Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth?????

[nevrenuf]

I'm ready for exhaust mods. No limits. Am looking for the highest gains possible. I'll be doing heads/cam/stroker/supercharger within the next 6 months but want to get the exhaust done first. I'm very disappointed with some of the recent posts which only show a 12hp gain from headers, cats elimination, and corsa track.....$4K++ for 12hp, you've got to be kidding!!!!!!!!!!!!

Money is no object, I want the best header (i.e. tq/hp) and exhaust (dont care about noise, just no resonance), ...

WHAT TO DO FOLKS?????????????

 

[VIPER D]

12rwhp gain if your lucky. every one posts how much faster and stronger thew srt feels with after market headers but the truth is that i have never seen dyno charts to support that. The factory headers are very efficent. Also alot less under hood heat!!!

You can gain that much hp just by ditching the factory cats and mufflers. Or by doing a k$n system.

5,000 for just a better sounding srt thats joke!!!!


just my .02 cents


vd..

 

[vipersrt10]

the guys at westcoast vipers did a header with exhaust and got 33rwhp and 89 r w torque, i think the package is around 6500, im gunna do it soon.

 

[Skip White]

Tom, I can give you some pretty good advice on what's hot, and what's not for the car.

Skip White 423-288-3881

 

[doctorbob]

One of the members of the Arizona Club did belanger(sp?) headers and cats with loss of hp! Viper D is correct.

 

[ARMORGOD]

12rwhp gain if your lucky. every one posts how much faster and stronger thew srt feels with after market headers but the truth is that i have never seen dyno charts to support that. The factory headers are very efficent. Also alot less under hood heat!!!

You can gain that much hp just by ditching the factory cats and mufflers. Or by doing a k$n system.

5,000 for just a better sounding srt thats joke!!!!


just my .02 cents


vd..

Ignore VD... he must have had a bad experience with a header as a child. As soon as I saw this post, I knew he'd be in here bashing on 'em.

My car also has a Paxton blower (like his) but I put down 710-720 at the rear (and my timing is REALLY cut back, IOT keep the engine safe with the cast pistons - if we left the timing at the stock Paxton setting, I would be making making somewhere around 740). By themselves, the headers are definitely not the biggest "bang-for-the-buck". But, IMHO, if you know that you are going to be doing future mods that will benefit from the increased flow, headers are worth it. The air in my car moves so much better than stock that my engine (with the Paxton) literally could not get enough fuel through part of the power band. We had to go to larger fuel injectors IOT catch up with the air flow.

And the hp gain isn't the whole story. I bet that my power curve on the dyno looks better as well.

The exhaust not is only icing on the cake. It sounds great and is a marked improvement over stock. The added heat can be a genuine issue, however. The black flexi-tubing around some of the wires that were close to the headers melted smooth away after the first few days I was driving the car with the new headers.

If I were you I would give the Belanger guys a call and talk with them about the features/benefits of their headers and go from there.

Oh, and by the way, "5,000 for just sounding better" isn't a joke. But buying spinners for one of the dozen motorized vehicles that you feel the need to list out or doing nitrous and then dumping it to do a blower and then... now that's a joke.

 

[VIPER D]

12rwhp gain if your lucky. every one posts how much faster and stronger thew srt feels with after market headers but the truth is that i have never seen dyno charts to support that. The factory headers are very efficent. Also alot less under hood heat!!!

You can gain that much hp just by ditching the factory cats and mufflers. Or by doing a k$n system.

5,000 for just a better sounding srt thats joke!!!!


just my .02 cents


vd..

Ignore VD... he must have had a bad experience with a header as a child. As soon as I saw this post, I knew he'd be in here bashing on 'em.

My car also has a Paxton blower (like his) but I put down 710-720 at the rear (and my timing is REALLY cut back, IOT keep the engine safe with the cast pistons - if we left the timing at the stock Paxton setting, I would be making making somewhere around 740). By themselves, the headers are definitely not the biggest "bang-for-the-buck". But, IMHO, if you know that you are going to be doing future mods that will benefit from the increased flow, headers are worth it. The air in my car moves so much better than stock that my engine (with the Paxton) literally could not get enough fuel through part of the power band. We had to go to larger fuel injectors IOT catch up with the air flow.

And the hp gain isn't the whole story. I bet that my power curve on the dyno looks better as well.

The exhaust not is only icing on the cake. It sounds great and is a marked improvement over stock. The added heat can be a genuine issue, however. The black flexi-tubing around some of the wires that were close to the headers melted smooth away after the first few days I was driving the car with the new headers.

If I were you I would give the Belanger guys a call and talk with them about the features/benefits of their headers and go from there.

