Would going from 2 1/2 to 3'' exhaust be worth it???

[69wannabe]

I'm running a mild cammed 493 cubic inch stroker in my charger. It's a street driven weekend driver with mild 9.8 or so dish pistons and a XE285 comp cam. Got cast iron 346 heads with 214/181 valves and mild port work and the RPM intake and 850 DP holley carb. The headers are the hedman 1 3/4 headers with 2 1/2 pipe out the back. I have other mopar guys tell me the car needs 3'' exhaust since its a stroked 440. I am wanting to change the tips and put some more correct ones on there but would like input on the 3'' recommendation. Thanks

[green69rt]

Just to get the discussion started....  A bigger exhaust will only help when running at the top RPM with a big cam.   Correct that...it will help MOST running at top RPM and a big cam.  Otherwise it's mostly bragging rights.   I doubt if you could tell in day-to-day driving or even at the stop light.   It might show up on a dyno but not much, only at the top end.   With a fairly mild cam you need to enhance the low end torque, which translates to seat-of-the-pats kick.   For that you need to keep the exhaust velocity up at low RPM.  With a 3" exhaust, you will reduce the low RPM velocity. 

[JB400]

I would have to agree.  Since it's just a street car, 2 1/2 is enough.   If it's going to spend quite a bit of time on the track, then the 3 inch would be more justifiable and necessary.

[68X426]

Ron will hopefully post on this topic, with way more knowledge than I have. But as I understand the science of this, the point to headers and the big exhaust is to not restrict the flow of the heads (in the final analysis).

The heads are not large enough flow to call for 3". In other words, 2.5" is not restricting the flow, so it's not worth the expense.

[Cooter]

OP, you sure they ain't 1 7/8" headers?
I think you'll benefit from a free flowing 3" exhaust if for nothing more than to change the sound of the car and free up a few ponies up top. plus, if you go with aluminum heads later, you have the pipe.

[tan top]

yeah stroker motor ,  3inch pipe  & its all ready there should you feel the need to ad more speed parts 
stock 383 or 440   , with no plans  of looking for more power !!   2 1/2 inch   

[Ghoste]

I think in your case the 3 inch will make a difference given the cubic inches you are moving.  It's going to set off car alarms driving around town but that can be amusing in its own way too.

[1974dodgecharger]

If u have da money I say do it...I have 3 inch exhaust myself love tye sound

[Back N Black]

I think a 2.5'' exhaust would be go up to 500 hp. Anymoe than 500 hp go with the 3'' exhaust.  

[John_Kunkel]

My '62 Dart Max Wedge car had the original 2 1/2"/2 1/4" exhaust, replaced it with a 3" system from TTI. Starting the motor after the new exhaust install it idled 200 rpm faster and had noticeable better throttle response.

Downside...very noisy (to my taste).

[firefighter3931]

A 3in mandrel bent system with an X-pipe and straight-thru style mufflers would be a nice improvement. The welded UltraFlow mufflers would be my first choice. 


Ron

[Mopar Nut]

A 3in mandrel bent system with an X-pipe and straight-thru style mufflers would be a nice improvement. The welded UltraFlow mufflers would be my first choice. 


Ron

Mine too with a 493 cubic inch stroker.

[ACUDANUT]

 I never did find a Muffler shop around me who could give me a 3inch exhaust.  Their systems could only bend 2 1/2.  It works for me.

[BSB67]

Do those of you that believe that 3" is better also think that hp level is not pertinent?

Do you believe that the OP is making more than 500 hp?

Do you believe that a 440 with the same hardware (cam, heads etc.) should have a 3" system too?

Do you believe that there would be and increase in 1/4 mile mph (i.e. average power)?

Do you believe that there would be more than 10 hp increase at max power (5000 rpm or so)?

Do you believe that there will not be a degradation of throttle response below 3000 rpm?

Just curious

[69wannabe]

If u have da money I say do it...I have 3 inch exhaust myself love tye sound

What mufflers are you running? I am currently running super turbo's and they have been on the car for years and I like the way they sound. They are very noticeable at idle and smooth and mellow down the road. I had 3 chamber flow masters a long time ago on there but they resonated through the car and I didn't like that at all. Guess i'm getting old and don't like the noise!

[69wannabe]

A 3in mandrel bent system with an X-pipe and straight-thru style mufflers would be a nice improvement. The welded UltraFlow mufflers would be my first choice. 


