False dyno reports from magnaflow

[achieftain]

Originally Posted by MTS Adding higher flowing exhaust WILL increase horsepower without a tune. .................................. I can garantee my car is making about 260rwhp right now with catback, downpipe and boost controlled 17psi.

Adding higher flowing exhaust CAN increase horsepower, but not always. I can show you that certain vehicles will run like crap if you remove the exhaust system, for example by blowing a hole in the header pipe or cat or muffler. You have effectively decreased backflow which is what higher flow does (just another name). To test this for yourself you would have to disconnect your exhaust (and drive only off-road or on a dyno)

At 18% loss (avg) that means you ahve successfully achievd about a 22% increase in engine power from stock of 260 to about 317. Congratulations.

[perris]

Originally Posted by Jack B If you want a true gauge, the 60 is not a good bench mark, there are too many variables. The true yardstick would be to have the same car run the quarter multiple times at the same ambient air temp and watch the mph, that is the true indicator of hp. The comparison made before and after mods would tell all. Basically that is how you tune at the strip, for mph, not ET. I am going to the drag strip next week. I have all those no-value mods, most of these cars run about 98-99 stock, it will be interesting where the cars ends up at.

ya,/ agrees...with automatic transmission to reduce human factor

[Mallard]

Originally Posted by Jack B Thanks - that even makes less sense, since HP Tuners recently posted that they cannot find the key to unlocking the ECU.

They have GXP/Redline tuning out for 'beta' testing right now.

[RPIpower]

Originally Posted by MTS Adding higher flowing exhaust WILL increase horsepower without a tune. Depending upon the application it can add a little or a lot (relatively) horsepower. If the ecu pulls timing or whatever after the fact because it calculates a high torque value, than so be it... Doesn't mean adding exhaust wont add power claimed. Just means the ecu is holding the potential of the ecu back. One can raise boost, and tune the car, to take full advantage of a higher flowing exhaust. I can garantee my car is making about 260rwhp right now with catback, downpipe and boost controlled 17psi.

WRONG. Increased exhaust gas velocity is what makes the power. Making power with a high flow exhaust is an internet forum tuning myth. Now, we know where you got your info. The exhaust NEEDS to be tuned. There is no question about it. We have tried 4 different sizes with combinations of 3 different types of Y pipes to get the results we concluded with. Simply increasing the flow rate or decreasing back pressure can many time hurt your hp numbers.

When you simply increase exhaust tubing diameter, it cools the exhaust gasses making it more dense, thus slowing down the velocity. The trick to increasing performance on an turbo exhaust system is to relieve the turbo of back pressure, then maintaining EGV through out the rest of the system.

Originally Posted by Jack B Thanks - that even makes less sense, since HP Tuners recently posted that they cannot find the key to unlocking the ECU.

Exactly. Thats why we were not able to increase the limits set on the stock ecu. We dynoed a 25whp increase with our stage 2 intercooler yesterday. The customer will be driving for 1000k+ miles before returning for another dyno session. The key is to figure out of what parameters, does the pcm restrict torque.

[perris]

Originally Posted by RPIpower WRONG. Increased exhaust gas velocity is what makes the power. Making power with a high flow exhaust is an internet forum tuning myth. Now, we know where you got your info. The exhaust NEEDS to be tuned. There is no question about it. We have tried 4 different sizes with combinations of 3 different types of Y pipes to get the results we concluded with. Simply increasing the flow rate or decreasing back pressure can many time hurt your hp numbers. Exactly. Thats why we were not able to increase the limits set on the stock ecu. We dynoed a 25whp increase with our stage 2 intercooler yesterday. The customer will be driving for 1000k+ miles before returning for another dyno session. The key is to figure out of what parameters, does the pcm restrict torque.

I would love to see the new dyno after 1000 miles.

[Red Devil]

Originally Posted by RPIpower Increased exhaust gas velocity is what makes the power...Simply increasing the flow rate or decreasing back pressure can many time hurt your hp numbers.

amen..................

[MTS]

Ok here's a question for ya... why would anyone buy a $1000 exhaust system with your logo on it if they can get a magnaflow for nearly half that, that increases performance just as well (or hardly at all according to you) ?? Do you have some dyno tested design advantage that you've patented in five countries and will not disclose for fear magnaflow may steal it? I thought not. Why? Because after all 3" exhaust is pointless because it decreases exhaust velocity which hurts your car's performance (which is why your system and magnaflow's is 3" ) You want high velocity out of the turbo, yes! Heat wrap that downpipe! but you dont want a 2.5" down pipe now do you? 3" would allow the turbo to move a lot more volumn now wouldn't it? We're not talking about putting a 4" cat-back on this car bud; it's a free-flowing muffler (or none at all) that helps reduce the backpressure (IN A TURBO CAR'S CASE THIS IS A GOOD THING FOR TOP END POWER) and let the motor/turbo move exhaust faster out of the vehicle. Will removing backpressure add a little lag? Yes (but moot on this tiny twin-scroll turbo)... will less backpressure allow the turbo to move exhaust faster? YES! AMAZING! I KNOW!

