2.5" Exhaust - How much bottom end power lost?

[Admiral_Awesome]

Hey guys im looking at getting 2.5" single catback without the rear resi put on my VX V6.. but i heard you lose some power/torque down low. How much exactly is lost? Is it a noticeable amount that you can feel while driving?

Would adding extractors justify this loss of power or not really do anything down low?
And whats the go with high flow cats? Is it worth getting one as i heard that they dont really do much and make it sound worse??

Sorry lots of questions but i dont know too much at all when it comes to exhausts

Thanks guys

 

[2DIE]

If the 2 1/2" loses power due to loss of back pressure then adding a high flow cat will lose more.

Depending on budget with a few small mods, about $1000 including 2 1/2" you will have more power over the whole rev range.

Cat back - $200
Plenum spacer - $150
Manifold spacer - $150
1:9:1 rockkers - $500
Memcal tune - $70

Maybe extractors after that then a high flow cat wouldn't hurt.

Sorry cant say from experience if you will lose bottom end power from the exhaust but lots of people say you will and others will say you gain more.

 

[nathanVY]

You'd be lucky to get a decent catback done for $200, try at least $300. I think twin 2 1/4" merging into a single 2 1/2" near the end is the best for a v6.

 

[Admiral_Awesome]

Thanks guys.. got all those mods in mind actually but they wont be happening for a while..
And with the memcals.. is it true that you cant just swap em over on the VX like you can on the VT and earlier commodores?

 

[acarmody]

Correct. VX and VY use a flash module. I think the only people in QLD that do them are Chiptorque.

 

[2DIE]

Lukey and Red Back cat backs are about $160 each + $40 or so postage, bolt up your self. No resi though, just 1 muffler.

I plan to get one sooner or later and get a hot dog fitted before the tip.

 

[nathanVY]

Ah yeah fitting yourself is a different story. Redbacks sound like rubbish, go with a lukey system.
It's worth getting pacemaker extractors too, huge difference.

 

[Admiral_Awesome]

yeh looking towards a lukey catback. it just seems everybody has a redback :/ hotdog idea sounds good

still does anyone know how much power im looking at losing down low? i probably will be looking at just a stock ecotec with a catback for a while.. so i dont want it to be painfully gutless down low :/

 

[Jezza]

i have a vy with a lukey 2.5" catback and i didnt notice any power loss low down at all

 

[one_and_only2004]

yeh looking towards a lukey catback. it just seems everybody has a redback :/ hotdog idea sounds good

still does anyone know how much power im looking at losing down low? i probably will be looking at just a stock ecotec with a catback for a while.. so i dont want it to be painfully gutless down low :/

You're not going to lose 50kw through an exhaust swap, You'll hardly notice the difference.