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Compensating for an exhaust

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#1
So i just installed the FSWerks exhaust, and adore it, however, i feel as though i need to compensate in my ap tune, and i do have ATR. However, my knowledge is limited, and it is a total noob question, but i figured i'd start somewhere. How does one go about compensating for a different system in a tune? i know gains will be nominal at best, i just want the peace of mind knowing all my performance modifications are accounted for.
 


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#2
Long story short, there's really nothing to adjust for a cat-back exhaust on a stock turbo. I assume you're running an OTS Stage 1 right now?

I highly recommend reading Cobb's Ford Tuning Guide, Octane Adjust Ratio, and Ecoboost Wastegate Strategy documents. Then read them again, because I'm not sure anyone can soak up all the info in one sitting.

Next thing is to do some datalogs and see if your setup is achieving and/or exceeding target torque and load while staying under TIP desired max ceiling. If you're seeing ETC closures during WOT then you'll have to raise the load and/or boost targets. That's the starting point.
 


iso100

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#3
There is no need to alter anything in your tune related to the exhaust with a stock internal wastegate.
 


AzNightmare

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#4
Bumping this because I need some clarification:

So if I install an exhaust, there's no need to get a new tune for it?
What about those power gains claimed by "X" vendor for their exhaust. Are those gains acquired automatically? Or acquired after a tune? Or those projections are complete BS?
 


GAbOS

Active member
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#5
You are probably lower than .5% on average with a tune and X brand exhaust unless you go big turbo.

Let's say an average $700 exhaust could go towards a lot more bits and bobs.
 


jmrtsus

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#6
From the few dyno tests of exhausts I have seen the Hp gains claimed are at the higher rpm range. Even a 5hp gain in the last 1000 rpm before redline would only be in play for a split second in an acceleration run. Would you feel or even measure a difference? Doubtful to me.....but then I did not buy my ST to drag race but to carve curves and with the mp-215 has all the power I will use for now. So I do not consider an exhaust as a big performance gain. On the other hand I do like a nice sounding exhaust so I am more concerned about the sound, and cosmetics, than any very slight performance increase. Come the day I have the $$ and the warranty is over I may do the FMIC, tubes, catted pipe, exhaust and upgrade to the Mountune MR-230. Until then I will be happy with my resonator deleted stock muffler. I do love the sound of the Borla. The sound reminds me of my '73 Saab 99 with an Abarth exhaust. The car was anything but sexy but the sound was devastating......
 


AzNightmare

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#7
So in other words... I don't need a tune???

Sorry, those posts didn't really answer my question. lol
 


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Clyde
#8
So in other words... I don't need a tune???

Sorry, those posts didn't really answer my question. lol
The common consensus is you don't need to re-tune for a cbe. As for gains to be had, it's unlikely you'll notice anything. I did mine for sound and in preperation for big turbo.
 


jmrtsus

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#9
No, you do not need a tune.........

Without opening the entire air/exhaust system the overall air flow will not increase by much so a "tune" will do nothing for you but empty your wallet. Wait until you have a high flow intake (which at this moment is not available for our 2016's), high flow FMIC and tubes and a high flow downpipe. At that point a tune will adjust the fuel flow/timing/boost to allow a power increase.

Think of your engine as an air pump. The flow will be determined by the most restrictive device. Even the factory exhaust is not that restrictive as an overall 197 Hp package. So if like me you cannot afford to do the whole replacement at one time then do what you can. It sounds like you are on track with the exhaust so pick your next upgrade in the air/exhaust path. Maybe an intake hose? 15 minute install. Mishimoto is releasing one soon and Mountune says they are also. Changing the FMIC and tubes will be the big costs and both should be done at the same time. Then a high flow downpipe, in my case a catted pipe must be used. THEN get a "tune" to utilize the increased airflow......all it takes is time and $$. Time I have. Enjoy your FIST and Wrench On!
 


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#10
Wait until you have a high flow intake (which at this moment is not available for our 2016's), high flow FMIC and tubes and a high flow downpipe. At that point a tune will adjust the fuel flow/timing/boost to allow a power increase.
I'm not an expert, but I know there are some experienced tuners on here who would argue that none of those things you mention are a significant choke point for airflow on the stock turbo. The turbo itself is the choke point and the tune is only limited by your ability to keep the air cool, hence the benefit of a larger FMIC.
 


jmrtsus

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#11
Joker328----I am not an expert by a far cry, I am much more comfortable with a 60's -70's small block V8, carbs and distributor.......What ebowtheryan asked implied to me he was under the impression that a "tune" would unlock hidden Hp in an exhaust. I did not address the turbo at all because of the costs involved and the where do you stop chatter. If you do the turbo and such and are now getting for example 275Hp do you now upgrade the suspension, LSD, brakes, tires and wheels? I don't think many of us have a desire or budget to sink $6k or more in our ST's. I am sure some people do and if I was 40 years younger and still working I would be one of them. If you are changing a turbo the other things will also be determined by the turbo change, like exhaust diameter.

I doubt all of this without a turbo change will add very much usable horsepower. What it will give me is a little better throttle response, lower charge temps and quicker recovery. The point is that I think at least 90% of this forum users will use some aftermarket products of some kind. I would venture a guess very few will spend the money for a turbo change along with all the other items to utilize it. I am sure you are perfectly correct in the stock turbo being the choke point, all I am trying to get across is that short of of a turbo change all you can do is to optimise what can be easily and affordably done and not send the dealer through the roof in my case. I may at end of warranty install the Mountune MR-230 or a Cobb tune but at this point I don't see an immediate need for more than 215Hp for driving the TN back roads and the TOTD.

Again your comments about the stock turbo I am sure are true.......
 


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