On Friday I picked up an 07 SS and I want a ask a few upgrade
questions about from people I'm sure have already done them.

Brake upgrades, I think they were 94+ F-Body Brakes.
Is there a write up, or link to parts needed for swap?

Looking for a set of Headers, but I cant justify $550+
for headers to gain a few hp/trq. Are there any good,
yet cheaper headers out there? OBX headers good?

What do Factory 06/07 SS Wheels (8/10) with decent
tires (BFG Comp 2s) also about 7/10 usually sell for?

Any way to make the exhaust NOT sound like total
Dog $H!T? To me it sounds like the old school glass
packs, or like a tractor trailer with the jake brake on.

Any good replacement fog lights out there?

 

I don't know much about the monte SS, but I thought the F body upgrade was mainly for the older w body cars? Maybe you can get the GP GXP brakes as they're a 13" rotor?

Unfortunately the $500 OBX are the cheap headers. They ripped off the general layout of the Doug Thorley headers. Lots of people run OBX on many platforms, and with any Chinese header, it's a mixed bag of quality. They're generally decent, but just keep in mind if fitment isn't perfect or it cracks a weld - you get what you pay for.

I used to have a GP GXP, and I was in the same boat as you - paying that much money and that much labor for a tiny increase didn't seem worth it to me.

Not much unfortunately, they aren't a highly sought after wheel. Because shipping is so high, your best bet is to post them locally. For reference, a few years ago, I picked up a nice set for my 96 with good tires for like $200.

What exhaust do you have on it now? Has the tune been modified? The most common complaint on LS4 exhaust is when cylinders get deactivated and it drops down to 4cyl mode. Deleting that (either in the tune or mechanically) will give the nicer V8 sound all the time at the expense of some gas mileage.

 

Well that blows. Are the GXPs a direct bolt on, or need to mods things to make them work? What all is needed, Link/Write-Up?

Understandable, the DTHs are like $800+ so...... Yeah, Ummm..

Ok Then

My car has a few mods done; Dyno Tuned 340hp & 313trq to the ground, DOD was deleted, Car has Stock CatBack (for now, 3" on
the way) the rear mufflers have been 86ed in favor of Flows (not my doing). Sounds good, but lil louder than what I'd like form a DD.

Once I upgrade to my 3" exhaust I wanted to do Headers next, then get it ReTuned, & ReActivate DOD at 65+ (in OD n under 2000rpm)
Drove home from Medford NY to Philly Pa area 5+ hour ride with a lot of traffic n doing 75/80 on the Turnpike while getting 23+ MPG so
I want the DOD back so I can get or top 30 MPG. Does a SSs auto trans eat 20% of the power? If so, I'm making 425hp n 390trq +/- a lil.

 

Can't be of help on that, I've never done a GXP swap personally. They do sell a kit on ZZPERFORMANCE for it though, maybe they could advise. Another option you could try searching is the CTS-V 4 piston caliper swap, but you've got to be careful on wheel sizing with that.

Are those the only power mods? That seems way too high for those mods.

20% is probably a good ballpark, but no one really does back to back engine vs wheel dynos to see what they really eat at different power levels. Crank numbers don't really mean anything anyways.

 

Brakes - I believe there's a CTS-V brake conversion that you can do but it's not cheap and since it requires more clearance I don't think you can run the stock wheels.

Headers - I think Thorley has sales once in a 'great' while or you could find a set from someone that bought and never got around to having it installed - I know I've run into that a few times. I'm interested in headers myself, and a cutout. I tend to pay more for quality stuff but this is definitely one area I'd rather pay for quality. I'd hate to tear the front end apart twice just because of the headers.

Exhaust - Some have explained the 4cyl exhaust sound as a 'helicopter'. I myself am not really bothered by it but, like Bumpin said, the way to get around that is to tune out DoD so you're running on 8 cyl all the time.

 

Car has a ZZP Down Pipe, K&N Intake, + the Flows. I know on the Truck 5.3s a programmer (all stock, n canned tune)
give 25hp+ n 30trq+ So with a few lil mods n a custom dyno tune on a LS I could see it being around 400ish HP. I'm just
going off what the dyno sheet shows. Trans is said to have some work done, I know it doesn't add any horse power. IDK...

 

Kewl, Thanx.

DOD/4 Banger mode has Already been turned off. From a dead stop, normal1/4 throttle I can hear it.

 

Not to be rude, but those dyno numbers are meaningless if that's the mod list. The stock LS4s I've seen have done 235-250 whp, it's not possible to pick up 100 whp from a couple bolt ons and a tune.

Maybe the dyno output was trying to display an estimated crank hp since that seems closer to the right ballpark? Maybe they had the correction factors super jacked up?

 

I don't really care, its my new dd.

We will find out when I get my 3"
exhaust on that just arrived today.

My DP is also 3", I just noticed as
I was under the car today looking
to see if I can put a normal muffler
up near the cat so I don't have to
buy/run 2 mufflers. But Nope, a
Normal sized muffler wont fit there.

I'll get the car ReTuned, n DOD turned
back on (65+ in 4th 2000 rpm & under)