2.2 JTS Exhaust upgrades? - Alfa Romeo Forum
You are currently unregistered, register for more features.    
Tuning & Upgrades Discuss performance enhancements for your Alfa Romeo

Reply
 
Thread Tools
(Post Link) post #1 of 65 Old 22-12-08 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
2.2 JTS Exhaust upgrades?

Has anyone upgraded any section of the 2.2 exhaust (Brera/Spider or 159?)

As the car is naturally aspirated, I've been advised not to change the cats to sport cats as I need to keep the back-pressure up to maintain low end torque.

However an exhaust tuning company has suggested that replacing the centre section and/or back boxes may reduce pressure at the rear of the system them freeing a few horses without reducing the low end torque - is that possible? Anyone got any opinions?
Commanderfish is offline  
Sponsored Links
Advertisement
 
Status: Breraless :(
AO Platinum Member
 
Squadrone Rosso's Avatar
 
Join Date: Aug 2005
Location: United Kingdom
County: Neath Port Talbot
Posts: 30,126
Re: 2.2 JTS Exhaust upgrades?

Hi CF. Check my Longlife thread. I'm considering as it should sound a bit fruitier IMHO
Squadrone Rosso is offline  
(Post Link) post #3 of 65 Old 22-12-08 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

I've read that, good thread! Let me know what happens if and when you change your bits! Do you think you will get any power increases?
Commanderfish is offline  
Status: always bored
AO Member
 
ricey25's Avatar
 
Join Date: Oct 2006
Location: United Kingdom
County: West Yorkshire
Posts: 350
Re: 2.2 JTS Exhaust upgrades?

Quote:
Originally Posted by Commanderfish View Post
Let me know what happens if and when you change your bits!
ricey25 is offline  
(Post Link) post #5 of 65 Old 05-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

Ha ha!

Bump!
Commanderfish is offline  
CPH
Status: -
AO Member
 
Join Date: Dec 2005
Location: Essex
Posts: 253

Member car:

Alfa 33 16v

Re: 2.2 JTS Exhaust upgrades?

This back pressure issue is a totally wrong interpretation.

Replacing sections will help, because you can't make the exhaust any cheaper than from factory. If I where not sure that Italy is lacking the needed woods, I would be certain the Alfa exhaust have been made around trees.
CPH is offline  
(Post Link) post #7 of 65 Old 06-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

Thanks CPH, the cheap exhaust bits seem to make sense!

What the guys were saying to me is that if it were a turbo engine it would be well worth replacing the whole exhaust, but that a naturally aspirated needs some back pressure at the manifold to maintain low end torque. Is this wrong?
Commanderfish is offline  
CPH
Status: -
AO Member
 
Join Date: Dec 2005
Location: Essex
Posts: 253

Member car:

Alfa 33 16v

Re: 2.2 JTS Exhaust upgrades?

Quote:
Originally Posted by Commanderfish View Post
Thanks CPH, the cheap exhaust bits seem to make sense!

What the guys were saying to me is that if it were a turbo engine it would be well worth replacing the whole exhaust, but that a naturally aspirated needs some back pressure at the manifold to maintain low end torque. Is this wrong?
A n/a exhaust is a much more delicate system to design. But it has nothing to do with what people interprete as back pressure.

If you make the pipes too big, the peak power point shifts up the rpm range. At the same time the low rpm power is being reduced. It is like shifting the power graph along the rpm band.

You would get ultimately more power from a big bore exhaust. But only way above the rev limiter, which obviously is of no use when the engine can't go there.
CPH is offline  
(Post Link) post #9 of 65 Old 08-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

I get you. Thanks CPH! Might just go for new straight through back boxes instead of a new centre pipe. Probably sound a bit better (it's virtually silent at the moment) but I'm guessing no power increase?
Commanderfish is offline  
Oggy_GTA
Status: - Update
Guest
 
Posts: n/a
Re: 2.2 JTS Exhaust upgrades?

The 2.2 spider (brera) exhaust note is so disappointing, I agree.
 
(Post Link) post #11 of 65 Old 09-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

Well I don't know, Oggy. It seems they have designed it on purpose to be ultra quiet to cater to the luxury market along with the really comfortable ride; it's one of those things that annoys some old school Alfisti but can be easily cured.

