FI Reliability Support— Beyond OPG/CS

[Zrussian13]

I’m sorry guys. I really am not trying to start some sort of thread that causes you to be annoyed. I’m just trying to learn.

The truth is, there are plenty of people just like me that come and go in this community. I truly wish I had the knowledge based that you guys do. But the cold hard truth is, I don’t. I didn’t have a father that took the time to show me these things, and I’ve not been blessed with resources and opportunities to learn. People like me are creating those opportunities and trying to not reinvent the wheel by connecting with knowledgeable people. There is no better place to do that than on an online forum where people literally go to discuss things of this nature.

Just trying to learn something here and put together a thread that could be useful for somebody down the road.

There's 100 threads just like this one so of course we are going to give you shit! Don't take it personally. Some of us enjoy messing with people. Enjoy your learning. Gotta start somewhere.

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[Angrey]

This type of question gets asked a zillion times, because everyone is interested in economizing their efforts to make the car better/faster (and not push it to the point of failure). It gets asked in every type of enthusiast group that involves mechanical systems that produce an output.

But it's kinda like asking "how long will a piece of rope last" and the answer is largely,..........that depends on a lot of things.

The difficult part about truly addressing the question is there are just so many variables, and that leads us to my point which is, OEM manufacturers recognize that there's a ton of variables in the equation (how the driver will use or abuse the car, fuel, temperatures, load, etc) which is why they choose the output they do.

Could Ford release their motors with tunes that make more? (setting aside the EPA and economy pressures) absolutely. And they do offer SOME improvement with FRPP tunes/components.

I myself am on my 3rd mustang build and I learned (both from personal experience and from others) that the correct approach is more like the OEM approach, overbuild it and underutilize it.

If I want it to last at 800 rwhp, I'm going to take what everyone says is good for 1200 hp and build it that way. Lots of guys will say "that's not necessary" but until you've been on the side of the road, in the dark, with the flashers on, waiting for the tow truck, with that sick feeling in your gut, wondering what it is THIS TIME and how much it's going to cost, it's hard to learn the discipline of "over engineer and under utilize."

I've also tried to learn over the years what types of use actually put more stress and strain on the power train and supporting systems.

So in summary, if you want to drive any which way (redline shifts at WOT, dropping the clutch or a 2 step from the roof on a launch, hot lapping the car back to back to back or pulling all the way to redline for extended periods of time, etc, etc) then you need to overbuild it. If you're selective in how you abuse the car, it will last longer (but still be a risk if you run it right to the edge).

The other aspect here is that tuners have to produce results that keep them competitive with other shops. Most tuners will NOT give you a safe tune. They'll give you a safe tune FOR THE DYNO. You actually have to demand or request that they back it down from where they would normally like to keep the tune.

Just because you CAN run 21 degrees of timing, should you? Just because you CAN run .82 Lambda on fuel, should you?

The optimal approach for any tune is to creep up on diminishing marginal returns (i.e. you've added another degree and instead of bumping 25 hp, it's now bumping 12 hp). Is that extra 12 hp worth the additional real world risk?

My last tune, I ran it out to 21 degrees, with fat fuel and actually had the tuner back it off a full 4 degrees. .75-.78 lambda at WOT enrichment. I could have redlined at 9k with built valve train components, but why? We capped it at 8k. As a result, the car made 100 less horsepower and about 70 ft-lbs less torque. But you know what? It'll live a LOT longer there than it would out near the edge of dyno sheet land.

The amount of performance you want as a goal, is simply an arbitrary number. Can you be happy at 900 horsepower or do you want the clout of 4 digit 1000 rwhp? What can you do at 1000 rear wheel horsepower that you can't do at 900? When is enough enough?

These are all philosophical things that come into play in this discussion. In the end, pick a number you want and you'll know you'll be "satisfied" and build it to actually handle more than that. Then beat on it and enjoy it to your liking.

 

[beetle6986]

1. Cats
2. Ring lands
3. Lots of drivetrain stuff
4. Opg/cs

So it's highly likely that Cats are on borrowed time with FI? Why do these cars in particular have this issue and what is recommended? offroad headers or aftermarket high flow cats?

 

[engineermike]

So it's highly likely that Cats are on borrowed time with FI? Why do these cars in particular have this issue and what is recommended? offroad headers or aftermarket high flow cats?

