minimum hp gains from gmpp headers/A.I./catback?

[Speed74SS]

From looking at some corvette LS3 dyno's with shorties, cat back, intake and a tune - we are looking at 400-415 rwhp. Stock LS3 dynos are showing 380 rwhp average from the research I have done on the corvette forums.

[headpunter]

Originally Posted by Speed74SS

From looking at some corvette LS3 dyno's with shorties, cat back, intake and a tune - we are looking at 400-415 rwhp. Stock LS3 dynos are showing 380 rwhp average from the research I have done on the corvette forums.

sounds right on

[Evotion]

The only experience I can speak from is on the Evo, in it's particular case, they are de-tuned before shipping over here. A simple ECU flash, was gaining 40hp on the IX's.

Not saying that will happen on the LS3, especially knowing what it is rated in the vette. I would be more comfortable looking at the stock maps before even guessing what gains we might get out of the GMPP stuff.

As far as the parts w/o a tune, I can assume that the ECU will eventually adjust to the increased airflow, exhaust, etc. Is this correct?

Up to this point, reading new little tidbits every day, is about as exciting as we can get. But in 6 months, when we start to get the really good details, when we aren't driving them, we will be back here comparing notes...

That's when the REAL fun starts

[BeermanSS]

Yeah can't wait to start tuning these monsters. That is gonna be fun.

[Rekt]

Originally Posted by logan1080

will long tube headers fit in the car?

Looks like they will fit just fine.

[Mblock66]

I think you guys are going to be pretty dissapointed with these bolt ons without a proper tune of the ecu. Especially on the intake. The ECU can only trim so much and "learn" and depending on how poorly the GMP intake was made it might actually cost you power.

If you can't tune these parts b/c you want to save your warrenty, save your $ or risk it and go aftermarket. Usually the companies outsource these parts to other companies anyway. For example in the past GM performance exhausts were borla built with a little leass quality then the normal borla. In subaru the intakes and exhausts were all made by a well known performance company. But in the end they didn't live up to the advertised gains.

I will certainly not be a guinnea pig on these parts. Wait until someone buys into it, takes it to a local shop does a baseline, then intake no tune. And the same for the shorties and cat back. Gains WILL be minimal.

[TAG UR IT]

tune the puppy. just DO IT!

[383ss]

Originally Posted by Speed74SS

From looking at some corvette LS3 dyno's with shorties, cat back, intake and a tune - we are looking at 400-415 rwhp. Stock LS3 dynos are showing 380 rwhp average from the research I have done on the corvette forums.

damn good info. I was too lazy to search for it

[Speedy1975]

Originally Posted by Mblock66

I have working the tuning industry (mostly subarus) and you need to be careful withyour predictions. The cars brain is the ECU and it tells the car exactly how to run with what it knows. No there is some level of "learning" in these ECUs but not very much when you add mods like these.

We have seen the addition of a Subaru Performance Parts Intake to a stock application and the car LOST 7hp. After the tune it was up 3hp (this is to the wheels). The stock ECU couldn't understand the new MAF readings and all the additional air so it actually performed worse until tuned.

As for cat backs there is really nothing to tune there but in todays cars there is really not much of a gain there since the stock systems are pretty unrestrictive. Maybe 5 hp TOPS. These are mostly for sound.

Now for headers, shorties will do little for a car tuned for them let alone untuned. The real gain in headers is in long tubes (preferably without cats or hi flow cats). This is where the gains are. Shorties slapped on there with no tune will result in very very little. Maybe another 5.

So you may actually net nothing by adding all of these parts without a tune. And no GM will not be tuning your car lol. If you decide to put them on to "get extra warrentied performance" you probably did nothing but make the exhaust note cooler and empty your wallet. Now if you take that car and get it tuned for the mods, it will get you some better gains but now your warrenty will not be honored and they do have ways to detect if you have flashed the ECU.

I am telling you this from first hand experience, never trust a dyno plot of a part from an actual manufaturer. Subaru provides a dyno plot of their intake on an otherwise stock car with 11hp gain. We did the exact same test on the same car and got -7hp. You can make a dyno look anyway you want it is simple drag and drop lol. Only trust dynos from 3rd party tests and real world applications.

My advice. If you are going to mod....go aftermarket and do it right and cheaper. But understand you pay to play. Once you go this route you need to accept that you may get voided on powertrain when you have an issue. It is just the risk you take.

Either stay stock and stay happy or deal with the problems out of pocket if you decide to mod....

This is all pretty good info, but something to note is that adding aftermarket parts won't necessarily void your warranty. The Magnum Moss act protects consumers from this very thing. It was originally introduced to keep dealers from forcing consumers into buying oil/oil filters/air filters from them, but the word of the law opens it up to other bolt ons as well. Now let's say you bolt on aftermarket headers, and they crack 2 years from now...will that be warrantied like the factory GM manifolds....NO, however the headers should have their own warranty from the manufacturer.

Now let's take this same scenario and say that you have bolted on aftermarket headers and 20,000 miles later you burn a valve. Will GM deny the warranty on that valve because you have aftermarket headers installed? They may try, but the burden is on GM to prove the headers actually cased the valve failure.

I've been down this road with motorcycles and everything else, and it's unlikely any part of your warranty will be denied because you bolt on a few hop up parts.

