3 inch exhaust

[That_Tall_Dude]

Cool, didn't think there would be.
Engine specs are: 440 .030 over with KB step top pistons, 10.3 static 8.6 dynamic CR, Hughes Engines 228/232 -110ºLSA cam, mildly ported 346 heads.

Mark

That cam would really like headers; reasons not going that route?

I could run the dyno simulator with manifolds and headers and overlay them if you want

 

[hunt2elk]

What don’t you like about the sound? Just wondering...

I have been running the 2.5" versions of Dyno Max Ultra Flow's as well as their Super Turbo's on my last 4 cars and am quite used to the sound each make. The cars all have TTI headers and TTI 2.5" full exhaust systems. On this last one I went with the ST knowing that the 3" system would probably be louder than what I am accustomed to. While it is louder than I was hoping, it also has a different sound that I don't care for. Also is very tight by the fuel tank. Just me, but I will never use 3" again, and may end up swapping this system out eventually....

 

[That_Tall_Dude]

I have been running the 2.5" versions of Dyno Max Ultra Flow's as well as their Super Turbo's on my last 4 cars and am quite used to the sound each make. The cars all have TTI headers and TTI 2.5" full exhaust systems. On this last one I went with the ST knowing that the 3" system would probably be louder than what I am accustomed to. While it is louder than I was hoping, it also has a different sound that I don't care for. Also is very tight by the fuel tank. Just me, but I will never use 3" again, and may end up swapping this system out eventually....

kinda funny... I have the same exhaust and feel similar, but haven’t had 2.5” systems to compare

it’s pretty loud, then gets quieter as it comes off idle... is a little odd...

 

[Charged440]

I've got a Skylark and a Charger, both 69s, both big blocks with headers and similar cams. Both have the same Dynomax super turbos but the Mopar has 2.5" and the Buick had 3.0" pipes. They both sound different and the Buick was louder, especially inside. In my case it seems the 3" pipes drone a lot more for whatever reason.

 

[That_Tall_Dude]

I've got a Skylark and a Charger, both 69s, both big blocks with headers and similar cams. Both have the same Dynomax super turbos but the Mopar has 2.5" and the Buick had 3.0" pipes. They both sound different and the Buick was louder, especially inside. In my case it seems the 3" pipes drone a lot more for whatever reason.

They all offset-in & center-out?

edit:
the ST has slightly different internals depending on that; tone and drone might be affected

(offset-in & offset-out would should be louder than center-out for the ST)

but yeah the 3” I have is a lot louder than I expected

 

[Master Gunner]

That cam would really like headers; reasons not going that route?

Had a lot of cars and trucks with headers, and with clearance issues, fitting issues, normal maintenance issues, (ie changing spark plugs) and always having to tighten header bolts I decided headers belong on the track. Just my opinion, and that and a buck will get you a cup of coffee. This is my street car that just might see 5500 RPM once in a while.
Still, it might be interesting to see how much I'm giving away.

Mark

 

[Charged440]

They all offset-in & center-out?

edit:
the ST has slightly different internals depending on that; tone and drone might be affected

(offset-in & offset-out would should be louder than center-out for the ST)

but yeah the 3” I have is a lot louder than I expected

Yes, they are all configured the same, actually the 3" ones were only 2.5" on the inside bc all they did was weld on larger inlets/outlets

 

[That_Tall_Dude]

Yes, they are all configured the same, actually the 3" ones were only 2.5" on the inside bc all they did was weld on larger inlets/outlets

yeah I noticed they reduce down, I think it bigger than 2 1/2” but it definitely isn’t 3”


on the center out, the flow has to pass under and over the outlet pipe.

heard of if you have an x-pipe can cause resonance or amplify sound since they are in sync, and easy way around that to have different mufflers, so I may do that

hey gunner,

sorry about the thread jacking, but it’s sorta on topic

will do that header vs manfolds overlay if you want it... just lemme know

 

[That_Tall_Dude]

Had a lot of cars and trucks with headers, and with clearance issues, fitting issues, normal maintenance issues, (ie changing spark plugs) and always having to tighten header bolts I decided headers belong on the track. Just my opinion, and that and a buck will get you a cup of coffee. This is my street car that just might see 5500 RPM once in a while.
Still, it might be interesting to see how much I'm giving away.

Mark

This is just some software so you know, but it’s saying 50 ft-lbs across the board.

hp is torque multiplied by rpm & a constant, so kinda proportional as it goes up, and ~ 50 hp from from 4K - 6k:

 

[That_Tall_Dude]

Oh hey sorry for the delayed response. Missed your response this morning until this evening somehow

Makes sense on the manifolds. Spark plug access sucks, starter too.

TTI fit great on mine, clearance seems good, left the studs in too

passenger side was installed in 15 minutes, just removed the motor mount bolt jack it up a bit and it was cake.

driver side ended up having to slip out the torsion bar; might of gone in without that if I pulled the studs and used header bolts; dunno. Also had interference with trans cooler lines and the trans shifter needs the clamp swapped 180.

fussed with it for a while before going the torsion bar route.

