Dyno - headers

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moparstud440

moparstud440

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I didn't want to hijack the other thread but curious has anyone dyno'd a motor and compared underchassis/fenderwell headers of the same size? I'd imagine that dyno headers would give the best results, but realistically how many can use them in their car. Curious to how all 3 would compare on the same engine.
 
I don't know if Engine Master ever did that test but i bet they have.
Here is my thoughts, chassis header, by design, has to have a sharp turn down at the flange. fender headers don't. chassis header have smoother, shorter bends.

My guess would be that the fender header would win in most case. If the eng would tune better with a shorter header length then maybe not................

I think the biggest down side for fender headers is tire clearance. But if your running a skinny up front already. it would be much less of a issue.
 
I'd love to see a head to head header comparison. The only one i've ever seen is the schumacher vs. TTI 2"
 
The problem with fender well headers is primary tube length being to long for a good top end HP number to be produced.
However, I have seen them perform toe to toe with dyno headers and normally designed headers. This leaves me to one conclusion, it’s all combo dependent.

So when guys point out that my headers suck, I have no idea what I’m doing, they know better, etc….
I just say show my your own personal dyno runs and explain your combo choices. No one has yet to come forward and accept the challenge. No one can. There all bench racing idiots that take TV shows and internets heroes as law of what will happen & the way things are in concrete.

I should make “Combo Dependent” a catch phrase in my sig.
 
rumblefish360 said:
The problem with fender well headers is primary tube length being to long for a good top end HP number to be produced.
However, I have seen them perform toe to toe with dyno headers and normally designed headers. This leaves me to one conclusion, it’s all combo dependent.

So when guys point out that my headers suck, I have no idea what I’m doing, they know better, etc….
I just say show my your own personal dyno runs and explain your combo choices. No one has yet to come forward and accept the challenge. No one can. There all bench racing idiots that take TV shows and internets heroes as law of what will happen & the way things are in concrete.

I should make “Combo Dependent” a catch phrase in my sig.
Click to expand...
dont forget the car meet crowd :)
 
rumblefish360 said:
The problem with fender well headers is primary tube length being to long for a good top end HP number to be produced.
However, I have seen them perform toe to toe with dyno headers and normally designed headers. This leaves me to one conclusion, it’s all combo dependent.

So when guys point out that my headers suck, I have no idea what I’m doing, they know better, etc….
I just say show my your own personal dyno runs and explain your combo choices. No one has yet to come forward and accept the challenge. No one can. There all bench racing idiots that take TV shows and internets heroes as law of what will happen & the way things are in concrete.

I should make “Combo Dependent” a catch phrase in my sig.
Click to expand...



It’s always about the combo. It’s like eating cereal without milk.
 
Cudafever said:
I don't know if Engine Master ever did that test but i bet they have.
Here is my thoughts, chassis header, by design, has to have a sharp turn down at the flange. fender headers don't. chassis header have smoother, shorter bends.

My guess would be that the fender header would win in most case. If the eng would tune better with a shorter header length then maybe not................

I think the biggest down side for fender headers is tire clearance. But if your running a skinny up front already. it would be much less of a issue.
Click to expand...


If someone wants to loan me a set of 2 inch chassis big block headers I’ll do the test.

As long as the chassis headers are adjustable they will beat up fenderwell headers every time. There isn’t an engine out there (with correct cam timing) that wants a primary tube that long.

In fact, IMO as the primary diameter goes up, the primary length needs to go down. That may seem counterintuitive but it’s not. In that case you are tuning primary length against primary diameter.
 
Here’s the question of the day….

How to use ping tube headers effectively?
 
Rat Bastid said:
If someone wants to loan me a set of 2 inch chassis big block headers I’ll do the test.

As long as the chassis headers are adjustable they will beat up fenderwell headers every time. There isn’t an engine out there (with correct cam timing) that wants a primary tube that long.

In fact, IMO as the primary diameter goes up, the primary length needs to go down. That may seem counterintuitive but it’s not. In that case you are tuning primary length against primary diameter.
Click to expand...
Would you make up the length with collector?
 
Engine masters season 5 episode 71. Header test on a run of mill 450hp sbc.
3EDEFACA-5601-4664-9870-27B77C8BC9D0.png
 
Find the one where they do the fender well headers!
Wait… edit… didn’t they do a big block version of this at some point?
 
Not all “fenderwell” headers are created equal.

So, what the results of a test between a particular pair of headers on a 450hp SBC does......... has no bearing on what might happen on a different set of headers on a 600hp BBM.
The results might be similar, they might be way different.

