zero hp gain
#26
Wait! so you removed the cats, but didn't advance the timing? i thought you were having it dyno tuned? if you were just removing the cats without advancing the timing, then there is your problem...
#27
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2003 C32 AMG BLACK
wait, what? sue someone for selling things legal to make because they CAN be used illegally? Let's get together and sue wrigley while we're at it.
But I agree with your main point... I can understand why the car would not make more power.. the headers are restricting the hell out of the engine already... so a small amount of exhaust moving at very high speeds aren't affected at all by the cats because there isn't enough of it moving at one time.
But I agree with your main point... I can understand why the car would not make more power.. the headers are restricting the hell out of the engine already... so a small amount of exhaust moving at very high speeds aren't affected at all by the cats because there isn't enough of it moving at one time.
The cats are not a bottle neck with stock tuned ecu (or even a car win an ecu upgrade. Now if you were to buy a set of kleemann V8 headers that have a collector chopped off and closed off (they will make them for a V6k) and run no cats you will see a HUGE incrase in power.
Kleemann runs car without the first set of cats and without the cats you can advacne the timing a great deal and see a very nice increase in power. The ECU's designed to run with the cats do not advance the timing enough to see any real increase in power by taking out the cats.
Now yes it is not legal to run around without cats and at your next smog check they will have to go back on the car (at least the main cats) but buy some headers for 3-4k and see maybe a 45 hp increase in power.
Now I really dont know how kleemann gets away with this since any of us could call the EPA and get them shut down and fined up the rear end for selling parts that are known to going on cars for street use without the first set of cats.
Kleemann runs car without the first set of cats and without the cats you can advacne the timing a great deal and see a very nice increase in power. The ECU's designed to run with the cats do not advance the timing enough to see any real increase in power by taking out the cats.
Now yes it is not legal to run around without cats and at your next smog check they will have to go back on the car (at least the main cats) but buy some headers for 3-4k and see maybe a 45 hp increase in power.
Now I really dont know how kleemann gets away with this since any of us could call the EPA and get them shut down and fined up the rear end for selling parts that are known to going on cars for street use without the first set of cats.
#28
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If you look at my signature, you'll see that I already have headers on the car
#29
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We spoke with Kleeman before we got started. My ECU is currently tuned for the mods I have minus the cat removal. I was originally going to switch over to a custom Kleeman ECU flash because they can remove the CE light for no cat, and also to get a better tuned map. Once we saw that the spacers were enough to prevent the CE light from coming on, we spoke with Kleeman again, and they said that I wouldn't really gain anything by switching to their ECU. My AFR is still on target.
#30
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So are the primaries back on now? If so how's the car running with just the secondaries off? Oh your getting me worried like I should get my secondaries put back on. When you fine out the numbers with just the secondaries off please post them up. I hope there is no torque loss.
#31
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But I agree with your main point... I can understand why the car would not make more power.. the headers are restricting the hell out of the engine already... so a small amount of exhaust moving at very high speeds aren't affected at all by the cats because there isn't enough of it moving at one time.
#32
The cats were removed, then the car was driven around to let the car adjust, then it was dynoed again. The ECU's ignition mapping was not changed.
We spoke with Kleeman before we got started. My ECU is currently tuned for the mods I have minus the cat removal. I was originally going to switch over to a custom Kleeman ECU flash because they can remove the CE light for no cat, and also to get a better tuned map. Once we saw that the spacers were enough to prevent the CE light from coming on, we spoke with Kleeman again, and they said that I wouldn't really gain anything by switching to their ECU. My AFR is still on target.
We spoke with Kleeman before we got started. My ECU is currently tuned for the mods I have minus the cat removal. I was originally going to switch over to a custom Kleeman ECU flash because they can remove the CE light for no cat, and also to get a better tuned map. Once we saw that the spacers were enough to prevent the CE light from coming on, we spoke with Kleeman again, and they said that I wouldn't really gain anything by switching to their ECU. My AFR is still on target.
then one of two things is happening with kleeman:
1. either they don't really have complete control over the timing and fuel in the ecu...
2. or they don't really know what they are doing or are not willing to go through the process of actually taking the time to get it right...
it is common practice among tuners that are experienced to advance the timing about 4 degrees as a starting point when removing cats, then working from there...
#34
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then one of two things is happening with kleeman:
1. either they don't really have complete control over the timing and fuel in the ecu...
2. or they don't really know what they are doing or are not willing to go through the process of actually taking the time to get it right...
it is common practice among tuners that are experienced to advance the timing about 4 degrees as a starting point when removing cats, then working from there...
