Fordmods Logo

exhaust size 

 

Page 2 of 3 [ 37 posts ] Go to page Previous  1, 2, 3  Next

 
Posted: Sun Dec 28, 2008 1:31 am 
Getting Side Ways
Offline
User avatar

Age: 40

Posts: 747

Joined: 16th Dec 2008

Gallery: 1 images

Ride: AU2 75th Anniversary Futura

Location: Adelaide
SA, Australia

metasaiah wrote:
Personally I don't think there's any real need for anything bigger than 2.5" unless you want a big turbo setup. 2.5 is still a very big pipe and will cater for most applications without compromise. It's also way cheaper to keep a 2.5 quiet if that's what you're concerned about. But I look at it like this:
You want a blower later on. It might happen.
You want a cam and head work. It probably will happen.
You want a huge pipe that will never need upgrading. When you get a few quotes, you then decide you can live with an "average" exhaust upgrade. It's a certainty.

No offence intended mate. We have all been there (or are still there) :)


you hit the nail on the head. pretty much summed it up in one.

the thing i may not have elaborated on was that if the boosted setup goes ahead, i wont be going big power, just a st1-st2 setup. Maybe look at 250rwkw???

But yeah i spose im not alone in the above thought.

 

_________________

Cheers
Shav

Top
 Profile  
 
 
Posted: Sun Dec 28, 2008 6:08 pm 
Getting Side Ways
Offline
User avatar

Age: 28

Posts: 4326

Joined: 30th Oct 2006

Gallery: 18 images

Ride: Envi EF

Location: Grafton
NSW, Australia

A 3" wont cost much more than a 2.5", as you can get the rear section from redback in 3" off the shelf (listed for V8s) - then all you need is a basically straight bit of 3" from the cat to the diff with a muffler on it.

 

_________________

>>>EF Futura T build<<<

Top
 Profile  
 
 
Posted: Sun Dec 28, 2008 6:54 pm 
Getting Side Ways
Offline
User avatar

Age: 31

Posts: 11103

Joined: 15th Nov 2004

Ride: AU III XR8 Pursuit 250 ute

Location: Hobart
TAS, Australia

If you go forced induction, having to fork over a couple of hundred more dollars for a new exhaust will only be a minor expense.

If your cars auto I definately wouldn't even consider the 3" with NA.


alfy wrote:
GeZza200 wrote:
mmm im thinking about getting a 3" now lol, it would be bloody loud though wouldn't it.


friend of mine went from a 2.5'' Lukey to a 3'' Manta on his VS Commodore, and f**k me its probably 5 times louder. i can hear it from almost 4 blocks away.


That can be more to do with the choice in mufflers (i.e. brands, models, styles) than the actual pipe size.

 

_________________

Heaps of performance EF/L parts for sale, including supercharged VCT motor!

2002 Ford AU Series III Falcon XR8 Pursuit 250 ute - 5.6L of V8 Windsor!

Top
 Profile  
 
 
Posted: Sun Dec 28, 2008 10:17 pm 
Getting Side Ways
Offline
User avatar

Age: 40

Posts: 747

Joined: 16th Dec 2008

Gallery: 1 images

Ride: AU2 75th Anniversary Futura

Location: Adelaide
SA, Australia

thanks fellas.

the car is auto and that was my next issue. the last thing i want is issues of poor back pressure for an oversized exhaust.

i think the conclusion is get the 2.5" system now with the cam, head and edit and run that for as long as possible, then when its time to boost, upgrade the exhaust then and just fork out for it.

OR

Be patient, hold off with fitting cam, head and edit and buy s/c or turbo kit and fit it all at once, doing it one time only.

Question is, do I have the will power to wait for more power so I can do it all at once? hmm tough decision

 

_________________

Cheers
Shav

Top
 Profile  
 
 
Posted: Mon Dec 29, 2008 4:01 pm 
Getting Side Ways
Offline
User avatar

Age: 28

Posts: 2515

Joined: 27th Mar 2006

Gallery: 1 images

Ride: FG MkII Xr6t Ute

Location: Brisbane
QLD, Australia

shav wrote:
thanks fellas.

the car is auto and that was my next issue. the last thing i want is issues of poor back pressure for an oversized exhaust.

i think the conclusion is get the 2.5" system now with the cam, head and edit and run that for as long as possible, then when its time to boost, upgrade the exhaust then and just fork out for it.

OR

Be patient, hold off with fitting cam, head and edit and buy s/c or turbo kit and fit it all at once, doing it one time only.

Question is, do I have the will power to wait for more power so I can do it all at once? hmm tough decision


backpressure is a myth.

 

_________________

EVL098 wrote:
Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
Seriously do people google "f**k up modifications for Fords owned by Jews" and get linked straight to this site nowadays?

AU,factory fitted tickford kit/IRS, t5,Sports ryder/KYB: gone.

Top
 Profile  
 
 
Posted: Mon Dec 29, 2008 4:04 pm 
Getting Side Ways
Offline
User avatar

Age: 40

Posts: 747

Joined: 16th Dec 2008

Gallery: 1 images

Ride: AU2 75th Anniversary Futura

Location: Adelaide
SA, Australia

care to elaborate skidder?

 

_________________

Cheers
Shav

Top
 Profile  
 
 
Posted: Mon Dec 29, 2008 4:30 pm 
Getting Side Ways
Offline
User avatar

Age: 28

Posts: 2515

Joined: 27th Mar 2006

Gallery: 1 images

Ride: FG MkII Xr6t Ute

Location: Brisbane
QLD, Australia

I'm only gonna give the short version as there's several long versions I've written on here.

With an exhaust system you want minimal pressure. Hot air weighs less, cold air is more dense and weighs more (however the weight difference is greater than the difference of volume).

If you have a smaller diameter exhaust, velocity will be higher, meaning hotter air (which weighs less) is forced through cats/mufflers/resi's etc. The opposite will occur as the exhaust gets larger. Obviously having too small an exhaust will restrict the engine in higher revs and too small an exhaust will lead to lower velocity and heavier air being pushed through restrictive areas.

A cat back exhaust (when needed) should be designed to be able to flow accordingly to where torque is desired.

 

_________________

EVL098 wrote:
Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
Seriously do people google "f**k up modifications for Fords owned by Jews" and get linked straight to this site nowadays?

AU,factory fitted tickford kit/IRS, t5,Sports ryder/KYB: gone.

Top
 Profile  
 
 
Posted: Mon Dec 29, 2008 4:32 pm 
Getting Side Ways
Offline
User avatar

Age: 28

Posts: 2515

Joined: 27th Mar 2006

Gallery: 1 images

Ride: FG MkII Xr6t Ute

Location: Brisbane
QLD, Australia

Sorry forgot to state the obvious, hotter + lighter air being pushed through cats/mufflers/resi's being easier also means its less of a restriction on the engine.

And in relation to your question, either 2.5in or 3in will provide negligable difference performance wise N/A, I doub't you will tell the difference driving.

 

_________________

EVL098 wrote:
Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
Seriously do people google "f**k up modifications for Fords owned by Jews" and get linked straight to this site nowadays?

AU,factory fitted tickford kit/IRS, t5,Sports ryder/KYB: gone.

Top
 Profile  
 
 
Posted: Mon Dec 29, 2008 5:24 pm 
Getting Side Ways
Offline
User avatar

Age: 40

Posts: 747

Joined: 16th Dec 2008

Gallery: 1 images

Ride: AU2 75th Anniversary Futura

Location: Adelaide
SA, Australia

Thanks skidder, that makes sense to some degree for me. Its still a learning curve for me, but Im getting there.

Effectively speaking, Id like the power to be low - mid range as that is where the car's rev range is most often. Between idle and 4000rpm. But that doesnt mean I dont take it up to redline on occasions.

I think it just comes down to wanting N/A or forced induction, and choosing the appropriate parts from there.

 

_________________

Cheers
Shav

Top
 Profile  
 
 
Posted: Mon Dec 29, 2008 10:05 pm 
Getting Side Ways
Offline
User avatar

Age: 28

Posts: 2515

Joined: 27th Mar 2006

Gallery: 1 images

Ride: FG MkII Xr6t Ute

Location: Brisbane
QLD, Australia

pretty much, as was said if you go forced induction a new exhaust shouldn't eat into the budget as unless you are very good at doing stuff yourself it will be around 5% of the cost.

 

_________________

EVL098 wrote:
Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
Seriously do people google "f**k up modifications for Fords owned by Jews" and get linked straight to this site nowadays?

AU,factory fitted tickford kit/IRS, t5,Sports ryder/KYB: gone.

Top
 Profile  
 
 
Posted: Mon Dec 29, 2008 11:31 pm 
Getting Side Ways
Offline
User avatar

Age: 40

Posts: 747

Joined: 16th Dec 2008

Gallery: 1 images

Ride: AU2 75th Anniversary Futura

Location: Adelaide
SA, Australia

cheers.

thinking of sticking to N/A for now.

 

_________________

Cheers
Shav

Top
 Profile  
 
 
 Post subject: Re: exhaust size
Posted: Sat Oct 09, 2010 6:10 pm 
Fordmods Newbie
Offline

Posts: 7

Joined: 27th Oct 2008

Ride: XR6

Location: tamworth
NSW, Australia

stupid question guys but i've got a na BA with cat back exhaust wanting better sound, is the turbo or XR8 exhaust larger than 2 1/4 inch?
Top
 Profile  
 
 
 Post subject: Re: exhaust size
Posted: Sat Oct 09, 2010 7:08 pm 
Getting Side Ways
Offline
User avatar

Age: 40

Posts: 747

Joined: 16th Dec 2008

Gallery: 1 images

Ride: AU2 75th Anniversary Futura

Location: Adelaide
SA, Australia

violentg wrote:
stupid question guys but i've got a na BA with cat back exhaust wanting better sound, is the turbo or XR8 exhaust larger than 2 1/4 inch?


I believe xr6t exhaust has same volumetric efficiency as a 3" system. But don't quote me on this.

 

_________________

Cheers
Shav

Top
 Profile  
 
 
 Post subject: Re: exhaust size
Posted: Sat Oct 09, 2010 10:17 pm 
Getting Side Ways
Offline

Posts: 6449

Joined: 11th Nov 2004

there is a simple fix to the question of 2.5 or 3

Fit a 3inch cat back system with a good 3 inch cat. Only you mount the cat at the main system flange instead of the extractor flange. you then use a short 20-25cm long bit of 2.5inch pipe from the extractors back to the cat. problem solved.

You get good air speed through the 2.5inch pipe and the extractors will function as if there is a complete 2.5inch system fitted only they won't be a strangled at higher RPM.

 

_________________

PERMANENTLY BANNED

Top
 Profile  
 
 
 Post subject: Re: exhaust size
Posted: Tue Oct 12, 2010 2:35 pm 
Getting Side Ways
Offline
User avatar

Age: 40

Posts: 747

Joined: 16th Dec 2008

Gallery: 1 images

Ride: AU2 75th Anniversary Futura

Location: Adelaide
SA, Australia

tickford_6 wrote:
there is a simple fix to the question of 2.5 or 3

Fit a 3inch cat back system with a good 3 inch cat. Only you mount the cat at the main system flange instead of the extractor flange. you then use a short 20-25cm long bit of 2.5inch pipe from the extractors back to the cat. problem solved.

You get good air speed through the 2.5inch pipe and the extractors will function as if there is a complete 2.5inch system fitted only they won't be a strangled at higher RPM.


Interesting option there tickford. Have you seen this done before or is this just a suggestion?

Are you also saying to make the short piece of pipe adaptable with extra flanges to accept the extractors and cat?

 

_________________

Cheers
Shav

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 2 of 3  [ 37 posts ]  Go to page Previous  1, 2, 3  Next

Who is online

Users browsing this forum: Google [Bot] and 21 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

 

 

It is currently Fri Dec 15, 2017 8:18 am All times are UTC + 11 hours

 

 

(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names