Catted Down Pipe Tunes

[Ecto1]

I'm lost in downpipe land. Help. I've read that if I install a catted downpipe that I MUST also have a custom ECU tune. Without the custom tune the engine will run poorly, if at all, and will set tons of error codes (DTCs). But ... on the americanmuscle.com website they discuss downpipes and claim that a custom tune is NOT necessary with an aftermarket catted downpipe. The car will run fine but the performance will not be optimized.

So what's the truth? Can I really install a COBB or Mishi or Borla catted downpipe without a custom tune? Or without a COBB Access Port tune? Or will the car be useless without some sort of modified tune?

I understand that a custom tune will improve the performance of the car but the question is can I drive the car trouble free with a catted downpipe without the tune?

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[Coyote Chase]

I don't recommend going to a catted downpipe until you have installed a high flow air filter, an aftermarket Intercooler and a stage 2, 91/93 octane OTS tune.

 

[Ecto1]

Coyote Chase, Thanks for the prompt reply.

So now I'm even more confused. According to many of the on-line performance parts webpages: "The catted downpipe is the FIRST modification many EcoBoost owners perform. It has the most 'bang for the buck' of any performance upgrade." Is this just marketing BS?

Are intercoolers & air filters mandatory before any exhaust mods? Is the objective to minimize the restrictions in the intake path & lowering IATs first, before doing anything else?

And then the ECU tune next?

This seems backwards. Forcing more air in & trying to generate more power without addressing the restrictions in the exhaust first. But I'm old school and I admit that I really don't get this forced induction stuff. I'm trying to cope.

Thanks again.

 

[Vicr]

Your #1 mod is the intercooler. #2 drop-in filter, #3 one step colder plugs, #4 stage 1 custom tune, #5 exhaust and down pipe, #6 continue your custom tune process.

 

[ihasnostang]

you're not wrong about getting air out. Presumably there is enough overhead room in the flow capacity for most people in most situations. I just took a datalog and the calculated compressor outlet temp reached 400 degrees during a pull.

 

[Elamcup]

I'm lost in downpipe land. Help. I've read that if I install a catted downpipe that I MUST also have a custom ECU tune. Without the custom tune the engine will run poorly, if at all, and will set tons of error codes (DTCs). But ... on the americanmuscle.com website they discuss downpipes and claim that a custom tune is NOT necessary with an aftermarket catted downpipe. The car will run fine but the performance will not be optimized.

So what's the truth? Can I really install a COBB or Mishi or Borla catted downpipe without a custom tune? Or without a COBB Access Port tune? Or will the car be useless without some sort of modified tune?

I understand that a custom tune will improve the performance of the car but the question is can I drive the car trouble free with a catted downpipe without the tune?

NOTES
This product fits both stock and automatic transmissions; there are no additional parts needed for automatic transmission fitment. This downpipe cannot be used with the stock ECU programming. The customer must retune the vehicle's ECU after installing the downpipe. Power gains will vary depending on the type of ECU tune that is applied to the vehicle, and other supporting modifications that are installed.The Mishimoto downpipe is for track and off-road use only. The customer must have a professional engine tune/calibration after installing the downpipe.CATALYTIC CONVERTER OUTER MATERIAL 304 Stainless SteelCATALYTIC CONVERTER INTERIOR MATERIAL 200 Cell Spun Metallic Core

Straight off Mishimoto's webpage for the downpipe. My tuner told me that all 200 cell downpipes are about the same so I think this applies to all the aftermarket downpipes. For whatever reason not all manufactures give you this info. My tuner told me that I risk putting the engine into an overboost condition without the tune.
Where did you find a Borla downpipe? I wanted one because thier stuff is premo and the 3" Y pipe but could not find one anywhere.

 

[Ecto1]

Elamcup. Thanks for the info. I've seen similar postings by a few of the downpipe mfgrs but the webpage from americanmuscle.com confused the issue. I've been told by other members that the ECM well respond ... poorly ... to a catted downpipe without a custom tune. At best I won't be happy with the performance of the car. At worst it may damage engine internals. Yuck.

As for the Borla catted downpipe there may not be one. I just assumed that since Borla makes a cat back exhaust that they offer the downpipe as well. This may be a poor assumption on my part. But since I'm no longer pursuing the catted downpipe I'll never know for sure.

Thanks for the help.

 

[S1lv3rbull3t]

I'm lost in downpipe land. Help. I've read that if I install a catted downpipe that I MUST also have a custom ECU tune. Without the custom tune the engine will run poorly, if at all, and will set tons of error codes (DTCs). But ... on the americanmuscle.com website they discuss downpipes and claim that a custom tune is NOT necessary with an aftermarket catted downpipe. The car will run fine but the performance will not be optimized.

So what's the truth? Can I really install a COBB or Mishi or Borla catted downpipe without a custom tune? Or without a COBB Access Port tune? Or will the car be useless without some sort of modified tune?

I understand that a custom tune will improve the performance of the car but the question is can I drive the car trouble free with a catted downpipe without the tune?

The car would more than likely run fine without a tune but like you mentioned, the performance is not optimized without a custom tune. Before I put my car in the shop to have the bolt ons and custom tuning, I had just a drop in filter; Accelatac axle backs; Charge pipes; Turbosmart Kompact BOV and IGW75 wastegate w/7lb spring with tune from Brenspeed and I was gapping RT Charger and Challengers easy.

 

[Ecto1]

The car would more than likely run fine without a tune but like you mentioned, the performance is not optimized without a custom tune. Before I put my car in the shop to have the bolt ons and custom tuning, I had just a drop in filter; Accelatac axle backs; Charge pipes; Turbosmart Kompact BOV and IGW75 wastegate w/7lb spring with tune from Brenspeed and I was gapping RT Charger and Challengers easy.