Oh, and by the way, "5,000 for just sounding better" isn't a joke. But buying spinners for one of the dozen motorized vehicles that you feel the need to list out or doing nitrous and then dumping it to do a blower and then... now that's a joke.

I HAVE STOCK HEADERS, stock injectors, stock pully and all hp was an a real MUSTANG DYNO not SOME **** DYNO JET that shows 20% more rwhp and i will any day post my dyno sheet right after yours

i have never ever seen any of your hp claims. with about $10000 worth of extra parts you still are below me rwhp wise.

vd..


go ahead post it up big boy!!!


make my day

 

[VIPER D]

One of the members of the Arizona Club did belanger(sp?) headers and cats with loss of hp! Viper D is correct.

What people don't understand is that on gen 1 and some gen2 cars came with manifolds so when upgraded to headers there was a big improvement but as many things with a gen 3 car the manifold was changed to a very efficient stock header. You really can fix or improve what not broken or not needed to be improved. That's why aftermarket headers and gen 3 cars don't match! everyone that got ripped thinking they were getting a mod that will make more hp but no one that is well respected in the viper world will post big gains and back it up with a b/f and after dyno sheet.

so some people that got ripped to make themselves feel better, support the lie about headers and rant and rave how much hp they improved. what ever

hey what ever makes them feel better

vd..

 

[Vipera Russelli]

According to Jason Heffner, I went from
Stock 433.0 hp and 468.0 tq
to 467.5 hp and 503.0 tq
by adding Heffner’s headers (with Burns merge collector), RT steel cats and Corsa cat-backs with no cross-over.

While the SRT stock headers aren’t a manifold, as Viper D points out, looking at the pictures below showing both the stock headers and the Heffner headers I find it hard to believe that the stock headers are “very efficient headers.” And if so, then the Heffner headers are very, very, very efficient in comparison, hehe, or at least the pictures suggest as much to me. Has anyone just replaced headers and not the rest of the exhaust and done before and after dynos?

Also, and in all fairness I note that Viper D has not suggested otherwise, I think getting rid of the dreaded crossover, the four cats (or are two of them actually resonators?), stock mufflers and all the 2.5 inch choke points, in exchange for two cats and mufflers that you can actually see through perfectly, should increase airflow significantly. Before my headers/exhaust mods, my side pipes dripped any condensation in the pipes upon startup; after the mod, they sprayed condensation in a mist. We can debate the impact of the individual exhaust components, but there is no doubt that my exhaust mods as a whole significantly increased the air flow coming out of my side pipes. Did this increase in airflow in turn have something to do with the increase in my horsepower and torque measured by Heffner’s dyno before and after the exhaust mods? Naaaaaaah.

Nevrenuf, on another point, if you’re going with more mods after exhaust as you’ve suggested, I believe the conventional wisdom suggests that you’ll want a 5-to-1 merge collector on your headers. The two-to-one and three-to-one step down alternative, like you see in Belanger headers (pictured below), I understand are generally better than 5-to-1 collectors at purging exhaust from the chambers without further mods, but not as good at handling the larger quantities of exhaust you’ll see with a blower or other engine mods that result in more air movement. Others will disagree I suspect, and I will admit that this is just what I’ve read and researched. Maybe somebody has actual flowchart data on this issue or could let us know if they agree or not, all issues of sound aside.

 

[treynor]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

My $.02: spend the money on a Paxton, and keep the stock exhaust. You'll get a LOT more power per dollar spent, and the car will remain quiet, smog-legal, and cool underhood.

 

[SRTRICKY]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

Since the stock headers are very efficient do what I'm doing hi-flow cats and a new catback exhaust STill sets you back a good chunk of change but I'm hoping I don't burn my leg for the 3rd time after I get this done

 

[Skip White]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

Here's my 02 cents worth,(where the hell's that cent key?)

Long tube headers as the one's above are fabulous, but mostly on cars with modified engines, that require such flow. They make a great difference on ported heads with larger valves, and wilder cams. They are a must. On a mostly stock engine, the oem's are really pretty good. Supercharged engines will also benifit greatly, as they must get rid of much exhaust. I also think the long tube is known to help in other ways, that short tube does not. Tonal quality is affected. I wonder how hot things get around the exhaust ports on the heads, without the heat shield.

Why is there no flex coupler in those headers, or is it further down. I see a problem for sure if these cars are being ran without one. The soft mushy engine and trans. mounts create great movement, and those ruber pipe mounts on the Viper are hardly sufficiant to keep things from craking sooner or later. Cars with really long unrestrained pipe can handle this flexing, not the Viper.

I know some of you guys, have heard the rule of thumb on modding an engine,"air in and air out, without an imbalance"

Skip White

 

[DSR207]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

No "BS" here, before and after dyno done, and it showed a 33rwhp increase after B&B headers and exhaust...It also helps with the paxton as your TQ will increase.

