How much power can 2.25" exhaust support?

[Based]

I am about to order the Borla exhaust #140525. I'm just wondering if I wanted to go hybrid turbo in the future, how much power would the 2.25" exhaust be able to support? And when I order this exhaust (or any new exhaust), do I need to get any type of gasket(s)? For the downpipe?

 

[BoostBumps]

Exhaust Size Calculator

Turbo Exhaust Theory

 

[Based]

Exhaust Size Calculator

Turbo Exhaust Theory

I put 2.25" 1 pipe and it said 208bhp. That doesn't make any sense.

 

[BoostBumps]

Other pipe size estimate charts

 

[Based]

Wow I guess you gain a lot of potential just by going from 2.25 to 2.5"... But the Borla sounds so good :/. I don't really like how the bigger exhausts sound on this car it sounds to burbly

 

[STAZ15]

Wow I'm glad I went with 3 inch mbrp! But yes based it is so loud.


Sent from my iPhone using Tapatalk

 

[1azst]

I'm seeing 330 v dyno on a dhm360 with STOCK cat back, so...

 

[STAZ15]

I'm seeing 330 v dyno on a dhm360 with STOCK cat back, so...

That's pretty impressive!!


Sent from my iPhone using Tapatalk

 

[Quasar]

View attachment 13356

This doesn't seem accurate, unless I am reading it wrong. It seems like there are at least a few members making significantly more power than what the above specifies.

 

[kivnul]

This doesn't seem accurate, unless I am reading it wrong. It seems like there are at least a few members making significantly more power than what the above specifies.

From what I understand, the Volumetric Efficiency suffers if you restrict the exhaust after the turbo.. thus the turbo has to work harder to get the same HP. So it would totally be possible to run an undersized exhaust and get good power numbers, but you could get better numbers with a bigger exhaust.

 

[jmrtsus]

I find those number to be shaky, especially since we have a 2.17 system not even a 2.25........maybe the forced induction has something to do with it. The MP215's typically push close to 220 on the stock cat/exhaust. Many forum members far exceed these numbers.

 

[Quasar]

From what I understand, the Volumetric Efficiency suffers if you restrict the exhaust after the turbo.. thus the turbo has to work harder to get the same HP. So it would totally be possible to run an undersized exhaust and get good power numbers, but you could get better numbers with a bigger exhaust.

That makes more sense... the graph is a little misleading as it states "Max HP"

 

[1azst]

From what I understand, the Volumetric Efficiency suffers if you restrict the exhaust after the turbo.. thus the turbo has to work harder to get the same HP. So it would totally be possible to run an undersized exhaust and get good power numbers, but you could get better numbers with a bigger exhaust.

I imagine I could get another 30-50 whp with a 3". If there was a sort of quiet cat back, I would get it. I had a CPE cb for a few hours and went back to stock cuz it was so loud. I have no cat though.

 

[re-rx7]

I imagine I could get another 30-50 whp with a 3". If there was a sort of quiet cat back, I would get it. I had a CPE cb for a few hours and went back to stock cuz it was so loud. I have no cat though.

Not likely. It's been tested over seas that a larger exhaust nets almost njothing in the hp dept. DI changes everything.

 

[bigmanlittlecar]

For comparison I dynoed at 249/267 with C39 Hybrid on stock exhaust. During testing of DHM new 3" exhaust, which I am buying when it comes in, we Vdynoed 280/302. Mods in my sig. It was a noticeable difference we did not expect. Only thing I can think of is the hybrid likes the larger piping.

 

[1azst]

Not likely. It's been tested over seas that a larger exhaust nets almost njothing in the hp dept. DI changes everything.

So think the stock exhaust is not restricting my gen 2 gtx2860 dhm kit at 29 psi. Lol.

 

[re-rx7]

So think the stock exhaust is not restricting my gen 2 gtx2860 dhm kit at 29 psi. Lol.

Actually no. Not as much as you think. 5-10whp maybe. They tested a efr fist overseas with the large exhaust hardly anything. 30-50whp is funny though.

 

[A7xogg]

It's more than piping size, exhaust design plays a part especially if the exhaust design create swirl then the exhaust gases get forced out naturally. If an aftermarket DP doesn't make more power than stock one on stock turbo then exhaust size won't. Also if you don't dyno comparison at the same dybo on the same day, a dyno comparison means nothing especially a vdnyo because a vdyno adds more variables. On bigger than stock turbos I could see bigger exhaust adding power but not as much as venders and ppl think

 

[Based]

Well I decided to order the Borla. It sounds just too good for me not to get it


Sent from my iPhone using Tapatalk

 

[M-Sport fan]

IF there is one single area of the aftermarket where we have too many great choices for this car, it is catback exhaust systems.