DIY EXHAUST?

[TUNGSTEN GREY]

Hi,another new member here,great to see the '40 getting some recognition at last!I've got an 89 3.6 with a manual box-great fun but still sounds like tumble drier!I expect to get some fruity straight 6 burble i'd have to remove the back boxes,has any one done a diy silencer substitute or know of a "budget" option?Might even release a few horses too,cheers!

[xjr-ant]

http://www.jagweb.com/aj6eng/exhaust3.php

That's an option, i have them on my XJR but there really quite loud it's surprising... back boxes don't really seem to do anything on mine seems the centre boxes are the ones to eliminate for any type of gain.

[xj12-rob]

have a look at AJ6 enginneering, they do all sorts of exhaust upgrades for Jaguars

Ant is correct, ditch the centre box first, I've done this on one of my 300 R's and thrown the centre cat in the bin, liberates a few more horses, add a couple of Mina back boxes and Robert is your mothers brother!!, sounds good goes well

[majestic]

Got rid of the mid boxes via AJ6 engineering also on my V12.

But you can still sneak up on old ladies crossing the road very quietly and just blip the throttle and watch em move into supergran mode.

[Jaguarsport]

I'm planning on a few exhaust modifications too. I've got a non pre cat Jaguarsport XJR down pipe and a non cat centre section to fit, thinking of also getting the centre silencer substitute pipes.

[XJRTwinTurbo]

i too am going to be doing a diy exhaust system.

my xjr turbo has a bluddy great hole in the downpipe so ive gotta weld that up and i want it to roar so im possibly going to remove both boxes.

i had a quote of £700 for a complete stainless steel system from p d gough, when i can afford it im going to get it.

[Equinoxstudios]

Hi All!

I've looked at the options AJ6 Engineering have to offer and their tuned TT Extraction kit looks good to me except I've got nowhere to put my oxygen sensor.

I've got a late one of course and have two downpipe cats as well as two more underfloor cats. The oxygen sensor screws into the downpipe cat assembly into a hole just forward of the flare that joins it to the underfloor cat assembly.

Any idea if the non-cat underfloor pipe (one pipe to a short 1in-2out silencer) is the same length as the underfloor cats assembly?

My plan would be to keep the downpipe cats assembly for the sake of the oxygen sensor, use the standard Jaguar catless underfloor pipe, replace the two centre silencers with the pipe replacements from AJ6 Engineering and keep the standard back boxes.

So will it all fit?

[iainm9438]

yes, i am also interested to know if the 2 centre cats can be ditched with no MOT worries?
one of mine has just started to rattle a bit and if i can just remove them and replace them with a non- centre cat exhaust section i will.
will the downpipe cats be sufficient for emissions?
i want to keep the noise down so i will keep all of the rear silencers but just want to cure said rattle.
any ideas?

[david]

Hi All!

I've looked at the options AJ6 Engineering have to offer and their tuned TT Extraction kit looks good to me except I've got nowhere to put my oxygen sensor.

I've got a late one of course and have two downpipe cats as well as two more underfloor cats. The oxygen sensor screws into the downpipe cat assembly into a hole just forward of the flare that joins it to the underfloor cat assembly.

Any idea if the non-cat underfloor pipe (one pipe to a short 1in-2out silencer) is the same length as the underfloor cats assembly?

My plan would be to keep the downpipe cats assembly for the sake of the oxygen sensor, use the standard Jaguar catless underfloor pipe, replace the two centre silencers with the pipe replacements from AJ6 Engineering and keep the standard back boxes.

So will it all fit?

AJ6's performance gains appeal to me as well since my 3.2 does lack torque. One thing I haven't grasped is the legal situation if a TT extractor is fitted, since it involves removing all the catalysts, not just the ones under the floor. AJ6 claim this is legal and that provided the emissions are within prescribed limits, the car will pass an MOT.

The AJ6 website says: Exhaust Emissions. Contrary to widespread belief the UK MOT does not require a catalyst to be present, only that the car does not exceed the maximum gaseous emission levels specified for its year, which most cars will easily achieve without need of a catalyst. As an example the purpose of the Lambda feedback system of any modern catalyst car is to control the fueling so that the %age of CO in the exhaust before the catalyst is never more than about 0.1%. If it rises above this level the presence of a catalyst will reduce it but it is actually a symptom of a fault that is likely to eventually destroy the catalyst. As the UK pass level is either 0.2% or 0.3%, depending on the circumstances, the absence of the catalyst will not prevent a healthy car from satisfying the test. Much the same applies in other parts of the World including the USA although if a check includes a mandatory visual catalyst inspection then clearly the situation is slightly different.

In the long term (after my bodywork has been fixed and one or two other things have been attended to and my finances have recovered from all this) I would like to improve the performance of my 3.2. It isn't slow like some suggest and is a lovely smooth and free revving engine, but really if I'm honest, I could use some more horsepower. Their stuff is expensive, but I note AJ6 claim 35bhp and 13% more torque from their "plus torque" conversion, together with the TT exhaust would make my 3.2 develop more power than a 4 litre! Of course you could just fit a 4 litre for a lot less money, but that would be easy...

yes, i am also interested to know if the 2 centre cats can be ditched with no MOT worries?
one of mine has just started to rattle a bit and if i can just remove them and replace them with a non- centre cat exhaust section i will.
will the downpipe cats be sufficient for emissions?
i want to keep the noise down so i will keep all of the rear silencers but just want to cure said rattle.
any ideas?

If the 2 centre cats are removed there are still the 2 downpipe cats left - so there will be no problem for the MOT. I struggle to see how the TT exhaust complies though. I would want mine to stay quiet as well.

[iainm9438]

OK, thanks for that.

as far as the power difference between the 3.2 and 4 ltr goes..... i drove my mates 4 the yesterday and the only real difference i could see was it seemed to have slightly better throttle response and the gear changes were smoother.
it could be that i have a perky 3.2 or he has a knackered 4? (more likely as it has done 225 thou):?
i can't see me rushing out to buy a 4 ltr because it has stacks more power