Please there's really no need to come on to the internet and keep repeating how great you and your products are. I'm sure they will do the talking for themselves as they do look like quality pieces. Please don't feel threatened by magnaflow or any other business here, but you should know there ARE people on this website that DO have experience wrenching and tuning cars; and have knowledge about exhaust sytems, engine theory, intercooling, etc.

The point is you've been called on the fact that you shot yourself in the foot with the titling of this thread. You say magnaflow is lying about their hp rating essentially and then you say it's because of the ecu. You need to make up your mind...

Perhaps your intercooler dyno numbers will be fake when the customer comes back after 1k miles to discover only a 6hp increase? Perhaps someone can make a post here about it.

I'm done with this thread. If you've got something else to say about me then you can either PM me or come say it to my face.

Take care,
Rob
MTS - Our new slogan: we know nothing because we are internet-educated

[Red Devil]

Originally Posted by MTS We're not talking about putting a 4" cat-back on this car bud; it's a free-flowing muffler (or none at all) that helps reduce the backpressure (IN A TURBO CAR'S CASE THIS IS A GOOD THING FOR TOP END POWER) and let the motor/turbo move exhaust faster out of the vehicle. Will removing backpressure add a little lag? Yes (but moot on this tiny twin-scroll turbo)... will less backpressure allow the turbo to move exhaust faster? YES! AMAZING! I KNOW!

Simplistically speaking, there is zero need for an exhaust system on a turbocharged engine to optimize power. Even 1psi of backpressure anywhere in the powerband is too much. IMO, the whole issue of maintaining velocity/240ft per sec, etc...is negated in this forced induction application.

I struggle to find any example/condition where removing backpressure will add lag. Removing back pressure - in the turboback - will both reduce lag, and possibly increase operating range.

Or I'm reading you wrong?????? The topic was post-turbo exhausts...if you're talking about opening or restricting flow in the manifold pre-turbo or changing the exhaust A/R, than I'd agree with your statements above.

[perris]

Originally Posted by Red Devil Simplistically speaking, there is zero need for an exhaust system on a turbocharged engine to optimize power. Even 1psi of backpressure anywhere in the powerband is too much. IMO, the whole issue of maintaining velocity/240ft per sec, etc...is negated in this forced induction application. I struggle to find any example/condition where removing backpressure will add lag. Removing back pressure - in the turboback - will both reduce lag, and possibly increase operating range. Or I'm reading you wrong?????? The topic was post-turbo exhausts...if you're talking about opening or restricting flow in the manifold pre-turbo or changing the exhaust A/R, than I'd agree with your statements above.

my understanding would be as follows;

imagine if you had a dyno charged by the flow of water through a pipe.

take away the pipe, just about the same amount of water comes through without enough back pressure to spin the dyno

you're gonna have to have velosity and that's not gonna happen without backpressure

[Red Devil]

Originally Posted by perris my understanding would be as follows; imagine if you had a dyno charged by the flow of water through a pipe. take away the pipe, just about the same amount of water comes through without enough back pressure to spin the dyno you're gonna have to have velosity and that's not gonna happen without backpressure

Not for a turbocharged application.

Why would it be beneficial to maintain any type of flow optimization of the exhaust gas post the turbo? In essence, once it passes through the hotside of the turbo, it is no longer useful. If you have zero psi of exhaust resistance (backpressure) post turbo than you have optimized the system. Here's why:

1: In a turbocharged application, all of your power is coming from creating an artificial barometric pressure in the engine - compressed air.
2: In order to get that compressed air, you need to spin the turbo (that is powered by exhaust gas) as freely and quickly as possible.

So why do I want to impede on those principles by having pressure on the turbo to keep it from spinning? You have pressure one way - from the manifold through the hotside, pressure the other way (post turbo backpressure) only impedes your powerband.

[perris]

Originally Posted by Red Devil Not for a turbocharged application. Why would it be beneficial to maintain any type of flow optimization of the exhaust gas post the turbo? In essence, once it passes through the hotside of the turbo, it is no longer useful. If you have zero psi of exhaust resistance (backpressure) post turbo than you have optimized the system. Here's why: 1: In a turbocharged application, all of your power is coming from creating an artificial barometric pressure in the engine - compressed air. 2: In order to get that compressed air, you need to spin the turbo (that is powered by exhaust gas) as freely and quickly as possible. So why do I want to impede on those principles by having pressure on the turbo to keep it from spinning? You have pressure one way - from the manifold through the hotside, pressure the other way (post turbo backpressure) only impedes your powerband.

you make sense, however if the turbo is already making as much boost as you need or as much as the engine is designed to take, and if the turbo is capable of making more boost then it's allowed then lower exhaust pressure doesn't aid boost one bit

I am under the impression this turbo is restricted and lowering backpressure isn't going to add boost

[Red Devil]

Originally Posted by perris you make sense, however if the turbo is already making as much boost as you need or as much as the engine is designed to take, and if the turbo is capable of making more boost then lower exhaust pressure doesn't aid boost I am under the impression this turbo is restricted and lowering backpressure isn't going to add boost

Well, that's a question of the wastegate being electronically controlled and opening sooner than it should, etc...to control torque/power, along with possible timing adjustments by the PCM.

At the moment, this discussion regarding optimizing the GXP may be futile. But when someone cracks the PCM and you guys have full control and can alter the wastegate and timing, this will become a very real factor.

[RPIpower]

Originally Posted by MTS Ok here's a question for ya... why would anyone buy a $1000 exhaust system with your logo on it if they can get a magnaflow for nearly half that, that increases performance just as well (or hardly at all according to you) ?? Do you have some dyno tested design advantage that you've patented in five countries and will not disclose for fear magnaflow may steal it? I thought not. Why? Because after all 3" exhaust is pointless because it decreases exhaust velocity which hurts your car's performance (which is why your system and magnaflow's is 3" ) You want high velocity out of the turbo, yes! Heat wrap that downpipe! but you dont want a 2.5" down pipe now do you? 3" would allow the turbo to move a lot more volumn now wouldn't it? We're not talking about putting a 4" cat-back on this car bud; it's a free-flowing muffler (or none at all) that helps reduce the backpressure (IN A TURBO CAR'S CASE THIS IS A GOOD THING FOR TOP END POWER) and let the motor/turbo move exhaust faster out of the vehicle. Will removing backpressure add a little lag? Yes (but moot on this tiny twin-scroll turbo)... will less backpressure allow the turbo to move exhaust faster? YES! AMAZING! I KNOW! Please there's really no need to come on to the internet and keep repeating how great you and your products are. I'm sure they will do the talking for themselves as they do look like quality pieces. Please don't feel threatened by magnaflow or any other business here, but you should know there ARE people on this website that DO have experience wrenching and tuning cars; and have knowledge about exhaust sytems, engine theory, intercooling, etc. The point is you've been called on the fact that you shot yourself in the foot with the titling of this thread. You say magnaflow is lying about their hp rating essentially and then you say it's because of the ecu. You need to make up your mind... Perhaps your intercooler dyno numbers will be fake when the customer comes back after 1k miles to discover only a 6hp increase? Perhaps someone can make a post here about it. I'm done with this thread. If you've got something else to say about me then you can either PM me or come say it to my face. Take care, Rob MTS - Our new slogan: we know nothing because we are internet-educated

Now you are putting words into my mouth. I never said we were perfect or we were the best at everything. Yes, you will NOT get 30whp on the Magnaflow system. Both the Magnaflow system and our GT system are made for more hp. Why is there a price difference? Brand name and materials. T304 stainless steel is a little over double the cost of 400 stainless steel. Do I feel threatened? Not at all. Maybe you missed the fact that we are Magnaflow dealers?

http://magnaflow.com/03dealer_result...=250&x=36&y=11

Our products and service speak for themselves.



Customers send us their $100k+ cars from around the country. To install an exhaust? Intake? Chrome accents? No. We build the cars from the ground up. We have also been trusted to do factory warranty work. Many times we use Magnaflow mufflers and their other components for the projects. Nothing at all against Magnaflow as they have been a great product line for us for the past 9 years. We just believe in telling the truth. We dynoed a car at 14wh gain on our exhaust. We tried something on the intake and when we dynoed the car 2 weeks later, it was only 6whp over stock. Was it the exhaust? The intake? I dont know. The information is open for everyone so there is nothing ever hidden. The 25whp gained on the intercooler. I have openly said, we are going to test the car again after the customer has driven around to see if the ecu has made adjustments. Again, this information and testing sessions are open to the public.

[Jack B]

Originally Posted by Red Devil Simplistically speaking, there is zero need for an exhaust system on a turbocharged engine to optimize power. Even 1psi of backpressure anywhere in the powerband is too much. IMO, the whole issue of maintaining velocity/240ft per sec, etc...is negated in this forced induction application. I struggle to find any example/condition where removing backpressure will add lag. Removing back pressure - in the turboback - will both reduce lag, and possibly increase operating range. Or I'm reading you wrong?????? The topic was post-turbo exhausts...if you're talking about opening or restricting flow in the manifold pre-turbo or changing the exhaust A/R, than I'd agree with your statements above.

I agree 99%, but, you are talking about a DI engine that relies (to some degree) on scavenging by the exhaust - so your statement might have to be rethought.

[Jack B]

Originally Posted by Red Devil Well, that's a question of the wastegate being electronically controlled and opening sooner than it should, etc...to control torque/power, along with possible timing adjustments by the PCM. At the moment, this discussion regarding optimizing the GXP may be futile. But when someone cracks the PCM and you guys have full control and can alter the wastegate and timing, this will become a very real factor.

Red Devil:

believe me I am not picking on you, but, the timimg issue is not there. These engines use the burn rate at WOT to adjust the combustion timing process. They only run 12-13% at WOT, that is commanded, therefore, what the factory dialed in.