Aftermarket Cats advice with HSV exhaust setup

[Nefarious78]

I have 200's on vf2 calais v, went from stock to genie try-y 200 cel and factory bimodal cat back. Difference in sound was significant. Point of the story turning off bimodal is significantly quieter. No different to what it would sound like with stock and bi modal off.

Zero drone also with 200's but that could be tune.

One thing i have noticed is there is a big jump from closed to open and can be annoying (find myself removing the bi modal fuse time to time) as its not a fluid jump in sound. Makes people turn their heads though

 

[HyonV8]

Thanks for your reply nefarious.

You mentioned genie try y and factory bi modal. What did you have for Center pipe?

It’s good you have no drone. That’s what I’m after. Not sure I’ll get “ no drone “ with my set up.

Bit of a pain with the bi modal off and the rapid noise increase but can’t win them all. Are you finding it’s crazy loud or is it ok once your sitting on 100 and cruising. I have kids to think about so am trying to also find that happy medium.

 

[HyonV8]

Being a Series 1 (I bought the rears separately ) I don't have Bi Modal control, so mine are always open. I'm happy to help.
Also bear in mind that with HFC that you will get an error code from the rear O2 sensors without a tune.

Yeh aware of the tune which is what I was going to get. While I’m at it might as well drive out of the shop with something that sounds like a V8 but also keeping in a mind a budget. Wish I had 10gz laying around haha.

 

[Nefarious78]

Thanks for your reply nefarious.

You mentioned genie try y and factory bi modal. What did you have for Center pipe?

It’s good you have no drone. That’s what I’m after. Not sure I’ll get “ no drone “ with my set up.

Bit of a pain with the bi modal off and the rapid noise increase but can’t win them all. Are you finding it’s crazy loud or is it ok once your sitting on 100 and cruising. I have kids to think about so am trying to also find that happy medium.

Left it factory from cats. The sound in cabin is lot less than outside, but 100 cel would be louder again. As long as you are doing under 2800rpm or not accelarating enthusiastically the bimodal shuts off and its like a quiet family car (even at speeds above 100....a "friend" tells me ) in cabin that is.

The reason i left center was because i picked up headers cheap w/cats. Got about 35-40rwkw w/tune and OTR (I would strongly suggest you have CAI and tune as mentioned)

 

[HyonV8]

Left it factory from cats. The sound in cabin is lot less than outside, but 100 cel would be louder again. As long as you are doing under 2800rpm or not accelarating enthusiastically the bimodal shuts off and its like a quiet family car (even at speeds above 100....a "friend" tells me ) in cabin that is.

The reason i left center was because i picked up headers cheap w/cats. Got about 35-40rwkw w/tune and OTR (I would strongly suggest you have CAI and tune as mentioned)

Yeh I think the 200 cell is what I’ll get with the CAI and tune.

Good to know that when cruising it does quite down.

Is yours a sedan, wagon or ute?

I’m wondering whether the genie tri y is helping more so than stock hsv headers to keep that boomy/drone to a minimum or non existent. I guess the other aspect is that the stock VF2 exhaust has the Center mufflers to help with drone. The HSV Center doesn’t have that.

I’m not really all that knowledgeable with cars hence all the questions.

 

[Nefarious78]

Yeh I think the 200 cell is what I’ll get with the CAI and tune.

Good to know that when cruising it does quite down.

Is yours a sedan, wagon or ute?

I’m wondering whether the genie tri y is helping more so than stock hsv headers to keep that boomy/drone to a minimum or non existent. I guess the other aspect is that the stock VF2 exhaust has the Center mufflers to help with drone. The HSV Center doesn’t have that.

I’m not really all that knowledgeable with cars hence all the questions.

I have a wagon, would make stuff all difference probably fraction louder than sedan as boot is empty

Yeah exhausts is both known and unknown science. If you throw things together not always gonna get what y oui u want. Took a gamble worked for me.

The R8 headers i believe are try-y also so you probably get similar to genie. My headers are coated too. The cats will make difference though.

Good luck and talk to a reputable exhaust place, they will only sell you what they think you need as they usually got enough on they dont need to strip you of cash

 

[HyonV8]

I have a wagon, would make stuff all difference probably fraction louder than sedan as boot is empty

Yeah exhausts is both known and unknown science. If you throw things together not always gonna get what y oui u want. Took a gamble worked for me.

The R8 headers i believe are try-y also so you probably get similar to genie. My headers are coated too. The cats will make difference though.

Good luck and talk to a reputable exhaust place, they will only sell you what they think you need as they usually got enough on they dont need to strip you of cash

Thanks for the Info.
I spoke to a local place yesterday who said he wouldn’t recommend it. Reckons it will be a 8/10 for boominess inside the car and I won’t like it at all. Didn’t really trust what he said. Surely just changing the cats can’t increase it that high. Maybe it will who knows.

That’s what made me come to this forum and ask these questions. Was hopeful that someone had the same set up as me with the high flow cats and I could get the right Info right from the horses mouth so to speak

Thanks again

I’m all ears if anyone else has any info.

 

[Nefarious78]

Thanks for the Info.
I spoke to a local place yesterday who said he wouldn’t recommend it. Reckons it will be a 8/10 for boominess inside the car and I won’t like it at all. Didn’t really trust what he said. Surely just changing the cats can’t increase it that high. Maybe it will who knows.

That’s what made me come to this forum and ask these questions. Was hopeful that someone had the same set up as me with the high flow cats and I could get the right Info right from the horses mouth so to speak

Thanks again

I’m all ears if anyone else has any info.

100 cel maybe (doubt it, it is when you floor it) but remember the key reason to keeping bimodal you can always turn off and its quiet as hell. Then just have it on when you're driving solo.

Mate i have a family they love it. No complaints of noise. Except when i come home (its very loud on outside)

JUST DO IT !!! Hahaha. Get a cam while your at it

 

[HyonV8]

Yeh I think I’ll just get it done man.
Love to get a cam if you’re happy to pay haha. Need a second mortgage for that.

 

[MY17DIR]

Ive got the same headers and mid section ready to bolt on, had decided on 200 cell cats from what ive read on here in the past.
Let us know how you go with it