Bad day for ZZP
12-06-2007, 01:47 AM
#52
Original Hayden Fanatic
Platinum Member
On some cars back pressure can help with low end torque. It is never good for upper RPM HP. Since this build gained torque and lost HP, there is another issue at hand.
Selling to an inexperienced market can be tough. In the LS1 crowd you would never see a thread titled "these headers made me lose 10% of my HP" because they know better. In this market where somone obviously doesn't know much about performance we're actually having a debate about how much power the headers made you lose. It's frustrating.
In tuning we've done builds with strange results. Take a Grand Prix, put in a cam and not change plug gap. The car will misfire and you may lose 50 HP. Someone who doesn't know anything would declare "this cam sucks, it made me lose 50HP". To a good tuner, they know that increased airflow blows out spark and you have to tighten gap. Doing so might then yield 100 HP over the first numbers. What does this mean about the cam? Nothing.
Similarly we would need to hear the car run, have MAF readings, spark readings and wideband O2 readings to know why this build lost power with the headers. With that information I'm sure it would be easy to diagnose and fix the problem.
Selling to an inexperienced market can be tough. In the LS1 crowd you would never see a thread titled "these headers made me lose 10% of my HP" because they know better. In this market where somone obviously doesn't know much about performance we're actually having a debate about how much power the headers made you lose. It's frustrating.
In tuning we've done builds with strange results. Take a Grand Prix, put in a cam and not change plug gap. The car will misfire and you may lose 50 HP. Someone who doesn't know anything would declare "this cam sucks, it made me lose 50HP". To a good tuner, they know that increased airflow blows out spark and you have to tighten gap. Doing so might then yield 100 HP over the first numbers. What does this mean about the cam? Nothing.
Similarly we would need to hear the car run, have MAF readings, spark readings and wideband O2 readings to know why this build lost power with the headers. With that information I'm sure it would be easy to diagnose and fix the problem.
12-06-2007, 09:26 AM
#53
Senior Member
Thread Starter
There can't be much wrong with the tuner. I took it to him when I first had my GMPP intake and manifold and then it was at 154.99hp and 152.38tq and after the tune that day he bumped it up to 164.77hp and 159.03tq. After I installed the header I took it to him 2 months later (yesterday) and this was the result.
There is something else definitely wrong with the car, do you guys think you could give me a few ideas of things to check where the problem might be located so I can go outside and have a look. Otherwise I'm just a sitting duck here until Sunday.
There is something else definitely wrong with the car, do you guys think you could give me a few ideas of things to check where the problem might be located so I can go outside and have a look. Otherwise I'm just a sitting duck here until Sunday.
Last edited by BULLETSSMOKE; 12-06-2007 at 09:26 AM. Reason: Automerged Doublepost
12-06-2007, 09:35 AM
#54
Senior Member
well no offense to you or the guy but he's definately doing something wrong. either he made mistake and wont admit it, or he doesn't know what's going on. if I were you I'd look into this info for myself so that you can confront him with it (not necessarily in a nasty way, but just to see what he knows) and if he starts talking in circles or giving you crap answers, you know he's bs-ing you. I think zoomer is 100%, you can't just blame hp loss (and tq gain) on the headers cause it was the last thing you had installed. I'd check other stuff first. Like I said, bone up on tuning a bit, then confront the dude, and see what's up, who knows, maybe when this is all over you'll be able to tune yourself and get more hp out of your headers, you know? good luck man!
12-06-2007, 10:20 AM
#55
the ONLY way it's the products fault is if you have a bad cat.. however thats magnaflows fault...
it would raise EGT and cause a massive reduction in timing up top but thats the ONLY way and if thats the issue zzp will work with you if you're under warrenty
it would raise EGT and cause a massive reduction in timing up top but thats the ONLY way and if thats the issue zzp will work with you if you're under warrenty
12-06-2007, 01:38 PM
#56
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If you have a leak @ in the exhaust someware like the collector you can lose alot of HP. Not all Exhaust leaks are really loud either You just may notice a tone change Or like a tss tss tss sound really faintly. Ide check to make shure your collector or block connections to the headder are good. If your running copper gaskets check to make shure they are in correctally I had a Copper gasket in backwards and it made it sound like i had a sleight lifter tapping noise. Headders are almost always prone to regular leakage unless you use some uber fasteners and gaskets.
12-06-2007, 03:16 PM
#58
Senior Member
Thread Starter
Oh hell yeah. Its defintely noticeable that the torque hasnt changed too. I will need to check the exhaust because there HAS to be a leak or the cat is bad. One of the codes from the CEL said "The PCM has determined that the catalyst system efficiency for bank 1 is below threshold for the current engine operating conditions. (Bank 1 identifies the location of cylinder #1, while bank 2 identifies the cylinders on the opposite bank". Word for word. I took it to Chevy a while back and they said there was holes in my cat but I thought they were full of it so I dunno.
12-06-2007, 04:42 PM
#61
Oh hell yeah. Its defintely noticeable that the torque hasnt changed too. I will need to check the exhaust because there HAS to be a leak or the cat is bad. One of the codes from the CEL said "The PCM has determined that the catalyst system efficiency for bank 1 is below threshold for the current engine operating conditions. (Bank 1 identifies the location of cylinder #1, while bank 2 identifies the cylinders on the opposite bank". Word for word. I took it to Chevy a while back and they said there was holes in my cat but I thought they were full of it so I dunno.
