Is it worth upgrading standard headers with stock exhaust setup?

[BlackCalaisVVE]

Hi all,
I’m trying to decide on my next performance mod, the car (VE Calais V V8 not AFM) already has OTR and tune.
Wanted people’s opinions on what to do next. As I’m on a budget I thought I might just replace the standard headers with DiFilippo headers. I’m after power not sound, I don’t take the car down the quarter mile so it will be more for everyday driving and a small amount of track work. Would this best next budget mod to do?

I have searched the forum and couldn’t exactly find the answer I was after so I have a few questions.

If I was to change the headers what power increase would I be expecting (my tune will also be updated if I change the headers)?

I’m guessing the car will sound a bit gruntier, but will it be overly loud or cause any droning issue? I’m guessing not as these issues normally occur when changing the exhaust.

If I decide at a later date to upgrade my exhaust will there be much of an issue fitting it to the headers as I’m guessing the headers would have to be modified to fit the standard exhaust?

If I do the headers should I also replace the cats with better cats?

What price would I be looking out for fitment and supply? I’m guessing $1000-$1500 (I would go for the stainless steel headers).

Is there any down side to fitting the headers? For example would I sacrifice low, mid or high range power compared to my setup now. I’m assuming it would also actually improve fuel economy.

Would I notice the difference in everyday driving?

Sorry for the long winded post, any help would be appreciated.

Thanks,
David

[HEKYEH]

I'd do it the other way round.

Go the cat back exhaust first. Then, if u want to move on from there, do the headers and cats.

Cat back exhaust on the VE can be had for the $1000-1500 budget you have.

HM make a a good stainless steel cat back that will just bolt straight up to the stock cats.

[bouka]

If you want power do the headers, if you want drone, oops I mean sound, do the catback.

A nice set of headers and standard cat back would be a good option based on what you have said.

Would be much better with a cam as well!

[vschaser]

Speak to steve at oztrack, he has alot of experience with exactly what your asking. He has told me that the standard cat on a ve flows very well but there are decent gains to be had by upgrading extractors and cats.

[gavlotic]

Hey David,

i recon headers + cats would be good. I was always taught that most of the breathing and extra power was from the first 3feet of exhaust out of the motor namely headers and the pipe work with the cats up to the cat back.
so i recon if u did that + your tune & otr I recon it would work pretty good and have an element of stealth to it as well. Don't forget touch up to tune....

cheers,

Gav

[hRTHSV]

Have you thought about hunting around for a set of HSV extractors and cats, I'm sure there are some cheap ones around, certainly much cheaper than buying extractors and cats and only a little less power. If you find the right exhaust shop you might be able to pick them up for almost nothing and you can still get a HM cat back or save the money.

[jaykay]

I just sold my headers and cats off my E Series Senator for $75...

[fishla]

I just sold my headers and cats off my E Series Senator for $75...

Don't tell him that, tell him what you replaced them with :)

[DCV1NU]

You'll find most of the power gain will be from the headers & cats, so upgrade to a set of 1 3/4 or even 1 7/8 headers with some 3inch high flow cats & you'll be laughing.

[spanks]

I fitted X-Force headers and cats and 2 1/2" cat back system,but kept the factory rear mufflers. Is wifes car and she didn't want it as loud as mine. Is really not much louder than stock,just a bit deeper.Car has OTR and tune and it made 256rwkw. But regardless of the power,it is just so much more driveable. Ditching those factory cats certainly freed everything up.

[smokey777]

I'd do it the other way round.

Go the cat back exhaust first. Then, if u want to move on from there, do the headers and cats.

Cat back exhaust on the VE can be had for the $1000-1500 budget you have.

HM make a a good stainless steel cat back that will just bolt straight up to the stock cats.

he dont want sound.. to be honest i wish id just done headers, cats & cam & just left standard catback.

[toey]

the guys at castle hill exhausts done a ve wagon recently with headers and cats and stock cat back. i enquired about this as i wanted to do simlar to my wm, want the go and not a loud note. they said it still sounded like stock even with headers and cats.