Ron

Hey Ron, are these mufflers rather quiet?? I like the sound of the regular turbo's that are on it rite now verses it being loud.  I want the performance without the noise!! 

[ACUDANUT]

BSB....Nice car. 
Get the rear in the air.

[69wannabe]

BSB....Nice car. 
Get the rear in the air.

Thanks!! It actually sat a lil higher in the rear right after I put the new leaf springs on it but its been about 8 years ago and they are starting to slouch a little bit now. It is actually kinda aiming uphill in this pic so it looks even lower in the rear. If you look at some of the other pic's I posted it looks better on level ground. It has a decent stance but could use some new springs again I suppose.

[ACUDANUT]

Are BSB and 69 wannabe the same...?

[Ghoste]

Do those of you that believe that 3" is better also think that hp level is not pertinent?

Do you believe that the OP is making more than 500 hp?

Do you believe that a 440 with the same hardware (cam, heads etc.) should have a 3" system too?

Do you believe that there would be and increase in 1/4 mile mph (i.e. average power)?

Do you believe that there would be more than 10 hp increase at max power (5000 rpm or so)?

Do you believe that there will not be a degradation of throttle response below 3000 rpm?

Just curious

Absolutely great questions and clearly your car runs strong with manifolds and 2.5 exhaust.  Do you ever wonder how much you left on the table with the more restrictive exhaust? 

[green69rt]

No one will ever know unless its on a dyno or at the strip in a heads up comparison..  Again I say the bigger exhaust matters at the top end.  Am I wrong??

[Cooter]

No one will ever know unless its on a dyno or at the strip in a heads up comparison..  Again I say the bigger exhaust matters at the top end.  Am I wrong??

all depends on how the engine's built if you wanna get all the way into specifics.....

[green69rt]

No one will ever know unless its on a dyno or at the strip in a heads up comparison..  Again I say the bigger exhaust matters at the top end.  Am I wrong??

all depends on how the engine's built if you wanna get all the way into specifics.....

Nah, lets not go that far.  Too many possible scenerios and I don't want to hijack the thread.  

[BSB67]

BSB....Nice car. 
Get the rear in the air.

Thank you.  That aint the only rear end I have that seems to be getting lower to the ground.   

[BSB67]

Do those of you that believe that 3" is better also think that hp level is not pertinent?

Do you believe that the OP is making more than 500 hp?

Do you believe that a 440 with the same hardware (cam, heads etc.) should have a 3" system too?

Do you believe that there would be and increase in 1/4 mile mph (i.e. average power)?

Do you believe that there would be more than 10 hp increase at max power (5000 rpm or so)?

Do you believe that there will not be a degradation of throttle response below 3000 rpm?

Just curious

Absolutely great questions and clearly your car runs strong with manifolds and 2.5 exhaust.  Do you ever wonder how much you left on the table with the more restrictive exhaust?  

The cam was selected with the exhaust manifolds in mind, so I suspect that I'm probably not leaving as much on the table as you would think.  If it had a similar cam lobe sizes but designed for headers, it would probably make a bunch more power.  But then it probably would not run on pump gas.    

I know a guy making nearly 800 hp and trapping at 136 mph with 2 1/2" exhaust system.  Obviously it is a very specialized situation, but it is demonstrated as doable, by several people actually.  So it does make me wonder the real in the car performance difference on a 450 to 500 hp motor between 2 1/2" and 3".  My guess is that unless you are a techie working the tune base on regular track tuning, the average guy won't even find the potential power difference if there is one.  But that is just an opinion, I've never tested it.  And that is the problem, Who is going to buy two new exhaust systems and test them back to back ( adjusted for atmospheric conditions if not tested on the same day)?  Results from testing a used exhaust system to a new system is not indicative of the power increase from just the pipe size difference.  

[Ghoste]

True enough, outside of a magazine or TTI likely no one.

[69wannabe]

Are BSB and 69 wannabe the same...?

Sorry, I read that quickly and replied. I didn't see the mistake til later. My bad!!

[Cooter]

How do we know that that 800 HP engine wouldn't benefit from larger pipes?

One thing I've never figured out unless it has to do with flow speed, is why Damn near all BBC  headers come with a 3" collector and almost everybody drops that 2 1/2" system at the track, and the car picks up performance. Why neck that 3" down to 2 1/2"?

