2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

headers vs. downpipe....?

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Old 08-26-05 | 02:10 AM
  #26  
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Absolutely not true about headers not making much of a difference. Headers work better on ANY engine porting style. Here are the biggest gains you can get from your street engine in terms of noticable improvement in power/acceleration. Headers, lightweight flywheel, standlone ecu, porting. Porting being last! Intakes, manifold port runner matching, igniton systems etc come way down the list but the header should be the very first thing to get done. Even the Pacesetter header will out do a downpipe by a long shot. Way back when, I had the Rotary Performance downpipe and a Brullen catback system. I swapped out the downpipe for a cheap Pacesetter header and it wasn't even funny how much power picked up, especially on the low to midrange. Much more driveable, fun, and fast car. Huge difference. It's not about total airflow. Total airflow doesn't always tell you everything since air is funny stuff. It's about tuning.
Old 08-26-05 | 02:46 AM
  #27  
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I don't plan on porting my engine any time soon. Mater of fact the engine runs great now, as is....knock on wood...hehee.
I was just confused between the two.....
And I'm not a fan of the noise, especially when driving on the freeway.
Old 08-26-05 | 07:39 AM
  #28  
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Header...cause it looks cooler...LOL
Old 08-26-05 | 09:22 AM
  #29  
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learn to weld, i used 2.5" exhaust pipe, welded the flange cut from the first cat and the rear cat, used one 45 degree bend and welded it together. i did the air pump mod for the secondaries and ditched to stock mufflers for two front mufflers from a volvo 240 (75-93 240 volvlos have a front muffler that is 2.5" in and out, fit perfectly behind the bumper and only cost about 25 bucks a piece.(no back pressure at all!!, i tested it). You can use some crome tips or keep it under the bumper for stealth(like me). my motor is ported with a custom cold air intake, scoop on hood and cold air box. For a stock feul injection with a air flow meter, the car is a f**king rocket. WAY more power over stock. Remember hot air flows better than cold, so dont think it is better to run 4" exhaust like some people claim, it will acually make more back pressure than a smaller pipe. Turbos would be the only engines to benifit from this.
Old 08-26-05 | 12:01 PM
  #30  
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Originally Posted by suburban6lts
learn to weld, i used 2.5" exhaust pipe, welded the flange cut from the first cat and the rear cat, used one 45 degree bend and welded it together. i did the air pump mod for the secondaries and ditched to stock mufflers for two front mufflers from a volvo 240 (75-93 240 volvlos have a front muffler that is 2.5" in and out, fit perfectly behind the bumper and only cost about 25 bucks a piece.(no back pressure at all!!, i tested it). You can use some crome tips or keep it under the bumper for stealth(like me). my motor is ported with a custom cold air intake, scoop on hood and cold air box. For a stock feul injection with a air flow meter, the car is a f**king rocket. WAY more power over stock. Remember hot air flows better than cold, so dont think it is better to run 4" exhaust like some people claim, it will acually make more back pressure than a smaller pipe. Turbos would be the only engines to benifit from this.
Is this on an NA, since you need back pressure to actuate the 5th/6th ports. Or was that fixed by the 'air pump mod' (I'm not familiar with it).

Not trying to be a jerk, just hope to be enlightned.
Old 08-27-05 | 11:32 AM
  #31  
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Originally Posted by rotarygod
Absolutely not true about headers not making much of a difference. Headers work better on ANY engine porting style. Here are the biggest gains you can get from your street engine in terms of noticable improvement in power/acceleration. Headers, lightweight flywheel, standlone ecu, porting. Porting being last! Intakes, manifold port runner matching, igniton systems etc come way down the list but the header should be the very first thing to get done. Even the Pacesetter header will out do a downpipe by a long shot. Way back when, I had the Rotary Performance downpipe and a Brullen catback system. I swapped out the downpipe for a cheap Pacesetter header and it wasn't even funny how much power picked up, especially on the low to midrange. Much more driveable, fun, and fast car. Huge difference. It's not about total airflow. Total airflow doesn't always tell you everything since air is funny stuff. It's about tuning.
I find your statements much harder to swallow than a company that has spent big $$$ on research and development. Racing beat has been in buisness for a long time and has a track record to prove their knowlege. They've even had a couple cars in the salt flats. Bottom line. I'm going to believe them especially when they say they have done lots of dyno tests between the two, and state that their DP/presilencer is comperable to their header in a close to stock motor. Especially when their DP is cheaper than their header.
You'd think they would want to sell you their more expensive product asd opposed to their cheaper one.

