For Nowwhat...

[ViperTruck2933]

...... you really can't add longtubes with "no other changes." ......

Maybe Justin can clarify, but if I remember correctly he had the factory mids removed on the "Before" dyno run. Then a run with Headers as the only change. SO yes you can.

 

[FSTJACK]

John brought up thermodynamics.

Very good point as it is not just about the horsepower.

It is about holding/retaining the heat in the exhaust port.
This is very hard on valves.
A good set of headers will make the engine last longer with a proper tune.

This is one of the reasons that turbo motors are built with the best exhaust valves that money can buy.
The turbo exhaust retains/restricts the exhaust gasses and elevates the exhaust valve temps.
This will transfer more heat to the valve spring, shortning the springs life.
This also causes the oil to run hotter.
The cooling system has to work harder to properly cool the motor.
There is a propensity for hot spots in the exhust seat area of the combustion chamber.

A super charged motor needs to have as little exhaust restriction as possible.
A super charged motor is not dependent on exhaust scavenging to make more horsepower.
If you look at any kind of blown motor sports racing where noise constraints are not an issue, they do not even run a collector.
A collector is used only if the exhaust needs to be muffled for sound abatement.
The blower camshaft is of such a design as to properly fill the cyl under boost.
The main concern is to get the exhaust gasses out as fast and with as little restriction as possible.

 

[hunter_angler]

Maybe Justin can clarify, but if I remember correctly he had the factory mids removed on the "Before" dyno run. Then a run with Headers as the only change. SO yes you can.

You can't add longtubes with no other changes from the stock exhaust setup, and you can't use the same midpipes with longtubes that you use with factory manifolds, at least if you want everything to fit properly. As for the back-to back dyno test, even if the factory mids had been replaced before the first dyno run, the same mids could not have been used on the second unless they were cut and reconfigured. If the Bellanger mids were added to fit with the headers, that is another change.

As you say, perhaps we could get clarification on this, and more importantly, whether the cats were removed or switched out between tests, or even if the different mids used were the same diameter and/or both mandrel bent. There could be a lot of variables, some more important than others.

 

[FSTJACK]

Maybe Justin can clarify, but if I remember correctly he had the factory mids removed on the "Before" dyno run. Then a run with Headers as the only change. SO yes you can.

I designed and had Richard build a set of stepped, rotational firing, merged collector long tube headers. We used a single hiflow cat on each side. The entire exhaust was 3" with a custom made Bassani muffler with an X cross over built in.

The exhaust system made an increase of 44 RWHP on the same dyno without any other changes.
This system was originally designed for a suupercharged motor. I sold it when I cahnged to turbo's on the silver truck.
We did not make a jig so there is no easy way to duplicate these headers.

I sold the complete system and I wish I had it back, for the red truck.

 

[Nowwhat]

I designed and had Richard build a set of stepped, rotational firing, merged collector long tube headers. We used a single hiflow cat on each side. The entire exhaust was 3" with a custom made Bassani muffler with an X cross over built in.

The exhaust system made an increase of 44 RWHP on the same dyno without any other changes.
This system was originally designed for a suupercharged motor. I sold it when I cahnged to turbo's on the silver truck.
We did not make a jig so there is no easy way to duplicate these headers.

I sold the complete system and I wish I had it back, for the red truck.

yep...and a lot of the that rwhp was form the header back...yes?

 

[hunter_angler]

John brought up thermodynamics.

Very good point as it is not just about the horsepower.

It is about holding/retaining the heat in the exhaust port.
This is very hard on valves.
A good set of headers will make the engine last longer with a proper tune.

This is one of the reasons that turbo motors are built with the best exhaust valves that money can buy.
The turbo exhaust retains/restricts the exhaust gasses and elevates the exhaust valve temps.
This will transfer more heat to the valve spring, shortning the springs life.
This also causes the oil to run hotter.
The cooling system has to work harder to properly cool the motor.
There is a propensity for hot spots in the exhust seat area of the combustion chamber.

A super charged motor needs to have as little exhaust restriction as possible.
A super charged motor is not dependent on exhaust scavenging to make more horsepower.
If you look at any kind of blown motor sports racing where noise constraints are not an issue, they do not even run a collector.
A collector is used only if the exhaust needs to be muffled for sound abatement.
The blower camshaft is of such a design as to properly fill the cyl under boost.
The main concern is to get the exhaust gasses out as fast and with as little restriction as possible.

All true, but we were talking about the effect of adding headers to factory stock or mildly modded N/A engines.There isn't nearly as much heat buildup as with FI setups and boost, so there isn't as much concern about burning up valves.

