Full Exhaust vs. Dowpipe vs. Axle Back vs. ?

[dgDVM]

Has anybody compared the performance gains from upgrading the individual portions of the exhaust? Another way of asking the same question is which portion is the most restrictive?

Making up numbers here, but:
I hear one person say they swapped only the downpipe and gained 25 hp, another deletes the muffler and gains 25 hp. I'm sure that a full exhaust doesn't gain you 50 hp, so where's most the gain?

Ignoring sound for now, will I get any more significant gains from a full exhaust than I will from just the downpipe?

 

[brancky3]

Has anybody compared the performance gains from upgrading the individual portions of the exhaust? Another way of asking the same question is which portion is the most restrictive?

Making up numbers here, but:
I hear one person say they swapped only the downpipe and gained 25 hp, another deletes the muffler and gains 25 hp. I'm sure that a full exhaust doesn't gain you 50 hp, so where's most the gain?

Ignoring sound for now, will I get any more gains from a full exhaust than I will from just the downpipe?

No. Downpipes are typically the power adders on turbo cars. While full exhausts do make power, downpipes will get you much more.

 

[Angeski]

So if we upgraded the downpipe to 3in wide instead of factory (2in i think), we talking 25 hp?

 

[Adamdan]

So if we upgraded the downpipe to 3in wide instead of factory (2in i think), we talking 25 hp?

I thought I read downpipes gave 30whp. They are the same size as the stock pipes the gains are from deleting the second cat.

 

[niko]

I thought I read downpipes gave 30whp. They are the same size as the stock pipes the gains are from deleting the second cat.

The ssr downpour gave me 30who and 26trq I have the ssr axle back too which frees up a little more power but I don’t have a dyno on that yet.

 

[Doel]

the most gains are from deleting the cat as this is the most restrictive point of the exhaust, but this will make your car "illegal", road legal cars must have a cat. From the dynos I've seen I would probably guess 40-50 hp gains from a turbo back exhaust without cats with stock boost and turbos.

I used to have a 1.8T GTI with a 50 trim turbo, no cats, no muffler, open wastegate, that sucker was LOUD.

 

[Angeski]

Will there be any results if i just upgrade the downpipe on my stock exhaust system? Also, if i put HF cat on, will it signal a code on my dash?

 

[Adamdan]

Will there be any results if i just upgrade the downpipe on my stock exhaust system? Also, if i put HF cat on, will it signal a code on my dash?

Well there is a cat right up at the turbo then the o2 is up there. You could just remove the second cat and it will be just like the downpipes with no cats. I don’t know why they call this part a downpipe it’s more of a mid pipe.

 

[STINGER]

You can run good quality HFC's and stay legal and still make a lot of power.

 

[Angeski]

ok. I havent got under the car yet so the order for the exhaust is : manifold-turbo-cat-dp-catback exhaust- mufflers?

 

[Adamdan]

ok. I havent got under the car yet so the order for the exhaust is : manifold-turbo-cat-dp-catback exhaust- mufflers?

Manifold turbo cat o2 then secondary cat that can be deleted then cat back. You will get no check engine light from deleting the second cat.

 

[dgDVM]

I also haven't been under one yet, but from what I understand:
manifold/turbo, then a cat mounted basically directly on the turbo with O2 sensor. Most aren't messing with any of this.
Then, the downpipe with secondary cat. You can swap this out to larger diameter and without a cat for more power and no codes. Most gain is here.
Lastly, catback "might" get you a little more, depending on how free-flowing the stock system is. I haven't seen any comparisons on downpipe only vs. downpipe+catback. This was my question, how much more will I gain?

 

[Angeski]

Manifold turbo cat o2 then secondary cat that can be deleted then cat back. You will get no check engine light from deleting the second cat.

Ok. Thats good to know. So we add the DP by takimg out the second cat? Lol

 

[Angeski]

I also haven't been under one yet, but from what I understand:
manifold/turbo, then a cat mounted basically directly on the turbo with O2 sensor. Most aren't messing with any of this.
Then, the downpipe with secondary cat. You can swap this out to larger diameter and without a cat for more power and no codes. Most gain is here.
Lastly, catback "might" get you a little more, depending on how free-flowing the stock system is. I haven't seen any comparisons on downpipe only vs. downpipe+catback. This was my question, how much more will I gain?

Ok. If thats whats foing on, then im deleting the 2n2nd cat with the downpipe. Whatever the dp size is ill just go 1 in more or whatever the shop thinks.lol looking for a good sounds upfront more than the back atm.

 

[Adamdan]

Ok. If thats whats foing on, then im deleting the 2n2nd cat with the downpipe. Whatever the dp size is ill just go 1 in more or whatever the shop thinks.lol looking for a good sounds upfront more than the back atm.

There’s no point of going bigger I would just keep it the same size. You might as well just get them to cut out the cat and weld in a pipe... only downside is you cut up the stock exhaust.

 

[Angeski]

Talked with an exhust shop. They didnt even feel comfortable in doing anything to it. Jesus. I hear import mike is making downpipes and already made muffler deletes for the 2.0t. Could be something.

 

[Jonathan]

LAP3 | Product Page

I believe these just became available. Primary catless downpipes. Apparently the biggest choke point in the whole exhaust system.
The downpipes that SSR offers should be considered midpipes/secondary cats correct?

 

[Angeski]

Yea i believe so.. Thats awesome!! Now they need to make the 2.0T version. Crazy how they are charging that much for a little bit of piping.

 

[Adamdan]

LAP3 | Product Page

I believe these just became available. Primary catless downpipes. Apparently the biggest choke point in the whole exhaust system.
The downpipes that SSR offers should be considered midpipes/secondary cats correct?

I think those would throw a check engine light. And I though removing the primary cats caused car to over boost and to go into limp mode.

 

[Angeski]

Yea, i can see throwing codes for primary replace. If you have an ecu program, you could reset the code and adjust your boost i think.