HP exhaust manifold verses Header comparison

[moparedtn]

I don't think you get the mopar "blat" from headers that you do from manifolds! Nothing sounds better than brand new headers and mufflers at an idle, except a BBmopar with manifolds when you chop the throttle at 5K!

Brings up an interesting point - the sound of one versus the other.
I'm sure others are like me in this observation, but I've found over the decades that I can pick
out the distinct sound of a Mopar approaching vs. anything else.
Doesn't matter how the engine is built or if it's a BB, RB or LA - or even if it has headers or not,
there is a distinctive sound (feel?) to a Mopar V8 I can't describe - but it exists.
Maybe a more knowledgeable mechanical minded sort can explain why that is?

 

[BB BELLA]

I always thought it was the manifolds, the firing order is the same as most other v8's except the fords[sorry for the language} and that's why they had a unique sound!

 

[Turboomni]

Hadn't really thought about that. Before I had new dual exhausts installed in my Fury I would be at car cruises and such I would listen to the different Mopars and ask what mufflers they had. Most of the Cudas and such when I asked had Flowmasters especially when they wanted to look and sound like a street strip drag car. Many sounded basically the same . Because my car I felt had to have a different character of sound [I wanted a fuller fatter mellower sound} I went with Magnaflows. But I never thought about the character inherent in the factory cast iron exhaust manifolds and the "MOPAR" sound. Interesting.

 

[Cranky]

The sound of my cars were usually different than the others.....since most of them had straight pipes

 

[fratzog lover]

but stubbornly refuses to rot out so I can justify replacing it all with good stuff.

 

[4mulas]

Some people on here sure are passionate about trying explain their points of view.

Nicks garage shows about a 5% gain from manifolds to headers. If that’s worth $1000 usd (plus more in some circumstances) to you go for it.

Headers are cool.

Factory hi Po manifolds look super cool to me too and is what I opt for.

I can buy a set of them used for around $300, sandblast them for free, and paint them for about $20 bucks. They look awesome, don’t leak, and help the performance somewhat compared to smog manifolds. By the time I get tti headers shipped to Canada it’s a $1700 bill (shipping, exchange, tax, and duty all included) and that is definitely not worth it too me. The money I saved by not buying headers can pay for the full TTI dual exhaust system and tires for the car.

To each their own, you can’t go wrong. Good luck to the OP with their choice!

 

[fratzog lover]

Extrude hone has to be about highest cost per horsepower modification out there.

 

[moparedtn]

I always thought it was the manifolds, the firing order is the same as most other v8's except the fords[sorry for the language} and that's why they had a unique sound!

Hadn't really thought about that. Before I had new dual exhausts installed in my Fury I would be at car cruises and such I would listen to the different Mopars and ask what mufflers they had. Most of the Cudas and such when I asked had Flowmasters especially when they wanted to look and sound like a street strip drag car. Many sounded basically the same . Because my car I felt had to have a different character of sound [I wanted a fuller fatter mellower sound} I went with Magnaflows. But I never thought about the character inherent in the factory cast iron exhaust manifolds and the "MOPAR" sound. Interesting.

I don't think it has anything to do with type of manifolds/headers or mufflers (or not) when it comes to the Mopar
"heartbeat". I'm still hoping more knowledgeable folks weigh in here, but I'm thinking it's more to do with cam design
(LSA?) or some such - not to mention, it's known that Chrysler engineers were conscious of the sounds and looks
of their musclecar offerings, as were the competition I'm sure.

Whatever it is, Chevy V-8's have always sounded "generic" to me; the Fords of the day you could tell, too.
But now the Mopars? I could (and still can, mostly) tell them a block away when they're approaching.
They have a certain sound to them.

 

[Beekeeper]

Extrude hone has to be about highest cost per horsepower modification out there.

yep and hardly any gain to be had

 

[chargervert]

While I agree,a good set of headers will free up some horsepower,there are cars in the FAST class running 10s with stock HP manifolds.

 

[Turboomni]

While I agree,a good set of headers will free up some horsepower,there are cars in the FAST class running 10s with stock HP manifolds.

I dont know the rules for the FAST class racing but I think stock cast iron intakes from the year of production and model have to be used also. I think possibly extrude honing is allowed on intakes and exhaust manifolds but I am not sure. Then it would be worth it if you are into that type of racing. I have also heard of 10's not uncommon these days with stock type echaust manifolds.I also know in some types of FAST class type racing strokers are allowed BUT it all has to look stock.

 

[Cranky]

Some people on here sure are passionate about trying explain their points of view.

Nicks garage shows about a 5% gain from manifolds to headers. If that’s worth $1000 usd (plus in some circumstances) to you go for it.

Headers are cool.

Factory hi Po manifolds look super cool to me too and is what I opt for.

I can buy a set of them used for around $300, sandblast them for free, and paint them for about $20 bucks. They look awesome, don’t leak, and help the performance somewhat compared to smog manifolds. By the time I get tti headers shipped to Canada it’s a $1700 bill (shipping, exchange, tax, and duty all included) and that is definitely not worth it too me. The money I saved by not buying headers can pay for the full TTI dual exhaust system and tires for the car.

