Hey all,

Just had a sport exhaust from a TJ put on my car (TH Advance). It sounds much better but got a question for you all.........

I seem to have lost a fair bit low down power... I went to Mt Tamborine the other day with the missus, and anyone on the GOld coast would know that there is a **** load of hills on the way there and they are pretty big ones too.... I was driving behind a truck, and went to overtake when the overtaking lane came. It seemed to have gone past the threshold of kicking back to 1st so I was going up in second. There was absoloutly NO power, it felt as sluggish as hell. I had to wait to nearly 4500 rpm before the car started to pull well.. Is this what happens when a sports exhaust goes in?

Hey all,

Just had a sport exhaust from a TJ put on my car (TH Advance). It sounds much better but got a question for you all.........

I seem to have lost a fair bit low down power... I went to Mt Tamborine the other day with the missus, and anyone on the GOld coast would know that there is a **** load of hills on the way there and they are pretty big ones too.... I was driving behind a truck, and went to overtake when the overtaking lane came. It seemed to have gone past the threshold of kicking back to 1st so I was going up in second. There was absoloutly NO power, it felt as sluggish as hell. I had to wait to nearly 4500 rpm before the car started to pull well.. Is this what happens when a sports exhaust goes in?

I can show you the dyno graph from my KH with a sports muffler (a cat back exhaust will offer little improvement over stock) and the power curve shows consistent power delivery.

It could just be a combination of both the hill, the auto box and things heating up under load.

Putting a larger exhaust on an N/A car will typically cause a loss of torque at low revs, but allows the engine to rev more freely, typically making a bit more power at higher revs.

Cheers,
Martin.

It could be a combo of it all. Dont know. It was only my missus and me, half a tank and nothing in the boot. But yes, when you do rev the car all out it revs far more freely. Just was concerned with loss of torque down low.

An increased in fuel consumption, dont mind me asking honestly?

Yes. I seem to be going through more fuel. No its not coz i want to hear the sound, but in normal driving I have noticed using more fuel. I have also noticed the gearbox adjust, it seems to hold the gear longer than before. Sounds way better though... WAYY better

Yes. I seem to be going through more fuel. No its not coz i want to hear the sound, but in normal driving I have noticed using more fuel. I have also noticed the gearbox adjust, it seems to hold the gear longer than before. Sounds way better though... WAYY better

Thanks for the honest feedback, really appreciate. I guess is a price to pay for the sound. But still is supposed to give more power.

I placed a TJ sports muffler on my TJII exec, sounds awesome and i'm getting the same if not slightly better fuel consumption. Also i havn't noticed any decreases in power, only increases.
I think you'll find that because it accelerated in 2nd, you didn't get much kick. I've found dropping back to 1st much better for acceleration.

I'm a bit like Maddog i just added a canon BIG ONE to get rid of that crappy TJ muffler, they say a straight through gives u 8kw.
It seems to be just as good on fuel if its different its not noticable but YES it seems more slugish down low, like its lost some balls under 4000rpm but man when you get it up she just pulls away like a boosted car :)

I heard a story a couple of years ago with the SS Commodore, Clubsport or something like that, someone took the standard sports muffler off and replaced it with a smaller diameter one, and it actually increased the power. Having a too easy of a flow through is not necessarily a good thing, unless the exhaust is specially designed like the Vortex mufflers (the Queensland ones not the overseas ones).

I placed a TJ sports muffler on my TJII exec, sounds awesome and i'm getting the same if not slightly better fuel consumption. Also i havn't noticed any decreases in power, only increases.
I think you'll find that because it accelerated in 2nd, you didn't get much kick. I've found dropping back to 1st much better for acceleration.

As I said though, Ive got an auto and it had passed that threshold where I cant kick down to 1st anymore, even with teh selector lever... So I was stuck in second with no power...

As I said though, Ive got an auto and it had passed that threshold where I cant kick down to 1st anymore, even with teh selector lever... So I was stuck in second with no power...
Why couldn't you kick down with the lever?
I have an auto also, but mines tiptronic and my engine is the 155kw version, but that shouldn't make a huge difference, should it?