1. either they don't really have complete control over the timing and fuel in the ecu...
2. or they don't really know what they are doing or are not willing to go through the process of actually taking the time to get it right...
it is common practice among tuners that are experienced to advance the timing about 4 degrees as a starting point when removing cats, then working from there...
Last edited by jgsx; 10-06-2006 at 03:08 PM.
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2006 BMW X5 4.8is and 2005 C55 AMG
The primaries are going back on today or tomorrow. I'm going to leave the secondaries off for a while, and make sure that the car is behaving, then do another 93 octane pull. After that, I'm gonna fill up on 100, drive around for a while, then do yet another pull to see if that makes any difference
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2006 BMW X5 4.8is and 2005 C55 AMG
Well I'm not sure. I personally didn't speak with Kleeman. I had several conversations with Powerchip, and after speaking with them, I will never buy any of their products again. The rep that I spoke with didn't seem to know the basics of engine managment. My shop spoke with powerchip after I did and go the same impression. My shop then spoke with Kleeman a couple times, and at least they were able to help me (The original conversations were about removing the CE light for no cats).
#37
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1FASTC32, another thing that should be noted is that most people that remove secondary or primary+secondary cats do NOT get a custom tuned ECU after doing it. People add headers and don't touch the ECU and still see large gains, so I was hoping to see some gains from the more free flowing exhaust. I did this experiment just to see if removing the cats was an easy way to gain power.
If this data is correct, it would also suggest that putting a larger/more free flowing exhaust on the vehicle would not produce more power (which has pretty much been accepted by everyone).
My ECU has the stage 2 map, so I'm sure that the ignition is already advanced beyond stock. I agree with you that it could probably be advanced more, and I would see bigger gains after doing that.
If this data is correct, it would also suggest that putting a larger/more free flowing exhaust on the vehicle would not produce more power (which has pretty much been accepted by everyone).
My ECU has the stage 2 map, so I'm sure that the ignition is already advanced beyond stock. I agree with you that it could probably be advanced more, and I would see bigger gains after doing that.
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#39
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Hey since your going to be doing all these dyno's why don't you test out some different air filters, so we can see the difference k&n vs. stock. Maybe get some greens or BMC's which are suppost to be better then k&n to see if they really are. You could also do a run without filters to see how much gain there is.
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Where are you getting this 45hp number from? Is this an up in the air 'ohhhh, you'll gain abouuuuut, lets saaay, 45hp' guess? That kind of talk isn't worth anything. Do you realize what a huge gain 45 hp is? Just by switching my current headers and no cat system to the special Kleeman headers and advancing the timeing on pump gas I'll gain 45 up!? Don't spread such nonsense
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2006 BMW X5 4.8is and 2005 C55 AMG
If you still have the stock ones you could still do the dyno with stock vs. k&n vs. no filters.
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S600TT, R350
To get more benefit from removing primary converters you would need to make a long tube header. In the end stock exhaust port and cam timing is the ultimate limitation of how much of a restriction the converter will be.
How power did you put down on the dyno?
How power did you put down on the dyno?
#43
Well I'm not sure. I personally didn't speak with Kleeman. I had several conversations with Powerchip, and after speaking with them, I will never buy any of their products again. The rep that I spoke with didn't seem to know the basics of engine managment. My shop spoke with powerchip after I did and go the same impression. My shop then spoke with Kleeman a couple times, and at least they were able to help me (The original conversations were about removing the CE light for no cats).
interesting...thanks for the info
#44
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It put down 312whp. Before eveyone jumps on how low of a number that is, the pulls were done on a Dyno Dynamics dyno, which output significantly lower numbers than a Dynojet. Yes, I will be doing a pull on a Dynojet so that I have a number to compare with others.
EDIT: The 312whp was with all 4 cats on
Last edited by jgsx; 10-06-2006 at 08:12 PM.
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S600TT, R350
It put down 312whp
Heads and cams are the next step. There is really no other way on the 91 gas. More boost will only hurt the car.
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Audi C7.5 S6
Now this is an interesting quote:
http://www.amgpower.com/community/viewtopic.php?t=2076
axsaltc32
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"ALso, re: Kleemann, cory did mention evosport headers but says he isn't convinced with posted gains as oem down pipes are used which are pretty small."
I know the evosport header make power, according to the dyno sheets, but the the down pipes may be limiting some also?
If the down pipes are a limiting factor, before geting to the cat, then removing the cat does not help much. In the S4, the downpipe/cat upgrade improves flow a lot.
http://www.amgpower.com/community/viewtopic.php?t=2076
axsaltc32
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"ALso, re: Kleemann, cory did mention evosport headers but says he isn't convinced with posted gains as oem down pipes are used which are pretty small."