[69wannabe]

800 horse power would for sure benefit from 3 inch exhaust!! I figure my estimated 525 hp at the flywheel would be on the border line from either staying with what I got and installing new charger exhaust tips or running an all new 3'' exhaust with new 3'' tips winding up with bout $400 to $500 bucks in it. I would like the more throaty sound more than likely but the engine is very responsive on the low end which is the way I like it and I wouldn't want my lower RPM's to suffer. Its just a driver anyway and it doesn't  see the strip ever so it may stay the way it is. May not be worth the trouble unless I was trying to get better numbers on a time slip. Oh and yeah Cooter my headers are the hedman elite series 1 3/4 primaries with the 3'' collector.

[BSB67]

How do we know that that 800 HP engine wouldn't benefit from larger pipes?

It would

[2Luke2]

If you do go to a three inch and are looking for a set of the mufflers Ron suggested let me know. We have a brand new pair that has about 10-15 miles on them. We like the car LOUD lol... and it made it way too quite for our taste.

[myk]

If you do go to a three inch and are looking for a set of the mufflers Ron suggested let me know. We have a brand new pair that has about 10-15 miles on them. We like the car LOUD lol... and it made it way too quite for our taste.

Agreed.  Putting in an H-pipe and the Ultra-flows made my car more quiet...

[Ghoste]

Not really a safe extrapolation to say that benefiting from open headers at the track means a three inch system would be better on the street.  The track is an example of a WOT only condition.

[BSB67]

One thing I've never figured out unless it has to do with flow speed, is why Damn near all BBC  headers come with a 3" collector and almost everybody drops that 2 1/2" system at the track, and the car picks up performance. Why neck that 3" down to 2 1/2"?

My observation is that nearly all 12 second ish cars will pick-up .2 sec. and 2 mph, when they drop their old, 2 1/2" compression bent, cross flow muffler design exhaust system, irrespective of engine manufacturer brand

[Ghoste]

My 383 car picks up that much (but cam carb and intake all pretty much predict that).

[Kern Dog]

I am tempted to make this change. I have TTI 2" headers with 3.5 collectors. The rest of the exhaust is muffler shop 2.5" pipes and Flowmaster mufflers. I welded in my own H pipe. The engine is a 440/493 with ported Edelbrocks and a Lunati solid lifter cam. I'm guessing that I could benefit from a 3" system. I like the feedback I've read regarding the Dynomax Ultra Flo mufflers.

[Cooter]

Get rid of that "H" pipe, and install an "X" pipe. 3" kit. The ONLY time I run smaller is when space is at a premium.

[Mike DC]

 

Lots of cars sound better without crossover pipes.  

It's unconventional to purposely hurt the exhaust flow for the sake of a bit more badass sound, but it's no crazier than plenty of other things we do.  If any of us were building our cars 100% for speed then we wouldn't be building Chargers in the first place.  

[Ghoste]

Thats true.  I think a lot of people worry too much about badass sound, a cam that hurts performance but has a good lope, the aforementioned exhaust and so forth.
Me, I like the sound of a crossover better but sound is all subjective anyway.

[Cooter]

X pipes will outflow H pipes hands down. Plus, they offer more balanced sound. Gets rid of that 1970's goofy, raspy, sounds like you tied a piece of inner tube flapping behind the car, sound. Not that it's a bad thing if you like 90% of folks who won't say it to your face, but WILL say it after you leave with a WOT blast, how much it sounds like a 'pulp wood truck'.

[Ghoste]

Pulp wood truck, I like that. 
Here we always just called it a frap.

[c00nhunterjoe]

X pipes will outflow H pipes hands down. Plus, they offer more balanced sound. Gets rid of that 1970's goofy, raspy, sounds like you tied a piece of inner tube flapping behind the car, sound. Not that it's a bad thing if you like 90% of folks who won't say it to your face, but WILL say it after you leave with a WOT blast, how much it sounds like a 'pulp wood truck'.

Im not arguing the performance side of an x-pipe. But to say not running one makes your car sound like a pulp truck is a bit of a stretch. I dont run any kind of crossover pipe and i get asked all the time about my exhaust setup. People have followed me to ask about what im running because of how good it sounds. ive even had flowmaster bashers on this forum compliment my exhaust tone.

