Just got HSV headers

Also how hard is it going to be to change them with the car on jack stands?
Or am better off taking it to an exhaust shop to get done

 

If you are good with spanners do it your self or take to exhaust shop it’s not hard to do your self just study what’s there and work on a process of elimination to remove and fit new headers,a shop will charge about $250 or there about to do it,if you have a good one it’s the best bet,no lost skin or bloody driveway.

 

Yeah ill do mine myself coz im a stinge and its fun and easy with boltons

 

Forgot to add you don’t need to replace header bolts as they are not yield bolts,you can use your old gaskets as well just remember which way they were when you removed them and put anti siez goop on bolts before refitting.

 

Cheers @LS1SS I’m going to give it a go at home and see how I go

 

Be very careful not to move the steering rod or steering wheel while it's disconnected. It will stuff the clockspring.

 

As Cuda says about steering rod,undo it it’s easy if you have your wheels straight on car ramps,another thing Mattricho is before you pull the dip stick tube out look very closely at its path to sump to refit it,to remove oxy sensors use a 7/8ths ringy,don’t use open ended or you will round em off,get old ringy and cut slot in the ring so you can fit wires thru,count how many twists when you undo them and when refitting them twist them up same amount,don’t try and undo the plug from up on top of gear box it will do your head in and use anti seize on thread.

 

Cheers @426Cuda @LS1SS I’ll be careful with the steering rod and wheels if I have a go at it.
Is there any particular anti seize to use or just anything high temp well do??

 

Just use any heat proof anti seize on all bolt threads,I found best way to do the job is car on ground undo/ remove manifold bolts except the middle one,just loosen this one,drive car up on ramps,chock rear wheels,take out plugs so you don’t bust em,undo sensors count twists,remove nut/bolt from steering rod and push this up a bit and DONT twist,undo nuts off cats and pull free,back in engine bay,remove bolt from dip stick tube and pull twist out carefully,remove last bolt and gently lower cats/manifold down,if you can drag them out you can split cats from manifolds now,now sit down have beer n relax,finnish beer n assemble in reverse.

 

Sorry to reignite an old thread, but I am looking at doing exactly this, so if i do either option for my VF2 Redline, I can still use the existing system, just focus on Headers and Cats and this is where I will get best bang for buck?? if I was to go after market 4 into 1's which would you recommend?

Seems hard to find HSV Headers and Cats at the moment. Guessing with both you should still do an OTR also??

 

Don't need to at all. OTR is freeing up intake with slightly colder air at a better intake position than stock. Hsv system frees up exhaust slightly over stock. You can tune with either either, neither or both.

 

And to further balance the perspective, the main downsides to the OTR air intake location is that it picks up dirtier air coming into the front of the car from road traffic than does the stock intake pickup location.
Additionally, the high flow air filters don’t filter the air as thoroughly as does the stock filter.
Depending on your driving conditions, you may need to keep a close eye on your air filter cleanliness and ensure you have a complete seal around the filter.
Because slowly sandpapering the engine internals is typically not an outcome we have in mind when modifying the intake to chase more torque/power.

 

Just some information on the exhaust bolts thought I’d call and ask Holden how much for them $212 for 12 bolts I said **** that

 

considering that, is one CAI better than another due to location?, or if leaving stock, how much will that restrict the benefits of say Headers and H Flow Cats with a Tune??

 

A CAI that draws from the stock location will draw the cleanest air you can probably expect to get. An Over The Radiator will draw dirtier air depending on driving conditions.

I’ve read a few times on this forum and the SS forums that the stock intake does not cause a restriction until you start getting into the territory of larger cams and/or forced induction.

So if that’s true, the stock intake should still allow scope for fitment of headers, hi-flow cats and exhaust to improve engine breathing and throttle response. A tune will add to that again.

Happy for someone who knows more to add to that.

 

Hi all, just an update I finally got the 340 headers fitted on the car I ended up going to a exhaust shop as I needed to get some stuff and I really couldn’t be bothered.

Anyway I don’t think it’s made much of a difference. The car is a bit deeper (more bass-y) at idle and there use to be drone between 1600/2000rpm that’s gone.

When you put the old boot in to it sounds really good and aggressive ( as aggressive as a stock L77 can be) other then that I don’t think there’s much difference between the standard logs or the 340kw tri Y sound wise.

Power feels more responsive/ eager to go from about 1200rpm up to redline.

Are they worth it?? If you already have the 2.5” mid section and bimodel mufflers probably not but if you can find a set and then change everything thing out at the same time it’s probably worth doing just so it’s all 2.5” front to back

P.S I’m trying to get a video of it but the weather has been s**t and I haven’t had a lot of time

 

Here is a video of my car start up and drive reving to about 3000rpm

 

and this is a cold start till the reves drop down.

at about 8secs you can hear a pop and crack that was quite loud.

 

Did you change the CAT's to a 200 or 100 cell? I think there is alot of nice sound and power to be had in changing the CAT's, that's my gut feeling anyway...

 

You are rite about changing cats,I had HSV headers and cats and mid section with std bimodal cans,was not impressed with the sound,it was a loud and tinny,was going to change the cats to 200 cell but thought bugger spending money for the same sound,a good deep note I was after,so I spent big $ on Hurricane headers with manta quiet back,got the note I was after.Cought up with cuda 426 from Wagga on Thursday when I was down that way,we were discussing exhausts and he started up his VF redline,it has HSV headers after market cats with HSV mid and std cans,I can say what a nice exhaust note it had nice and deep,I couldn’t believe the difference a set of aftermarket cats to change the sound,wished I had gone with after market cats and saved lots of $,with this system and a good tune you would be more than happy with minimal outlay of $.