What constitutes a restrictive exhaust? I had cams fitted recently and I am unsure if that altered the situation or not, but the mechanic said I had an exhaust the blows out the rear too fast (on idle heated up)caused by a restricted exhaust. I wonderd why this would be the case given the mods i have done. Has anyone noticed if their car blows exhaust fast out the rear compared to others? What could be done to fix it? Is it a problem?

I thought having a more free flowing exhaust was a good thing? maybe im an absolute noob aswell though :redface:

Your profile says you've got a Redback system, which is 2.5"s wide all the way. I really don't think that would be restrictive, even with all your NA mods. Even most of the guys running forced induction still have 2.5" systems.

I'm not sure how tough the muffler is on the Reback systems... but I haven't heard of anyone having problems yet.

I thought having a more free flowing exhaust was a good thing? maybe im an absolute noob aswell though :redface:

The more free flowing, the more peak power and less bottom end torque. Bottom end
torque needs backpressure to work. People free up their exhaust even further with forced
induction because forced induction generate a hell lot more of exhaust.

What constitutes a restrictive exhaust? I had cams fitted recently and I am unsure if that altered the situation or not, but the mechanic said I had an exhaust the blows out the rear too fast (on idle heated up)caused by a restricted exhaust. I wonderd why this would be the case given the mods i have done. Has anyone noticed if their car blows exhaust fast out the rear compared to others? What could be done to fix it? Is it a problem?


It's a common problem. I often blow it out the rear too fast. :bowrofl: :bowrofl: :bowrofl:

Did the mechanic use a machine of any sort to verify this? Like a probe in the rear? :P

Seriously, it sounds very subjective. You have a Redback exhaust. They have a hi-flow muffler. The only restriction could be a blocked Cat.

You have RPW Cams, yeah? I'd be ringing them to see if they know of this problem.

But, choose your words carefully...lol

were those his words? "it blows out the rear to fast" ?? if it was id get a new mechanic..... reminds me of that family guy episode, where the gynocholigist didnt finish med school... "now meg, lets take a look at that bergina" haha

What constitutes a restrictive exhaust? I had cams fitted recently and I am unsure if that altered the situation or not, but the mechanic said I had an exhaust the blows out the rear too fast (on idle heated up)caused by a restricted exhaust. I wonderd why this would be the case given the mods i have done. Has anyone noticed if their car blows exhaust fast out the rear compared to others? What could be done to fix it? Is it a problem?

That dosn't make any sense at all if it was restrictive it would be blowing out the exhaust to slow ,Restrictive = Blocked.:nuts:


were those his words? "it blows out the rear to fast" ?? if it was id get a new mechanic..... reminds me of that family guy episode, where the gynocholigist didnt finish med school... "now meg, lets take a look at that bergina" haha
:stoopid: :stoopid: :stoopid: :stoopid:

That dosn't make any sense at all if it was restrictive it would be blowing out the exhaust to slow ,Restrictive = Blocked.:nuts:


:stoopid: :stoopid: :stoopid:

lol
wrong its the opposite, the exhaust gasses travel faster through smaller pipes and when under pressure (in his restrictive exhaust) they are forced out quicker... just like when you put your thumb over the end of a garden hose that has no nossle on it

lol
wrong its the opposite, the exhaust gasses travel faster through smaller pipes and when under pressure (in his restrictive exhaust) they are forced out quicker... just like when you put your thumb over the end of a garden hose that has no nossle on it

I second that. When I got the exhaust done for my old KS, during idle, i could barely feel
any pressure at the back as opposed to with stock exhaust.

I stand corrected :redface:

Did the mechanic use a machine of any sort to verify this? Like a probe in the rear? :P .

It was on a dyno.... but it was noticed most at idle


Seriously, it sounds very subjective. You have a Redback exhaust. They have a hi-flow muffler. The only restriction could be a blocked Cat.

I had a new cat installed as well

how big is the new cat?? with exhausts it only flows as well as the weakest link. I had a stocko 2" cat and replaced so my whole system is 2.5" --> revs out alot better.

how big is the new cat?? with exhausts it only flows as well as the weakest link. I had a stocko 2" cat and replaced so my whole system is 2.5" --> revs out alot better.

Pacemaker extractors, 21/2" Hi flow cat,Redback catback system

What I might do is leave it for now and wait till the dyno day and see the exhaust guys there