallurgical analysis, or inside information on the design limits of the stock pieces, you can't make a judgment just by looking at them. Lots of old engines may look like they have "beefy" components that doesn't mean they are stronger than brand new designs.

Google "cracked rods" and this is the first image that comes up:

 

[arghx7]

Gotta give the guy the benefit of the doubt.

Stock rods simply don't have enough meat through the beam to account for the crippling stresses that are seen at these higher than 'design-to' loads.

The stock rods were designed to be robust to low speed preignition, so they have some reserve strength in them. Engines that aren't designed that way can blow up when stock. Look at the Hyundai 1.6 and 2.0 turbo DI engines.

Basic solution would seem to be to keep cylinder pressures at a safe level, but spin the little guy faster

Hard to do that without measuring cylinder pressure, which will cost as much as your car does.

 

[Juben]

It blows my mind to think that Ford would have put weaker rods in the 2.3 than it did with the 2.0 (FoST/Fusion) from which is was based. As popular as the EB platform has grown to be in the aftermarket, and especially with this being in a Mustang, you'd think they'd be fully aware that people are going to beat on them some.

Those cars (FoST) reliably put down over 400+ whp/wtq without problems. I might be proven wrong, but I really think we'll see these motors reliably produce similar numbers.

 

[Herr_Poopschitz]

The stock rods were designed to be robust to low speed preignition, so they have some reserve strength in them.

Correct...strength taken account in what some in other industries call 'design-to' loads. Designing beyond this either means the rod is too heavy to meet performance targets or too expensive to manufacture...designing below comes up w/ negative MS's, which will usually fail at the slightest hiccup.

Hard to do that without measuring cylinder pressure, which will cost as much as your car does.

Correct me if I'm wrong, but torque output is a good indicator, no? You don't need physical pressure sensors for what's at best eyeball engineering in the aftermarket world.

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