2nd Decat 2006 STI?
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Hi all
I want to replace the second cat with a decat section. I have looked at the usual places and they seem to be around the £120.00 mark with postage.
I got a quote from a company called Lifelong Exhaust for £99.00 fitted! this seems really good has any one used a fabricator? do you know if they will be able to refit the heat shield? Cheers Gonzo.
I want to replace the second cat with a decat section. I have looked at the usual places and they seem to be around the £120.00 mark with postage.
I got a quote from a company called Lifelong Exhaust for £99.00 fitted! this seems really good has any one used a fabricator? do you know if they will be able to refit the heat shield? Cheers Gonzo.
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Hi all
I want to replace the second cat with a decat section. I have looked at the usual places and they seem to be around the £120.00 mark with postage.
I got a quote from a company called Lifelong Exhaust for £99.00 fitted! this seems really good has any one used a fabricator? do you know if they will be able to refit the heat shield? Cheers Gonzo.
I want to replace the second cat with a decat section. I have looked at the usual places and they seem to be around the £120.00 mark with postage.
I got a quote from a company called Lifelong Exhaust for £99.00 fitted! this seems really good has any one used a fabricator? do you know if they will be able to refit the heat shield? Cheers Gonzo.
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What makes you say that!
I'm trying to mod the same as a prodrive pack but in stages and I thought it would be a good start.
I have read that it needs no remap after fitting and should give me a few horses and a little more rumble!
I'm trying to mod the same as a prodrive pack but in stages and I thought it would be a good start.
I have read that it needs no remap after fitting and should give me a few horses and a little more rumble!
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Oh i see what you mean
Do you think its worth wrapping with that heat wrap stuff?
just looked at your spec D same as mine but with loads more mods.
just what I am looking to do .
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Do you think its worth wrapping with that heat wrap stuff?
just looked at your spec D same as mine but with loads more mods.
just what I am looking to do .
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I'm assuming you mean replacing the downpipe, and the heatshield you're referring to is the one over the turbo? It should go back on real easy with a bit of trimming. Leaving it off will increase underbonnet temps, and as its right next to the master cylinder that ain't good.
You *may* get a CEL when you remove the downpipe cat- some do, some don't, and you'll probably get boost spikes. It will also likely run like a bag of crap unless you have it mapped.
You *may* get a CEL when you remove the downpipe cat- some do, some don't, and you'll probably get boost spikes. It will also likely run like a bag of crap unless you have it mapped.
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Reading that again, maybe I've misuderstood; I took the '2nd cat' reference as you'd already removed the first.
Is thats not the case, and you're planning on removing the 'rear' cat for want of a better word, then don't worry about heat shields or remaps as neither will be necessary. I really would recommend that you go for a 'named' backbox though or you could just end up with 'noise' if that makes sense?
Is thats not the case, and you're planning on removing the 'rear' cat for want of a better word, then don't worry about heat shields or remaps as neither will be necessary. I really would recommend that you go for a 'named' backbox though or you could just end up with 'noise' if that makes sense?
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Yeah sorry for the bad wording it is the rear cat!
do you think I will be able to notice any power gains
Already have a Prodrive back box so hoping to get a little more rumble as well!
do you think I will be able to notice any power gains
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Already have a Prodrive back box so hoping to get a little more rumble as well!
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It is a waste of time replacing just the second cat. you will gain about 2bhp if you are lucky... Most people, including I think the PPP replace the cat in the downpipe (either decat or sports cat) and the second cat with one pipe. This obviouslt removes the second cat in the process. There is a resonator, not a cat, in the centre pipe. This can be replaced to make the exhaust louder.
Basically, replace the centre pipe (£100) and get either a decat or sports cat downpipe (£150-£400 depending on what you go for) and that is all you need. Then a remap, which you only need when you replace the downpipe.
Basically, replace the centre pipe (£100) and get either a decat or sports cat downpipe (£150-£400 depending on what you go for) and that is all you need. Then a remap, which you only need when you replace the downpipe.