There is literally no good answer.

 

[SheepDog]

So it's highly likely that Cats are on borrowed time with FI? Why do these cars in particular have this issue and what is recommended? offroad headers or aftermarket high flow cats?

Long tube headers with slip fit catalytic converters that can easily be removed, inspected, and replaced as necessary. If you are racing, get a cat delete section that you can swap back and forth.

 

[Angrey]

So it's highly likely that Cats are on borrowed time with FI? Why do these cars in particular have this issue and what is recommended? offroad headers or aftermarket high flow cats?

Cats can fail in several ways. There are chemicals and compounds that poison the catalysts and reduce it's ability to spur combustion for unspent fuel over time (this is where running oil additives or fuel additives that are meant for offroad come in). If it fails for performance, you'll get codes because the 02's front and rear won't be registering a high enough delta.

But more commonly, heat and temperature can eventually melt them. The cats get hot from two sources, the amount of unspent fuel that it has to try to combust and also, just the sheer thermal transfer from hot exhaust. Having a boosted setup increases both. Even if you hold the same AFR, the boosted setup is just moving MORE exhaust so they have to work that much more to combust all the unspent fuels AND they're getting more heat transfer just from additional Q from the exhaust flow.

The failure once they melt is plugged exhaust.

The GT500 cats seem to be better, but they're wildly expensive. Some guys have reported success for a time using high flow cats, but there seems to be a crude power level that once you exceed, you eventually melt them.

 

[engineermike]

I’d like to see someone try hellcat converters. Might be a more economical but robust solution:

https://www.ebay.com/itm/1662623985...224687&hash=item26b602de2c:g:I0MAAOSwAehkzB9P

 

[beetle6986]

Cats can fail in several ways. There are chemicals and compounds that poison the catalysts and reduce it's ability to spur combustion for unspent fuel over time (this is where running oil additives or fuel additives that are meant for offroad come in). If it fails for performance, you'll get codes because the 02's front and rear won't be registering a high enough delta.

But more commonly, heat and temperature can eventually melt them. The cats get hot from two sources, the amount of unspent fuel that it has to try to combust and also, just the sheer thermal transfer from hot exhaust. Having a boosted setup increases both. Even if you hold the same AFR, the boosted setup is just moving MORE exhaust so they have to work that much more to combust all the unspent fuels AND they're getting more heat transfer just from additional Q from the exhaust flow.

This all makes perfect sense. The thing that seems odd to me is why don't other cars have this issue? I don't recall this being an issue with the 03 Cobras even when running higher HP levels. My car is already loud enough with the Borla Atak exhaust. I definitely don't want catless like Sheepdog mentioned.

 

[SheepDog]

This all makes perfect sense. The thing that seems odd to me is why don't other cars have this issue? I don't recall this being an issue with the 03 Cobras even when running higher HP levels. My car is already loud enough with the Borla Atak exhaust. I definitely don't want catless like Sheepdog mentioned.

I was really only recommending the catless setup for track use. These Coyotes are moving a ton of air when boosted and No catalytic converter is going to survive the heat and fuel forever. Being able to easily inspect and replace cats when necessary is your best option, which you cant do with the OEM manifolds. I had this discussion with a Gesi representative, and he told me that my only hope was to use the G-Sport 85230 - GESI 400 CPSI GEN 2 Advanced EPA Compliant cats, and even then, they won't last forever.

 

[Angrey]

This all makes perfect sense. The thing that seems odd to me is why don't other cars have this issue? I don't recall this being an issue with the 03 Cobras even when running higher HP levels. My car is already loud enough with the Borla Atak exhaust. I definitely don't want catless like Sheepdog mentioned.

As with most things, the OEM overdesigns components, to a degree. The 03 terminators were blown from the factory, so I'm imagining that they had room to spare in the cats for mildly modifying. Same with the Roush cars. The new gen GT500 etc.

With the stock coyote (not with a blower) it has some room to grow (out to say a Roush kit) but once you start exceeding those levels, it's well beyond it's performance range.

Most guys don't have problems with the cats at pedestrian boost levels (i.e. 750 or 800 crank HP), but when you start getting into 800 REAR wheel horsepower and above, you're talking about basically DOUBLE the output of the motor. There weren't a lot of 800 hp terminator's running around with cats still on the car (that I remember)

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