Oh and I missed a vacuum hose on the first start up on the headers; was running bad I was all WTF is this. Ran maybe 5 minutes and noticed one of the tube was glowing

got it hooked up quick but still toasted ~ 6” of the ceramic coating on that tube; that was not awesome

 

[moparedtn]

I've got a Skylark and a Charger, both 69s, both big blocks with headers and similar cams. Both have the same Dynomax super turbos but the Mopar has 2.5" and the Buick had 3.0" pipes. They both sound different and the Buick was louder, especially inside. In my case it seems the 3" pipes drone a lot more for whatever reason.

Yeah, the 3" on Fred drones terribly at certain RPM - usually, highway cruising speed. Oy...
That combination of loud drone and the freaking HEAT coming off the pipes up under our feet sucks.
On the other hand, the car makes all the cool NASCAR sounds when you hammer on it, so...

I'm sitting here recalling the first car I ever rode in that had headers and 3" on it, a '66 Charger hemi (a real one).
Way back in the early 80's, caught a ride with a fella at some national show (can't remember which one) to
get some dinner locally from the hotel.
Dude had a pretty radical setup for the street, but the interior wasn't really finished - heck, the seats
didn't even match, stuff missing from the dash, all that.
I had been told by several friends that I "HAD to get a ride in that car!", so off we went after introductions.
Headers, a short amount of 3" pipe and some crappy glasspacks....
That car was so radical the engine was basically an on-off switch - barely idled without help, but when he
hammered it, it was all GOD OF THUNDER! Absolutely sounded like the soundtrack of NASCAR and good LORD
would that thing move...
I couldn't have lived with that car, but DAMN I WANTED IT!

 

[493 Mike]

3” will be louder...

If your trying to maximize peak hp, then 3” probably makes sense.

But since you’re doing manifolds it looks like you favor practicality (balancing performance, quiet, maintenance, access, etc), then 2.5” is probably the way to go

Most stuff seems to say 3” for over 450 hp...

if you wanna geek out on back pressure & velocity this one is fun

A little late to add this but, in HS (mid 60s) I wrote a essay about ram tuning and this video brought back some good memories! Thanks.
Mike

 

[747mopar]

Wow, didn't expect to see so much 3" hatred lol. I'm scratching my head on the whole.. to loud, sounds terrible and is hard to fit comments? I was on the fence with whether or not to use 3" on my 456 stroker but in the end I knew it would likely never stay at 500ish hp and being all stainless I wanted a one time investment. It's went from side exit to now rear exit where I had no problem routing the pipes and it sounds great but everyone's perspective on great is different? As far as sound goes there's so many things that play into that, I've added tips that drove me absolutely mad, had Flowmasters that rattled my teeth out but this exhaust is a nice balance, I don't see the negatives?

That said, I'm with everyone on it not being worth it if your running manifolds or a mildly built motor.

 

[Ron H]

My read up on how influential the size of the exhaust is - is something I would a liked to pay more attention to sooner than later. I trusted a builder with a long standing phenomenal reputation doing mopar motors suggesting 3" on my built poly. Not the 1st time I didn't listen to what was swirling in my head, finding out later I might a been better trusting it.

 

[64BEL]

For those who get Motor Trend TV, the episode of Engine Masters tomorrow night at 7:00pm Central Time is 2.5" dual exhaust vs 3" single exhaust for horse power comparisons. I'm sure no one here is running single 3", but it sounds like it'll be interesting. I always enjoy watching Freiburger and Dulcich anyway.

 

[Joske2]

For those who get Motor Trend TV, the episode of Engine Masters tomorrow night at 7:00pm Central Time is 2.5" dual exhaust vs 3" single exhaust for horse power comparisons. I'm sure no one here is running single 3", but it sounds like it'll be interesting. I always enjoy watching Freiburger and Dulcich anyway.

You will be surprised

 

[33 IMP]

For those who get Motor Trend TV, the episode of Engine Masters tomorrow night at 7:00pm Central Time is 2.5" dual exhaust vs 3" single exhaust for horse power comparisons. I'm sure no one here is running single 3", but it sounds like it'll be interesting. I always enjoy watching Freiburger and Dulcich anyway.

Got both episodes set to record. Thanks! (And the new roadkill garage that follows. )

 

[steve340]

Would you guys mind giving a quick update on what the results are?
I would be interested in finding out.

 

[33 IMP]

Two episodes tonight. Second is easy, they compared an aluminum head to an identical iron head. The aluminum won.
The first was a dual 2 1/2" system with turbo mufflers vs. straight thru, and a 3" single exhaust system, also with a turbo and straight thru.
For the duals, the straight thru was slightly better than the turbos (no surprise). The single three, with a "t" connection or a "y" was horrible with a turbo, down 40hp. The surprise was the single 3" with the straight thru was the top power of all the combos. 3" headpipes apparently made the difference IF the muffler can flow enough. The single turbo couldn't.

 

[64BEL]

It was an informative, interesting show. Too bad they didn't do a dual 3", too. Would have been interesting to see how that compared to the single 3".