Also, Do you have any dyno sheets to back your statements up. The butt dyno isn't very accurate. It seems to be a lot like the placebo effect. I remeber seeing dyno reports of a header only getting you 1hp. Seems hardly worth it to me. If I remember correctly, It was a Pacesetter. I can't remember the gains from the RB unit but it was pretty minimal without a bunch of other mods.

Last edited by inflatablepets; 08-27-05 at 11:41 AM.
Old 08-27-05 | 02:50 PM
  #32  
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Originally Posted by inflatablepets
I find your statements much harder to swallow than a company that has spent big $$$ on research and development. Racing beat has been in buisness for a long time and has a track record to prove their knowlege. They've even had a couple cars in the salt flats. Bottom line. I'm going to believe them especially when they say they have done lots of dyno tests between the two, and state that their DP/presilencer is comperable to their header in a close to stock motor. Especially when their DP is cheaper than their header.
You'd think they would want to sell you their more expensive product asd opposed to their cheaper one.
Finally. Thanks for the post, my thoughts exactly. Never could understand why no one ever said it.
Old 08-27-05 | 03:35 PM
  #33  
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oops......speed bump....
 
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thank you guys....
Old 08-27-05 | 05:54 PM
  #34  
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Originally Posted by inflatablepets
I find your statements much harder to swallow than a company that has spent big $$$ on research and development. Racing beat has been in buisness for a long time and has a track record to prove their knowlege. They've even had a couple cars in the salt flats. Bottom line. I'm going to believe them especially when they say they have done lots of dyno tests between the two, and state that their DP/presilencer is comperable to their header in a close to stock motor. Especially when their DP is cheaper than their header.
You'd think they would want to sell you their more expensive product asd opposed to their cheaper one.

Also, Do you have any dyno sheets to back your statements up. The butt dyno isn't very accurate. It seems to be a lot like the placebo effect. I remeber seeing dyno reports of a header only getting you 1hp. Seems hardly worth it to me. If I remember correctly, It was a Pacesetter. I can't remember the gains from the RB unit but it was pretty minimal without a bunch of other mods.
lol, I was going to say the same thing, so I checked the racing beat site to make sure thats what they said but then I got side tracked.
Old 08-28-05 | 01:09 AM
  #35  
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Originally Posted by BlaCkPlaGUE
lol, I was going to say the same thing, so I checked the racing beat site to make sure thats what they said but then I got side tracked.
Not sure if it was on their site. I do know it's in their catalog. It's excellent bathroom reading. If you order somthing from them, be sure to ask for the catalog. It's really nice. Full of tech tips, and color pictures.
Old 08-28-05 | 01:48 AM
  #36  
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The only advantage you gain through an aftermarket exhaust is that the exhaust gases can flow through the pipes faster, and hotter. This is due to the design of the pipes. Steel is smooth, it doesn't impede air flow. Cast iron however, is incredibly rough compared to steel. This will slightly effect air flow. That said however, the main restriction in the factory exhaust system are, like the 3 cats that are on the car. Using a downpipe/presilencer combo will completely eliminate them, therefore freeing up the exhaust gas flow, and furthermore, freeing up power for the engine, as backpressure will be significantly reduced.
Old 08-28-05 | 03:02 AM
  #37  
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Originally Posted by inflatablepets
I find your statements much harder to swallow than a company that has spent big $$$ on research and development. Racing beat has been in buisness for a long time and has a track record to prove their knowlege. They've even had a couple cars in the salt flats. Bottom line. I'm going to believe them especially when they say they have done lots of dyno tests between the two, and state that their DP/presilencer is comperable to their header in a close to stock motor. Especially when their DP is cheaper than their header.
You'd think they would want to sell you their more expensive product asd opposed to their cheaper one.