[BlackCalaisVVE]

Thanks for all the reply's guys keep them coming. I was originally going to replace my stock headers with HSV ones as my mate was going to give me his of his Maloo, but he decided to keep them as he was having issues with his modded setup. I thought going for aftermarket headers you would see more of a power gain than from the standard HSV headers, happy to be corrected though.
The car is currently running just over 242rwkw from tune and OTR so was hopping the headers would take it over the 250rwkw mark.

[surfwagon]

Mines not a VE but I fitted extractors and high flow cats to my VZ Senator with std HSV cat back and it was exactly what I wanted, a bit more go but with out attracting attention.
In actual fact the std VZ HSV exhaust has a slight drone at highway speeds and the extractors and cats removed that slight drone completely and made the note a little deeper with out being louder.



__________________________________________________ _________
my senator http://www.ls1.com.au/forum/showthread.php?t=121025

[DCV1NU]

Thanks for all the reply's guys keep them coming. I was originally going to replace my stock headers with HSV ones as my mate was going to give me his of his Maloo, but he decided to keep them as he was having issues with his modded setup. I thought going for aftermarket headers you would see more of a power gain than from the standard HSV headers, happy to be corrected though.
The car is currently running just over 242rwkw from tune and OTR so was hopping the headers would take it over the 250rwkw mark.

Upgrading to the HSV headers & cats wont do much in terms of power gain, but if you upgrade to a set of 1 3/4 headers with some 3inch high flow cats you'll make your 250rwkw mark easy(should make around 10rwkw extra with this setup).

[Typhoon BF]

The stock exhaust would clog up any benefits from cats/headers.

If there is a kink in a hose, dont matter if you got headers up front.

[DCV1NU]

The stock exhaust would clog up any benefits from cats/headers.

If there is a kink in a hose, dont matter if you got headers up front.

:rofl::lmao:

[Typhoon BF]

:rofl::lmao:


Not sure where the comedy is mate?

If the stock exhaust is any good how does a cat back aftermarket make more power with stock headers? Does it miraculously open up when headers are fitted?

Sams performance did a test on headers only and even the stock headers made more power than some aftermarket.

Whats the comedy?

[DCV1NU]

Not sure where the comedy is mate?

If the stock exhaust is any good how does a cat back aftermarket make more power with stock headers? Does it miraculously open up when headers are fitted?

Sams performance did a test on headers only and even the stock headers made more power than some aftermarket.

Whats the comedy?

Stock headers out performing aftermarket headers...Seriously?!

Dude...Just quit while your ahead and save yourself even more embarasment.

[Typhoon BF]

Why dont you read that thread with the test by same performance, there wasnt even 5hp difference between the lot, stock headers performed near the top

This is on an otherwise stock car as the op has.

You should read that thread then come back and apologise

[DCV1NU]

Why dont you read that thread with the test by same performance, there wasnt even 5hp difference between the lot, stock headers performed near the top

This is on an otherwise stock car as the op has.

You should read that thread then come back and apologise

What thread?? I've searched but didnt find anything remotely related to Sams Performance+Exhaust test.

And i would not classify an otr & tune as "stock"

Have a look at this video that HP-F recently did regarding exhausts - http://www.ozgarage.com.au/season2-video/season-2-episode-9-online-exhaust-comparo

[Wonky]

On my previous SSV sedan I gained 15rwkw going from HSV headers and cats (with 3" system) to Pacey 4-1 and high flow cats. Readings were done on different days so that may account for some variation but I know Mustanger and others had similar results. I'd expect the gains over stock headers to be even better, though I don't know what affect keeping the standard catback would have.

[Wonky]

Why dont you read that thread with the test by same performance, there wasnt even 5hp difference between the lot, stock headers performed near the top

This is on an otherwise stock car as the op has.

You should read that thread then come back and apologise

That test was done many years ago on LS1 and I suspect has little relevance these days given improvements in extractor design, especially on a VE 6 litre which is a totally different beast to LS1. I also suspect that in order to meet newer pollution laws VEs are more strangled from the factory, hence have more to gain.

[Oztrack Tuning]

VE L98 and LS3 respond strongly to extractors and cats. catback is mostly for sound. We have seen close to our top dyno figures for stock cammed cars on a few occasions from cars with stock exhaust and small quiet catbacks.

[Oztrack Tuning]

BUT they had extractors and cats upgraded.