[rwicks10]

Hi there, I am looking to start modifying my Zuk and thought I would seek some advice regarding an exhaust upgrade for a J20a. I have checked out the forums and have not being able to find anything regarding an exhaust for a SV420 in detail.

Headers seem to be out of the question unless I would like them custom fabricated, so I was thinking a 2 to 2.25 Inch exhaust with a high flow cat. I am not sure if this is the best option as the cat seems to be quite expensive and maybe of little value over the standard item due to using the standard exhaust manifold. The vehicle has 180,000 km and I am also looking at upgrading to a K&N filter and fitting a snorkel.

If anyone can suggest the correct diameter exhaust and their opinion on the cat, any assistance would be appreciated. Cheers, rwicks10

[atari4x4]

I'm running a 2 1/4 press bent flanged exhaust with a metallic hi flow cat & some sort of sports muffler. I think most of the increase came from the hi flow cat, Fatzook has got some extractors for the SV420.

[ninjamoses]

I believe hurricane headers make extractors to suit the j20a vits

[Fatzook]

Yep. Hurricanes. Get some prices locally, I could probably get them posted to you for $350 all up. Retail is $380ish

As for the rest, go 2" mandrel bent, or 2.25" press bent.

[Daly87]

Just jumping in on a thread but has anyone ran a sv420 with a 2" exhaust and just a sports muffler? Or is that going to be too loud and I should get a resonator? ?

[Gwagensteve]

I think you'll want a resonator.

Steve.

[Daly87]

Cheers steve.

300 for a pipe and muffler, 380 with a resonator.

Seems ok?

[Daly87]

For an FYI we tested the car with just a muffler ( the one in between a straight through and a tripple pass) and it was ridiculous. Loud and the drone at 100k was unbelievable. Stook in a hotdog resonator where the cat was and it was great. Nice enough sound with no drone but louder than stock obviously.

[Daly87]

Another update, took the vit to Brunswick Junction on Saturday and the hour or so drive was tiresome, what I thought was an OK exhaust with the resonator in turned out to be annoying on the long haul.

What's left to do? Not much room under there for anything else...

[JrZook]

What brand of muff was it?

[Daly87]

Not too sure... I noticed a fair few redback mufflers on his shelve but not sure if this is on my car

[oneinkedgeek]

ninjamoses wrote:

I believe hurricane headers make extractors to suit the j20a vits

Yeah your right, i got some sent to NZ from AU, got them installed, removed the cat, added a high flow res and muffler at the back.... made a big improvement.

[DarkHorse]

My experience with redback exhausts is that they are very loud and very droney. There'll be a plate on it if it's a brand name unit.

[Chop]

The secret with redback mufflers is to get one that is as close as possible to the size of the original muffler. But alas everyone goes smaller!

[Daly87]

Ill check in the morning. I might take it back and see if he will swap it out for a larger one!

[Daly87]

was just messing around under the engine today. Just cleaning stuff and took the heat shield off to see the above, Im no expert but I'm pretty sure that's not supposed to be like that....

Could this cause any of the following. power surging, o2 sensor code 13, high fuel consumption....

[Daly87]

Also my muffler has no marking on it. So I assume its not a redback?

[JrZook]

Yep! O2 readings will be all over the shop due to the extra air getting sucked in. That will cause a code and your fuel economy will dip

[Daly87]

Thanks mate I have all 3 of the symptoms. I wasnt sure because I was thinking that air wouldn't be sucked into it because the pressure would be forcing air (exhaust gases) out??