Also, Do you have any dyno sheets to back your statements up. The butt dyno isn't very accurate. It seems to be a lot like the placebo effect. I remeber seeing dyno reports of a header only getting you 1hp. Seems hardly worth it to me. If I remember correctly, It was a Pacesetter. I can't remember the gains from the RB unit but it was pretty minimal without a bunch of other mods.
First off I am a huge Racing Beat supporter and have never said anything about them being wrong so don't make it look like I did. I never disagreed with them in the slightest. You are just very narrowly focused on where power is actually measured. Get off of dyno numbers or at the very least learn how to interpret their data. All you guys do is look for peak power anyways since this is what gets quoted everywhere. Take a look at average power sometime. This is where the big difference is.

It's pretty obivous you've never actually had a header and felt the difference between it and a downpipe before. If you would find out for yourself before you pass on information that another inexperienced person told you, you'd agree. Take off your catco front exhaust and stock manifold sometime and actually try a header out before you open your mouth next time.

Don't get on my case about a Pacesetter. It's always the people that have never had something that seem to be the experts about whether it works or not. Why does that seem strange? I said that even a Pacesetter makes a big difference in power over the stock manifold. It does. There is a huge powerband difference. Go buy one instead of listening to hearsay all the time. I have also had the Racing Beat streetport system on my 1st gen which is a long primary, a short primary system, true duals on my 2nd gen, downpipe on my 2nd gen, and a couple of other variations of these that I just welded up to try out on these cars. Sorry if I don't dyno everything so I can prove the results to some little kid on a forum who doesn't know what he's talking about. You do not need a dyno to tell you what drives better and what doesn't if there is truly a difference. I'm not talking about all the morons who add cone filters to their n/a's and claim a noticable gain in power. There isn't one. I'm not talking about just replacing just the mufflers and saying you feel the car accelerate faster. You won't. I'm not talking about adding an ignition box and saying that your n/a is faster now. It isn't. It's all about exhaust tuning differences of different systems and their effect on the usable powerband and not just peak power numbers. All of these systems have very different powerbands. If all you are concerned about is PEAK numbers, you are missing 99% of the story. Peak numbers mean nothing unless you want to brag online. It may let you win an internet race but it makes you no faster in the real world. Average power makes you faster. If you'd go out and try some different systems, you'll see that there is far more than a couple of horsepower difference between each of them. As far as peak numbers go there might not be much difference. There is a very large difference everywhere else though where it counts.

If you want dyno proof I'm right, why don't you go give me some dyno proof I'm wrong? Make it on your own personal car too. Don't use someone else's work since you apparently would expect the same results from me. You can start by dynoing your catco system with the stock manifold. Then go buy any header out there and dyno it again. Look at the powerband across the entire board. You'll see. If you can't give it out yourself, don't ask for it in return especially when you've never tried more than the one system on your car. If you haven't even had any different systems, you can't really get on my case about anything anyways. I've tried alot of different systems. I know which ones you can feel and which ones you can't. Does that make me an expert on the subject compared to Racing Beat? Nope, but it gives me enough experience to say I at least know more than you do on the subject.

It's nothing personal against you even though you did single me out as your target. You'll learn one day after you try some things for yourself. Until you do, don't tell anyone else what works and what doesn't. You aren't qualified to. It's sad that people actually agree. I do find it strangely ironic that every one of these people all have downpipes! Looks like a little bias based on lack of experience with any other system.