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You're quite right they do just replace that cat on the PPP for the 2.5. Surely it is better value for money doing the downpipe properly (i.e. sports cat/decat) if doing it yourself?
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Just to make things clear I will be changing the 1st cat (down-pipe) to a sports cat at a later stage.As at the moment I do not have the money for a remap.
I thought it would be a good start to get rid of the rear cat,And spread the cost of things![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
Does the 2.5 struggle come MOT time with just a sports cat??
If prodrive leave the standard downpipe in do you think its worth changing?? maybe you can still achieve good power figures with the standard after all a sports cat is not cheap!
I thought it would be a good start to get rid of the rear cat,And spread the cost of things
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Does the 2.5 struggle come MOT time with just a sports cat??
If prodrive leave the standard downpipe in do you think its worth changing?? maybe you can still achieve good power figures with the standard after all a sports cat is not cheap!
Last edited by greatgonzo; 01 October 2008 at 04:40 PM.
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It should be fine with a sports cat at MOT time, but then again so is a decat in selected outlets
A decat is best.
A sports cat is almost as good.
The standard cat is restrictive and the turbo will spool up slower. You could still achieve around 320-330bhp with the standard cat and a remap I think, which is very respectable. Every tuner worth his salt will tell you to sort the cat is the first and best mod you can do, but it does require a remap especially with a 2.5 engine (or so I have been told).
If funds are limited, I would just save up and do it right personally or you'll end up paying more in the long run. If you are thinking of just changing the second cat and not remapping then you will not really notice a difference. With a remap you will, but then you might as well sort the cat before doing that.
You could just change the backbox and centre pipe for a better sound, which is cheap but completely ineffective performance wise.
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A decat is best.
A sports cat is almost as good.
The standard cat is restrictive and the turbo will spool up slower. You could still achieve around 320-330bhp with the standard cat and a remap I think, which is very respectable. Every tuner worth his salt will tell you to sort the cat is the first and best mod you can do, but it does require a remap especially with a 2.5 engine (or so I have been told).
If funds are limited, I would just save up and do it right personally or you'll end up paying more in the long run. If you are thinking of just changing the second cat and not remapping then you will not really notice a difference. With a remap you will, but then you might as well sort the cat before doing that.
You could just change the backbox and centre pipe for a better sound, which is cheap but completely ineffective performance wise.
Last edited by Mikkel; 01 October 2008 at 07:46 PM.
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Aye centre pipe will improve the revs, smoother and less juddery on pull off IMO. Get it all done at once I would. Second cat is dirt cheap and wouldn't add much to the greater cost of remapping anyway. Problem you will have without remapping is the potential for overboost without remaping. People reckon the second cat removal is ECU friendly but this is not necessarily the case with the 2.5's
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#17
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2.5 sti spec d fitted with secondhand hawkeye ppp exhaust (same as RB320 mot friendly) get a remap from Andy Forrest
circa 335bhp and 372ft/lbs
Keeps standard cat down pipe, 2nd cat replaced by prodrive ss silencer with standard heat shields re-fitted no problem , standard resonated mid section, prodrive ss back box, standard fuel pump has enough spare capacity
My priority at present is for car with standard parts & dealer friendly, sounds good and has plenty of push down the road
![Notworthy](https://www.scoobynet.com/images/smilies/notworthy.gif)
Keeps standard cat down pipe, 2nd cat replaced by prodrive ss silencer with standard heat shields re-fitted no problem , standard resonated mid section, prodrive ss back box, standard fuel pump has enough spare capacity
My priority at present is for car with standard parts & dealer friendly, sounds good and has plenty of push down the road
![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
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Aye centre pipe will improve the revs, smoother and less juddery on pull off IMO. Get it all done at once I would. Second cat is dirt cheap and wouldn't add much to the greater cost of remapping anyway. Problem you will have without remapping is the potential for overboost without remaping. People reckon the second cat removal is ECU friendly but this is not necessarily the case with the 2.5's![Thumb](https://www.scoobynet.com/images/smilies/thumb.gif)
![Thumb](https://www.scoobynet.com/images/smilies/thumb.gif)
Or do you mean that even when replacing the 2nd cat with a straight through pipe a remap is recommended?