The only conclusions that can be drawn from a header swap test on a given engine is........ that’s how those parts worked on that particular engine.

Any trying to correlate that data into another build is just a guess.
 
PRH said:
Not all “fenderwell” headers are created equal.

So, what the results of a test between a particular pair of headers on a 450hp SBC does......... has no bearing on what might happen on a different set of headers on a 600hp BBM.
The results might be similar, they might be way different.

The only conclusions that can be drawn from a header swap test on a given engine is........ that’s how those parts worked on that particular engine.

Any trying to correlate that data into another build is just a guess.
Click to expand...
Completely agree
 
PRH said:
Not all “fenderwell” headers are created equal.

So, what the results of a test between a particular pair of headers on a 450hp SBC does......... has no bearing on what might happen on a different set of headers on a 600hp BBM.
The results might be similar, they might be way different.

The only conclusions that can be drawn from a header swap test on a given engine is........ that’s how those parts worked on that particular engine.

Any trying to correlate that data into another build is just a guess.
Click to expand...

Same as the X vs H vs straight pipe exhaust debate. Results are totally combo dependent.
 
@Rat Bastid I can loan you a set of headers, but they aren't 2".
They are headers for a big block a-body but they are 2 1/4 ", roughly 40" primary tube length, 4" collector 9 1/2 long
They are a mixboxel set, one side has 1 tube thru the k member, the other three thru the wheelwell, other side has one under chassis, two thru the wheelwell, and one thru the k member.
My guess is that you would need a LOT of motor to see an improvent over a 2" set.
 
Last edited:
33IMP said:
@Rat Bastid I can loan you a set of headers, but they aren't 2".
They are headers for a big block a-body but they are 2 1/4 ", roughly 40" primary tube length, 4" collector 9 1/2 long
They are a mixboxel set, one side has 1 tube thru the k member, the other three thru the wheelwell, other side has one under chassis, two thru the wheelwell, and one thru the k member.
My guess is that you would need a LOT of motor to see an improvent over a 2" set.
Click to expand...
Cool !
 
33IMP said:
@Rat Bastid I can loan you a set of headers, but they aren't 2".
They are headers for a big block a-body but they are 2 1/4 ", roughly 40" primary tube length, 4" collector 9 1/2 long
They are a mixboxel set, one side has 1 tube thru the k member, the other three thru the wheelwell, other side has one under chassis, two thru the wheelwell, and one thru the k member.
My guess is that you would need a LOT of motor to see an improvent over a 2" set.
Click to expand...

See what the shipping is to 98942 and let’s see what happens. I’m game for about any test.
 
Rat Bastid said:
See what the shipping is to 98942 and let’s see what happens. I’m game for about any test.
Click to expand...
Okay, I'll see if I can find a box and see how much shipping will cost.
Before I retired, boxing and shipping something like this was a piece of cake, with my ups account.
Now, not so easy.lol
 
Another test I'll do is the 4500 to 4150 adapter with a 3 circuit 1050 with the fenderwell headers, then both my carbs on with better headers.
Will be testing some spacers however I don't have many to test, I bought a 2 inch super sucker merge but I figure with annular boosters that maybe another upstairs power loss...or rpm limitation but I don't know for sure yet
 
MOPARMAGA said:
Another test I'll do is the 4500 to 4150 adapter with a 3 circuit 1050 with the fenderwell headers, then both my carbs on with better headers.
Will be testing some spacers however I don't have many to test, I bought a 2 inch super sucker merge but I figure with annular boosters that maybe another upstairs power loss...or rpm limitation but I don't know for sure yet
Click to expand...

Damn, I forgot that thing was a 3 circuit. It‘ll be pig fat rich. I’ll do some work and see if we can make it 2 circuit without changing meeting blocks.
 
A question I have for any of you guys who've done testing is, could a cam with less degrees of duration on the exhaust make a fenderwell header work better. Now my half cocked theory is hard to explain since I'm only seeing it in my head lol
 
Rat Bastid said:
Damn, I forgot that thing was a 3 circuit. It‘ll be pig fat rich. I’ll do some work and see if we can make it 2 circuit without changing meeting blocks.
Click to expand...
Oh yeah we were thinking about doing that. I guess we can see how fat pig it is then change it up.
 
MOPARMAGA said:
A question I have for any of you guys who've done testing is, could a cam with less degrees of duration on the exhaust make a fenderwell header work better. Now my half cocked theory is hard to explain since I'm only seeing it in my head lol
Click to expand...


Maybe. I’m beginning to think any head with a decent exhaust port needs less duration. And by that I mean less duration than the intake lobe.
 
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