Last edited by rotarygod; 08-28-05 at 03:07 AM.
Old 08-28-05 | 03:14 AM
  #38  
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Good point rotarygod. While there may not be any total hp gains, there IS more power lower down. I know this is far from definative, but I was told by the guy at Pro Tech in Austin (who has a dyno) that the RB header would yeild more usable power than the downpipe alone. He would get no extra money out of this, so I don't see why he would tell me something that was unsubstantiated.
Its a moot point anyway, he already has the header.
Old 08-29-05 | 10:27 PM
  #39  
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While I did have a Pacesetter, I did seem to notice the powerband had changed. I didn't like the header. It kept blowing gasket out (probably due to poor fittment and quality issues) I decided to go with a home made downpipe and stock manifold. I actually prefer the latter setup. Partially due to less noise and the powerband I was in. I am contemplating what to do with my next exhaust setup while my engine swap is in progress (it will be a while yet) I don't have any dyno pulls to tell you with my findings. I wish I did, just didn't have time on dyno day locally. with all due respect, I can agree with you on some but disagree on thers. So, I guess I can only say I will agree to disagree.

As far as the next engine swap, I am going to use my good N/A for a while. I haven't decided which avenue to go but it will be toward the dark side. I am leaning toward a 6pi turbo at the moment but that may change. So, I won't be investing too seriously in a N/A exhaust system.

BTW I like the avatear rotarygod
Old 08-30-05 | 04:06 AM
  #40  
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The Pacesetter gasket sucks and the flange is thin. The Pacesetter by no means is an optimal header since the front pipe is 8+ inches longer than the rear. It still made a noticable powerband difference but definitely made the car MUCH louder. My Racing Beat header was nicer but still isn't the perfect header. I currently have a home made long primary system that I love.

If you look at the tuning of the stock manifold vs different headers, the effective length of the stock exhaust pipes in the block and the manifold is only about 2". It's pretty short. That nevertheless does do something to the powerband. Useful in some parts, not so much in others. It should have peak efficiency at around 7000 rpm or so but also other certain spots in the powerband. There are actually several different lengths that can tune there based on the order of reflections in the system. When you have a system tuned to one spot, it is also tuned to other spots as well. In between these it is worse than with different lengths. If you had a header that was 30" long or so, it would have peak efficency around 5000-6000 rpm but possibly less than the stock manifold immediately above and below these points then make more power again off idle. The effects of scavenging in addition to the tuned length could possibly make up for the losses in some spots but again, hurt in others.

A stock manifold can make decent power in spots and so can a header. A short primary header will do it over a narrower range than a long primary. A dual is different still. You probably spent most of your time where the header wasn't much of an advantage but was more noise than anything. The Pacesetter doesn't give as nice a powerband as an equal length unit does. My big issue is that people so often only focus on peak horsepower numbers when these are the absolute least important numbers to focus on. Alot of people completely ignore everywhere else even though they all spend most of their time driving there. Headers can have a huge impact on your powerband. It is all dependent on length. Some header lengths aren't as friendly to power as others. The problem is that alot of people don't recognize the differences between them and just randomly spout off how they "don't make more power". Some headers can make much more peak power, some can make much more average power, and if you do it wrong, some can make less peak or average power. A nice set will definitaly make more power than a stock manifold and do it over a very wide range.

Got no problems with people disagreeing. It's actually far more accurate to disagree with some things and not others than to just say yes or no like it's the gospel. I've got a problem with kids who don't know better (not you) trying to give advice and tell people that have tried things what works and what doesn't. That's annoying and is sadly half of the advice available online.
Old 08-30-05 | 04:33 AM
  #41  
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having had the racing beat header with single pre-silencer and dual 50mm hks sport mufflers and the full RB system headers, mufflers and single presilencer i can tell you the horse power gains are great from both, also with a tuned header you will always get more and better gains throughout the power band than from straight or "downpipe" also i can give over 100,000 miles of back up of how the racing beat setup preforms, and how easy it is to install your self and never once had a gasket blow or something rust out
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