Y piece project

Y piece project

Author
Discussion

Smokey Boyer

Original Poster:

509 posts

130 months

Monday 27th July 2015
quotequote all
Some advice please if I may...

I have a plan in mind to cut open the original TVR Y Piece, remove the CAT, and weld it back together. At the same time I want to relocate (remove and fit a new one) the boss for the wide band lambda sensor from the right hand manifold to the central section of the pipe at the base of the Y as it currently only gets readings from one bank. The lambda sensor is connected to a MS2 ECU. I know the lambda sensor has to go before the CAT, but as there will not be any assume it is ok to go at the base of the Y. Is relocating the lambda sensor worth the effort?


I have a willing helper who can help do the cutting and welding, given it is outside of my comfort zone. This is also where I need the most advice.

So, first of all is decatting the Y piece like this a good idea or not? The PreCats have already been taken out. Yes I know it is going to be noisier but the car is not exactly quiet at the moment, Whilst I would like to get an ACT of Clive decat Y price, my available budget will not stretch to that at the moment and I long list of jobs that need attention.

Secondly, how easy is the main CAT to get out?

Thirdly, what is the original Y piece made from? Is it stainless steel, does anyone know what type of stainless it is?

Finally, and this might really highlight my ignorance, I assume from a welding point of view the sensor boss needs to be the same type of metal as the Y piece. Is that correct, or can you weld stainless and mild steel together?


I am aware that this can cause issues with the MOT, and have already taken that in to account.


Thanks in advance of your help and advice.

Nosh

982 posts

166 months

Monday 27th July 2015
quotequote all
This may not help, but it may........

I considered the same path you are thinking of taking.

After I weighed up all the pros and cons, I decided to stick with removed the pre cats from the manifold myself and just bought a clive Y Piece.

Glad I did - worked for me and the car sounds very nice smile

Each to his own though.... wink

Keep us all posted on what you decide to do (and please update any work you do).

Regards

Nosh.


Smokey Boyer

Original Poster:

509 posts

130 months

Monday 27th July 2015
quotequote all
what swayed the decision for you to go down the Clive route?

sapper

1,133 posts

204 months

Monday 27th July 2015
quotequote all
Why not just swap he main cat for a piece of stainless steel pipe and weld it back up. There are plenty of options on eBay for diameter and length.
I don't know what grade SS the exhaust is but SS is pretty easy to weld and quite forgiving to grade mismatch as long as you have a good filler and all is clean. Make sure all carbon is removed or you will get cracking.
You can weld MS to SS if the filler is SS.

jojackson4

3,026 posts

136 months

Monday 27th July 2015
quotequote all
Did this last year hope this lot helps






Bassfiend229hp

5,530 posts

249 months

Monday 27th July 2015
quotequote all
Since getting my main cat removed I really need to get some silencers fitted back into my exhaust... frown

jojackson4

3,026 posts

136 months

Monday 27th July 2015
quotequote all
Not doing Mrs knightly and silencers
What's going on

QBee

20,904 posts

143 months

Monday 27th July 2015
quotequote all
I have heard that the TVR Y piece, decatted, has all the harmonic subtlety of a large dustbin farting.....but I have not heard it myself.

If you want to listen to/ride in a Chim with the pre-cats removed and a Clive Y, plus standard exhaust, Jeremy, just ping me an email and we can meet up no trouble.

jojackson4

3,026 posts

136 months

Monday 27th July 2015
quotequote all
QBee said:
I have heard that the TVR Y piece, decatted, has all the harmonic subtlety of a large dustbin farting.....but I have not heard it myself.

If you want to listen to/ride in a Chim with the pre-cats removed and a Clive Y, plus standard exhaust, Jeremy, just ping me an email and we can meet up no trouble.
That's what I had heard that's why I put the cone in to stop it

QBee

20,904 posts

143 months

Monday 27th July 2015
quotequote all
jojackson4 said:
QBee said:
I have heard that the TVR Y piece, decatted, has all the harmonic subtlety of a large dustbin farting.....but I have not heard it myself.

If you want to listen to/ride in a Chim with the pre-cats removed and a Clive Y, plus standard exhaust, Jeremy, just ping me an email and we can meet up no trouble.
That's what I had heard that's why I put the cone in to stop it
Oh, I thought that was the Yorkshire way of stopping the kids from eating all the ice cream? confused

whistle

jojackson4

3,026 posts

136 months

Monday 27th July 2015
quotequote all
biglaugh

Nosh

982 posts

166 months

Monday 27th July 2015
quotequote all
Smokey Boyer said:
what swayed the decision for you to go down the Clive route?
Mostly laziness.....if I am being honest.

And it looks the nuts, to be fair...

Alan461

853 posts

130 months

Monday 27th July 2015
quotequote all
N
jojackson4 said:
That's what I had heard that's why I put the cone in to stop it
Did the cone make a difference and was it worth the extra effort?

Bassfiend229hp

5,530 posts

249 months

Monday 27th July 2015
quotequote all
QBee said:
I have heard that the TVR Y piece, decatted, has all the harmonic subtlety of a large dustbin farting.....but I have not heard it myself.

If you want to listen to/ride in a Chim with the pre-cats removed and a Clive Y, plus standard exhaust, Jeremy, just ping me an email and we can meet up no trouble.
...all being well you'll get to hear mine on Friday. hehe

No precats, no main cat, cone in the main bucket, sleeved silencers ... It's 'kin loud!

QBee

20,904 posts

143 months

Monday 27th July 2015
quotequote all
Bassfiend229hp said:
...all being well you'll get to hear mine on Friday. hehe

No precats, no main cat, cone in the main bucket, sleeved silencers ... It's 'kin loud!
Sadly mine has to pass the 100 dB noise test at Castle Combe.....eek

Bassfiend229hp

5,530 posts

249 months

Monday 27th July 2015
quotequote all
QBee said:
Bassfiend229hp said:
...all being well you'll get to hear mine on Friday. hehe

No precats, no main cat, cone in the main bucket, sleeved silencers ... It's 'kin loud!
Sadly mine has to pass the 100 dB noise test at Castle Combe.....eek
Mine doesn't ... I do have pair of track day silencers though to try and appease the neighbors a little...

QBee

20,904 posts

143 months

Monday 27th July 2015
quotequote all
I got around that - nearest neighbour is about 400 yards away

jojackson4

3,026 posts

136 months

Monday 27th July 2015
quotequote all
Alan461 said:
N
jojackson4 said:
That's what I had heard that's why I put the cone in to stop it
Did the cone make a difference and was it worth the extra effort?
I do not know I whent from cat to my mod so can not say if it was or not

sgrimshaw

7,311 posts

249 months

Tuesday 28th July 2015
quotequote all
In most peoples mind a modified original CAT Y-piece is not a nice sound.

Getting a decat Y-piece from either ACT or CliveF is by far the best route.

Two main reasons:

1. They sound much better.
2. You can retain the original for MOT or future sale. It WILL fail the MOT once decatted.


Smokey Boyer

Original Poster:

509 posts

130 months

Tuesday 28th July 2015
quotequote all
Any thoughts about the lambda sensor location from those that understand this sort of thing?

Certainly get the impression that my DIY idea might not get good results as far as a pleasant sound is concerned. Anyone got a spare ACT or Clive Y piece they want to sell?