L76 Extractors

[VZGEN4]

After having the thunder for a few months now with the 2.5" cat back exhaust fitted, it's come time to get rid of the rest of the exhaust and add some extractors.

Just wondering if there's a specific type I should be going for with the L76? I know there's plenty of threads on exhausts on the LS1 but I don't want to go bolting something up that doesn't suit the engine.

You guys out there with the L76 and extractors what are your experiences with extractors and what did you go for?

I'm no expert when it comes to exhausts so any help would be much appreciated.

Cheers!

[GHZ28]

I got Hi-Tech ones with HPC coating. Not sure on power increase, but the aural improvement was pretty good.

Ran a 12.9@108.8 with 3.73s so guess didn't hurt the power ;)

gh

[SLugg]

genie make some shortys that allow you to keep the cats in the std position and O2 sensors as well

[Wonky]

genie make some shortys that allow you to keep the cats in the std position and O2 sensors as well

So do HM. See http://hmheaders.com.au/products/index.php?action=list&make=Holden HM120SS and HM121SS.

[VZGEN4]

Thanks for the info guys.

I was thinking i'd do away with the 2.25" pipes and go 2.5" the whole way.

Just not sure what would be more suited to the L76 with it's low down torque. Tri Y's or 4 into 1's?

Also would it be worth while fitting up headers designed for the LS1 or wait until something is developed specially for the L76?

Thanks!

[Alex81]

i got 4-1 on my ls2 then 2.5 inch the whole way with 2 straight through mufflers full manderal bent, sounds good and know drone over 100km/h

[Churchy]

What is the optimum size for headers ?

I am going to put a set on an LS1, and was wondering what size primaries ?

[swingtan]

I have the DiFillipo 4-1's and full 2 1/2" system under my SS. Low down it's great and sounds fantastic. I've been meaning to do a short video to show off the sound but so far only have one at idle. Not particularly great, but I can post it if you like.

Simon.

[Churchy]

DiFillipo is also going to get my busniess, but I can't decide between 1 3/4" or 1 5/8" primaries. What are the pro and cons of both sizes

[BEWARE]

I have Pacemaker Tri-ys on my L76, into twin 2.5in with only mufflers in the middle, sounds good I reckon, and with just a tune and 3.9s it goes pretty well. Bare in mind the cats will need to be moved and O2 sensor extensions needed for these extractors though.

I was told by many shops that 4-1s wouldn't be the best idea, unless more mods are planned later down the track to get the most out of them!

[planetdavo]

LS1/LS2/L76 headers are all interchangeable (subject to centre exhaust flange location), BUT, be wary of using any that move the cats down under the floor unless you get the PCM reflashed to suit. VZ's use 4 oxy sensors, and we get SO MANY VZ's in with repeated check engine lights that have had the cats moved.

[vyssbeast]

I have the DiFillipo 4-1's and full 2 1/2" system under my SS. Low down it's great and sounds fantastic. I've been meaning to do a short video to show off the sound but so far only have one at idle. Not particularly great, but I can post it if you like.

Simon.

i'd love to hear it mate also when you make a video of it being pushed aswell (from the outside)
i also want to make some videos. i heard mine from the outside the other day and :love2: lol

[swingtan]

BEWARE: I initially had the "check engine" alert on my system. I haven't done the full tune / edit yet, but the error was caused by the ECU checking the temps of the 2 "O2" sensors on each side, and comparing them with each other. The error would come up if the "O2" sensor temps were too far off. I think the check was simply disabled in mine.

yyssbeast: I'll get onto those videos !!!!

[SLugg]

Im keeping the std cat back on mine and going the HM shorty 2.25" headers
then a Street Tuner tune and Ill be happy till the cam goes in:love2:

[swingtan]

Ok people,
I've posted a short video taken from inside the car. It's on public roads so I only took it up to the speed limit ;).

http://www.youtube.com/watch?v=WG_2sXUWuU8

It's taken from inside the car and has some short WOT sequences and a bit of just normal driving.

[BEWARE]

I never saw any warning lights or check engine lights when I had mine fitted or up til now!

[MNR-0]

SES lights are to be expected when fitting LTs. There's nothing wrong. Just need to find someone to disable the codes and preferably re-tune her for idle.

Once the O2s throw an SES code your tune fails over to OPEN LOOP and doesn't run off your O2s anymore. This can cost you drivability and economy big time.

[swingtan]

SES lights are to be expected when fitting LTs. There's nothing wrong. Just need to find someone to disable the codes and preferably re-tune her for idle.

Once the O2s throw an SES code your tune fails over to OPEN LOOP and doesn't run off your O2s anymore. This can cost you drivability and economy big time.

Interesting, I had the codes disabled, but I don't know if the idle was done. Mine idles at about 600 which may be lower than normal, I don't know.

When I did get the "check engine" warning though, it still ran fine and economy didn't seem too bad.

[Wonky]

Ok people,
I've posted a short video taken from inside the car. It's on public roads so I only took it up to the speed limit ;).

http://www.youtube.com/watch?v=WG_2sXUWuU8

It's taken from inside the car and has some short WOT sequences and a bit of just normal driving.
Sounds great!!

[VZGEN4]

Thanks for the video swingtan sounds nice!

Beware did you have your cats moved further down?

So now I need to make a decision as to 4-1 or try-y's... time to do some reasearch!

Thanks for the info guys.