Now, if you install a Supercharger running 10lbs of boost, flash the ECU, and your tranny has problems, THEN GM WOULD have a leg to stand on by denying the warranty on the tranny due to the level of mods.

Just use common sense here.

As for the power gains....all will be minimal with the bolt ons. I'd wager you'll get MORE gains from a proper tune WITHOUT ANY OTHER MODS vs. bolting on an intake, shorty headers, and cat back with no tune.

Proper air fuel ratio makes a significant difference in performance. From the factory these cars will run at 14.7:1. Proper tune is somewhere around 13:1 for naturally aspirated.

[Rekt]

The only GMPP part I might buy would be the hot cam. Nothing else.

[GTAHVIT]

^that and maybe the cai....

That's what I'm thinking....

[Mblock66]

Originally Posted by Speedy1975

This is all pretty good info, but something to note is that adding aftermarket parts won't necessarily void your warranty. The Magnum Moss act protects consumers from this very thing. It was originally introduced to keep dealers from forcing consumers into buying oil/oil filters/air filters from them, but the word of the law opens it up to other bolt ons as well. Now let's say you bolt on aftermarket headers, and they crack 2 years from now...will that be warrantied like the factory GM manifolds....NO, however the headers should have their own warranty from the manufacturer.

Now let's take this same scenario and say that you have bolted on aftermarket headers and 20,000 miles later you burn a valve. Will GM deny the warranty on that valve because you have aftermarket headers installed? They may try, but the burden is on GM to prove the headers actually cased the valve failure.

I've been down this road with motorcycles and everything else, and it's unlikely any part of your warranty will be denied because you bolt on a few hop up parts.

Now, if you install a Supercharger running 10lbs of boost, flash the ECU, and your tranny has problems, THEN GM WOULD have a leg to stand on by denying the warranty on the tranny due to the level of mods.

Just use common sense here.

As for the power gains....all will be minimal with the bolt ons. I'd wager you'll get MORE gains from a proper tune WITHOUT ANY OTHER MODS vs. bolting on an intake, shorty headers, and cat back with no tune.

Proper air fuel ratio makes a significant difference in performance. From the factory these cars will run at 14.7:1. Proper tune is somewhere around 13:1 for naturally aspirated.

The aftermarket loves to throw around the Mag Moss Act but the long and short of it is that you will have to hire a lawyer which will cost you more time and money to fight then if you just pay for the repair.

I have been through this more times then I can count and BELIEVE me they will have the upper hand on you. They don't have to prove anything. They will simply call in the "regional rep" who will look at the car, see that you have an intake on there and not allow the head gasket blow repair to happen (or whatever is the issue). They will tell you that you have altered the specs and the internal performance of the engine to the point that it caused the issue to happen. END OF STORY. That is all they need, the word of a regional rep is enough to prove that they aren't going to cover it. Then if you want to fight you need a lawyer which will cost thousands.

So although this law is out there, it rarely works. Now if they claim your radio broke b/c of an intake this law will work. Otherwise you will be sol.

[1_2Many]

Originally Posted by Mblock66

I think you guys are going to be pretty dissapointed with these bolt ons without a proper tune of the ecu. Especially on the intake. The ECU can only trim so much and "learn" and depending on how poorly the GMP intake was made it might actually cost you power.

If you can't tune these parts b/c you want to save your warrenty, save your $ or risk it and go aftermarket. Usually the companies outsource these parts to other companies anyway. For example in the past GM performance exhausts were borla built with a little leass quality then the normal borla. In subaru the intakes and exhausts were all made by a well known performance company. But in the end they didn't live up to the advertised gains.

I will certainly not be a guinnea pig on these parts. Wait until someone buys into it, takes it to a local shop does a baseline, then intake no tune. And the same for the shorties and cat back. Gains WILL be minimal.

Your advice is appreciated, but not sure it's valid in regards to the Camaro. You say your experience is with Subaru's...I assume WRX's and Legacy's which are turbo motivated. Intake and exhaust mods likely have less of an impact on a turbo powered vehicle than a N/A one. I for one drove a 1st gen SRT-4 and ran the stage 2 upgrade...the biggest gain for me in my turbo was thru the ECU, but that won't be the case for the Camaro.

Bottom line is this isn't really an apples to apples comparison.

[Mblock66]

Originally Posted by 1_2Many

Your advice is appreciated, but not sure it's valid in regards to the Camaro. You say your experience is with Subaru's...I assume WRX's and Legacy's which are turbo motivated. Intake and exhaust mods likely have less of an impact on a turbo powered vehicle than a N/A one. I for one drove a 1st gen SRT-4 and ran the stage 2 upgrade...the biggest gain for me in my turbo was thru the ECU, but that won't be the case for the Camaro.

Bottom line is this isn't really an apples to apples comparison.

We didn't tune ONLY subarus. We specialized in them but everything from camaros to audis to supras to mustangs came through. The scale isn't the same due to the output of a 4 vs 8 but the priciples of tuning are the same. If you dont account for how the AFRs deal with the increased flow you could have a negative result using the stock tuning on an NA car as well. Seen it happen. Then post tune +7hp ish. So yes it is apples to apples. And you are wrong if you don't think a proper tune will be the best bang for the buck on these cars. There is no bolt on that will give you more (other then a FI kit) then a tune.