I currently have the Corsa Touring system installed and have a high-flow 2.5" cat and Pacesetter header to install with it. I checked in my hometown for pricing first because usually everything is 50% cheaper than Columbus.

My dilemma is that there isn't a place to get mandrel bent custom pipes for the downpipe and such in my hometown. So, I'm wondering if it would affect performance at all to have the pipe between the High-flow Cat and Header, and the downpipe made without mandrel bending it?

It will cost me more than 150$ in Columbus to have this done and I could probably get it all done and installed in my hometown for less than 100$...what do you guys think?

 

if you're worried about you should get it done right, otherwise you'll wish you had, even if just for knowingthat it is or isn't. Don't know what ther performance differnce would be, but even if there was NONE it would still bug me knowing I didn't go for the extra effort.

I don't know if that makes sense to anyone else...

 

Don't cheap out now. Mandrel bends will help reduce turbulence and increase flow.

 

buy an extra one for me...

 

I seriously doubt you have enough power at this point to make mandelr bent an advantage over crush bend. I may be wrong about your poser what kind of mods do you have?

 

Whether if he's running 500 HP or 140 HP, the type of bend can either hurt or give you better performance.

The problem with crush bends is that they typically are bend poorly which can cause it to be smaller in the actual bend than the rest of the exhaust system (example: you buy a 2 1/2" exhaust system and at the bend it's crushed to 2 1/4"). By this happening, it's causing more restriction, which defeats the point of you upgrading your exhaust system.

Getting it mendrel bent will gaurantee to have a perfect bend, no decrease in diameter. It's more expensive because of the machine they use to make that type of bend...it's expensive...that's why most places don't have that type of bends available.

Lastly I will say this, 2 1/2" exhaust is too big for your motor. I recommend you taking out that 2 1/2" diameter catalytic converter and getting a 2 1/4" one and also getting a 2 1/4" cat-back setup...unless of course you're planning to boost. Naturally aspirated, 2 1/2" is too big.

 

2.5" is fine. ran it on a cav and thought it worked out nicely with all other bolt ons.

pacesetter/monza is 2.5" and it offers some pretty nice gains, despite not being stainless steel.

 

very well said

 

Thank You

 

Well, I do plan to boost later on down the road, but the Corsa system's are all built with 2.5" pipe and they are seeing the largest gains out of all the other systems out there right now.

I do know that by opening up to 2.5 I could be losing some power, but I'm pretty sure I'll gain that and more back once I get the parts for the engine and the turbo installed.

 

I have an automatic 2.2L with the Pacesetter Cat-Back (2.5") and I plan on getting a pacesetter header so I was going to upgrade to a high-flow cat so what size cat would you recomend. I don't know if I'm going to be going the forced induction route (if I do it will be with a supercharger) but I plan on getting a Stage 1 cam.

 

Well I think NJHK's reasoning is because of where your powerband will peak at, which is typically what I try to explain to people. The 2 1/2" piping will be reach the proper velocity higher in the rev range than say 2 1/4" would. Generally I've noticed with the 2.2 Ecotec that 2 1/4" is the most balanced. Considering how there's a rev limiter just shy of 6500RPM, there's no real reason to go with 2 1/2" short of having the engine work to require that sort of breathing potential, and/or some sort of forced induction (chemical or otherwise). Then again, in stock form the power does drop off around 5600RPM, so it might help shift things up a bit if that's what you want your setup to be.

Before someone tries to jump in with the backpressure argument, it has nothing to do with that. Backpressure = Bad, Velocity = Good.

BlackLS get the same size high-flow cat as the rest of your piping (i.e. 2 1/2) if you want to balance it out. I wouldn't go any larger than that, and any smaller will cause a restriction. Those cams are going to like the increased flow as well.

 

Your air flow is not great enough to where tha 1/4 in will make a huge difference at this point in time.

 

Thanks for the help

 

It's not too big. That's why Corsa did chose to use 2.5" exhaust for the 2.2L. Tests were done that have proven that the optimum exhaust pipe diameter for a 3.8L V6 Camaro is 3". Yes, it's huge but that's the optimum size for maximum N/A horespower; I figured that 3" would have been to big I'd have thought 2.5" on the 3800. I say you rightly spent your money on the Corsa 2.5" exhaust and I will e-mail Paul and have a reply to post for your NJHK.

 

I e-mailed Paul at Corsa and here is his reply:

Hello Scott,

It was touched upon below in a response noting that velocity is key.
That statement is correct to a certain degree... By our specific/ patented muffler design; it allows for higher flow potential without any form of turbulence added within the exhaust path.
This is actually why we can utilize a larger diameter where most other muffler manufacturers can not.
Due to the limitations associated with the "typical" muffler designs out there in the market place, which use a series of baffles, chambers, or just a steel wool packing material, the capability to increase velocity is not there.
Through extensive amounts of path design, flow testing, and to also include the many hours in sound level development, our muffler systems are dynamically tuned around each vehicle for this purpose.
We are literally the only performance exhaust manufacturer who can not only deliver on maximum performance potential, but can also go the extra step to assure a resonant free sound quality in the vehicle when driving at cruise.

Thank you for the added interest and inquiry, we trust that this proves to of some help.

Sincerely,
Paul Santiago
CORSA Performance
Automotive Technical/Sales Rep.
Direct Line: 440-260-3135
Toll Free: 800-486-0999 ext.135
Fax: 440-891-1868
www.corsaperf.com


There you have it!!

Scott

 

while I don't agree with his last statement in that paragraph, he's spot on, which I'd expect from Corsa. your two main enemies are turbulence and restriction (which some would also say go hand in hand). the mandrel bends along with higher diameter piping is exactly what allows "higher flow potential without any form of turbulence added within the exhaust path." later on I would consider upgrading to 2 1/2" piping because of my flow demands with the setup I run, but I really like my Borla system as it is now. maybe I'll adapt a cobalt system to work on mine.

this is a very common discussion in the world of n/a 4cyl cars, and I'm glad that more people question both sides of the arguments, and understand it now as well. while I run 2 1/4 on the Ion, I have 2 1/2 on my wife's 99 SC2, and have had no power loss with a very peaky powerband, which is exactly what the LLO wants.