Is yours 4sp or 5 sp? I think any tranny, once they pass their threshold cant be brought back to 1st. Which is what happened with me. My TH is 147kw but I dont think that could have made a difference. I was probably going say 50 or maybe higher or lower not sure, came to a hill behind a truck became an overtaking lane and put foot to floor and it was at about 2500 rpm in second. It felt like a slug and took ages to reach 4000 rpm. Once it reached there it felt like a sudden boost of power and started to pull hard..

Is yours 4sp or 5 sp? I think any tranny, once they pass their threshold cant be brought back to 1st. Which is what happened with me. My TH is 147kw but I dont think that could have made a difference. I was probably going say 50 or maybe higher or lower not sure, came to a hill behind a truck became an overtaking lane and put foot to floor and it was at about 2500 rpm in second. It felt like a slug and took ages to reach 4000 rpm. Once it reached there it felt like a sudden boost of power and started to pull hard..
Yup i know exactly what you're talking about now. If i was you i would have downshifted (would have been hitting about 3.5-4k revs, but 1st is good (well at least in my TJ) to go 80, maybe even 85. Mines only a 4sp as well. I think you were just in the spot that's no good for quick acceleration lol.

I changed the standard sports muffler on my tj sports magna a few years back with a redback straight through, and yes I noticed that you definitely loose a degree of engine responsiveness down low. This can be a little annoying when combined with an auto, as when left in auto mode, the revs always drop back to a minimum when cruising, and that low down loss of responsiveness can be felt. I combined this with a K and N pod, and holy crap, the low down hole was huge. What a waste of money the pod was. Sold it a few months later for a pittance, but car felt heaps better with the standard filter. Im thinking of changing the redback muffler to something with a bit more back pressure to see if I can restore some lowdown power, and maybe improve fuel consumption. Im getting sick of the noise anyway!

Like I've posted in another post I have one of these mufflers on my TP (granted it is manual) installed.

http://www.vortexexhausts.com.au/

Thats just one website, I don't think thats the manufactures website. These are supposed to improve performance right across the rev range, and I'd have to agree my car feels a LOT better now! Its actually classified as a fuel saver muffler, and it has decreased my fuel usage. I drive it really hard but I'd have to get back to you on the exact economy. Also sounds really good, not too loud but does give the 4 cylinder some life.

It works on a vacuum principle, instead of a backpressure principle :D

*scratches head* I didn't lose any power down low, and my fuel consumption was better

:confused:

*scratches head* I didn't lose any power down low, and my fuel consumption was better

:confused:

But you have a Barry fuel rail kit fitted dont you?

But you have a Barry fuel rail kit fitted dont you? :bowrofl:

No just a "Ralliart" sticker on my back window and a jesus fish in the corner. He's good for 5kwatw

No just a "Ralliart" sticker on my back window and a jesus fish in the corner. He's good for 5kwatw

Oh sh*t, i thought you were gunna say you have one of those famous peter brock polariser fitted to your car! :bowrofl:

I wonder how long before someone on here makes some of them and flog them off for a 100 bucks each, claiming they give 10kws and fix your exhaust drone by aligning the particles in the car. lol lol

Hey Jason what are your thoughts on Barrys kit? Have you tried one?? Just want to get someones opinion on someone who has knowledge on these engines which you do based on your experiences.

Regards

I changed the standard sports muffler on my tj sports magna a few years back with a redback straight through, and yes I noticed that you definitely loose a degree of engine responsiveness down low. This can be a little annoying when combined with an auto, as when left in auto mode, the revs always drop back to a minimum when cruising, and that low down loss of responsiveness can be felt. I combined this with a K and N pod, and holy crap, the low down hole was huge. What a waste of money the pod was. Sold it a few months later for a pittance, but car felt heaps better with the standard filter. Im thinking of changing the redback muffler to something with a bit more back pressure to see if I can restore some lowdown power, and maybe improve fuel consumption. Im getting sick of the noise anyway!
Pretty sure both me and fivefourv8 upgraded TOO standard sports mufflers (off a TJ sports) on a our execs. So go figure?