Main cat removal pros and cons

[Meatball]

Whats the pros and cons of removing the main cat??

Already removed pre cats and centre box (straight through pipes)

Any power gains or is it just about noise?

[blitzracing]

Its about geeting an MOT. You need one !!

[Meatball]

blitzracing said:

Its about geeting an MOT. You need one !!

Dont need an MOT ive already got one

Come on folks enough of you have done this mod, apart from the obvious why remove it..?.

[clive f]

it you want more bhp with the extra noise then go for it, if you don` t like frightening people, continously driving through tunnels and narrow streets with close buildings either side, and always driving with your window down or roof off listening to it pop an bang on the overrun, then its not for you.

[Meatball]

clive f said:

it you want more bhp with the extra noise then go for it, if you don` t like frightening people, continously driving through tunnels and narrow streets with close buildings either side, and always driving with your window down or roof off listening to it pop an bang on the overrun, then its not for you.

Clive, Is it worth much bhp..? and when will those manifolds your working on be available and how ££££££
cheers Ben

[raceboy]

Well the pros for me were the main and pre cats were knackered so they had to come out, that was about 5 years ago now, can't say I've noticed a great deal of performance gains but then I've not really done any back to back testing, and now it's running straight through pipes as well the noise is a little loud and the flames can be a little worrying to those behind.

[Meatball]

S4it mines a little too loud as it is

[Vixpy1]

Pros?

Watch the vid on myvids on my profile

Cons?

Can you speak up a bit..

[Meatball]

What about the tune resistor thingy?
where can i get one and were does it go?

[clive f]

Meatball said:

What about the tune resistor thingy?
where can i get one and were does it go?

YHM.

on the dyno, a full decat gave 15 hp over the standard set up, and 15ftlbs of torque, using my own pipes of course.

[Pupp]

Meatball said:

What about the tune resistor thingy?
where can i get one and were does it go?

Stangely, they seem to work best decatted with the cat resistor left in

[blitzracing]

Meatball said:

What about the tune resistor thingy?
where can i get one and were does it go?

You can change the resistor thingy if you want, but its likely switch to the non catalyst Range Rover Map that runs seriously lean higher up the rev band, and is a definate no no for a TVR.(you might only want to consider this only to overcome the cars snatching problems with an additional variable fuel pressure - not otherwise) Better off sticking to the catalyst fuel map with all its mixture control, plus it all goes open loop when you boot it anyway, so you dont loose out on ultimate BHP.

[Meatball]

Clive suggests fitting an adjustable resistor as per his website and blitzracing say`s its not a good idea.
i dont doubt you both know what your talking about but whos right???

[clive f]

some people use it, some don`t, as blitzracing says, it only affects things under 3000rpm anyway, I had mine checked whilst running on a dyno and it worked fine on the green tune, rather than the white cat tune resistor.
but like most things tvr, they all seem a little different.

[blitzracing]

You can make the tune resistor switchable, if you want to change maps for experment and compare the fueling back to back, nice and easy, just throw the switch. (It does make the ECU produce an error code, but it still switches OK). If you run the green tune resistor (non cat), with catalysts, you loose all the lambda control that keeps the cat's at best performance, and they will fail in a shorter period.This normally means the matrix in the catalyst overheats and can melt, blocking the exhaust. If the CO adjustment is not spot on, that could be a very short time untill cat' death. As the ECU contains 5 fuel maps in total, you dont really know what the exact effect of switching to another map will be, unless you can speak to the origional person who did the remapping, and find out if the non cat' map is modified for maximum performance. The Range Rover non cat map certainly is not, its around 12 bhp down on the 3.9 TVR catalyst map on a fairly standard engine.

Mark

[clive f]

mark, a little confused, the fuel resistor swith is for decatted cars, so no worries on messing up the cat, its no longer present!

[blitzracing]

Your OK then, I was just giving the details of the effect, should people think simply switching to the green tune resistor will suddenly release extra horsepower.

Mark