to y pipe or not to y pipe

[Shinjuku]

It looks as though some exhaust systems come with a y pipe and others do not.

 

Is there any need to change the y pipe - ie if you dont it will rust through. Or is it personal choice. If the latter what is the effect of substituting it with a non oe unit.

 

Cheers

Shinjuku

[Ekona]

Do it, OEM one is very restrictive.

[coldel]

+1 what he said

 

Y pipe OEM is very restrictive try a Stillen from Tarmac?

[Watshot]

As above, if you have a DE. Apparently the HR Y pipes are better iirc. (Thankfully)

[Neilp]

As above, if you have a DE. Apparently the HR Y pipes are better iirc. (Thankfully)

im sure somebody had issues fitting an hr y-pipe to a de engine. The de-revup y-pipe is a different shape

[Shinjuku]

So what is the greater restriction on the de engine. The y pipe or the standard cat. No point changing y pipe if the CAT is still a greater upstream restriction

[Neilp]

the full thing is restrictive compared to its aftermarket parts. Cats are very restrictive, y-pipe is crap, system is very restrictive. Most people replace the full lot.

[Shinjuku]

The choice between expensive high flow cats and rattleing decats though means that I will probably not change the cats.

 

So given that is there any point changing the y pipe or is the cat basically the restraining point of what is left?

 

Cheers

Shinjuku

[Neilp]

The choice between expensive high flow cats and rattleing decats though means that I will probably not change the cats.

 

So given that is there any point changing the y pipe or is the cat basically the restraining point of what is left?

 

Cheers

Shinjuku

the y-pipe wont make much difference without changing the cats. I have decats and its slightly rattley but nothing annoying at all, silenced decats quieten it a bit, hfc's still give a bit of rattley noise.

[Watshot]

As above, if you have a DE. Apparently the HR Y pipes are better iirc. (Thankfully)

im sure somebody had issues fitting an hr y-pipe to a de engine. The de-revup y-pipe is a different shape

 

I wasn't suggesting putting an HR pipe on a DE.

 

Trying to clarify whether, if the op had a DE, then the advice already given was good, but if he had an HR then having read about restrictive y pipes everywhere (relating to a DE) then he might want to re-consider.

[Dicky]

I was told by a Powerflow tech the other day that you run an increased risk of failing an MOT with high flow cats fitted. Is this true?

[Neilp]

I was told by a Powerflow tech the other day that you run an increased risk of failing an MOT with high flow cats fitted. Is this true?

Not really, just make sure they're warmed up

[Shinjuku]

The choice between expensive high flow cats and rattleing decats though means that I will probably not change the cats.

 

So given that is there any point changing the y pipe or is the cat basically the restraining point of what is left?

 

Cheers

Shinjuku

the y-pipe wont make much difference without changing the cats. I have decats and its slightly rattley but nothing annoying at all, silenced decats quieten it a bit, hfc's still give a bit of rattley noise.

 

Thanks for the clarification neil.

 

I dont think I will bother with the y pipe then. I live in an urban area and something making a noise at around 2-3 thousand rpm would probably drive me up the wall so cat changes are out for me!

 

Shinjuku

[Mark@Abbey m/s]

The stock system from Y pipe back isnt that restrictive , w ehave seen FI cars with stock rear section flowing 400bhp. If you want a quiet car leave the stock system fitted.

 

Running HFC's with a good Y pipe and system works and sounds good.

[Neilp]

The stock system from Y pipe back isnt that restrictive , w ehave seen FI cars with stock rear section flowing 400bhp. If you want a quiet car leave the stock system fitted.

 

Running HFC's with a good Y pipe and system works and sounds good.

Wassos set up sounds very nice with stock sections