Vz sv6 extractors and high flow cats

[Chewysv6]

Hi guys,
Got some extractors and high flow cats the other day. Was thinking about putting them on with some mates. Was just wondering if anybody has any experience in doing this and has any tips such as do I need new gaskets, what do I seal them on with, is there any welding involved etc?
Any tips would be helpful

 

[exanVZ]

Hey mate, I'm not an expert but it should be pretty straight forward. There should be gaskets to go from the exhaust manifold to the headers on either side, you need to clean off all the old **** (make sure it doesn't fall in) and then you can seal the new ones on with some exhaust seal. Between the headers and cats you will have metal gaskets too, usually 4 bolt and will depend on the size of your pipes. Same deal just clean off any old crap and put a bit of sealant in with the new gaskets and bolt it up. If everything you have bought is 'bolt on' there will be no welding required. If you have just bought type of cats that need to be welded in, you will need to get some pipe made up for it. Not sure if the alloytecs need O2 sensor extenders or anything, I did on my LS1. Hope this helps a bit. Mostly pretty straight forward.

 

[Not_An_Abba_Fan]

Actually, the VZ is a prick of a job. There is a coolant pipe that runs down the RHS of the engine that needs the brackets undone so it can be moved to get to the bolts. Also, the front bolt on the RHS is a bastard to undo. You need a wobble head extension to get to it.

You won't need O2 sensor extensions, but you will need gaskets. Use sensor safe sealant on them, something like Ultra Blue.

 

[Chewysv6]

Thanks guys, that helps a lot. I've got a book that goes through how to remove and refit the manifold so I'm not too worried about that. I'm afraid though that I think Iv got the weld on cats, what would be the deal there, would I have to cut into the cat back since the extractors are longer than the original manifold?

 

[Not_An_Abba_Fan]

You will need to cut the engine pipes so that the cats sit between the end of the extractors and the bend where the pipes point out to join the cat back. There are flanges there so you don't need to cut the cat back.

 

[Walshie93]

What sort of gains do you get out of full exhaust systems? Ive got twin 2.5" cat backs, though I'm considering getting extractors and hi flow cats. Would it be worth it?

 

[Chewysv6]

Pacemaker claims 10% and Iv heard it gains on the bottom end. A full cat back unleashes the full benefit of extractors and high flow cats as the whole system is high flow, so I think it would be worth it. Although be careful with the sound cuz Iv heard a few people say on here that a full system makes them sound ****

 

[Not_An_Abba_Fan]

The wrong system makes them sound like ****. Trying to quantify gains is a hard thing to do, every car is different. All I will say is that it will improve acceleration and highway economy. What the actual figure will be is hard to guess.

 

[Chewysv6]

The wrong system makes them sound like ****. Trying to quantify gains is a hard thing to do, every car is different. All I will say is that it will improve acceleration and highway economy. What the actual figure will be is hard to guess.

I was just gonna keep my stock exhaust and just off the muffler, due to the wrong system sounding like ****, soo many people have said soo many different sized cat backs sound the best. So I don't really wanna spend the money on a cat back for it to end up sounding like ****. Do you have any suggestions for what would sound good?

 

[Not_An_Abba_Fan]

Yes actually. I do a system that is 2 1/4" twin off the cats into a single 3". Sounds nice and deep, no drone. I have done a lot to people on here and never had a bad word said about it. Do a search for Manta VZ and it should come up with a few threads on it.