jangy

So I am getting sucked into these exhaust threads and have always wanted to have a shop fabricate me one to my specs from the headers to the Mufflers.

I would really love DATA or theory behind the use of X or H pipes. Please include the entire picture and give examples of what manufacturers do, too. Thanks.

Oh yeah, here are the few things I want:

Intake: I want more volume of air and less resistrance. More to come on this, but I've spent $250 and have a pretty cool solution...more to come after I tell the affected...

Headers: I am torn between the shorty style and long tubes. I will likely have a setup that has both integrated in, even if it just uses some OEM parts that have the OEM sensors, etc. I also may want to go all out with long tubes. I am not into sound at all. I love it in other cars, but want mine quiet as can be given the gains. For now, I will likely get the VRP HEMs and a set of some custom bent tube design from an animal I know...

Stainless 75mm tubes on both sides. If my goal is to really boost true power from the car (i.e. not NOS), then I had better plan on having huge air flow. I like the post showing the flexible link to alleviate tension on the headers and wondered if it add turbulence much?

If I go true duals (meaning even that little crossover behind the cats is gone), someBODY tell me about the need for an X pipe to add performance.I have always seen them as turbulence. I see what you mean by scavenging, but the tubes should have decent laminar flow. Does the pipe really add anything? If it is even just a touch, then I'll add one but please convince me.

I want to keep the mufflers as the are. Is that bad? Will they be too restrictive given the added flow? If so, i may have them slightly punched.

The cats are the HUGE issue. What do i do?? I want to have no engine lights (like now), but I also want power and the shortys are just hard to design right with that little bit of room and quick drop.

Last thing I'd like feedbback on are these cut offs. We played with Rooshe's last year, but they were at the muffles. Now, i see one mounted just aft the headers (which is where I am used to seeing them with fire ). So, what is the deal with cutouts? Personally, i hate them but am researching for a close friend.

bobgodd

If you plan on doing headers and then straight pipes into the stock mufflers, then you may gain a few hp by using an x-pipe. It all really depends on the collector design of the header coupled with/without an x or h-pipe. If the merge collector on the header is a 4 into 1 design, you should benefit more from the x-pipe as opposed to a header with a merge collector of 4 into 2 into 1; as the later will have more efficient scavenging properties, and the x-pipe will always scavenge better than straight pipes. Also if a priority of yours is to keep your car relatively quiet, straight pipes is the anti-quiet lol.


Exhaust cutouts are a worthy investment, especially electric cutouts. With the flip of a switch you go from street legal to open header. This really comes in handy when going to the track and "such".


Where are you getting your work done?? RPM on Melrose in Vista is the best shop around!

chiromikey

in my experience cutouts are to make noise, NOT power...and i've yet to see a bolt-on cutout prove me wrong (maybe because the system they get bolted onto wasn't designed for them). i doubt the outcome would be any different for a 55k car.

google all the questions you have because ALL of the theories have been discussed for decades and you won't find any new information here.

jangy

That is also what I had always thought. I see some cutouts at the mufflers and some post the headers. I just worry that we already have backpressure issues and that a cutout at the headers may actually hurt the heat getting out.

Sorry for asking again, but this is a big project and the cutouts are for a friend so I want to have all the facts.

jangy

Man, thanks for the lesson. It was dead on for what I need. Luckily, I work just off of Melrose in Vista, so RPM it is. What else do they do?? HAHAH!! I'll see if they are willing to knock out a few pretty parts for us.....

bobgodd

RPM (Richards Performance Muffler) is just south of the Oceanside Blvd and Melrose intersection. As far as I know he only does exhaust, but they do a very nice job, and they'll do it up all custom if you like.

jangy

I'll check them out next week. I need someone who can do all the bending I need.

bobgodd

I might actually be there on Wednesday if my loser roommates cancel our planned trip. They'll bend anything you need. Decent prices too!

http://rpmmuffler.com/

jangy

Let me know and we can meet up there.

dyno

i think that the closer to downpipe you'll place cutouts, the more loud it will be and .. least efficient

to obtain from cutouts something like instead-of-muffler-mod I think is possible: just place them to the end of the exhaust system ... by means of and additional pipe bypassing the muffler ( or, better say, adding on it... maybe of smaller diameter, just to avoid too much freeflow increase).
result: when cutout opens, it just renders the muffler a bit more freeflowing (while keeping stock sound when closed).
I would also pay attention when making the cutout-provision, to avoid blind room/flow rebounds when cutout is closed.