Now I actually kind of like the fact that it is quiet as I like listening to my music and not sounded like Chav scum when I leave people for dust at the lights (yes, this is surprisingly easy to do in a run-in2.2!!). The Pirelli P Zeros are a bit noisy at speed and you notice this as the rest of the car is so quiet. In fact the exhaust is so quiet that you hear the induction noise quite clearly; (BTW may I suggest the Autodelta air filter for improved induction noise).

Anyway a little noise improvement by changing the back boxes rather than the centre pipe may be nice, but would I see any power gain at all low down the revs? The low rev performance is really more important for day to day driving (and remaps allegedly make a big difference there, but it would be magic to get an extra 15bhp peak out of a set of improvements as then it would be a 200 bhp Brera weighing 1470kg

Brat Pack no.8

Last edited by Commanderfish; 09-01-09 at 11:04.
Commanderfish is offline  
Oggy_GTA
Status: - Update
Guest
 
Posts: n/a
Re: 2.2 JTS Exhaust upgrades?

No, the exhaust is far too muted, even for a cruiser.

What I do appreciate is how quiet it is when you're trundling along country roads, top down, taking in the sounds and smells of the country, however, it really should sound like this when you put your foot down ...

YouTube - Alfa Romeo Brera 2.2 Ragazzon Exhaust

The before and after transformation is amazing
 
(Post Link) post #13 of 65 Old 09-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

Yep that Ragazzon is pretty good but not exactly what I'm after... it sounds a bit "farty" sometimes when it's coming back down through the revs. I quite like the Bertocchi one that' on youtube.

OF course it would be great to have that deep V6 idle sound, that is great!
Commanderfish is offline  
Oggy_GTA
Status: - Update
Guest
 
Posts: n/a
Re: 2.2 JTS Exhaust upgrades?

Quote:
Originally Posted by Commanderfish View Post
Yep that Ragazzon is pretty good but not exactly what I'm after... it sounds a bit "farty" sometimes when it's coming back down through the revs. I quite like the Bertocchi one that' on youtube.

OF course it would be great to have that deep V6 idle sound, that is great!
I know what you mean, but I quite like that "farty" sound. Of course in "normal" driving you never hear the revs drop off like that 'cos you've just snatched a lower gear as you dive into that hairpin!! Oh, sorry, I'm dreaming again

The idle sounds really nice.
 
(Post Link) post #15 of 65 Old 09-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

Ah good point Oggy... hmm options options...

Would I have to notify my insurers if I changed the back boxes? Doesn't seem like much of a mod... Could it invalidate the warranty?
Commanderfish is offline  
Oggy_GTA
Status: - Update
Guest
 
Posts: n/a
Re: 2.2 JTS Exhaust upgrades?

Sadly I think it's yes to both of those ... best enquire about the warranty. I can't do it on the Spider yet 'cos it still belongs to Fiat!
 
(Post Link) post #17 of 65 Old 09-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

I get CPH's point that we don't want to make the pipes too wide or we will loose low rev power - but what about straight through back boxes? Would those alone drop the low rev power, or make a slight improvement to power and throttle response?

And would a slight width increase to the centre pipe avoid dropping the low rev power? All this stuff is an education to me gents!
Commanderfish is offline  
Oggy_GTA
Status: - Update
Guest
 
Posts: n/a
Re: 2.2 JTS Exhaust upgrades?

Quote:
Originally Posted by Commanderfish View Post
I get CPH's point that we don't want to make the pipes too wide or we will loose low rev power - but what about straight through back boxes? Would those alone drop the low rev power, or make a slight improvement to power and throttle response?

And would a slight width increase to the centre pipe avoid dropping the low rev power? All this stuff is an education to me gents!
The most critical place for back pressure maintaining torque is in the design of manifold. I reckon it wouldn't make much difference elsewhere in the system, except at higher revs when you want it as free flowing as possible. Depends what you mean by straight through - Supersprints have an S shaped path in their back boxes. Straight through might be a bit noisy ???
 