2.5 sti spec d fitted with secondhand hawkeye ppp exhaust (same as RB320 mot friendly) get a remap from Andy Forrest
circa 335bhp and 372ft/lbs
Keeps standard cat down pipe, 2nd cat replaced by prodrive ss silencer with standard heat shields re-fitted no problem , standard resonated mid section, prodrive ss back box, standard fuel pump has enough spare capacity
My priority at present is for car with standard parts & dealer friendly, sounds good and has plenty of push down the road![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
![Notworthy](https://www.scoobynet.com/images/smilies/notworthy.gif)
Keeps standard cat down pipe, 2nd cat replaced by prodrive ss silencer with standard heat shields re-fitted no problem , standard resonated mid section, prodrive ss back box, standard fuel pump has enough spare capacity
My priority at present is for car with standard parts & dealer friendly, sounds good and has plenty of push down the road
![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
Isn't the PPP exhaust basically a straight through decat pipe (I didn't know they replace the 2nd cat with a silencer) and backbox? At least for the WRX?
Last edited by fpan; 01 October 2008 at 09:42 PM.
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2.5 sti spec d fitted with secondhand hawkeye ppp exhaust (same as RB320 mot friendly) get a remap from Andy Forrest
circa 335bhp and 372ft/lbs
Keeps standard cat down pipe, 2nd cat replaced by prodrive ss silencer with standard heat shields re-fitted no problem , standard resonated mid section, prodrive ss back box, standard fuel pump has enough spare capacity
My priority at present is for car with standard parts & dealer friendly, sounds good and has plenty of push down the road![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
![Notworthy](https://www.scoobynet.com/images/smilies/notworthy.gif)
Keeps standard cat down pipe, 2nd cat replaced by prodrive ss silencer with standard heat shields re-fitted no problem , standard resonated mid section, prodrive ss back box, standard fuel pump has enough spare capacity
My priority at present is for car with standard parts & dealer friendly, sounds good and has plenty of push down the road
![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
Or does this ppp exhaust from the RB320 have a sports cat as standard?
Does Andy F dyno map or road map? as I have heard some dyno maps are all for figures?
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2.5 sti spec d fitted with secondhand hawkeye ppp exhaust (same as RB320 mot friendly) get a remap from Andy Forrest
circa 335bhp and 372ft/lbs
Keeps standard cat down pipe, 2nd cat replaced by prodrive ss silencer with standard heat shields re-fitted no problem , standard resonated mid section, prodrive ss back box, standard fuel pump has enough spare capacity
My priority at present is for car with standard parts & dealer friendly, sounds good and has plenty of push down the road![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
![Notworthy](https://www.scoobynet.com/images/smilies/notworthy.gif)
Keeps standard cat down pipe, 2nd cat replaced by prodrive ss silencer with standard heat shields re-fitted no problem , standard resonated mid section, prodrive ss back box, standard fuel pump has enough spare capacity
My priority at present is for car with standard parts & dealer friendly, sounds good and has plenty of push down the road
![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
53WRX, doesn't the PPP for the 2.5 consist of a straight through pipe in place of the second cat? Yes it does
Or do you mean that even when replacing the 2nd cat with a straight through pipe a remap is recommended? Yes I do
The PPP comes with a remap via the ECU
![Thumb](https://www.scoobynet.com/images/smilies/thumb.gif)
Or do you mean that even when replacing the 2nd cat with a straight through pipe a remap is recommended? Yes I do
![Thumb](https://www.scoobynet.com/images/smilies/thumb.gif)
The PPP comes with a remap via the ECU
![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
I have the same goal ![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
Isn't the PPP exhaust basically a straight through decat (2nd
retains cat in downpipe) pipe Yes it is
(I didn't know they replace the 2nd cat with a silencer They don't, they replace it with a decat pipe
) and backbox? At least for the WRX? Silenced centre pipe remains unchanged and the Back Box is substituted for a prodrive one
![Smile](https://www.scoobynet.com/images/smilies/smile.gif)
Isn't the PPP exhaust basically a straight through decat (2nd
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Thanks again!