 

[VIPER D]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

here is my version of no b/s

keep in mind that the dip in the dyno sheet was due to tire spin at like 120 mph (lol) if the tires held It would if been even higher.

all was done on a:

stock pulley (soon to be replace to a DLM SETUP)
stock headers
stock fuel rails
stock injectors
stock roller rockers
stock internals
just alot of help from Doug Levin and Bill Ma and many, many dyno hours.

also this was done a mustang dyno witch always shows low readings so this same dyno sheet on a dyno jet would be like 760ish rwhp. and 750ish rwtq. And thats even with major tire slippage. I could only imagine what this car will do when I put another $10,000 into it. I will tell you one thing its not going to go into the headers thats for sure!!!!!

so much or the long tube header theory!!! But what do I know right?


MAYBE MY SRT MAKES MORE POWER B/C IT STAYS WAY COOLER UNDER THE HOOD. I know lond tube headers are major heat ovens!!!

I do have exhaust work but header back.

vd..

 

[VIPER D]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

No "BS" here, before and after dyno done, and it showed a 33rwhp increase after B&B headers and exhaust...It also helps with the paxton as your TQ will increase.

Did you dyno the car with the supercharger and stock headers 1st? If you have no cats and this was done on a dynojet machine then your tq is low. Maybe due to headers. I know it sounds crazy but I have seen it b/f espically on supercharged cars. I saw it first hand on a 2003 supercharged mustang svt that lost power due to headers.



vd..

 

[STUGOTS]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

here is my version of no b/s

keep in mind that the dip in the dyno sheet was due to tire spin at like 120 mph (lol) if the tires held It would if been even higher.

all was done on a:

stock pulley (soon to be replace to a DLM SETUP)
stock headers
stock fuel rails
stock injectors
stock roller rockers
stock internals
just alot of help from Doug Levin and Bill Ma and many, many dyno hours.

also this was done a mustang dyno witch always shows low readings so this same dyno sheet on a dyno jet would be like 760ish rwhp. and 750ish rwtq. And thats even with major tire slippage. I could only imagine what this car will do when I put another $10,000 into it. I will tell you one thing its not going to go into the headers thats for sure!!!!!

so much or the long tube header theory!!! But what do I know right?


MAYBE MY SRT MAKES MORE POWER B/C IT STAYS WAY COOLER UNDER THE HOOD. I know lond tube headers are major heat ovens!!!

I do have exhaust work but header back.

vd..

I bet you would put down a little more then 760/750 on a dynojet, when I did a dynojet after a mustang dyno (same mustang dyno as you actually) I hadalmost EXACTLY 15% more then the mustang dyno said.

Bill M is an awesome tuner and will get MAX power out of that vec 2.

 

[Skip White]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

Mid range power loss with headers is common, but they do make up for it on the big end. The dip in torque is small, and not noticable with the 500 cube engine.

I believe the shorter headers create a sort of scavenging effect, and the long ones do it in a different way. There is much to know about headers and exhaust. You could read for days, and you would have to allready have a good understanding of engine dynamics to know what they are talking about.

Skip w

 

[Franko]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

A reputable tuner told me that headers are a must if you install a paxton because of heat issues. I thought i just read that headers cause more heat? I'm confused.

 

[tmcphail]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

I saw it first hand on a 2003 supercharged mustang svt that lost power due to headers.

Hey VD can you expand on this ? My wimpy little 03 cobra easily puts down 700/700 on my so called **** dynojet dyno and yes it has long tubes and cats to boot. This all while most with the same combo minus headers make way more HP then TQ.

Side note I am new to the V10 realm and dyno tune Ford's for a living. Different dynos, different atmospheric conditions = different numbers. That still is irrelevent on the street or track. The dyno is no more then a measurement tool which allows me to calibrate vehicles sitting still and much faster then on the street.

 

[VIPER D]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

I saw it first hand on a 2003 supercharged mustang svt that lost power due to headers.

Hey VD can you expand on this ? My wimpy little 03 cobra easily puts down 700/700 on my so called **** dynojet dyno and yes it has long tubes and cats to boot. This all while most with the same combo minus headers make way more HP then TQ.

Side note I am new to the V10 realm and dyno tune Ford's for a living. Different dynos, different atmospheric conditions = different numbers. That still is irrelevent on the street or track. The dyno is no more then a measurement tool which allows me to calibrate vehicles sitting still and much faster then on the street.

yea with 30 lbs of boost and race gas right???? and how long will it run??? hahah good luck. Also If it a fully built motor than why?? you could of done that to a viper and had 1200 rwhp.

