Just Dyno'ed my C55
Last edited by hooleyboy; May 6, 2008 at 10:25 PM.
ya, the two ways to tune are pulling the ecu and flashing (10 minutes) or plugging into the diag port (1 hour).
Will be cool to see what you put down after your tune!
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Last edited by hooleyboy; May 7, 2008 at 03:19 AM.
The Best of Mercedes & AMG
^^^ this just does not make sense to me?
Headers are designed to be free flowing and relieve back pressure. Back pressure robs you of HP. Exhaust systems rob you of HP thats why drag racers disconnect there exhaust...Example.... "Let exhaust exit more easily - If air resistance or back-pressure makes it hard for exhaust to exit a cylinder, it robs the engine of power. If the exhaust pipe is too small or the muffler has a lot of air resistance then this can cause back-pressure. High-performance exhaust systems use headers, big tail pipes and free-flowing mufflers to eliminate back-pressure in the exhaust system." source below
http://auto.howstuffworks.com/question395.htm
You want air in and out as fast as you can. with no resistance or "Back pressure" at 2700RPM's I was already Making 300lbs of torque. I was able to sustain that to around 4700RPM's with a slight drop off at 4700-5500RPM's.
I dont want to come off sounding like you dont know what your talking about (as sometimes text posts can) we just disagree on a topic that has people on both sides of the fence.
Anyway I dont feel having a res-delete would have gotten me power that would have put me into the 300's for HP. the only thing that would have gotten me more power was if i was on a Dyno-jet and having HP added for reasons that few understand. I bet I would have been in the 310 -320hp on a dyno-jet.... from what i hear.
Headers are designed to be free flowing and relieve back pressure. Back pressure robs you of HP. Exhaust systems rob you of HP thats why drag racers disconnect there exhaust...Example.... "Let exhaust exit more easily - If air resistance or back-pressure makes it hard for exhaust to exit a cylinder, it robs the engine of power. If the exhaust pipe is too small or the muffler has a lot of air resistance then this can cause back-pressure. High-performance exhaust systems use headers, big tail pipes and free-flowing mufflers to eliminate back-pressure in the exhaust system." source below
http://auto.howstuffworks.com/question395.htm
You want air in and out as fast as you can. with no resistance or "Back pressure" at 2700RPM's I was already Making 300lbs of torque. I was able to sustain that to around 4700RPM's with a slight drop off at 4700-5500RPM's.
I dont want to come off sounding like you dont know what your talking about (as sometimes text posts can) we just disagree on a topic that has people on both sides of the fence.
Anyway I dont feel having a res-delete would have gotten me power that would have put me into the 300's for HP. the only thing that would have gotten me more power was if i was on a Dyno-jet and having HP added for reasons that few understand. I bet I would have been in the 310 -320hp on a dyno-jet.... from what i hear.
Drag cars disconnect there exhaust because there always going to be at full throttle since there racing for times.
This is where street cars and race cars are different. I assume your not always going to be driving your c55 at full throttle every time, AMG assumed this as well.
This is why they optimized the exhaust system with the cat and reasonator in mind. They used the back pressure created from the cat and reasonator to add the low to mid end torque.
You see this trick seen on lot of economy cars, hence why there exhaust system is usually around 2''-2.25.
Why do you think there no real aftermarket exhausts for the c32 and c55? Its because the stock exhaust system is already tuned really well from the factory.
Yes a larger exhaust is better for making more power out of a engine when it warrants it...ie FI or a higher end NA Build. If you lose too much back pressure, you can't maintain any kind of velocity through the system, so you lose power.
Going off the logic in your example, switching to a 3'' exhaust system should yield greater power since there's less back pressure robbing the car of its power. In real life, you'll end up losing power on a stock engine.
Just search the threads of other people that deleted there reasontor. They all talk about how they lost some mid to low end torque from stock. I agree the power difference from the reasonator delete probably wouldn't yield 300hp, but you never know. Its really easy to lose power when you mess with a finely tuned optimzed system created by AMG.
Last edited by TemjinX2; May 7, 2008 at 05:10 AM.
Drag cars disconnect there exhaust because there always going to be at full throttle since there racing for times.
This is where street cars and race cars are different. I assume your not always going to be driving your c55 at full throttle every time, AMG assumed this as well.
This is why they optimized the exhaust system with the cat and reasonator in mind. They used the back pressure created from the cat and reasonator to add the low to mid end torque.
You see this trick seen on lot of economy cars, hence why there exhaust system is usually around 2''-2.25.
Why do you think there no real aftermarket exhausts for the c32 and c55? Its because the stock exhaust system is already tuned really well from the factory.
Yes a larger exhaust is better for making more power out of a engine when it warrants it...ie FI or a higher end NA Build. If you lose too much back pressure, you can't maintain any kind of velocity through the system, so you lose power.
Going off the logic in your example, switching to a 3'' exhaust system should yield greater power since there's less back pressure robbing the car of its power. In real life, you'll end up losing power on a stock engine.
Just search the threads of other people that deleted there reasontor. They all talk about how they lost some mid to low end torque from stock. I agree the power difference from the reasonator delete probably wouldn't yield 300hp, but you never know. Its really easy to lose power when you mess with a finely tuned optimzed system created by AMG.
There is too much confusion from what I read between right and wrong. The fact is race cars with a specific purpose are way different than a street car for how the power should be made the best overall way.
Headers are designed to be free flowing and relieve back pressure. Back pressure robs you of HP. Exhaust systems rob you of HP thats why drag racers disconnect there exhaust...Example.... "Let exhaust exit more easily - If air resistance or back-pressure makes it hard for exhaust to exit a cylinder, it robs the engine of power. If the exhaust pipe is too small or the muffler has a lot of air resistance then this can cause back-pressure. High-performance exhaust systems use headers, big tail pipes and free-flowing mufflers to eliminate back-pressure in the exhaust system." source below
http://auto.howstuffworks.com/question395.htm
You want air in and out as fast as you can. with no resistance or "Back pressure" at 2700RPM's I was already Making 300lbs of torque. I was able to sustain that to around 4700RPM's with a slight drop off at 4700-5500RPM's.
I dont want to come off sounding like you dont know what your talking about (as sometimes text posts can) we just disagree on a topic that has people on both sides of the fence.
Anyway I dont feel having a res-delete would have gotten me power that would have put me into the 300's for HP. the only thing that would have gotten me more power was if i was on a Dyno-jet and having HP added for reasons that few understand. I bet I would have been in the 310 -320hp on a dyno-jet.... from what i hear.
https://mbworld.org/forums/showthrea...565&highlight=
I've heard the same sort of stuff about dyno-jet vs. mustang vs. dyno-dynamics, but I think only a couple people on these forums have actually taken their cars to different ones to test the results
dynos can be set up and configured however the operator wants. you input a number of variables and from that comes the calculation that takes into account the rollers. its not about "awd vs 2wd dynos" its about what type of dyno it is and how its set up.
furthermore, backpressure is not some power robbing thief, it is a component of a proper design...removing exhaust backpressure isnt like removing a stain, the more you get out the better off you are, thats not how it works. there is a proper amount of backpressure needed to make optimal power. a car manufacturer will walk the balance between performance and exhaust noise and implement a system in between. could there be benefits to removing a resonator, sure, but to say it hands down makes a difference or doesnt will depend on the application. removing a muffler or resonator does not always result in power gains. in fact for a lot of cars, you'll gain 1-2whp up top for 300 rpm and lose 8-12 ft/lbs 3000 rpm in the midrange. IE, no likey.
dynos can be set up and configured however the operator wants. you input a number of variables and from that comes the calculation that takes into account the rollers. its not about "awd vs 2wd dynos" its about what type of dyno it is and how its set up.
I agree with you on the dyno. Its all up to the operator of the dyno, even when strapping down it can make a difference. About the rwhp those # seem correct. The resonator is a straight pipe with some muffling thing around the inside but does not obstruct the pipe and just quites down the exhuast so there is no (back pressure) to lose. If interested in seeing the inside of it i can post some pics. The headers on this car can get you about 12-16 rwhp & torque so i don't understand why is there so much concern about (back pressure) without some real dyno's to prove you really do lose (hp) or (tq). Btw i have done plenty of dyno runs to see what works and what doesn't and by far the exhuast is the way to go on a C55 i don't know about the rest this is what i have tested. As a matter a fact i don,t even have the primary cats nor the resonator and the car gives me plenty of power with no losses. Hope this helps.