I found there exist at least 3 types of cutouts:

- vacuum controlled cutouts: widely use din Germany; usually located at the end of a modified muffler .



this system wa soriginally used by BMW (I think during '90s in a 528 series)



I think it is the system also by Porsche for its performance version.
The vacuum device allows to automatically open the flap when surpassing a certain rpm or loading range.

It can be also electrically controlled. here's another one:



If you look for "Abgasklappe" you'll find a lot of tuner using it
you can see and hear it at work:
http://www.sportwagen-herrmann.de/in...ercedes-tuning

or here: http://www.hms-tuning.de/ ..go to "sound"

then we have

- APEXI Spring controlled exhaust valve
this is not electric but hand-controlled

but they just developed The APEXi Dynamic Electronic Control System (DECS) is an improved version of APEXi’s Exhaust Control Valve (ECV).
http://mufflerguys.com/ps-3161-1-ape...universal.aspx

then, we have QTP
https://shop.quicktimeperformance.co...oduct_list&c=4

this is the system I like mostly ... except for the cutout location tha tin my mind should have a provision just upon the bend of stock pipe.
.. unfortunately I don't remember the name of its owner

dyno

this DIY for the Vacuu design is also interesting

.. indeed cant' understand where they are connecting the control module to ..


ah, Jangy, btw you ar eon the bandwagon .. what do you think of having the secondary cat delete pipes muffled more or less like this



i don't know wheather the FLEX has a muffling effect or not

see this: Klappe + Flex

just to remain as close as possible to stock .. before switching to on the hell


should you go for Vacuum Klappe, 2 sizes available: 58 and 70mm (open at vacuum) or 73 (closed at vacuum)
... just found the producer

Dr. C36

cut outs are for dumb drag racing rednecks, they are terrible for flow and create serious turbulence in the exhaust setups. Its just to show your nascar lovin' buddies "HERE"S MY MUUUUSCLE CAAARRRR"! Design a proper exhaust system.

bobgodd

Isn't that the exact reason you'd use the cutouts at the drag strip???

Any cutout on most systems should be good for high rpm HP, which would come in handy at the strip.

ChicagoX

I did both, thanks.

I race both at the strip and road course....I'd love to see some of your lap times/slips rather than your derisive remarks.

You don't see anyone here slamming your ricer e-bay CF gauge surround, ghetto head unit and cheap HIDs do you?

jangy

OK dyno. I'll look into the cutouts. I wasn't going to go that route but we will....

I like the flex piece especially to save the headers since they will be the tightest for room.

splinter

Take it easy, Charlie.

Dr. C36 is already far quicker and faster at any venue than any of us could ever aspire to be.

His formerly unbeknownst formula...https://mbworld.org/forums/c36-amg-c43-amg-w202/230116-weight-reduction-thread.html

gonzjed

dayum thats gotta hurt

ChicagoX

I apologize and stand VERY corrected. He adds lightness like nobody's business.

jcjmw

Jangy, when you do your custom exhaust and everything, can you see if you can do a weight comparison? I am curious to see the weight savings between the stock exhaust components which you are replacing with the custom exhaust. I too am thing of a custom exhaust but for the purpose of saving weight.

jangy

I definitely will. That is one main area to look into.

dyno

guys
I don't see any word about those sound clip links

.. means you don't like that genre

psk145

damn jangy.....you really like having your car in the shop huh??? As soon as its out, you're looking to put it right back in!

jangy

I'm just not a sound clip fan. In the end, I want it to sound as stock as possible. I am all about power. If it has to sound louder too, then so be it. But, i don't like it.

jangy

Oh yeah. That's why the second car. I still have a load to do....

bobgodd

Surprisingly my roommates haven't cancelled yet lol, so RPM is out of the picture for now. Post up if you go!