Thanks Silv3rBull3t. After some conversations with other forum members and a few cat pipe vendors it seems that without a custom tune the free-flowing catted down-pipe will lead to significant confusion for the ECU. It's not worth the risk to install the down-pipe and then find out that the ECU simply can't manage the engine properly. The cost of a tune plus a tuning device (Access Port or similar) makes the desire to install the down-pipe a non-starter for me. I'm not interested in a tune to boost the performance of the car so the custom tune would be a huge waste of money. It would only be done to accommodate the down-pipe. So the best answer for me is to forget about the down-pipe.

 

[junits15]

Elamcup. Thanks for the info. I've seen similar postings by a few of the downpipe mfgrs but the webpage from americanmuscle.com confused the issue. I've been told by other members that the ECM well respond ... poorly ... to a catted downpipe without a custom tune. At best I won't be happy with the performance of the car. At worst it may damage engine internals. Yuck.

As for the Borla catted downpipe there may not be one. I just assumed that since Borla makes a cat back exhaust that they offer the downpipe as well. This may be a poor assumption on my part. But since I'm no longer pursuing the catted downpipe I'll never know for sure.

Thanks for the help.

There is alot of misinformation circulating here


The reason people tell you you need a tune is because any and all downpipes will set the P0420 DTC for catalyst inefficiency. In the past when you went to a tuner and told them you had a downpipe they would disable this code and prevent the check engine light. However due to EPA crackdowns, many tuners no longer disable this DTC. This is why many people now use non-foulers when running an aftermarket downpipe.

There is no danger to the motor at all, engine performance will not be degraded, you can run this configuration indefinitely with no issues. However, without a tune you will not see any power gains. You will remain at stock power levels if you do not tune. Why spend the money on a downpipe if you're not going to take advantage of it?

You shouldn't waste your time with a DP this early on, you should do as others said and get an intercooler and a drop in filter first.

If you really would like to do this correctly, you should do all these mods all at once, that way you don't need to waste money buying new tunes in the future as you add parts to your build.

 

[Maggneto]

I will add my 2 cents since I actually run a catted downpipe with both the OEM tune and the Bama 91 perf tune. I have been running this configuration for about 12k miles with about half the miles untuned vs. tuned. I haven't noticed any difference other than the obvious power gains when tuned.

I have my exhaust configured with a 2.25(OEM diameter) glasspack between the MBRP Race catback and catted DP.

The 2.25 restriction helps cut down on the drone inside the cabin and also adds backpressure so the OEM ECU can adjust the AFR correctly and safely. I would not run a full 3 inch catted system without an ECU flash but I have no data suggesting the OEM ECU would not be able to maintain a safe AFR with a full 3 inch catted system. I am no mechanic and this is just my opinion based on data I have read on the subject.

 

[Coyote Chase]

Coyote Chase, Thanks for the prompt reply.

So now I'm even more confused. According to many of the on-line performance parts webpages: "The catted downpipe is the FIRST modification many EcoBoost owners perform. It has the most 'bang for the buck' of any performance upgrade." Is this just marketing BS?

Are intercoolers & air filters mandatory before any exhaust mods? Is the objective to minimize the restrictions in the intake path & lowering IATs first, before doing anything else?

And then the ECU tune next?

This seems backwards. Forcing more air in & trying to generate more power without addressing the restrictions in the exhaust first. But I'm old school and I admit that I really don't get this forced induction stuff. I'm trying to cope.

Thanks again.

I'm also old school and when I purchased my 1st Mustang, I immediately went out and got a set of headers! So I'm not surprised the downpipe and exhaust, plus blow off valves are popular.
Over on mustang ecoboost net, we're chatted about the topic and pretty much agree that the Intercooler is the most important, and for the price, a high flow air filter plus 91/93 octane fuel is a good starting point.
From what other members of the forum have stated, the factory ECU has the ability to learn and safety make adjustments and increase power without an aftermarket tuner.
However, I like my handheld turner for data logging troubleshooting. So for me, if I started over, I'd probably get some sort of data logger (tuning device) and record a base log and track and record every mod independently. Just to make sure you're moving in the right direction.

PS,: I do agree with your statement about making sure you can move air out, before you bring more air in. And as for the high flow air filter... All the data I've seen, has been collected under lab conditions. You may want to search for someone who did a real life test and log.

 

[Buldawg76]

I'm also old school and when I purchased my 1st Mustang, I immediately went out and got a set of headers! So I'm not surprised the downpipe and exhaust, plus blow off valves are popular.
Over on mustang ecoboost net, we're chatted about the topic and pretty much agree that the Intercooler is the most important, and for the price, a high flow air filter plus 91/93 octane fuel is a good starting point.
From what other members of the forum have stated, the factory ECU has the ability to learn and safety make adjustments and increase power without an aftermarket tuner.
However, I like my handheld turner for data logging troubleshooting. So for me, if I started over, I'd probably get some sort of data logger (tuning device) and record a base log and track and record every mod independently. Just to make sure you're moving in the right direction.

I agree as well and now wish I had used that approach as well. I did do a couple 1/4 mile pulls when completely stock so have those numbers recorded in the track apps of the car but not data logs. Then did another two 1/4 mile pulls after installing all the mods I have now but no logs of those either except what's in track apps.

Coyotes approach is the right way to do it so you can see what helps and what does not or actually take you backwards.

BD

 

[Ecto1]

Thanks for the suggestions. I'm still waffling on the downpipe at this point. While I still think it is the right starting point the risks to ECU tunes and DTCs make it less compelling.

Thanks again everyone.

 

[Buldawg76]

I have a catted DP to install but will not until my warranty is up since I am pretty certain a dealer will void any powertrain warranty if one is installed.

BD

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