Benefits of decat Y piece
Discussion
I've done some searching and have read 2 different thoughts of the benefits of decatting.
Some say its all about the bigger sound.
Some say it delivers more HP.
Well a Y piece change just for sound isn't something I'm interested in but I'm considering some head and induction work on my car and if a change of Y piece will deliver more power, then I'd be interested.
I'm keen to see/be told of any Dyno difference that just a Y piece change has delivered.
Some say its all about the bigger sound.
Some say it delivers more HP.
Well a Y piece change just for sound isn't something I'm interested in but I'm considering some head and induction work on my car and if a change of Y piece will deliver more power, then I'd be interested.
I'm keen to see/be told of any Dyno difference that just a Y piece change has delivered.
You could always use the freed up space for something else 

King Tubby 1 by pupp777, on Flickr
Another benefit not mentioned above is (much) lower under-bonnet temperatures; suspect I might be about to lose that one....


King Tubby 1 by pupp777, on Flickr
Another benefit not mentioned above is (much) lower under-bonnet temperatures; suspect I might be about to lose that one....
Edited by Pupp on Saturday 9th November 22:33
Pupp said:
You could always use the freed up space for something else 

King Tubby 1 by pupp777, on Flickr
Another benefit not mentioned above is (much) lower under-bonnet temperatures; suspect I might be about to lose that one....
Surely that's just going to be a huge restriction Pupp 

King Tubby 1 by pupp777, on Flickr
Another benefit not mentioned above is (much) lower under-bonnet temperatures; suspect I might be about to lose that one....
Edited by Pupp on Saturday 9th November 22:33

Awesome
If you are short of something to do next Saturday, pop over to Snetterton and come and see at least 6 Chimaeras, a couple of , I suspect a Cerbera or two, and I am not sure what else, in various engine sizes, states of tune and cat/decat and see what you think. Passenger rides will cost you about £20 for the whole day. Its a track day, so bring a helmet if you have one. I may be able to lend you one if you don't have one. They hire them at the track for a tenner.
You will be able to compare yours with ours. At least two of the Chims are 360bhp varieties.....
You will be able to compare yours with ours. At least two of the Chims are 360bhp varieties.....
Karl, your not just about to head down the slippery slop are you? Induction mods, decat and of course to make the best of all this new found power possibly a tornado chip and remap or mega squirt/ emerald? Looks like the wife's Christmas pressie is getting smaller unless she was after something shiney... Like.... a new Y piece for instance?
Bobgriff said:
Karl, your not just about to head down the slippery slop are you? Induction mods, decat and of course to make the best of all this new found power possibly a tornado chip and remap or mega squirt/ emerald? Looks like the wife's Christmas pressie is getting smaller unless she was after something shiney... Like.... a new Y piece for instance?
Rob,I'm toying with the idea of Stage 3 heads, induction kit and Y piece.....
I guess the current map wouldn't cope so would have to consider benefits of Tornado v MS/Emarald.
The engine was rebuilt in March with a stealth cam so I figure that I'm not using it to its full potential with very thing else standard.
It's all window shopping at the moment. My boy £££’s kitty has taken a battering this year but I should be able to syphon a few quid from my annual bonus in February to the Tvr kitty.
300hp from the 450 would be nice.

