Exhaust Advice

SCchick3

Registered User
Hey guys! Hope you all had fun at the Shootout, wish we could've made it! We are doing some brainstorming on exhaust options because I've got too much restriction going on...

I would like a full system (manifold to the muffler branch) but I already have flowmaster mufflers...i'm open to someone throwing in their used system to sell ;)

I've been checking out spinning wheels and debating whether or not to do true duals vs. two to one, back out to two. I was wondering the performance and experience everyone has had with either. Any help/advice would be helpful :)
 
so 2-1-2 is deeper sounding than true dual, but I feel true dual sounds better with an aggressive cam.

My advice for exhaust is to do it once...if you plan to heavily modify in the future then just set up your exhaust for that now. 2.5" piping works for good HP #s.

The biggest difference between mufflers/brands is sound...turbos are probably of the quietest where welded will be louder...smaller mufflers are louder than larger ones. People here tend to like borla.

also these cars drone alot once you go up to 2.5" piping so be ready for that.

I highly recommend a resonator whether you go 2-1-2 or dual.

Lastly, exhaust is the most talked about subject here so feel free to search the forum as there will be a lot of info there.

GL
 
hey...seems to be a lot lot of opinons on which is best but I can never find an absolute and which is best...but first have to define do you want best sound or performance....I can't ever seem to settle on an idea...so many options and variations, seems to be a lot of preferance too...:)
 
piping size seems to be the most relative factor to how well the exhaust flows, mufflers and their location seem to just change the sound.

I have true dual with dual cats and a dual in/out muffler in place of resonator and straight piping all the way back and it yields me the best power. But will you like the way it sounds...? Check out my dyno run.

http://www.youtube.com/watch?v=lxuggjqVCaU
 
Blownbird - do you have 2.5 duals all the way back? If so, do you have the newer gas tank or did you have it specially bent for you? I just can't see how in the world I could get 5+" in the drivers side of the gas tank! lol

Mel- I def want performance versus sound. I'm getting way too much restriction in my exhaust vs. what my cam/port/polishing is putting out. I have NO top end lol Hopefully I can make this work and find a mandrel bender in my area!
 
You have to ask yourself how much power you want to make because the exhaust won't "make" any power, but it will "support" certain power levels. If your exhaust is too big for a given power level, it will make unnecessary noise and sound farty while actually decreasing part throttle response and low end power. An exhaust system that keeps velocity up while maintaining sufficient flow to support your power goals, is the right balance to look for.

For the above mentioned reasons it's not always possible to "do it once and do it right" because your goals and needs may change over time. For example, we built an exhaust system for my son's car that performs and sounds awesome, but it is only designed to support about 300rwhp. Since he is now at that level, we are looking to go bigger. For example, his car has a cam, mildly modified heads, an MPX, and makes nearly 20psi boost. It also drives almost like stock and gets nearly 26mpg on the highway. When the blower was making 15psi this was an ideal combination but now at 20psi, the exhaust isn't big enough.

If you have fully ported heads, bigger cam, and want to make 350+rwhp, then you'll have to go bigger. If you run true duals, be sure to use a decent resonator in the middle so that the pulses are equalized or else it will sound really farty. If you go with the dual system from mandrelexhaustsystems it is available in both 2.25 and 2.5" versions. If you have an early style tank I can tell you that the pipes don't fit well, so plan on getting a late model tank if you go this route.

If having it built locally or building it yourself, I suggest using a 2 into 1 resonator and then re-splitting the exhaust behind the axle. If mandrel bent, then 2.25" twin pipes going into a 3" mid pipe is best. If you need 2.5" twin pipes due to your anticipated power levels, then you need a 3.5" in the middle to keep up with it. The popular 2.5-3.0 combo is just not a good match, particularly when the pipes are crush bent as the 3.0 " is small already and is impacted worse by the crush bends.

In my experience, glass packed resonators don't hold up well due to the heat of a supercharged engine. If possible I think it's best to use a chambered, all steel muffler in the middle and then a packing style muffler in the back. Open chamber baffled mufflers in the rear are generally very loud and raspy. A chambered muffler with packing is generally pleasing when used in the rear though they may be restrictive depending on desired power/airflow levels.
 
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Blownbird - do you have 2.5 duals all the way back? If so, do you have the newer gas tank or did you have it specially bent for you? I just can't see how in the world I could get 5+" in the drivers side of the gas tank! lol

Mel- I def want performance versus sound. I'm getting way too much restriction in my exhaust vs. what my cam/port/polishing is putting out. I have NO top end lol Hopefully I can make this work and find a mandrel bender in my area!

You can cheat some ... http://www.mandrelexhaustsystems.co...ord-cln-89-dsh-97-Ford-Thunderbird/Categories has prebent systems for our cars.

They CAN fit dual 2.5" in the old style gas tank, however, if you do that, be SURE to have the installer put a "spacer" between the pipes in two or three spots around (the cheap shops will use some rebar, for stainless you really want a stainless rod between them). That's so that they don't shift and rattle against each other. Oh, it'll work fine without them, but your car will rattle like it's coming completely apart :eek::eek:

RwP
 
Ceramic ball bearing mufflers tend to make the most power:eek:

On a serious note, I've always like the sound of lt headers feeding a prochamber and flow 40's.
 