I know the evosport header make power, according to the dyno sheets, but the the down pipes may be limiting some also?
If the down pipes are a limiting factor, before geting to the cat, then removing the cat does not help much. In the S4, the downpipe/cat upgrade improves flow a lot.
#47
Now this is an interesting quote:
http://www.amgpower.com/community/viewtopic.php?t=2076
axsaltc32
AMG Enthusiast
"ALso, re: Kleemann, cory did mention evosport headers but says he isn't convinced with posted gains as oem down pipes are used which are pretty small."
I know the evosport header make power, according to the dyno sheets, but the the down pipes may be limiting some also?
If the down pipes are a limiting factor, before geting to the cat, then removing the cat does not help much. In the S4, the downpipe/cat upgrade improves flow a lot.
http://www.amgpower.com/community/viewtopic.php?t=2076
axsaltc32
AMG Enthusiast
"ALso, re: Kleemann, cory did mention evosport headers but says he isn't convinced with posted gains as oem down pipes are used which are pretty small."
I know the evosport header make power, according to the dyno sheets, but the the down pipes may be limiting some also?
If the down pipes are a limiting factor, before geting to the cat, then removing the cat does not help much. In the S4, the downpipe/cat upgrade improves flow a lot.
why would they post something that they can't back up? Vadim, can you shed any light on this subject? anyone else have the evoport headers? this is what i am planning on getting mainly because the cost is astronomical on any of the other companies...
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E36M3 race car/Ferrari F355 GTS/1973 Mini 1275GT/Fiat Abarth/ML63/SLK55
interesting thread.
here's my experience.
in an effort to produce more exhaust noise as rpm feedback for my track driving I decided to "vent" the stock exhaust. i got to 16mm bolts/nuts from home depot. the bolts were cut short so that when threaded into nut they were fully enclosed. i then had the nuts welded into the outside of piping of stock exhaust on the bend before the muffler. intent was to remove the bolts at track hence allowing unmuffled gas/sound to escape. the nuts do not protrude into the exhaust piping so there is no reduction in flow through system.
results.
yes louder (actually nice) but not loud enough to overcome wind noise at speed. still; i am able to hear rpms when cornering.
power! yes more power. with the full thermo insulated sl55 intake there is a definite increase in midrange power. the gain seem synergistic vs intake/ exhaust. seat of pants 15-20hp??
my plan is to insert 4 more bolts into exhaust making it evem less restrictive. this is almost like a supertrapp system.
i guess the inference here is that the stock exhaust is restrictive. maybe the cats do flow well but this is the choking point???.
I would not recommend venting the exhust in this manner for everyday driving as hot gas will be percolating upwards around the rear of car (gas tank). not an issue at 120 mph tho!
here's my experience.
in an effort to produce more exhaust noise as rpm feedback for my track driving I decided to "vent" the stock exhaust. i got to 16mm bolts/nuts from home depot. the bolts were cut short so that when threaded into nut they were fully enclosed. i then had the nuts welded into the outside of piping of stock exhaust on the bend before the muffler. intent was to remove the bolts at track hence allowing unmuffled gas/sound to escape. the nuts do not protrude into the exhaust piping so there is no reduction in flow through system.
results.
yes louder (actually nice) but not loud enough to overcome wind noise at speed. still; i am able to hear rpms when cornering.
power! yes more power. with the full thermo insulated sl55 intake there is a definite increase in midrange power. the gain seem synergistic vs intake/ exhaust. seat of pants 15-20hp??
my plan is to insert 4 more bolts into exhaust making it evem less restrictive. this is almost like a supertrapp system.
i guess the inference here is that the stock exhaust is restrictive. maybe the cats do flow well but this is the choking point???.
I would not recommend venting the exhust in this manner for everyday driving as hot gas will be percolating upwards around the rear of car (gas tank). not an issue at 120 mph tho!
#49
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I just picked up the car. The primary cats are back on, but the secondaries are still off. Just as a reminder, the car sounded AWFUL with all the cats off. The car sounds so much better now, but it still sounds a little like a riced out Civic under some WOT conditions. I'm probably going to put the secondaries back on, but I want my car back for now
#50
this is what i am worried about...i don't want the car to be loud at all, i have been down that road with other cars and i enjoy the fact that i can drive this car everyday and not worry about it being too loud or annoying the crap out of me...i guess i want my cake and eat it too, but that is why i bought an AMG...
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