(Post Link) post #19 of 65 Old 09-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

Mmm good point, what do we consider straight through? Well I don't want it too loud, so as you say, an s-shaped path is probably sensible - but less layers than the crazy silencing these cars must have at the moment to be so quiet!
Commanderfish is offline  
Status: -
AO Member
 
Join Date: Aug 2007
Location: Australia
County: New South Wales
Posts: 446
Re: 2.2 JTS Exhaust upgrades?

Commanderfish,Ragazzon make 2 styles for your car, however the smaller tips may not sound as good as the larger tips as on Lovivs Brera.
Why don't you ask him if power changed, I would only expect 5 or 6 hp.
For the price you will not find anything that sounds better on a 2.2, in fact I think it could even sound better than the 2 or 3 x the price Japanese exhaust.Ask your insurance co, they should not have a problem as it is only exhaust pipes nor should they cause warranty issues, but ask your dealer.
Kanga is offline  
CPH
Status: -
AO Member
 
Join Date: Dec 2005
Location: Essex
Posts: 253

Member car:

Alfa 33 16v

Re: 2.2 JTS Exhaust upgrades?

Quote:
Originally Posted by Oggy_GTA View Post
The most critical place for back pressure maintaining torque is in the design of manifold. I reckon it wouldn't make much difference elsewhere in the system, except at higher revs when you want it as free flowing as possible. Depends what you mean by straight through - Supersprints have an S shaped path in their back boxes. Straight through might be a bit noisy ???
Unfortunatelyyou are wrong here. Changing the back coxes and reducing the diameter on commanderfish's car made a massive difference thoroughout most of the rpm range.

I am sure he will put up the before and after graphs soon.
CPH is offline  
(Post Link) post #22 of 65 Old 12-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

Hiya CPH, really good to meet you at the weekend. I don't think Oggy meant that the power would not increase, I think he was saying I wuoldn't lose torque - so you're both right! 17bhp and 9lb/ft increase!!!

Only problem is it is much too loud under acceleration - probably need to have a much quieter centre silencer I'm guessing?

Oh, and it sounds more like a V6!
Commanderfish is offline  
Oggy_GTA
Status: - Update
Guest
 
Posts: n/a
Re: 2.2 JTS Exhaust upgrades?

Quote:
Originally Posted by Commanderfish View Post
Hiya CPH, really good to meet you at the weekend. I don't think Oggy meant that the power would not increase, I think he was saying I wuoldn't lose torque - so you're both right! 17bhp and 9lb/ft increase!!!

Only problem is it is much too loud under acceleration - probably need to have a much quieter centre silencer I'm guessing?

Oh, and it sounds more like a V6!
Yeah, wasn't implying the torque would change much - but glad it has!
Sounds like a really rorty car now Any chance of a vid?
 
Status: Breraless :(
AO Platinum Member
 
Squadrone Rosso's Avatar
 
Join Date: Aug 2005
Location: United Kingdom
County: Neath Port Talbot
Posts: 30,126
Re: 2.2 JTS Exhaust upgrades?

The reason I'm looking at a Longlife Custom system is the sound can be tailored to suit your needs.

I want a burble at idle and a rasp when blipping the throttle but otherwise I want it to be quite discreet.

Trouble is, I'd like to hear a 2.2 with a Longlife system first as c£400 is a lot to pay if you're not happy once it's built
Squadrone Rosso is offline  
(Post Link) post #25 of 65 Old 12-01-09 Thread Starter
Status: V8, baby. V8
AO Silver Member
 
Commanderfish's Avatar
 
Join Date: Apr 2007
Location: SW London
Posts: 5,559
Re: 2.2 JTS Exhaust upgrades?

Quote:
Originally Posted by Oggy_GTA View Post
Yeah, wasn't implying the torque would change much - but glad it has!
Sounds like a really rorty car now Any chance of a vid?
Haven't got one, though am meeting Joe and some of the guys frm the site tonight, maybe one of them will oblige
Commanderfish is offline  
Reply

Go Back   Alfa Romeo Forum > Supported Alfa Romeo Models > Technical & Vehicle Assistance > Tuning & Upgrades

Tags
exhaust , jts , upgrades

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome