New de cat pipes
Discussion
Ok so I'm on a mission to get the car to ASBO loud, not everyone's taste I know, but I want my road car to sound like my race car!
Picked up the de cat pipes today, but to be honest I was very disappointed with the appearance, so I spent the evening taking out all the burrs on the edges and machine polished them so they look a bit better :-)
Picked up the de cat pipes today, but to be honest I was very disappointed with the appearance, so I spent the evening taking out all the burrs on the edges and machine polished them so they look a bit better :-)
Those arent decats are they, they're just cats with the core knocked out. I can't remember who it was (might have been Clivef) but am pretty sure someone tested act type decats and empty cats and the decats flowed much better, than old cats with the core knocked out.
Edited by m4tti on Thursday 10th October 23:48
Edited by m4tti on Thursday 10th October 23:49
it wasn`t me who did the decat testing, but general rule of thumb in exhaust design, when changing from large pipe diameter to a smaller diameter the transition piece, or cone, needs to be as long as you can get it for smoother flow, 7 to 10 degrees slope is ideal if you have room.
a short cone which will then have steep sides giving an angle of up to 45 degrees is not good.
a short cone which will then have steep sides giving an angle of up to 45 degrees is not good.
You must have some of the worlds best tig welders in Mclaren Special Operations.. surely they could have knocked you out something special 
Im pretty sure if you do a search there were claims that the decat with out remap can cause the engine to run lean.. who knows if this is correct i havent seen any data to substantiate it.
Im pretty sure if you do a search there were claims that the decat with out remap can cause the engine to run lean.. who knows if this is correct i havent seen any data to substantiate it.
Edited by m4tti on Friday 11th October 09:17
threestacks said:
When you say not good, do you mean that my ones could cause some kind of damage ?
In which case would you recommend taking these ones back and getting the cone type?
what I mean is that the flow of the exhaust gases will not be as efficient, the gases will build up as they try to find their way out of the pipe, instead of being gradually guided out by a smooth tapered cone, it wont cause any damage and the ones you have are the same as the catted pipes with the same angle at the back going into the exhaust, you`ll just loose a little bit of bhp.In which case would you recommend taking these ones back and getting the cone type?
Pity I'm not making them any more. The stuff people are selling these days are horrible. They don't even bother to argon back purge them to give a smooth internal finish. I did quite a lot of development work before I started supplying them. Tried all sorts of shapes but we opted for these:
On the rolling road there was no difference between this shape and the longer cone. The longer cone was much more expensive to make so I opted for the one above.
The empty cat cans sound bloody horrible and those in the picture don't even look particularly well made!
On the rolling road there was no difference between this shape and the longer cone. The longer cone was much more expensive to make so I opted for the one above.
The empty cat cans sound bloody horrible and those in the picture don't even look particularly well made!
Well I really appreciate all the feedback. After speaking with NTEL and Edward Quick, I have returned the "de-cat pipes" above and Edward is sending me a pair of his finest conical de-cat pipes
Racing Green were very good in giving me a no quibbles refund, although I seem to have returned them a better finished product than I received in the first place!
Feel better already
Racing Green were very good in giving me a no quibbles refund, although I seem to have returned them a better finished product than I received in the first place!
Feel better already
threestacks said:
Well I really appreciate all the feedback. After speaking with NTEL and Edward Quick, I have returned the "de-cat pipes" above and Edward is sending me a pair of his finest conical de-cat pipes
Racing Green were very good in giving me a no quibbles refund, although I seem to have returned them a better finished product than I received in the first place!
Feel better already
Francis do u have Edwards quicks contact details. I need a pair of these.Racing Green were very good in giving me a no quibbles refund, although I seem to have returned them a better finished product than I received in the first place!
Feel better already
Cheers
Buzz
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