12-06-2007, 04:59 PM
#63
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Some Great reading: Full Article here
http://www.superchevy.com/technical/...exh/index.html
Section pertaining to this.
"Headers -- Primary Pipe Diameters
Big pipes flow more, so is bigger better? Answer: absolutely not. Primary pipes that are too big defeat our quest for the all-important velocity-enhanced scavenging effect. Without knowledge to the contrary, the biggest fear is that the selected tube diameters could be too small, thereby constricting flow and dropping power. Sure, if they are way under what is needed, lack of flow will cause power to suffer. In practice though it is better, especially for a street-driven machine, to have pipes a little too small rather than a little too big. If the pipes are too large a fair chunk of torque can be lost without actually gaining much in the way of top-end power.
At this point determining primary tube diameters is starting to look like a tight wire act only avoidable by trial and error on the dyno. Fortunately, a little insight into what it is we are attempting to achieve brings about some big-time simplification. Our goal is to size the primary pipes to produce optimum output over the rpm range of most interest. The rate exhaust is dispensed with, and consequently, the primary pipe velocity, is strongly influenced by the port's flow capability at the peak valve lift used. From this premise it has been possible to develop a simple correlation between exhaust port-flow bench tests and dyno tests involving pipe diameter changes. This has brought about the curves shown in the graph Fig. 4 which allow primary sizing close enough to almost eliminate the need for trial-and-error dyno testing."
It's not the fault of the product, its the decision and application of the user.
http://www.superchevy.com/technical/...exh/index.html
Section pertaining to this.
"Headers -- Primary Pipe Diameters
Big pipes flow more, so is bigger better? Answer: absolutely not. Primary pipes that are too big defeat our quest for the all-important velocity-enhanced scavenging effect. Without knowledge to the contrary, the biggest fear is that the selected tube diameters could be too small, thereby constricting flow and dropping power. Sure, if they are way under what is needed, lack of flow will cause power to suffer. In practice though it is better, especially for a street-driven machine, to have pipes a little too small rather than a little too big. If the pipes are too large a fair chunk of torque can be lost without actually gaining much in the way of top-end power.
At this point determining primary tube diameters is starting to look like a tight wire act only avoidable by trial and error on the dyno. Fortunately, a little insight into what it is we are attempting to achieve brings about some big-time simplification. Our goal is to size the primary pipes to produce optimum output over the rpm range of most interest. The rate exhaust is dispensed with, and consequently, the primary pipe velocity, is strongly influenced by the port's flow capability at the peak valve lift used. From this premise it has been possible to develop a simple correlation between exhaust port-flow bench tests and dyno tests involving pipe diameter changes. This has brought about the curves shown in the graph Fig. 4 which allow primary sizing close enough to almost eliminate the need for trial-and-error dyno testing."
It's not the fault of the product, its the decision and application of the user.
12-06-2007, 07:16 PM
#65
Senior Member
Thread Starter
Actually they also said that the GMPP intake and catback wasn't under warranty so I thought EVERYTHING that he said was full of **** if you get what I'm saying. It may be fucked up, I hope so because that would source the problem and cats are the LEAST expensive part of the exhaust thank the lord. I took a look under the car without jacking it up (I cant jack it up until Sunday) and I didn't really see a problem on the under flat side of it but who knows. I've been getting lots of different answers and came across that my only solution would be to take off everything header-back and replace gaskets and check inside the pipes for anything and look for cracks and leaks and whatnot. I am having some fun though with this little bit of extra torque. Daily driving is more fun up to 4k RPM and it really hauls but I don't feel like keeping it this way that's for damn sure.
12-06-2007, 07:21 PM
#66
Actually they also said that the GMPP intake and catback wasn't under warranty so I thought EVERYTHING that he said was full of **** if you get what I'm saying. It may be fucked up, I hope so because that would source the problem and cats are the LEAST expensive part of the exhaust thank the lord.
12-06-2007, 07:24 PM
#67
Senior Member
Thread Starter
12-06-2007, 07:39 PM
#69
Senior Member
Thread Starter
My first thing would be to check if there's even anything wrong with it lol. I did run it kind of car when I first got it and AFTER I did that someone told me your supposed to take it easy for 250 miles.
12-06-2007, 08:29 PM
#71
Senior Member
Thread Starter
12-06-2007, 10:52 PM
#74
Senior Member
Thread Starter
If it is the cat then I ran into another problem. The downpipe is prewelded from ZZP to the cat. Should I call them and talk about warranties or do I need to buy ANOTHER downpipe and cat combo. It's $199 on their site but I'm not sure if the one they are selling will fit the midlength header that was in the combo I bought.
12-06-2007, 11:05 PM
#75
well, first i would talk to zzp, then magnaflow. do you have your receipts, or proof of purchase? i'm guessing your order with dates is saved in your log-in on their site. if they won't help you, since you said that you didn't break it in properly, and that's most likely the reason it's failed, you don't have to get a new one. any exhaust shop can cut out the cat and weld a new one in. shouldn't be that expensive at all to have done.
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