Finally deciding to go stage 3 this summer. I have decided on mostly everything my setup is going to involve what I am posting on here for is to double check I have everything I need and to make sure I am not wasting money on items I don't need as well as making sure I will not be harming my car. I want to spend as minimal as possible but I will spend what I need to make sure my car will function to it's fullest capability. I also have questions on some of the extras that come with these parts that zzp offers mainly exhaust stuff. I have a stock 2006 SS g85 that I will NOT be taking to the track I am just making my DD a little more fun and I will probably not be making anymore modifications unless I go with a 2.8 pulley and decide to go 2.7 later. My planned mods are:

zzp Stage 3: 2.8 #60, zzp 3in. intake S3 H/E, Dual pass endplate or can I go 2.7 with #80 safely with everything I'm going to list.

Getting HPtuned: Wideband (obviously) but do I need the interceptor or will I not need it with a DD?

(Here come the exhaust questions) I won't mind it if it's slightly louder than stock but I'm looking for as quiet as possible that doesn't restrict and still sound good.

zzp 3in. downpipe: 200 cell cat (3in exit) or 400 cell cat (3in exit) Which one is better for me? What's the difference?, front and rear gaskets, 02 wideband bung since I am getting wideband.

zzp 2.5in. Cat back ehaust: With the bolt up to the 3inch downpipe and the 3 chambered muffler.

zzp Header? Not really sure what I should get here (longtube, shorty, midlength?)and with what options with my specifications. Again looking for quiet but best possible gains.

Sorry it was long but I think I covered everything. If you notice anything I should add or change feel free to give me recommendations.

 

Getting HPtuned: Wideband (obviously) but do I need the interceptor or will I not need it with a DD?
You don't "NEED" an interceptor, but it is a very, very nice thing to have to monitor things.

(Here come the exhaust questions) I won't mind it if it's slightly louder than stock but I'm looking for as quiet as possible that doesn't restrict and still sound good.

zzp 3in. downpipe: 200 cell cat (3in exit) or 400 cell cat (3in exit) Which one is better for me? What's the difference?, front and rear gaskets, 02 wideband bung since I am getting wideband.
Don't know the difference between the cells. Never heard of them. I have ZZP's dp and it's fairly quiet.

zzp 2.5in. Cat back ehaust: With the bolt up to the 3inch downpipe and the 3 chambered muffler.
If you're going to get the 2.5" catback, you might as well get a 2.5" dp too.....

zzp Header? Not really sure what I should get here (longtube, shorty, midlength?)and with what options with my specifications. Again looking for quiet but best possible gains.
If you get the longtube, then there is no need to also buy a dp. It will give you the best gains.

 

Thanks for the quick reply and detailed. I'll go ahead and get the 3inch exhaust then I was on the fence about which one would be better.

You said for the Header I can just get the longtube and exhaust and not have to worry about the downpipe?

What about the 2.7#80/2.8#60 pulley what would you recommend with the stuff I will be getting.

 

The 3 inch zzp exhaust is a little loud for a daily driver. I would get the 2.5" catback with a catted longtube header. 60lb injectors will be plenty for any size pulley you run on the m62 as long as you are only running pump gas and not E85. When I was zzp stage 3, I ran the 2.7 pulley with 60s and it was pretty fun.

 

The header is kinda like a "one piece" header and dp. It will bolt right up to the catback. No need for a dp.

And my opinion is the smaller pulley the better haha. Really just up to you. If you plan on doing future mods, then just go ahead and get the 80's.

 

For a dd I would go with a 2.90. 2.80 is okay buy your gonna find out youll want a front mount heat exchanger. These m62's are quite inefficient and create alot of heay. 60s can be good but can have some idle issues if not tune right. You can go with the 80s and thay will allow you to run e85 of you like. So to answer your question 2.8 with 80s and a heat exchanger. I went with a 2.90 and 42s I got lucky in the fact that my IDC isnt maxxed.

 

How much boost and WHP/WTQ do you think I would get out of stage 3 2.7 #60, s3 H/E, zzp 3in. intake, dual pass, Longtube header dp combo and 3in. zzp exhaust on a HPtune?

 

you don't have enough engine to run a 3in exhaust stay 2.5

 

Listen to Mr B. 3" is to big for the heaton.

Two reasons
1-The exhaust is not the restriction on our cars. It's the ports. Unless you are having the head done you will add very little if any at the very top end.

2-exhaust gas scavenging. The smaller exhaust keeps the velocity up which basically helps pull exhaust gases out of the engine almost like a syphon. Going to a larger exhaust will leave more exhaust gases in the engine at part throttle and transitions. Since you can't burn them again it will reduce power at all those points.

In other words you might add a tiny bit at the very top end but you will lose everywhere else and the car will feel and be slower.