Well, some recent posts I have been reading really have me questioning if I have the right exhaust. I love the sound of my car but I wonder if I am getting good performance from it.
First let me summarize what I have.
S&S headers
2.5 Braided flex couplers
A pair of Magnaflow high flow cats
Magnaflow X-pipe
Magnaflow resonators
Magnaflow mufflers
Magnaflow tips
2.5 mandrel bent stainless piping all the way.

Here are my reasons for the questions.
1. I really think the Rush headers will be better than the S&S although jbrady has me questioning that.
2. I could eliminate the cats. We don’t have emission checks here in KS. Am I losing that much power with them there? Are the cats really giving me anything?
3. How much power is lost thru the resonators? I love the cars sound, there is absolutely zero drone noise at any speed.
4. I am preparing to install a stand alone with more boost so the OBDII requirement for 02 sensors in front and behind the cats go away.


I wonder how much power I would gain if I installed a set of Rush headers and dumped it straight back to the mufflers. If its 5 or so HP who cares but if it’s more like 20 I might do it. Just a tid bit more info. The car made a little over 230RWHP with this exhaust (BEFORE SUPERCHARGING) no dyno numbers currently.

Here are some old pics of the exhaust.

 

taking out the kind of resonators you have dont give you very much gain.
I really can't see how going from one aftermarket header to another will give you more power unless one of them is badly designed/smaller diameter.

The only thing i can think of is if you are on boost you could loose the X Pipe. all its doing is creating turbulence in your exhaust system. you have a V8, run each bank separately as nature intended. (notice at the middle of the X-pipe, its only as thick as one of your pipes)

 

definitely go with the rush headers, because I want to buy your S&S ones

i wouldn't bother deleting the resonators, i doubt that would give you any gains at all, seen as they're just straight through anyways.

as for the x-pipe, maybe get rid of that, and try something else. either an H, a different X pipe or nothing at all.

I've added pics about what I don't like about the magnaflow x pipes. I'm assuming they are single wall, and the exhaust has to flow through the crappy shape at the exit of the X. Other X pipes don't have the left over metal (red circles) from when the 2 pieces are stamped, because they're made from 2 curves, not stamped from 2 sheets. If the 2 pieces aren't a tight fit, i can see them having really crappy flow characteristics.

 

Scott,

I'm not an expert but, I really doubt you would see enough gain from the Rush headers to make it worth the money.

As far as the cats, xpipe and resonators..If you think you'll gain something, try it. Shouldn't cost too much to delete them.

Now, in my case (not to hijack, but I think my thread was the cause of you starting this thread, LOL) there are likely huge gains to be had. First off, I'm still on the OEM manifolds. And, although I think my current setup is better than stock, it's still not great. I currently have 2.25 (two pipes) all the way back to a couple of stupidly small resonators. 2.5 inch from the resonators to the Dynomax's, which are three pass BTW. None of the piping is mandrel bent and there are a couple of ugly bends that should really be fixed.

Anyway, an example of an exhaust not really worth messing with (yours) and one that could benefit from messing with it (mine).

If you can't help yourself, I might buy your current header back setup. LMK, LOL.

KC

 

In my opinion, I very much doubt another exhaust set up will net you 20hp more than what you have now. Different set ups will likely be able to bias the bulk of your power higher or lower into the rpm range. But, with the S&S Headers and mandrel bent piping, you have to be acting at near peak efficiency given the components that are on the aftermarket. If you love the sound and there is no drone, I would be particularly willing to stick with what you have that is working.

The 2.5" piping will supply enough flow, even if you spin the M90 so hard that it blows. The S&S Headers are giving you a more positive low end than the Rush headers would, with smaller primary pipes supplying more efficient exhaust flow when exhaust gas velocity is relatively low. Rush headers with 2.5" piping would give you tons of flow, but that set up would ask a lot out of the blower to pick up the slack on the low end. Ultimately, the options are endless, with each decision biasing the power slightly differently. At the end of the day, the set up you have is simiarly good to any of these "ideal" set ups.

If I had your car, I would simply bypass the catalytic converters with straight 2.5" piping and call it a day. The added uniformity of the exhaust piping will only assist the flow of the exhaust gases. The removal of the cat will probably increase sound ouput a few decibels with the resonators still preventing any drone. All in all, it will be a minor adjustment, which is the most your set up needs. A major adjustment is not in order at this point (in my opinion).

I should have my headers from Neil in hand a month from now. Unless gold and paper money is coming out of my exhaust when I install them, I would stick to your current set up (perhaps bypassing the cats since they are only an unneeded restriction).

 

Personally I would take the cats off and the X pipe, run 2 pipes straight to the muffler as far back as you wanna go. The resonators dont really do anything as far as losing performance. I would say with a new setup you'd gain maybe 3-9 HP and a lot more throttle response.

 

I'd rip that one off an d sell it to me for $4 . No actually i like that one keep it.

 

Scott, Before boosting, did you have any kind of hesitation off the line or under low RPM? I have nearly the same setup as you do right now (minus the headers/cats/resonators) and since installing it, I'm having some issues. It certainly has added power and sounds great in the higher rev range though.

 

I had no hesitation at all. I am not sure what you have going on. Are you obdI or II?

 

OBDII ('97). Sounds like it's not the exhaust that caused my issues. BTW if I were you I would keep the setup you have. I doubt you could squeeze much more power out of it to really make it worth the loot it would likely cost. Plus it looks really solid. Are those high flow cats you're using?

 

I would think that duming the cats between the two O2 sensors could be causing your problem.

 

Didn't mean to jack your thread, I saw you responded in my other one. Thanks man. Keep your current setup, it's impressive.

 

I like the way your exhaust is setup. The mandrel bends are perfect.

You could have no cats, no resonators, no X pipe. Since you are boosted you will have all the back pressure you need. Of course it will be much louder and you'll probably gain a couple more horses and some extra smoke. Not really worth it since I bet this is your daily driver. I say keep what you currently have. If anything I'd probably just delete the resonators. Good luck.

 

Scott,

So I'm curious, what have you decided?

I'm still at a loss on what to do with mine.

I'm fairly sure I'm going to go 2.5 inch. Playing with the idea of buying some pre fabbed mandrel bends. Still don't know about mufflers. X-pipe for sure.

KC

 

I bought some stainless tube, I am going to pull out my Magnaflow Cats.