Drag cars disconnect there exhaust because there always going to be at full throttle since there racing for times.
This is where street cars and race cars are different. I assume your not always going to be driving your c55 at full throttle every time, AMG assumed this as well.
This is why they optimized the exhaust system with the cat and reasonator in mind. They used the back pressure created from the cat and reasonator to add the low to mid end torque.
You see this trick seen on lot of economy cars, hence why there exhaust system is usually around 2''-2.25.
Why do you think there no real aftermarket exhausts for the c32 and c55? Its because the stock exhaust system is already tuned really well from the factory.
Yes a larger exhaust is better for making more power out of a engine when it warrants it...ie FI or a higher end NA Build. If you lose too much back pressure, you can't maintain any kind of velocity through the system, so you lose power.
Going off the logic in your example, switching to a 3'' exhaust system should yield greater power since there's less back pressure robbing the car of its power. In real life, you'll end up losing power on a stock engine.
Just search the threads of other people that deleted there reasontor. They all talk about how they lost some mid to low end torque from stock. I agree the power difference from the reasonator delete probably wouldn't yield 300hp, but you never know. Its really easy to lose power when you mess with a finely tuned optimzed system created by AMG.
Your just flat out wrong. I've dyno'd my car about 30 plus times on a dyno-jet with resonator on and off and secondary cats on and off. With the res off it made NO difference, however on one run though it showed a 1.5hp gain, but that means nothing. With the secondary cats off I actually gained 8hp and 12tq, but I put them back on after awhile because I didn't like the sound it made.
As for the dynos- I'm just going from what I heard the majority of the time when I spent an extended amount of time at a speed shop a few summers ago. I also had my turbo s2000 dyno'd at a place that had both an AWD Mustang dyno and a dyno pack. The owner of the facility told me I could have strapped my car on the dyno pack after using the mustang and yielded 30 more hp for bragging rights if I had the time.
I fully agree that how the dyno is set up also has a huge roll in everything. Even how the pull is set up can alter the numbers.
dynos can be set up and configured however the operator wants. you input a number of variables and from that comes the calculation that takes into account the rollers. its not about "awd vs 2wd dynos" its about what type of dyno it is and how its set up.
furthermore, backpressure is not some power robbing thief, it is a component of a proper design...removing exhaust backpressure isnt like removing a stain, the more you get out the better off you are, thats not how it works. there is a proper amount of backpressure needed to make optimal power. a car manufacturer will walk the balance between performance and exhaust noise and implement a system in between. could there be benefits to removing a resonator, sure, but to say it hands down makes a difference or doesnt will depend on the application. removing a muffler or resonator does not always result in power gains. in fact for a lot of cars, you'll gain 1-2whp up top for 300 rpm and lose 8-12 ft/lbs 3000 rpm in the midrange. IE, no likey.
Also what tool/s does one need to install a Tune via Diag. port Guys?
Drag cars disconnect there exhaust because there always going to be at full throttle since there racing for times.
This is where street cars and race cars are different. I assume your not always going to be driving your c55 at full throttle every time, AMG assumed this as well.
This is why they optimized the exhaust system with the cat and reasonator in mind. They used the back pressure created from the cat and reasonator to add the low to mid end torque.
You see this trick seen on lot of economy cars, hence why there exhaust system is usually around 2''-2.25.
Why do you think there no real aftermarket exhausts for the c32 and c55? Its because the stock exhaust system is already tuned really well from the factory.
Yes a larger exhaust is better for making more power out of a engine when it warrants it...ie FI or a higher end NA Build. If you lose too much back pressure, you can't maintain any kind of velocity through the system, so you lose power.
Going off the logic in your example, switching to a 3'' exhaust system should yield greater power since there's less back pressure robbing the car of its power. In real life, you'll end up losing power on a stock engine.
Just search the threads of other people that deleted there reasontor. They all talk about how they lost some mid to low end torque from stock. I agree the power difference from the reasonator delete probably wouldn't yield 300hp, but you never know. Its really easy to lose power when you mess with a finely tuned optimzed system created by AMG.
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