Dp and exhaust size test results

[Fasta123]

http://www.superstreetonline.com/how-to/engine/modp-1102-exhaust-test-tech/

Ok I know in the article the supra has far more hp but the exhaust there discussing is 3in vs 3.5 and the gains are like 60whp! So for our cars could 3in all the way vs 2.5 yield some gains?

 

[DaveG99]

I don think 3" is necessary until you upgrade your turbo.

 

[Fasta123]

I don think 3" is necessary until you upgrade your turbo.

The article says that they gains 100whp actually and more importantly they said at 300whp a jump from a 3in to 3.5 in gained 20 whp in turbo cars... So at 220whp 2.5 to 3 surely nets something?

 

[Fasta123]

Dam 80-120mph in 1.8s

 

[Boricuakid]

I dont think a stock turbo 1.6 is going to benefit from a 3 inch. Take off that hot side tube and you will see just how tiny this turbo really is.

 

[frankiefiesta]

Aren't most aftermarket exhausts 3" anyway? Besides the 2.5" transition at the cat/catback. I've seen a few people get it made into a true 3" exhaust but haven't seen any gains or data from it

 

[Fasta123]

I dont think a stock turbo 1.6 is going to benefit from a 3 inch. Take off that hot side tube and you will see just how tiny this turbo really is.

I feel u, have there been any Dynos dome of hot side pipe upgrade vs stock? I no the difference would be rly small if any, I'm just curious

 

[Fasta123]

Aren't most aftermarket exhausts 3" anyway? Besides the 2.5" transition at the cat/catback. I've seen a few people get it made into a true 3" exhaust but haven't seen any gains or data from it

Is a "true" 3in exhaust a 3in dp and exhaust? Bc Isnt the Cobb dp 3in? And bro exhaust is 3in... That's my setup

 

[2006ser]

I think with a 3 inch exhaust will gain a few more hp but not a lot..

 

[frankiefiesta]

Is a "true" 3in exhaust a 3in dp and exhaust? Bc Isnt the Cobb dp 3in? And bro exhaust is 3in... That's my setup

What I mean by "true" 3 inch is when somebody gets a muffler shop to make the exhaust 3" all the way through. Majority of the aftermarket exhausts have a 2.5" flange so it is compatible with stock cat/catback.

Aftermarket cat has a 2.5" flange on one end that connects to catback
Aftermarket catback has 2.5" flange that connects to 2.5" flange on cat.

 

[Fasta123]

What I mean by "true" 3 inch is when somebody gets a muffler shop to make the exhaust 3" all the way through. Majority of the aftermarket exhausts have a 2.5" flange so it is compatible with stock cat/catback.

Aftermarket cat has a 2.5" flange on one end that connects to catback
Aftermarket catback has 2.5" flange that connects to 2.5" flange on cat.

I see, does this hold true for the Cobb dp as well?

 

[Fasta123]

I think with a 3 inch exhaust will gain a few more hp but not a lot..

In such a light car I feel that every little goes a long way though... Like a 3in setup,an aftermarket hot side pipe etc.. Extre 5whp+ a pro tune + e40 ur looking at another 20whp possibly that would be quite nice if ur trying to keep stock turbo for the quick spool

 

[MitchsFiesta]

CP-E DP and CBE are TRUE 3". No 2.5" piping at all.


While I agree you don't NEED 3" for a stock turbo FiST, turbocharged cars benefit from larger diameter exhausts.

 

[Fasta123]

CP-E DP and CBE are TRUE 3". No 2.5" piping at all.

Interesting... So ur non chatted dp with my exhaust would prob be pretty nice

 

[Tesco2015]

I'm no expert, but I had an Injen catback (3in more or less) and when you see how big the piping is of that exhaust versus the size of the turbo, I have a hard time believing you'll gain power. If anything, I'd almost be afraid you'd lose some power, particularly down low. I think 3in is too big, especially when you compare the Injen to the stock exhaust. Ford stuck with 2 1/4in piping and most aftermarket companies say 2.5in is about the sweet spot. Obviously Ford's priority is emissions, noise level, etc and not particularly performance, but they could have easily done a 2.5in or greater and still have it plenty quiet. I think they have a reason why they kept it that size. Same with the intake, people were quick to upgrade the intake to larger piping that "flows" better, but it turns out the stock intake is plenty for the stock turbo, just needs a different filter if anything.

I'm now straight-piped using the most of the stock exhaust and I can't really say I've noticed a power difference between the Injen or the straight-pipe on the stock tune...

If you're focus is to make more power, the exhaust is not a priority unless you've done everything else and are trying to squeeze out everything. But at that point, I'd argue you're better off just using a different turbo...

 

[madfiesta14]

You will regret 3" full turboback especially non catted and non resonated. My 2013 Fiat Abarth sounded great, was loud, but it "fit" its personality. It was a scrappy car at 26lbs of boost!!!! I wouldnt want that sound out of my FiSt. Stay 2.5 resonated with catless. Loud when you want it.....

 

[Tesco2015]

You will regret 3" full turboback especially non catted and non resonated. My 2013 Fiat Abarth sounded great, was loud, but it "fit" its personality. It was a scrappy car at 26lbs of boost!!!! I wouldnt want that sound out of my FiSt. Stay 2.5 resonated with catless. Loud when you want it.....

Straight-pipe using 2 1/4in pipe sounds absolutely glorious and is surprisingly liveable for the FIST. Crackles and pops for days. Sounds like the Abarth.

 

[mercdank]

I'm sure [MENTION=3805]Tune+[/MENTION] will be able to explain it better, but basically, due to the small size and quick spoolling nature, decreased backpressure from an increase in exhaust piping diameter does not translate to the same type of gains you would see on a "normal"turbo car, ie one that takes more time to spool but sustains that boost pressure until redline.

Our small turbos hit peak boost before 4k rpm and then tapers down as it approaches redline. A normal turbo car hits peak boost much later and usually maintains that boost all the way to redline. It's physics in the differences is the compressor wheel, housing size etc. In this type of turbo application, reducing backpressure by increasing piping diameter allows this slower spooling system to work more efficiently and hence increase power. With the small turbo in the Fiesta, the flow from the stock downpipe is not inhibiting the turbo efficiency since the spool characteristics are not like that of a bigger turbo equipped vehicle.

It's like the hotdog in a hallway metaphor. The stock downpipe is already matched well with the stock turbo, that it shouldn't need upgrading until you do modified or big turbo. By swapping the downpipe on the stock turbo, you will get quicker spool, and you'll get it right away. This translates to a sharp spike in low end, immediately available torque that the Fiesta is known for. However, this comes at the sacrifice of top end power since the already quick spooling turbo is hitting peak boost sooner and "running out of steam" ie becoming more inefficient as rpms increase.

Until you upgrade the turbo or swap it out, you'll see better performance with the stock downpipe. Me personally, I absolutely love the sound a catless downpipe and exhaust combine to produce on the Fiesta, and I didn't mind the reduced top end performance over the incredible sound. That being said, I'm going with cyborg modified turbo upgrade, where the benefits of the high flow will be taken advantage of.

 

[madfiesta14]

Straight-pipe using 2 1/4in pipe sounds absolutely glorious and is surprisingly liveable for the FIST. Crackles and pops for days. Sounds like the Abarth.

I had enough "crackles and pops from my Abarth" I want the Fist to sound refined and have sic midrange. I will spend my money in other places besides exhaust.

 

[madfiesta14]

I really like the Maperformance cat back sound, I think that with a catless DP would be perfect sound. I still plan on catless downpipe and fmic with AP first...



exhaust will be the absolute last mod.