Aftermarket Exhaust

zorroespanol

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The ******* contest is getting old.

What ******* contest? This is one of the most civilized discussions we've had here in some time.

If you want to see ******* contests read the old threads.

PA Viper, lets see what you know about exhausts and how an engine works. Please enlighten us with your vast knowledge.

Cheers!
 

PaViper

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The ******* contest is getting old.

What ******* contest? This is one of the most civilized discussions we've had here in some time.

If you want to see ******* contests read the old threads.

PA Viper, lets see what you know about exhausts and how an engine works. Please enlighten us with your vast knowledge.

Cheers!

Lighten up, I was just kidding, but you have to admit you have been involved in some marathon threads :)
 

zorroespanol

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The ******* contest is getting old.

What ******* contest? This is one of the most civilized discussions we've had here in some time.

If you want to see ******* contests read the old threads.

PA Viper, lets see what you know about exhausts and how an engine works. Please enlighten us with your vast knowledge.

Cheers!

Lighten up, I was just kidding, but you have to admit you have been involved in some marathon threads :)

Jerks have an affinity for me... DevilDog even proposed to me once.
 

INSOMNIAC

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Actually, there is good information here about how running catless and/or with high flow headers affects the car, a/f ratio, tune, etc.

I still think "Any otherwise stock SRT-10 with cat deletion or high flow headers will run rich unless the ECU is tuned."

I might be wrong but I'll need some dyno sheets to convince me.

Cheers.
 

zorroespanol

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Actually, there is good information here about how running catless and/or with high flow headers affects the car, a/f ratio, tune, etc.

I still think "Any otherwise stock SRT-10 with cat deletion or high flow headers will run rich unless the ECU is tuned."

I might be wrong but I'll need some dyno sheets to convince me.

Cheers.

Ok, last post here I promise! (will try)

Exhibit A - Stock SRT dyno results X A/F mixture
Exhibit B - Stock SRT minus cats, plus you put a POTATO in the exhaust pipe.

since the dyno sample sensor is placed at the exhaust tip, exhibit B WILL BE LEANER. Why?? because even with less flow because of the potato :) the cats are not there to burn the excess fuel, therefore there will be more oxygen which means less burned fuel, which the computer assumes as "leaner" but the truth is that the amount of fuel and air dumped in/out of the combustion chamber was the same on both cases.

If this is not clear, I give up!!!
 

INSOMNIAC

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The higher flow due to not having the 4 flow-cutting cats and/or high flow headers will lean you out

Actually all this time I’ve agreed with half of what you said.
I am saying that the higher exhaust flow due to eliminating the cats and/or installing high flow headers will lean the engine and therefore cause an increase in the a/f ratio.
I guess we are on the same page here.


the ECU will see this and counteract, causing the car to run rich.

But where I differ from you is that once the stock ECU sees the leaning in the a/f, it counteracts and dumps fuel, making the car run rich. The ECU constantly interacts to make the car run presumably better and that’s a part of the ECU relearn process.

Jut like when you install a K&N intake, you will see a difference on how the car drives after the relearn process of the ECU and couple hundred miles vs the second after you install the intake.

Hmmmmm ? :D :D
 

SD SRT Coupe

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I am an expert on nothing, however, my story may be useful. One week ago I took my stock SRT-10 to West Coast Vipers (in Temecula) and had 1 3/ inch long tube headers, with highflow cats, into 3 inch corsa track exhaust installed (along with Green filters). The car was then dynoed with no tuning. According to John (the shop owner) the air/fule ratio was very good without tuning. He said that he could likely tune maybe 10 more hp out of it. It put 495hp to the wheels. He said it was not running rich (with the stock tune).
 

twinturbo3150

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Belanger full system...........incredible sound like a Viper should sound like. A tad costly over the other systems.

Patrick

what does a complete belanger full system cost?
 

Viper X

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Bob K,

FYI, the mopar race controller deactivates the "code throwing" portion of the computer's program, therefore, no codes.

If you think about it, codes don't make much sense on a race track or in a race controller.

Dan
 

1DumpedViper

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I am an expert on nothing, however, my story may be useful. One week ago I took my stock SRT-10 to West Coast Vipers (in Temecula) and had 1 3/ inch long tube headers, with highflow cats, into 3 inch corsa track exhaust installed (along with Green filters). The car was then dynoed with no tuning. According to John (the shop owner) the air/fule ratio was very good without tuning. He said that he could likely tune maybe 10 more hp out of it. It put 495hp to the wheels. He said it was not running rich (with the stock tune).

I'm not an expert but I dont see how thats possible. You completely changed the air coming in and out of the motor. I picked up over 27 rwhp with just a tune from DC. I would call Dan Cragin. My car ran SOO much better after the tune and I could definatley feel the difference. Just an FYI.
 

SD SRT Coupe

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I'm not an expert but I dont see how thats possible. You completely changed the air coming in and out of the motor. I picked up over 27 rwhp with just a tune from DC. I would call Dan Cragin. My car ran SOO much better after the tune and I could definatley feel the difference. Just an FYI.

[/QUOTE]

I don't know either, however, it does not make sense for John to lie to me about this since he would make more money by telling me a tune is worth a lot so I would buy one. I also think it may have something to do with the the fact that SRT-10s run rich stock (to protect the motor). When the exhaust is opened up then it leans them out since the car now pulls more air through (but this is just my uneducated guess). I also have the air/fule graphs from the dyno and for those of you who know what it should read, please let me know if the follwing numbers sound good:
at 3000 its 15
at 3500 its 14
at 4000 its 13
at 4500 its 12
at 5000 its 12
at 5500 its 12
at 6000 its 12
 

Viper X

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Back when my SRT-10 was stock, it made 500 rwhp with B & B stepped headers, high flow cats, K & N's and the factory tune, so your results sound about like mine.

Your air / fuel ratio seems a bit rich for peak performance as the engine speeds up but John would know.

Dan
 

SD SRT Coupe

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Back when my SRT-10 was stock, it made 500 rwhp with B & B stepped headers, high flow cats, K & N's and the factory tune, so your results sound about like mine.

Your air / fuel ratio seems a bit rich for peak performance as the engine speeds up but John would know.

Dan

My headers are not stepped. I hear (from John) that the stepped headers make slightly more power than mine. So this all sounds about right. Now how do we explain my car not running rich?
 
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