To your point many maintain that free flowing factory type manifolds or shorty headers with large primaries are best for supercharged engines due to the lack of need for the scavenging effects of longtubes, unless you want longer primaries to shape the torque curve for more bottom-end. This is probably more necessary with centrifugal blowers than with Roots or twin screw types. The shorter primaries will actually offer less restriction overall to pressure air through and allow more top-end power. Of course turbo setups functionally seldom allow for longtubes.

Another funny argument is how folks always say longtubes make so much more power than shorties, comparing results from 1 3/4" - 1 7/8" longtubes to those from 1 1/2 -1 5/8" shorties. With equal diameter primaries and collectors it's more about where in the powerband power is made, not how much. The shorties on the market have smaller primaries because too much low end is sacrificed with bigger tubes in the majority of applications which are N/A. Diameter and length of the primaries both have a big effect on exhaust velocity and the torque curve.

Sorry if I am getting off track here. Just think longtubes are generally overated for many applications.

 

[ViperTruck2933]

You can't add longtubes with no other changes from the stock exhaust setup, and you can't use the same midpipes with longtubes that you use with factory manifolds, at least if you want everything to fit properly. As for the back-to back dyno test, even if the factory mids had been replaced before the first dyno run, the same mids could not have been used on the second unless they were cut and reconfigured. If the Bellanger mids were added to fit with the headers, that is another change.

As you say, perhaps we could get clarification on this, and more importantly, whether the cats were removed or switched out between tests, or even if the different mids used were the same diameter and/or both mandrel bent. There could be a lot of variables, some more important than others.

Maybe I didn't explain myself clearly.

He made a dyno run with OEM manifolds, straight thru no cat 3" midpipes, CAI and tune.

Then he installed long tube headers, straight thru no cat 3" midpipes, CAI and tune.

That means there were no changes but the headers.

It's not that hard to understand, really. Just think about it.:dontknow:

 

[ViperTruck2933]

Another funny argument is how folks always say longtubes make so much more power than shorties, comparing results from 1 3/4" - 1 7/8" longtubes to those from 1 1/2 -1 5/8" shorties. With equal diameter primaries and collectors it's more about where in the powerband power is made, not how much.

Here's something else to ponder regarding long tubes.

My neighbor had Ram SRT with Stage II tune, NO CAT midpipes, Bassani short tubes and JMB CAI.
I had Stage II tune, Belanger long tubes with High flow cats, and JMB CAI.

He made 430 rwhp and I made 467 rwhp. Looks like there's a difference in shorties and long tubes to me. :dontknow:

 

[Nowwhat]

Here's something else to ponder regarding long tubes.

My neighbor had Ram SRT with Stage II tune, NO CAT midpipes, Bassani short tubes and JMB CAI.
I had Stage II tune, Belanger long tubes with High flow cats, and JMB CAI.

He made 430 rwhp and I made 467 rwhp. Looks like there's a difference in shorties and long tubes to me. :dontknow:

your kidding right....2 different trucks....you can't compare 2 different trucks...the difference bewtween bassani's and long tubes...single digits..

 

[ViperTruck2933]

your kidding right....2 different trucks....you can't compare 2 different trucks...the difference bewtween bassani's and long tubes...single digits..

Of course I know it's 2 different trucks and they'll make different numbers.

And I was responding to this:

Another funny argument is how folks always say longtubes make so much more power than shorties, comparing results from 1 3/4" - 1 7/8" longtubes to those from 1 1/2 -1 5/8" shorties.......
Just think longtubes are generally overated for many applications.

I'm just saying I wouldn't be so quick to dismiss the differences in shorties and long tubes. Every other truck that I have seen with long tubes has put down more peak hp than trucks with shorties (and similar mods). IMO that that tells you there is a difference.








Besides, Mike you can't even grasp the benefits of headers over stock manifolds. There is no way you are going to understand the benefits of long tubes over shorties. :rofl::rofl::rofl:

 

[Nowwhat]

Besides, Mike you can't even grasp the benefits of headers over stock manifolds. There is no way you are going to understand the benefits of long tubes over shorties. :rofl::rofl::rofl:

benefits...sure....if we get you the right set we can get you to 537 rwhp.... ....

537 is a good number you can still let your wife drive the truck

 

[ViperTruck2933]

benefits...sure....if we get you the right set we can get you to 537 rwhp.... ....

537 is a good number you can still let your wife drive the truck

See, the trick wasn't getting to 537 rwhp.

The trick was getting there for under 8K. :rock: :rock: :rock:

 

[Nowwhat]

See, the trick wasn't getting to 537 rwhp.

The trick was getting there for under 8K. :rock: :rock: :rock:

true enough.....great build for the $$$....for sure....

pssst.....100 shot....