Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

New Headers Advice

Jackel

Member
Joined
Jan 18, 2019
Messages
157
Reaction score
14
Points
18
Age
47
Location
Oakleigh
Members Ride
Vf ssv 2
I have a sensitive nose and don't notice any difference in fumes from 100 or 200 cell cats fitted to stock or tuned engines compared to the stock cats.
Thats very good! Its my only sticking point cause some say 200 cell cats make it fumey while others like yourself dont notice any difference in fumes compared to stock 400 cell cats.





.
 

Mavericks Choice

Well-Known Member
Joined
Aug 29, 2007
Messages
280
Reaction score
25,254
Points
93
Location
NSW
Members Ride
VF2 SSV M6, VF2 LS3 Calais V, VZ 6L M6 Crewie
Nice! Thats exactly what im looking at too.
How is the performance improvement? Better bottom end torque? More responsive? Did you get bimodals and noticed it to be fumey due to the 200 cell cats?
It appears to have improved bottom end performance, though hasn't been tuned yet. Mine is a VF2 with bimodals, relay pulled already. Haven't noticed any excessive fumes. My preference now is to retain bimodals & fit a custom mid section. So far no mil light, but we will see.

Edit: Done a little poking around today as my installer mentioned the o2 extension harnesses were not required, he has moved these out of their retainers from the back of the block to give them more slack. I will fit the extensions & tidy that up.
Also anyone fitting these long tubes check all the electrical cables running near the pipes. Mine were too close, went out & bought more heat shield & ties to keep a safe distance from those. My pipes are ceramic coated but still put off a considerable amount of heat.
 
Last edited:

Thomas_D

Active Member
Joined
Apr 13, 2020
Messages
113
Reaction score
26
Points
28
Age
42
Location
Sydney
Members Ride
VF2 SSV Redline
Folks,

Does anyone know what type of cats I would need if my aim was to keep my emissions within EPA (NSW) regulations. I'm guessing there's no way a high flow cat will pass emissions regardless of the tune?
Would changing to an aftermarket full exhaust system minus the cats (keep factory) be pointless? VF2 Redline, possibly supercharged soon.
Perhaps HSV headers and cats will bolt on to existing midpipe-back?
 
Last edited:

[paradox]

Well-Known Member
Joined
Feb 4, 2018
Messages
655
Reaction score
365
Points
63
Location
Sydney
Members Ride
VF2 SSV-R
Does anyone know what type of cats I would need if my aim was to keep my emissions within EPA (NSW) regulations.
the ones from the factory
I'm guessing there's no way a high flow cat will pass emissions regardless of the tune?
if all you get looked at is a CEL then you can tune that out, but if they were to actually measure particulate. nope.
Would changing to an aftermarket full exhaust system minus the cats (keep factory) be pointless?
cat back? sure plenty of people do it.
possibly supercharged soon.
obviously LSAs come with cats from factory but depending on your intended power levels, you will likely blow out the cats if you plan big numbers.
 

Thomas_D

Active Member
Joined
Apr 13, 2020
Messages
113
Reaction score
26
Points
28
Age
42
Location
Sydney
Members Ride
VF2 SSV Redline
the ones from the factory

if all you get looked at is a CEL then you can tune that out, but if they were to actually measure particulate. nope.

cat back? sure plenty of people do it.

obviously LSAs come with cats from factory but depending on your intended power levels, you will likely blow out the cats if you plan big numbers.
Cheers
 

Milo 6.0

Active Member
Joined
Jul 8, 2019
Messages
447
Reaction score
206
Points
43
Age
46
Location
perth
Members Ride
2013 vf ssv wagon/2009 fg xr6t(daily
It appears to have improved bottom end performance, though hasn't been tuned yet. Mine is a VF2 with bimodals, relay pulled already. Haven't noticed any excessive fumes. My preference now is to retain bimodals & fit a custom mid section. So far no mil light, but we will see.

Edit: Done a little poking around today as my installer mentioned the o2 extension harnesses were not required, he has moved these out of their retainers from the back of the block to give them more slack. I will fit the extensions & tidy that up.
Also anyone fitting these long tubes check all the electrical cables running near the pipes. Mine were too close, went out & bought more heat shield & ties to keep a safe distance from those. My pipes are ceramic coated but still put off a considerable amount of heat.
Do they run super close to the starter too?
I know the 4 into 1 empire headers i tried hit literally everything(starter,trans cooler lines,wiring harness),i spoke to my tuner and he said most 4 into 1 extractors are the same(hit almost everything).
 

PeteSS

Active Member
Joined
Dec 12, 2015
Messages
574
Reaction score
193
Points
43
Location
Sydney
Members Ride
VF Series 2 SSV Redline
Folks,

Does anyone know what type of cats I would need if my aim was to keep my emissions within EPA (NSW) regulations. I'm guessing there's no way a high flow cat will pass emissions regardless of the tune?
Would changing to an aftermarket full exhaust system minus the cats (keep factory) be pointless? VF2 Redline, possibly supercharged soon.
Perhaps HSV headers and cats will bolt on to existing midpipe-back?

You get more power gain (especially on VF1) from a cat back with standard headers and cats, then you do from putting just headers and hi flo cats.

Unless you're going to cam it, i wouldn't be too concerned about EPA issues.
 

Mavericks Choice

Well-Known Member
Joined
Aug 29, 2007
Messages
280
Reaction score
25,254
Points
93
Location
NSW
Members Ride
VF2 SSV M6, VF2 LS3 Calais V, VZ 6L M6 Crewie
Do they run super close to the starter too?
I know the 4 into 1 empire headers i tried hit literally everything(starter,trans cooler lines,wiring harness),i spoke to my tuner and he said most 4 into 1 extractors are the same(hit almost everything).
Appears to have plenty of room at the starter, no worries there, fit was good.
 

Thomas_D

Active Member
Joined
Apr 13, 2020
Messages
113
Reaction score
26
Points
28
Age
42
Location
Sydney
Members Ride
VF2 SSV Redline
the ones from the factory

if all you get looked at is a CEL then you can tune that out, but if they were to actually measure particulate. nope.

cat back? sure plenty of people do it.

obviously LSAs come with cats from factory but depending on your intended power levels, you will likely blow out the cats if you plan big numbers.
The plan is to supercharge it and stay under 450rwkw.
A number of tuners I spoke to want to cam it as well in order to relieve some cylinder pressures. Other tuners say the SC will work fine with the factory cam providing it's tuned accordingly.
One tuner says he can do SC, high flow cats, AND cam that will pass emissions no probs, I'm guessing an E85 tune.

Re: the cats, I'm leaning towards 200 cell although most tuners warn against them in case of a failure with SC applications, mainly heat issues disintegrating them.

Decisions decisions.....

PS. I've heard it mentioned that most aftermarket high flow cats are shitezner for durability anyway.

So, how to find a cat that will pair up well with a SC, be relatively not fumey but not disintegrate either....
 
Last edited:

07GTS

Well-Known Member
Joined
Sep 8, 2013
Messages
4,954
Reaction score
6,511
Points
113
Location
Australia
Members Ride
VEGTS BUILT BLOWN E85
if u want to pass emissions with a blower and cam u need the LS9 cam it does a decent job for factory, using the factory LS cam will work but does drop of quick after bout 6k as u just cant get the exhaust out so it just bottles up and kills power, the LS9 cam with the 230 exhaust lets more out which is why it helps, i had some cheap metal cats that lasted for years without issues boosted and would still be going if i didnt upgrade exhaust not sure what brand they were tho, also mounting cats further back will help them survive the heat (but may not pass tests) e85 will help as it has much lower exhaust temps
 
Top