DrewPeacock76
Member
- Joined
- Sep 16, 2017
- Messages
- 32
- Reaction score
- 18
- Points
- 8
- Age
- 48
- Location
- Sydney
- Members Ride
- 2017 VF II SSV Redline
All good. Found em
Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.
Yes, a 3" will make more power than a 2.5" if the engine can use it. I wouldn't consider a 3" on an LS3 unless the engine was making around 380kw on the dyno, then a 3" is worth a try." exhausts make more power because they are less restrictive overall at WOT.
I'm also not a fan of stainless headers, or exhausts, unless they are 321
I find that I don't like the "tone" that cheap 304 stainless exhaust makes
The loss of output from a 3 inch on a minor modded car over a 2.5 inch is minimal at best and for a street driven car it's something that you'll never legally get to experience or ever tell from seat of the pants driving.
A 3 inch over a 2.5 inch for a street car comes down to what you prefer sound wise and of course there are many other factors that play a part as well like cats, mufflers, stainless vs mild steel, header choice and and exhaust design.
I like the sound of a 3 inch and can easily live with the loss of power that I don't even notice.
The loss of output from a 3 inch on a minor modded car over a 2.5 inch is minimal at best and for a street driven car it's something that you'll never legally get to experience or ever tell from seat of the pants driving.
A 3 inch over a 2.5 inch for a street car comes down to what you prefer sound wise and of course there are many other factors that play a part as well like cats, mufflers, stainless vs mild steel, header choice and and exhaust design.
I like the sound of a 3 inch and can easily live with the loss of power that I don't even notice.
.
There used to be killer exhaust shop in Sydney called Lambros in Darlinghurst, they did a set of custom headers for us years ago with show quality TIG welding, awesome fabrication work!
The smaller exhaust will make a difference in lap times on a race track, it'll be a couple of tenths faster! People just don't believe how smaller headers and exhaust can improve lap times until they see it. V8 Supercars primarily run 1 7/8" headers and twin 3" exhausts to make 630hp in a narrow RPM band. When someone thinks a stock or cammed LS3 road car needs the same sizing, emphasises what they don't know about exhausts. If catless was legal, 1 3/4" tri-y's and twin 2.5" exhaust works best across the RPM band of an LS3 road car. Cats mess this up and often, the better cats on a 3" exhaust is responsible for the power increase seen on a dyno, not the pipe sizing.Correct.
When we bought my Redline it had a full 3 inch Pacemaker system. Was way too loud, so I changed it out to 2.5 inch Hurricane, with single outlet mufflers . Also changed out the 100cel cats to 200cel. It still has the Pacemaker 1 7/8 headers it came with.
The tuner reckons it made no difference to power. I certainly can't feel a difference
The smaller exhaust will make a difference in lap times on a race track, it'll be a couple of tenths faster! People just don't believe how smaller headers and exhaust can improve lap times until they see it. V8 Supercars primarily run 1 7/8" headers and twin 3" exhausts to make 630hp in a narrow RPM band. When someone thinks a stock or cammed LS3 road car needs the same sizing, emphasises what they don't know about exhausts. If catless was legal, 1 3/4" tri-y's and twin 2.5" exhaust works best across the RPM band of an LS3 road car. Cats mess this up and often, the better cats on a 3" exhaust is responsible for the power increase seen on a dyno, not the pipe sizing.
Someone in WA posted detailed drag racing results with header sizing on a cammed automatic VF SS with a hi-stall converter over the 1/4 mile and discovered that an 1 3/4" header was the fastest and optimum size and made a lot sense!