Do cats rob power?
#11
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From: Denmark and hopefully some place nice
#13
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From: Denmark and hopefully some place nice
[QUOTE=Ted G;3216155]Well, you can tune around most restrictions and still make good power, but if it is more restricted than it was specced for then you lose power. I bet your little German toy makes all kinds of power with cats on it 
A friend of mine who is a mechanic, told me that, when they tried to remove cat's on modern cars, to increase performance, it would work the other way, and they could not tune it to perform better. This was on Audi's, so not really boat related, so therefore my uncertanty, about the same issue on the V8's from merc.

A friend of mine who is a mechanic, told me that, when they tried to remove cat's on modern cars, to increase performance, it would work the other way, and they could not tune it to perform better. This was on Audi's, so not really boat related, so therefore my uncertanty, about the same issue on the V8's from merc.
#14
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From: San Diego
A friend of mine who is a mechanic, told me that, when they tried to remove cat's on modern cars, to increase performance, it would work the other way, and they could not tune it to perform better. This was on Audi's, so not really boat related, so therefore my uncertanty, about the same issue on the V8's from merc.[/QUOTE]
If they were unable to make more power, it was because they were unable to get the tune correct (F/AR ) That's a separate issue from the cats reducing flow.
Darrell.
If they were unable to make more power, it was because they were unable to get the tune correct (F/AR ) That's a separate issue from the cats reducing flow.
Darrell.
#15
Your right but my guess is instead of 520 those Audi krauts would of gotten 650 out of that Italian skirted kraut car if the cats did not need to be there!!!
#16
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From: Denmark and hopefully some place nice
[/QUOTE]If they were unable to make more power, it was because they were unable to get the tune correct (F/AR ) That's a separate issue from the cats reducing flow.
Darrell.[/QUOTE]
I know what your saying. But from what I understood, it was rather complicated. I think the thing is, that the entire engine is build to work with the cat's, and because of that, it can't work right without. So unless you make internal mods, and then do the removal and dyno tuning, it's no good.
I'm not a mechanic, but I'm allways eager to learn about this stuff.
Keep it coming
Darrell.[/QUOTE]
I know what your saying. But from what I understood, it was rather complicated. I think the thing is, that the entire engine is build to work with the cat's, and because of that, it can't work right without. So unless you make internal mods, and then do the removal and dyno tuning, it's no good.
I'm not a mechanic, but I'm allways eager to learn about this stuff.
Keep it coming
#18
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From: San Diego
If they were unable to make more power, it was because they were unable to get the tune correct (F/AR ) That's a separate issue from the cats reducing flow.
Darrell.[/QUOTE]
I know what your saying. But from what I understood, it was rather complicated. I think the thing is, that the entire engine is build to work with the cat's, and because of that, it can't work right without. So unless you make internal mods, and then do the removal and dyno tuning, it's no good.
I'm not a mechanic, but I'm allways eager to learn about this stuff.
Keep it coming
[/QUOTE]
I'd agree. A modern high performance engine is certainly tuned for the cats. They don't leave much on the table in street trim. If ya take a look at some of the one make sports car races(Porsche Cup for instance) those guys are able to get quite a few extra ponies by a simple de cat, and efi tuning. It all comes down to the EFI system being able to make enough adjustment to take advantage of the extra exhaust flow.
Darrell.
Darrell.[/QUOTE]
I know what your saying. But from what I understood, it was rather complicated. I think the thing is, that the entire engine is build to work with the cat's, and because of that, it can't work right without. So unless you make internal mods, and then do the removal and dyno tuning, it's no good.
I'm not a mechanic, but I'm allways eager to learn about this stuff.
Keep it coming
[/QUOTE]I'd agree. A modern high performance engine is certainly tuned for the cats. They don't leave much on the table in street trim. If ya take a look at some of the one make sports car races(Porsche Cup for instance) those guys are able to get quite a few extra ponies by a simple de cat, and efi tuning. It all comes down to the EFI system being able to make enough adjustment to take advantage of the extra exhaust flow.
Darrell.