I'm not a big fan of the flow masters. I like the sound of the magnaflow mufflers better and they flow better than the flow masters. The straight through muffler design is more efficient than the chamber style of the flow master. But anyways, kooks mid-length headers, true dual 2 1/2 inch exhaust with an x pipe, and some magnaflow mufflers would be the setup I would recommend.
 
I dont like either magnaflow (quality they rust and fall apart fast) or flow master. Borla is the way to go in my opinion and I have had them all. The Borle xs 2 2.5 in 3 out and 2 borla xs 2.5 in 2.5 out in the back.
 
I dont like either magnaflow (quality they rust and fall apart fast) or flow master. Borla is the way to go in my opinion and I have had them all. The Borle xs 2 2.5 in 3 out and 2 borla xs 2.5 in 2.5 out in the back.

I haven't had trouble with magnaflows rusting out or heard of them rusting out before. Flow masters on the other hand have been known for rusting out and falling apart. I haven't used borla mufflers before but I've only heard good things about them. So either magnaflow or borla would do.
 
Ok so I think I found what I want, and then I will have to choose mufflers. I think i'm gonna go with the SCP 3" - http://www.supercoupeperformance.com/partBrowser.aspx?partId=145
but now i'm torn on the headers to get. I would either like the mid or full length Kooks the SCP offers.

For those of you who don't know what I'm running and would like a better idea, I'm running a Comp Cams slightly modded street cam, 50lb injectors, 75mm TB, 76mm MAF, port/polished heads,intake,supercharger (also rebuilt) 10% OD on SC...I have a chip from Dalke but i'm sure its going to need redone after I get all the work I want to done to it. So i'm worried that with the full length headers that I wouldn't have enough back pressure or too little power for too long of headers...

any help would be appreciated!
 
So i'm worried that with the full length headers that I wouldn't have enough back pressure or too little power for too long of headers...

any help would be appreciated!

You don't want back pressure.

Anyone that tells you that doesn't know what they're talking about.

Now, as far as the SCAVAGING effect - you probably need to talk to Dalke or someone else to find out what the long tube headers will do in regards to that.

(Some may mistakenly call the scavaging effect "backpressure", but it's like calling your SC a FWD car ... )

RwP
 
Ralph - I appreciate it! Its embarassing when you're with your SC buddies and use the wrong terms :) I will most likely pm dalke...thanks for the help!
 
one thing I can tell you is that I installed cutouts on mine right after my muffler (sits in where stock resonator is), and with my setup (342rwhp), the car is slower with cutouts open than with them closed
 
SCP offers systems for both the old and new gas tanks and we can custom make a system for you with virtually any set of mufflers you wish.....from quiet to loud.

I do have my favorites as I know what tends to work well on these cars.

Give me a call to discuss which will work best for your setup.
 
I haven't had trouble with magnaflows rusting out or heard of them rusting out before. Flow masters on the other hand have been known for rusting out and falling apart. I haven't used borla mufflers before but I've only heard good things about them. So either magnaflow or borla would do.


My older brother had Flowmasters on his 4 x 4 for 13 years before they started to rust. I had mine on my 4 x 4 for 10. My younger brother has had a set on his 460 powered 78 F150 since 1996 and they still are as new. My 1990 n/a car currently has a Force II setup from my brothers wrecked 89 that was on his car since 1998. I just cleaned of some minor rust of the mounting hardware and repainted. These are vehicles driven in Canadian winters where a lot of snow falls. Flowmasters do not rust easy.
 
My 91 has a lot of the parts you have chick. I have not installed my cam or heads but I have a new rectangular with an MP inlet and a 5% jsp. I have the looks long tubes, magnaflow resonator and mufflers along with true duals 2.5" . I converted to the late model tank with a 255hp pump at that time. (You didn't mention if you have replaced your pump).

Performance is quite impressive but the system is very loud. This is most noticeable at light throttle until the car gets to speed and at heavy throttle.
 
My older brother had Flowmasters on his 4 x 4 for 13 years before they started to rust. I had mine on my 4 x 4 for 10. My younger brother has had a set on his 460 powered 78 F150 since 1996 and they still are as new. My 1990 n/a car currently has a Force II setup from my brothers wrecked 89 that was on his car since 1998. I just cleaned of some minor rust of the mounting hardware and repainted. These are vehicles driven in Canadian winters where a lot of snow falls. Flowmasters do not rust easy.

Don't be so sure. ;)

I've lived in the north, south, and now the NE US. Trust me, just about anything will rust here. Aluminum corrodes just from the humidity, you don't even need to get it wet. I think the Force II system on my Dodge lasted 3 years here in Ohio. The dry air in the cold north does an amazing job of keeping things decent for a long time. It really is different here.

That being said, Magnaflow mufflers don't rust, they are stainless steel. The packing will burn out though, so that is an issue, but Borla mufflers are the same design and suffer the same fate. Just ask John. ;)
 
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