Prodrive must make a few Quid for 2 bits of exhuast and a plug in ECU ????
£1700 I must be in the wrong game! Think I will start Doing similar for £1000
Prodrive must make a few Quid for 2 bits of exhuast and a plug in ECU ????
£1700 I must be in the wrong game! Think I will start Doing similar for £1000
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Hi greatgonzo
Fitted a secondhand ppp exhaust from a 56 reg 2.5 hawkeye wrx, bought from a scoobynet member, for £170 delivered.
My investigation/experience was that the same ppp exhaust components are sold to fit both hawkeye 2.5 wrx and sti and are also fitted as standard on RB320, ie all the same parts fit all and the changes are, 2nd decat replacement with a ss silencer (small, fits inside refitted heat shields) and back box.
Andy Forrest road map flywheel figures quoted, Andy has also mapped an unmodified standard spec RB320 (which has ppp comprising of exhaust as described, prodrive re-mapped ecu and uprated fuel pump) and achieved similar figures
Agreed that you will get more power and earlier spool up with a de cat downpipe or sports cat, but figures are not bad for the minor changes with approved parts at less than half the dealer £1700 price
Fitted a secondhand ppp exhaust from a 56 reg 2.5 hawkeye wrx, bought from a scoobynet member, for £170 delivered.
My investigation/experience was that the same ppp exhaust components are sold to fit both hawkeye 2.5 wrx and sti and are also fitted as standard on RB320, ie all the same parts fit all and the changes are, 2nd decat replacement with a ss silencer (small, fits inside refitted heat shields) and back box.
Andy Forrest road map flywheel figures quoted, Andy has also mapped an unmodified standard spec RB320 (which has ppp comprising of exhaust as described, prodrive re-mapped ecu and uprated fuel pump) and achieved similar figures
Agreed that you will get more power and earlier spool up with a de cat downpipe or sports cat, but figures are not bad for the minor changes with approved parts at less than half the dealer £1700 price
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Hi greatgonzo
Fitted a secondhand ppp exhaust from a 56 reg 2.5 hawkeye wrx, bought from a scoobynet member, for £170 delivered.
My investigation/experience was that the same ppp exhaust components are sold to fit both hawkeye 2.5 wrx and sti and are also fitted as standard on RB320, ie all the same parts fit all and the changes are, 2nd decat replacement with a ss silencer (small, fits inside refitted heat shields) and back box.
Andy Forrest road map flywheel figures quoted, Andy has also mapped an unmodified standard spec RB320 (which has ppp comprising of exhaust as described, prodrive re-mapped ecu and uprated fuel pump) and achieved similar figures
Agreed that you will get more power and earlier spool up with a de cat downpipe or sports cat, but figures are not bad for the minor changes with approved parts at less than half the dealer £1700 price
Fitted a secondhand ppp exhaust from a 56 reg 2.5 hawkeye wrx, bought from a scoobynet member, for £170 delivered.
My investigation/experience was that the same ppp exhaust components are sold to fit both hawkeye 2.5 wrx and sti and are also fitted as standard on RB320, ie all the same parts fit all and the changes are, 2nd decat replacement with a ss silencer (small, fits inside refitted heat shields) and back box.
Andy Forrest road map flywheel figures quoted, Andy has also mapped an unmodified standard spec RB320 (which has ppp comprising of exhaust as described, prodrive re-mapped ecu and uprated fuel pump) and achieved similar figures
Agreed that you will get more power and earlier spool up with a de cat downpipe or sports cat, but figures are not bad for the minor changes with approved parts at less than half the dealer £1700 price
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