To each their own, you can’t go wrong. Good luck to the OP with their choice!

So many have problems with header leaks and there's usually a reason for that. If you know what you're doing, even the cheaper brand ain't all that difficult to seal up. Also, everyone thinks that stock manifolds never leak. Well, for the most part, they are usually leak free but I've had them leak too. Thing is, I've learned how to prepare headers and manifolds or at least check them over well enough to ensure no leaks and the same techniques apply to both. One major problem with manifolds is if they are warped and you don't check for that and stick it on, the chance it'll crack is pretty high but the so is the chance of it leaking.

 

[Turboomni]

Here is some FAST racing rules. Strokers are not allowed in FAST.

https://www.fastdrags.com/factory-stock-rules

https://www.fastdrags.com/fast-rules

Engine:
Must be factory correct for the year, model, and horsepower claimed. Dealer installed engines and dealer performed engine modifications are not allowed. Casting numbers must be correct for the year and horsepower claimed including intake manifold, heads, and exhaust manifolds. Modifications are prohibited. Blocks do not have to be "numbers-matching," but they must be the correct displacement. Overbores up to .070" are allowed. Stock cranks only. NO strokers! Random P&G checks are possible. No lightweight cranks, connecting rods, or pistons allowed. Aftermarket pistons are allowed, but piston rings can be no thinner than 1/16", 1/16", and 3/16" for top, second, and oil rings, respectively. Gas porting of pistons NOT allowed. Metric and pressure-back-type rings (dykes, head land, etc.) are NOT allowed. Torque straps allowed. Torque straps are allowed. No after-market blocks allowed. Compression may be increased to the greater of NHRA allowable stock blue print or 1.5 over advertized compression. NHRA

 

[Turboomni]

F.A.S.T. racers break 9-second barrier

in 2010


https://www.hemmings.com/blog/2010/10/06/f-a-s-t-racers-break-9-second-barrier/

 

[Turboomni]

 

[Turboomni]

Tires & Wheels:
Reproduction tires or radial tires only. No soft compound tires of any kind allowed. Retread tires are not allowed. Use of traction compounds or rubber-softening chemicals on tires are strictly prohibited. Tire size must approximate what was originally installed on the car. All four tires must be the same size. No 60-series tires will be allowed unless they were originally available for the car's year and model. 60-series tires must be run on 15-inch rims as they were originally. Cars built before the introduction of 70-series Polyglas or Wide-Ovals are allowed to upgrade to 70-series tires of appropriate size for the car. Please call for clarification. Suspicious tires will be durometered. Factory wheels only. Wheels must be correct in size, offset, and style for the car's make, model, and year. All four wheels must be the same size and offset.

 

[Brandy]

I will chime in. I have stock HP manifolds and a set of block hugger shorty headers. I am also undecided on which to go with. I will be using the shorty chrome headers if possible I think. Clearance issues aside anyway. The heads are ported and will flow. 1973 .030 over 440 with a middling cam and ported heads, single plane & 750 Holley.

 

[33 IMP]

I think, but i am not sure, you are confusing FAST with Factory Stock. They have two different sets of rules. Factory stock is VERY strict, FAST much less so. I have definately heard of strokers and other extraordinary tricks in FAST, Dudeks car among them. FAST cars are around two seconds faster than Factory Stock.

 

[Turboomni]

I think, but i am not sure, you are confusing FAST with Factory Stock. They have two different sets of rules. Factory stock is VERY strict, FAST much less so. I have definately heard of strokers and other extraordinary tricks in FAST, Dudeks car among them. FAST cars are around two seconds faster than Factory Stock.

I may have confused the two. What are then the rules for the race class Dudek runs in? Are they running headers? Sorry if I goofed.

 

[Turboomni]

In the Hemmings article I posted above Dudeks car and the red Mustang are featured. Yes strokers are allowed but stock tire and manifolds.
From the article.

""Just for clarity’s sake, remember that the basic rules of this series dictate that competitors’ vehicles must look just like they did the day they rolled off the dealer’s lot – and they don’t mean Mr. Norm’s Grand Spaulding Dodge or Don Yenko’s Chevy store. The cars are to be pattered after factory-specified combinations, and to that end they are to use the properly coded castings and associated parts; there’s also the bit about running only a stock-type tire.

What can’t be seen is fair game, so stroker cranks, meticulously ported heads and manifolds and big compression ratios are the order of the day, but all that power still has to be put to good use through a relatively puny DOT-legal footprint. It’s a challenge that these guys have obviously taken quite seriously.""

 

[33 IMP]

In my humble opinion, it is fairly simple. If you have a 318 two barrel, or even a 360 or 383 with a stock cam and highway gears and low rpm, save your money, put a nice set of dual pipes and the mufflers of your choice to get the sound that you want. Headers might get you 5hp.
If you have a 512 with a roller cam and TF 270s and a dominator, manifolds will only cost 100-150 horsepower.
If you are somewhere in between, say a 440 with a cam, intake, 750 holley, it will be your decision. Just know the upsides and downsides of the decision you make.