[1974dodgecharger]

The only people who will say that your car sounds bad is the same folks who just ate your dust because thats the only way they are gonna find out that it sounds bad to them is when their behind....

[Cooter]

X pipes will outflow H pipes hands down. Plus, they offer more balanced sound. Gets rid of that 1970's goofy, raspy, sounds like you tied a piece of inner tube flapping behind the car, sound. Not that it's a bad thing if you like 90% of folks who won't say it to your face, but WILL say it after you leave with a WOT blast, how much it sounds like a 'pulp wood truck'.

Im not arguing the performance side of an x-pipe. But to say not running one makes your car sound like a pulp wood truckis a bit of a stretch. I dont run any kind of crossover pipe and i get asked all the time about my exhaust setup. People have followed me to ask about what im running because of how good it sounds. ive even had flowmaster bashers on this forum compliment my exhaust tone.

. Blown out glasspack or Flowbastards with no balance pipe at WOT, will sound like a pulp wood truck whether people are telling you it sounds good or not. For every person you claim to have that loves the sound, I can find an equal amount that think it sounds like a redneck Pulp wood truck. Some just seem to think that raspy flapping sound sounds good. These are usually the same types that remark about a '440 hemi". Afterall, the General Lee had this stupid sound, so it kinda goes with the car as 'correct'. Only thing worse would be Uber redneck by running straight pipes. This coming from a redneck himself.

Flowbastards are playing out. This coming from a used to be huge supporter.

[Cooter]

The only people who will say that your car sounds bad is the same folks who just ate your dust because thats the only way they are gonna find out that it sounds bad to them is when their behind....

Wrong. There are those who seem to think it's just grand to leave a car show sideways and WOT sounding like a pulp wood truck.

[Ghoste]

You gotta love the car show exits, it seems like the worse it performs the more they have to prove on the way out.

[Cooter]

You gotta love the car show exits, it seems like the worse it performs the more they have to prove on the way out.

Subsequently ruining it for the cars that would crush those. But, I degress. Idiots will be idiots.
straight pipes will be run, g lasspacks/Cherry bombs will continue to installed.

[Ghoste]

Getting off topic but the ones who frighten me even more at car shows are the idiots who display that behaviour but with real power under the hood.  Anyone stupid enough to pull a sideways wot tire screaming and smoking stunt leaving a public parking lot is typically not equipped with the skills to recover the car if it gets away from them.  (not to mention how it makes us all look in the public eye)

[Cooter]

That's why I said what I did about attempting a quieter ride by any and all means including, but not limited to running 3" exhaust.
bigger dia. Pipe muffles to a certain degree. Many here have begun the "if it really has balls, put it on the track where everybody can see the time" and are attempting to make it uncool to leave squeeling tires. If it's really badass, no need for that.


Our car club doesn't as allow it, will run your dumbass off for it, and actually condones quieter rides that still have balls.
there's simply no need to be obnoxiously loud in order to 'appear' like your car has what it takes...

I even told one douchebag that likes to try and hang around us, "you know Gordon, in alot of ways your just like your car. You make all kinds of noise, but when it comes to balls, you have none"...

[ACUDANUT]

Does anyone here hate their "too quiet" of exhaust ?

[Cooter]

With a 3" set up, there's a 'good' sounding loud....then, there's the obnoxious pulp wood truck loud, with long tube headers and 2" pipes, no balance X pipe, blown out Cherry bombs....

[c00nhunterjoe]

The only people who will say that your car sounds bad is the same folks who just ate your dust because thats the only way they are gonna find out that it sounds bad to them is when their behind....

Wrong. There are those who seem to think it's just grand to leave a car show sideways and WOT sounding like a pulp wood truck.

For your information, i dont leave car shows sideways. If i "make an exit" there are no other cars coming and i make the car hook and go in a straight line. and my car does not have the trade marked "tin can" sound associated with the name flowmaster. Most people dont beleive me when i tell them they are flowmasters on it. It has a unique muscle car deep powerful tone to it.

[Cooter]

The only people who will say that your car sounds bad is the same folks who just ate your dust because thats the only way they are gonna find out that it sounds bad to them is when their behind....

Wrong. There are those who seem to think it's just grand to leave a car show sideways and WOT sounding like a pulp wood truck.

