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Originally Posted by Griff
(Post 3216125)
496's don't have cats. You can put headers on them.b
Just the new 502's have cats. Last I looked at mercs web site, I'm pretty sure I saw them with cat's. I think they offered them from 2009, but I could be wrong. |
Originally Posted by GLH
(Post 3215986)
Any form of restriction however small robs power.
I'm right there with ya. Having seen dyno runs of Highflow cats VS test pipes, the test pipes won out every time. Darrell. |
[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 :evilb:
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.[/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. |
Originally Posted by Ted G
(Post 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
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[/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 :ernaehrung004: |
A-farkin-men!
This damn plane better take off. I am in need of booze soon!!!!! Fog at 436 pm.... Only in this sh!tpit.... JFK!!!! Wow number 27 for departure!!!! |
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 :ernaehrung004:[/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. |
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