Performance Gain Aftermarket Headers to Factory Tube Headers

[Vipuronr]

I did a search (Plum) but couldn't find a thread that gave me an answer.

As I understand it, the 1998 was the first year of tube headers, replacing the earlier manifold. So, if my '98 has factory tube headers, what is the increase in performance of moving to an aftermarket header and is it worth the expense?

I understand the change for the earlier cars, since they used a manifold.

Thanks!

 

[Fatboy 18]

Good post, I'm sure there is some improvement but not half as much as the early cast chunks. I too would like to know the figures on this, but the trouble is there will be a number of factors to make almost every car come out with a different BHP figure Lets face it, some have 3 inch cat back systems others have Hi flow cats, some have side exit systems and others rear exit systems, cross over balance pipes etc 2 1/2 inch system's, the list goes on

 

[Vipuronr]

This is true! I guess it would be more estimating based on experience...both cars being equal and the only difference is changing from factory tube headers to aftermarket.

I've been a motorhead my whole life. My experience from back in the day, was that factory tube headers weren't quite as radical as aftermarket headers and that the collectors tended to generate less performance. But, that said, if you compare the cost of a good set of headers US$1,500 or so plus install, do you really make that much more hp to justify an expense like that?

 

[Bill Pemberton Woodhouse]

The change to the tubular headers from the cast iron was primarily a weight savings with no hp increase shown in Dodge literature. Supposedly it was good for around 5+ hp, but the main advantage was the weight savings of close to 25 lbs ( if I remember correctly ).

The gain from headers , catback, etc. was still pretty good , as my 2000 was pushing close to 500 hp at the Flywheel with Archer headers , Corsa , smooth tubes and K&Ns.

Not sure Archer is still doing headers for the Gen IIs, and Belanger has a great set for a GTS.

 

[Fatboy 18]

Exactly, it is a big expense, you would probably get more bang for your buck with different gearing

 

[martyb]

I would assume all else being equal, maybe 15hp by changing to after market headers?? I asked the same question a while back.

 

[99 R/T 10]

On the Gen II forged cars with the 708 cam, you can expect anywhere from 25-35 RWHP depending on the type of header. Generally the Edelbrocks will give you about 25 RWHP, the M&M/Balanger/B&B/ headers will give you 35RWHP. The 2000-2002 typically don't pick up but about 15 +/- some. due to the change inthe overlap cam profile.

 

[costanZo]

On the Gen II forged cars with the 708 cam, you can expect anywhere from 25-35 RWHP depending on the type of header. Generally the Edelbrocks will give you about 25 RWHP, the M&M/Balanger/B&B/ headers will give you 35RWHP. The 2000-2002 typically don't pick up but about 15 +/- some. due to the change inthe overlap cam profile.

You didn't mention the American Racing Headers RWHP output, which I would imagine giving the same power gains as the M&M/Belanger/B&B

 

[Vipuronr]

Great feedback, thanks!

I did pick up on something from being on header sites - was just on American Racing Headers. The aftermarket headers are described as "long tube" headers, while from looking at my engine, the factory headers look "short"...only going from 5 to 1 and immediately into a regular pipe....not the typical aftermarket "collector" which helps direct the exhaust gases together for smoother (faster) flow.

I have lots of pricing questions for Chuck....da man!

For me, its comparing "all in" pricing against the net impact on performance. Its looking like changing headers could be around $2k. HS rr's running around $1,200-$1,300 with pushrods and gears maybe around $1,500. These are all guestimates based on looking up parts pricing and varying posts on here.

Just not sure, for my kind of local road driving (mostly), what would be the best thing to do first...I don't and won't be tracking my car.

Thanks again....still thinking!!!

 

[costanZo]

Great feedback, thanks!

I did pick up on something from being on header sites - was just on American Racing Headers. The aftermarket headers are described as "long tube" headers, while from looking at my engine, the factory headers look "short"...only going from 5 to 1 and immediately into a regular pipe....not the typical aftermarket "collector" which helps direct the exhaust gases together for smoother (faster) flow.

Are you referring to the ARH when you said this or your factory ones?

 

[Russ M]

On the Gen II forged cars with the 708 cam, you can expect anywhere from 25-35 RWHP depending on the type of header. Generally the Edelbrocks will give you about 25 RWHP, the M&M/Balanger/B&B/ headers will give you 35RWHP. The 2000-2002 typically don't pick up but about 15 +/- some. due to the change inthe overlap cam profile.

Do you have any before and after dyno numbers to back this up?

Every dyno test I have ever seen with headers involved on gen 2 cars indicates almost no power gain on an otherwise almost stock car. On cars with head work the gains are more obvious but on cars with say a catback/filters they seem to do nearly nothing.

 

[costanZo]

Do you have any before and after dyno numbers to back this up?