Edited by A900ss on Sunday 10th November 09:02
K
The remapping will cost you the best part of £1000 with the Lucas 14CUX, so
a) you need to budget for this and
b) you could consider an aftermarket ECU plus mapping, as better, distributor-free, coil pack controlled ignition should give you smoother power delivery and possibly extra BHP.
I budgetted £250 for a new Tornado chip, but it was a best guess map and was wrong, and the only real way to get the Tornado chip correctly mapped is to take it to Mark Adams and have the chip written on the rolling road, which cost me around £700 and half a day's work
The fully sorted aftermarket ECU can cost about £2,100, where for example you give the car to Lloyd Bros and two weeks later it comes back with a compete new CANEMS ECU, loom and coil packs, fully and correctly mapped. The job can be done cheaper, the hardware is only a part of this, but do allow for the cost of an expert to map it for you - its not a job for an amateur.
Alex warned me to go after-market, and I thought I could get away with the £250 chip upgrade. I was wrong, and if I was doing my 4 to 5 litre upgrade again I would take his advice and go for an aftermarket ECU.
Lets have some views fellas. I may be wrong about what causes the need for a re-map, as I am basing my comments on my own upgrade process.
One other point - I spent weeks struggling to get mine sorted, having expected that the hardware was all I needed. I also spent a fair amount on rolling roads, telephone calls, time, energy, trips to see people etc etc. The frustration levels in my house were pretty high throughout April - June. That has to be factored in too - a guaranteed solution delivering a fully working car has to be worth something.
A900ss said:
Rob,
I'm toying with the idea of Stage 3 heads, induction kit and Y piece.....
I guess the current map wouldn't cope so would have to consider benefits of Tornado v MS/Emarald.
The engine was rebuilt in March with a stealth cam so I figure that I'm not using it to its full potential with very thing else standard.
It's all window shopping at the moment. My boy £££’s kitty has taken a battering this year but I should be able to syphon a few quid from my annual bonus in February to the Tvr kitty.
300hp from the 450 would be nice.
The Y piece makes no difference to the map, but the stage three heads etc on the induction side do I believe mean a re-map, and if you end up above 280 bhp you might need bigger injectors (£300) and a bigger AFM (£75)..I'm toying with the idea of Stage 3 heads, induction kit and Y piece.....
I guess the current map wouldn't cope so would have to consider benefits of Tornado v MS/Emarald.
The engine was rebuilt in March with a stealth cam so I figure that I'm not using it to its full potential with very thing else standard.
It's all window shopping at the moment. My boy £££’s kitty has taken a battering this year but I should be able to syphon a few quid from my annual bonus in February to the Tvr kitty.
300hp from the 450 would be nice.

Edited by A900ss on Sunday 10th November 09:02
The remapping will cost you the best part of £1000 with the Lucas 14CUX, so
a) you need to budget for this and
b) you could consider an aftermarket ECU plus mapping, as better, distributor-free, coil pack controlled ignition should give you smoother power delivery and possibly extra BHP.
I budgetted £250 for a new Tornado chip, but it was a best guess map and was wrong, and the only real way to get the Tornado chip correctly mapped is to take it to Mark Adams and have the chip written on the rolling road, which cost me around £700 and half a day's work
The fully sorted aftermarket ECU can cost about £2,100, where for example you give the car to Lloyd Bros and two weeks later it comes back with a compete new CANEMS ECU, loom and coil packs, fully and correctly mapped. The job can be done cheaper, the hardware is only a part of this, but do allow for the cost of an expert to map it for you - its not a job for an amateur.
Alex warned me to go after-market, and I thought I could get away with the £250 chip upgrade. I was wrong, and if I was doing my 4 to 5 litre upgrade again I would take his advice and go for an aftermarket ECU.
Lets have some views fellas. I may be wrong about what causes the need for a re-map, as I am basing my comments on my own upgrade process.
One other point - I spent weeks struggling to get mine sorted, having expected that the hardware was all I needed. I also spent a fair amount on rolling roads, telephone calls, time, energy, trips to see people etc etc. The frustration levels in my house were pretty high throughout April - June. That has to be factored in too - a guaranteed solution delivering a fully working car has to be worth something.
Replacing the original Y piece with one of Clive's decat Y's was pretty much the last major mod to mine. At the same time that we replaced the Y we also removed the silencer box and re-stuffed it, putting it back to 'standard' spec (it had been sleeved). The pre-cats had been removed in 2011. I had this done at a specialist exhaust centre, about a half hour drive from home, and the work including the silencer box cut and shut took about 4 hours. The difference from driving the car there in the morning, and driving it home in the afternoon was astounding. Engine spec is in my profile and you can see that a lot of work had been done to the top end prior to replacing the Y. Based on personal experience I would say that the greater the breathing efficiency of the engine (by upgrading induction and heads) the greater the benefit you will see from main cat removal.
Before and after dyno's below
(yes I know it's on the dyno thread too but couldn't resist
)
Chilli

Before and after dyno's below
(yes I know it's on the dyno thread too but couldn't resist
)Chilli

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