If you tune or dyno cars like you say you do than i sure you heard this b/f (i know this isn't the 1st time hearing this) its a fact that mustang dyno's are way better for tuning b/c they actually put a load on the car! thus less rwhp than other dyno's that dont like dynojets.(spin a big drum) Espically needed for any boosted car. test it out buddy go and find a mustang dyno and throw it up on it. and see less hp but more accurate boost and afr #'s

vd..

 

[VIPER D]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

hey armor


where is that dyno sheet to support you hp gains?


still holding my breath

vd..

 

[DSR207]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

VD's car after headers install
Before..................................................................After

You must be registered for see images

I would not recommend headers unless Other power mods are planned, cost too much for the gain...

DYNO SHEET ANYONE ???? LOL

 

[tmcphail]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

yea with 30 lbs of boost and race gas right????

Actually no 20psi and a 50-50 mix of 110 / 93


and how long will it run???

A long time actually I tuned it myself and beat on it on a daily basis

hahah good luck.

Um thanks.

Also If it a fully built motor than why??

Actually the valve covers have not been off the car. Simple bolt-ons and me knowing how to tune it properly.

you could of done that to a viper and had 1200 rwhp.

4.6L vs 8.3L just a slight difference there.

If you tune or dyno cars like you say you do than i sure you heard this b/f (i know this isn't the 1st time hearing this) its a fact that mustang dyno's are way better for tuning b/c they actually put a load on the car!

I am well aware of the difference between the two. I spent a lot of time before I bought my dynojet doing the research on what I wanted to purchase to see which dyno fit my needs. Dynojet offers dyno's with variable load as well.

thus less rwhp than other dyno's that dont like dynojets.(spin a big drum) Espically needed for any boosted car.

If you were talking about a 7000lb turbo Diesel truck I would be inclined to agree with you but in this case no.

test it out buddy go and find a mustang dyno and throw it up on it. and see less hp but more accurate boost and afr #'s

Yes in general the mustang dyno's read lower. Does that change the 1/4 mile times at all ? Not at all. I run a wideband and boost guage in my car and guess what. They are dead accurate on the street in any gear of your choice and on the dyno.

 

[GR8_ASP]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

Love the dynojet vs Mustang argument. Clearly a variable load dyno like the Mustang allows more precise calibration as you can hold steady state points.

But for WOT calibrations the Dynojet is just fine. That is because how often do you find yourself at steady state at WOT? Hopefully not often, and then I would say only at or near fuel shut-off speed. With the hp that these Paxton equipped cars have the only people at WOT steady state are those with extrememly large ...

So, for basic tuning the Dynojet is just fine. Especially if using a wideband O2 sensor. Differences in hp measurement have more to due with the vehicle rotational inertia. But, in Dynojets defense, it is very difficult to drive the car on the street without the same rotational inertia effect. A Dynojet will meausure a hp increase by switching to a lightweight flywheel while a Mustang dyno will not. Which is the better answer

 

[tmcphail]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

You can hit all points of the calibration using a dynojet dyno to tune a vehicle. I do it with mine by either using 5th or 6th gear or by using the brake. Or i just log the vehicle on the street to sort out the rest of the curve and nail down drivability. Yes it would be easier if I had variable load on mine but at the time I couldn't justify the cost of it and I can always add it down the road.

I think a lot of people get caught up in trying to make one so much better then the other. Each has it's strength's and weaknesses like with anything. But guess what its nothing more then a measurement tool. It completely comes down to the competency of actual person that tunes your car as to how well the tune is. Heck I was tuning cars on the street long before I had the dyno.

 

[VIPER D]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

turning purple holding my breath............


see this is what i mean when i said that i have never seen any of these hp claims. All talk no proof.



vd..

 

[STUGOTS]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

im actually having my B&B headers installed as we speak on my gen 2, Chuck said that 17 RWHP is what you usually see from them, and IMO 17 hp is NOT worth $1,800, but since they were a christmas gift why not right lol

 

[VIPER D]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

on a gen 2 car its worth it b/c your going from manifolds to headers. UNlike gen 3. Go for it.



vd..

 

[Skip White]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

Dmitry, the Gen 2 cars went to short tube headers, back in 98 or 99. This is one on the things that made up for the down grade in cam overlap, therfore keeping the horsepower the same on the car. It really did help those cars a decent hand full of horses.

Skip

 

[JGK95]

Re: Headers & Cat Backs.... 10 to 60hp gains claimed.. what is the truth???

im actually having my B&B headers installed as we speak on my gen 2, ... but since they were a christmas gift why not right lol

Stugots,

How do you rectify giving yourself a christmas gift to saaaaay yourself like B & B headers not count??