Every dyno test I have ever seen with headers involved on gen 2 cars indicates almost no power gain on an otherwise almost stock car. On cars with head work the gains are more obvious but on cars with say a catback/filters they seem to do nearly nothing.

Are you referring to late GEN II models? I haven't heard this type of information at all... Everything I'm hearing you will gain at least 20-25rwhp with most headers, maybe even more with the right tune...especially on earlier GEN II Vipers. What your saying I heard is true towards GEN III Vipers, where the most power gains you will normally see is around 12-15rwhp on average.

 

[Dom426h]

Russ, Perhaps headers on a completely stock car dont do much but it is assumed that someone running headers also has a full 3"exhaust system.

The combination of the two exhaust mods does give some serious power as some Gen2's (like mine) dyno @ 450-460hp & 490-500tq. this compared to a Stock Gen2 dynoing at 400ish hp...
Sure some of the power comes from the smoothtubes/filters(10), Hiflowcats or catless(5-10), but the exhaust mods provide the big jump.

 

[costanZo]

Russ, Perhaps headers on a completely stock car dont do much but it is assumed that someone running headers also has a full 3"exhaust system.

The combination of the two exhaust mods does give some serious power as some Gen2's (like mine) dyno @ 450-460 & 490-500 tq. this compared to a Stock Gen2 dynoing at 400ish hp...
Sure some of the power comes from the smoothtubes/filters(10-15), Hiflowcats or catless(5-10), but the exhaust mods provide the big jump.

+1 Dom..

This sounds about right..

I figure with my setup below I should gain at least 40rwhp, considering I already have the K&N Dual FIPK.
American Racing Headers 1-5/8" X 1-3/4" step design
200 cell ultra high flow metallic substate cats
Corsa 3" Cat-back Exhaust

I'll be seeing an even higher rwhp number on the dyno though with new 1.7 Rockers, Lightweight Flywheel and SCT Tune which I'll be getting this summer as well.

 

[plumcrazy]

there are a nice set of belangers for sale on the alley right now for 850. thats a deal. scoop it up.

 

[eucharistos]

.....Just not sure, for my kind of local road driving (mostly), what would be the best thing to do first...I don't and won't be tracking my car.

Thanks again....still thinking!!!

Vipuronr

headers also add (good) sound, and rem hp gains may hurt you on the low end torque front (for my driving, i'd rather have the torque/throttle response)

based on how you describe your driving, gears and possibly lighter flywheel is what you want, bang for the buck

 

[Russ M]

Russ, Perhaps headers on a completely stock car dont do much but it is assumed that someone running headers also has a full 3"exhaust system.

The combination of the two exhaust mods does give some serious power as some Gen2's (like mine) dyno @ 450-460hp & 490-500tq. this compared to a Stock Gen2 dynoing at 400ish hp...
Sure some of the power comes from the smoothtubes/filters(10), Hiflowcats or catless(5-10), but the exhaust mods provide the big jump.

My observation has been on cars with exhaust/filters/small mods the only car I ever saw dyno @ 460 was a 96 gen 2 and that car had Bellanger headers and exhaust no cats, this car also had T&D rockers which is where the power really came from.

Gen 2's(non cream puff) pick up good power from a good exhaust good being Bellanger/borla and some others if its a Corsa then just be happy with your sound don't bother to dyno. So with a good exhaust you can expect ~430 rwhp, but as stated earlier when headers get involved the power seems to not change at least on the several dozen cars I have seen dyno with these type of mods.

The next step is to get the car tuned at which point you can get to roughly 450rwhp and 500+ torque, this is with factory shorty manifolds. Its possible that headers would benefit a car like this immensely but I have yet to see one on a dyno. And my car has since grown a pair of turbo's so it will not be me testing this.

 

[ViperTony]

(2007) Borla 1 5/8" Stepped Headers, B&B Catback, B&B Cat, Smooth Tubes/K&N, No Tune, No Rockers. 448rwhp/470rwtq. Mustang Dyno.

2008 Belanger Headers, Belanger Catback, RT Cats, Smooth Tubes/K&N, T&D Rockers, Vec3 Tune. 480rwhp, 525rwtq

2009 Belanger Headers, Belanger Catback, RT Cats, Smooth Tubes/K&N, T&D Rockers, SCT Tune. 446rwhp, 479twtq. Super Flow Dyno.

* We had a hell of time tuning this day but later found out I had exhaust leaks around the flanges. And my GenII was producing the same numbers as a GenIII with similar mods on this day.

I resolved the leak issue and numbers were back up but I can't find the dyno sheet for it.
I should also note that I later found out my T&D rockers were set incorrectly. I installed and set valve lash myself prior to the 2008 Dyno. I had a person check my work and they readjusted them, incorrectly.


