Hey guys, my current exhaust set up is a custom made 2.5" mid-pipe with a 33" long Magnaflow resonator and a Tanabe Concept G axel back.

The set up sounds great but resonator is just absolutely enormous. This wasn't too bad of a problem in Michigan, but now that I'm driving on the uneven roads of Louisianna it scrapes everywhere since it really does sit only about an inch and a half above the ground. I need to get a pic of this thing for you guys, its pretty funny, the bottom of it is so crushed in...

Point is, I'd like to have the resonator removed so I'm just running a 2.5" straight pipe to my axel back, but my concern is that I do not want to deal with having my tune adjusted.

I'm not familiar with the flow characteristics of resonators so can any one tell me would changing my exhaust in this slight way throw off my tune?

thanks for reading

 

As long as the resonator was a straight through design you shouldn't have any issues.

 

awsome, just wanted to be on the safe side. thanks for the input.

My real concern with the thing scraping and bumping everything is actually that I don't want to increase any possible chances of my manifold cracking (I promise I have the springs installed right )

 

Let's hope so

 

So I got in contact with a custom exhaust shop nearby. They seem like thy do really good work and my only concern is the type of metal they use. I told them I wanted them to use 304 stainless because the rest of my exhaust is all 304 and they told me they only stock 306 or 309 which they will only use if a customer insists on having stainless for cosmetic reasons. Otherwise they recommend aluminum coated steel.

They made a convincing argument concerning harmonics, sheer strength and what not... But I just find it strange that every performance company that makes an exhaust for the tC uses 304 stainless if it really such a poor choice.

Don, if you're still watchin this thread at all, could you chime in? I always trust the knowledge of Dezod over anything

 

Are you sure you don't mean 316 and 409?

 

I'm certain that the numbers I typed are what were said to me on the phone, I wont be surprised if you think the employee I spoke with is wrong.

I still find it fishy that they would say 304 is a poor choice of metal for exhaust piping. I know you guys make your system out of 304 and I'm pretty certain y'all would choose anything but the best lol

 

304SS is a great choice for a street after-market exhaust system. It's not terribly costly, it's quite strong, easy to weld and is quite readily available from most places making it an excellent choice.

 

Right, well I was never questioning this. I'm more concerned with weather or not o should let this shop use aluminum coated steel or if I should try to find a different place that stocks 304.

 

Well I was finally able to track down a shop that would use 304.

Got the resonator taken out just earlier today... sounds great

I took it home so I could snap some pics of the damage:

 

Cripes... That looks hurtful!

 

Was it raspy at all, looking at the last pic it has a hole from being broken.

 

if you need 304SS i can get u the raw material and see if you can take it to a shop to get formed for your exhaust if you want? i work at a metal shop and we could ship it to you also give you a quote on how much it would be

 

Yeah it sounds like the exhaust shop you spoke to was feeding you a line of bs.

Aluminized mild steel piping is cheap and that is why they use it. Most exhaust systems made for your everyday driver (think beretta, corolla etc) are aluminzed when made aftermarket. They rust and eventually fall off which makes you have to go get another one.

Where as stainless if welded correctly will last the life of the car. Stainless is sometimes mended using mild wire which is a no no because the weld will rust and crack open, most exhaust shops don't have a spool of stainless wire just sitting there or a dedicated machine (unless of course it's what they do for a specialty).

I would never ever consider using aluminized mild piping on anything, even my daily. Who wants to purchase another exhaust in a year or two. F that noise.

304 is a good choice, 304L is a better choice and 316 is an even better choice. However 316 is a little more expensive and harder to find.

 

thanks for the info Don, I'm glad I stuck to my guns and found a shop with 304
I didnt check if they used stainless wire though... I know a really good TIG welder back in Michigan though so I'll have him check it out when I have some free time over the summer

and yeah Dropzone it was definataly raspin up a bit, especially durin deceleration


Also pertaining to the original topic, I did end up havin to mess with the tune...
I did some WOT pulls to watch my AFRs after makin this thread and for some reason they were much leaner. I had noticed the rasp I mentioned above and I hoped it was a hole worn in the resonator causing the AFRs to bug out a bit which is why I was in such a rush to get it taken out.
After having the resonator taken out I did some pulls and for some reason the AFRs were still lean
Anyway I hope its just the exhaust modifications that have been throwing off the AFRs because I really dont want to have other issues to deal with.
I spent a few hours last night playing with the fuel map myself and I think I've got them under controll. I really don't trust myself to do more than highlight groups of cells and shift them up a few percents at a time so I was not able to get it pinned at 11.4 but pretty close.
When I floor it jumps rich and then creeps up to ~11.4 but it spikes as high as 11.5 and as low as 11.1 in several places :-/
I dont think this should be a problem and it still pulls hard and sounds mean!