For your information, i dont leave car shows sideways. If i "make an exit" there are no other cars coming and i make the car hook and go in a straight line. and my car does not have the trade marked "tin can" sound associated with the name flowmaster. Most people dont beleive me when i tell them they are flowmasters on it. It has a unique muscle car deep powerful tone to it.

For your info. I wasn't referring to you. Just those types in general.  You know who I'm referring to.

[70-500-SE-EXPORT]

I have a 3" flowmaster system with 1 7/8 headers on my 68 with a 383 and I like it. The motor ran much better with the free flowing exhaust. I'm happy I went with the 3". It is fairly loud so If you don't want to hear the exhaust all the time sick with a 2.5"..There is a mopar muscle article I remember seeing where they dyno tested a 440 with 2.5 and 3" exhaust. The larger system had substantial power gains.

[Ghoste]

Thats interesting.  I would think of it being overkill on a 383 unless it was heavily modified but I do have a buddy that had 3 inch behind a 390 Ford.

[Cooter]

I have a 3" flowmaster system with 1 7/8 headers on my 68 with a 383 and I like it. The motor ran much better with the free flowing exhaust. I'm happy I went with the 3". It is fairly loud so If you don't want to hear the exhaust all the time sick with a 2.5"..There is a mopar muscle article I remember seeing where they dyno tested a 440 with 2.5 and 3" exhaust. The larger system had substantial power gains.

[ACUDANUT]

Thats interesting.  I would think of it being overkill on a 383 unless it was heavily modified but I do have a buddy that had 3 inch behind a 390 Ford.

Have you ever had a built 383 ? They are not to be taken lightly. I love them.

[Ghoste]

Yes I most certainly have.  I'm trying to think of it in a context with 3" exhaust and admittedly my last 383 was a great deal better when the headers were uncorked but I still never considered a 3inch system.
Whether right or wrong I found it interesting.

[ACUDANUT]

My local Muffler guy does not have the equipment to bend 3 inch exhaust. So I guess I am stuck with 2 1/2.

[Mopar Nut]

My local Muffler guy does not have the equipment to bend 3 inch exhaust. So I guess I am stuck with 2 1/2.

It'll sound just as good. Is the guy charging less than TTi?

[Cooter]

Most of the time here, it's cheaper to just buy a mandrel bent system. Muffler shops are beginning to get crazy with custom prices.

[Ghoste]

Here too.  We have one independent guy in town that is a car guy and he is still a good option but if you go to the franchise places they only want to sell the pre bent stuff out of stock and expect to be allowed to hose you if you need something not in the rack.

[ACUDANUT]

My local Muffler guy does not have the equipment to bend 3 inch exhaust. So I guess I am stuck with 2 1/2.

It'll sound just as good. Is the guy charging less than TTi?

I never checked. Hmmm 

[shart70rt]

I am running a 496 stroker, Comp Hyd Roller (542 lift), Edelbrock heads, dual edelbrock 600's, 2" TTI headers and 3 inch TTI pipes with x crossover.

Develops 525 HP and 640 torque on dyno. Torque maxes out at 3400 rpm, and stays at max till 5500 rpm.

The engine sounds wicked through the pipes, and had no problems mounting the exhaust. Using the mufflers from TTI also. Have the 3" stainless Charger tips on them. I do have a 4 post lift that helped a lot on the exhaust install. Quality of hangers, clamps, etc on the TTI exhaust is fantastic.

I did have to buy a RobbMc starter to fit with the headers, because I have the large Lakewood Scattershield and 143 tooth flywheel.

It is not quiet - figure adding a stereo would be a waste of money. Will use mp3 player and headphones.

Stephen

[Kern Dog]

Most of the time here, it's cheaper to just buy a mandrel bent system. Muffler shops are beginning to get crazy with custom prices.

I agree. When I went from the 2 1/2" system to the 3 inch, I decided to buy a kit instead. Part of it was that the local muffler monkey is limited in his abilities. There is no way a shop can compression bend a 3" system without reducing the diameter in the process. The old system was already less than 2 1/4" in some places. By ordering a X section and four  3" mandrel bent sections, I welded it all myself with the car on jackstands. The system was a true 3" from the headers to the ends of the mufflers. Experts have said that tailpipes can be smaller than the middle section because the exhaust gases are much cooler at that point.
My 3" exhaust upgrade also included 3" Ultra Flow mufflers. The power increase was nice, but the reduction in sound compared to the Flowmasters was REALLY nice.