2011 - Greg Good Heads, GG Cam, 10:5 - 1 C.R., Custom Belanger Headers, RT Cats, Belanger Catback, Smooth Tubes/K&N, T&D Rockers, SCT Tune: TBD

If you're going to dyno after each mod, do it on the same dyno. I didn't care to track what each mod did for power so it didn't really matter to me. I stopped screwing around and got the GG treatment. Should be tuning in a week or two.

 

[costanZo]

if its a Corsa then just be happy with your sound don't bother to dyno.

I'm not sure if I'm misunderstanding what you wrote....but, are you saying Corsa just gives a good sound and doesn't help you add any power on the dyno?? As far as I know and from what many people have stated on this forum, adding Corsa gives you one of the highest power gains for any Cat-back Exhaust.. Not that it gives you a ton of power alone, but when having a complete exhaust setup. Corsa is possibly one of the best for any performance gain, not to mention the sound is quite good as you somewhat stated.

 

[Russ M]

I'm not sure if I'm misunderstanding what you wrote....but, are you saying Corsa just gives a good sound and doesn't help you add any power on the dyno?? As far as I know and from what many people have stated on this forum, adding Corsa gives you one of the highest power gains for any Cat-back Exhaust.. Not that it gives you a ton of power alone, but when having a complete exhaust setup. Corsa is possibly one of the best for any performance gain, not to mention the sound is quite good as you somewhat stated.

Unfortunately you are reading that correct, they add no power period but they sound fantastic!!!

 

[moparracing]

there are a nice set of belangers for sale on the alley right now for 850. thats a deal. scoop it up.

easier than most to install too.....

 

[costanZo]

Unfortunately you are reading that correct, they add no power period but they sound fantastic!!!

Damn.. really? It seems like a lot of posts I've seen, people compare the best setups for performance including either the Belanger setup or the Corsa setup. What is the best exhaust for performance gains then? Belanger and Borla can't be the only two right? What about B&B? I barely looked into B&B at all for headers and exhaust, but I heard a sound-clip on the Exhaust thread the other day and was pretty impressed by it.. I posted the video below of what the user nutkees posted the other day.. his setup is:

B&B headers
B&B Catback
High Flows
X-pipe

Here's the video, sounds awesome. I just bought American Racing Headers and their cats to go with my Corsa Exhaust, from everything I've heard and read it seems like my new ARH/Corsa would be one of the best setups for sound and performance, but hearing this video below makes me wish I looked a little bit more into the B&B setup.

someone made a film of me leaving a parking lot. Love the sound

[media]http://www.youtube.com/watch?v=cq7I4GYoO2U[/media]

 

[vp97]

More proof that a well made set of headers work! My 97 GTS engine has JM CNC ported factory heads, crower shaft rockers, 10.25 comp ratio, 4.020 bore, stock stroke, 225/234 @ .050 cam and no intake port work.

The first dyno sheet was with engine tuned with stock ex manifolds.

You must be registered for see images attach

First two pulls with SVS 1 1/2 stepped to 1 5/8, not tuned, as you can see. I had to install a Kenny Bell voltage booster to cure the fuel problem. I wish I had the final dyno sheet, I either lost it or it went with the car when I sold it. The final numbers were 598whp and 618wtq. Pretty good for a small cam!

You must be registered for see images attach

 

[cyaford]

I went from 449rwhp/470rwtq to 460rwhp/500rwtq after adding a set of Edlebrock headers to a full 3" exhaust. I have the usual bolt-ons. The car was tuned previously, so I'm not sure if it'll pick up any more after it's tuned for headers. I kinda doubt it. All dyno runs were on a DynoJet.

 

[ViperTony]

First two pulls with SVS 1 1/2 stepped to 1 5/8, not tuned, as you can see. I had to install a Kenny Bell voltage booster to cure the fuel problem.

I take it then your fuel pressure dropped off (prior to the voltage booster) and your engine was craving more fuel than the stock system could provide? That's a nice problem to have.

 

[vp97]

Yes the fuel pressure dropped quickly. I knew I was going to have fuel system problems but just not that early in the run. The voltage booster solved that problem. I never did check the pressure when the the booster was active. I wonder what it raises the fuel pressure to?

 

[KNG SNKE]

M&M headers. He is on this site under M&M Performance. They are built solid with no issues and are made in the same fashion as belangers at a fraction of the cost.

 

[Jack B]

Yes the fuel pressure dropped quickly. I knew I was going to have fuel system problems but just not that early in the run. The voltage booster solved that problem. I never did check the pressure when the the booster was active. I wonder what it raises the fuel pressure to?

It does not raise the pressure, it does give you a lot more flow. Did you change injectors, that is the big issue. The Gen2 injectors start going static at about 475-500 rwhp.

 

[viper067]

It does not raise the pressure, it does give you a lot more flow. Did you change injectors, that is the big issue. The Gen2 injectors start going static at about 475-500 rwhp.

What are the Gen 1 injectors good for?

 

[Jack B]

What are the Gen 1 injectors good for?

About 15% less.