ZO6 Exhaust

[Mr Cowl Hood]

I think some people don't realize this, but if you lose 10lbft of torque at 3000RPM to gain 5 HP at 6000RPM, you just slowed your car down on any acceleration test except one that starts well above 3000RPM.
:cheers:.......

-Dave C. '04 Z06

Sure, but who launches that low (3000)? LOL

 

[lg78VETTE]

Wow we could go on forever.Ill tell you what i did.I have astock 98 except for ablackwing and carbon power duct.I debated about exhaust and solved the problem by buying agood corvette friend of mines zo6 system for 350.I think thats a sweet deal .What do you think?Long tube headers and x pipe will be down the line.

 

[Edmond]

$350 for the Z06 exhaust is pretty much a steal!:L You'd spend at least double that on the Borla's and Corsa's.

 

[Robert YellowVette]

Sounds like headers yield the best gains. This is in line with what I've experienced through the years. The best investment for power for the lowest cost has always been a set of headers. Seems to still apply.

Might try the X-pipe though. H-pipes were always a good way to equalize flow in a dual exhaust system. Helped with back pressure and create a more laminar flow through the pipes. The X-pipe is a natural progression from the H-pipe. Be interesting to see what it does.

The Z06 uses a 'tri-y' exhaust manifold which is very streamlined and offers excellent flow characteristics, as good as any 'shorty' header system and is very close to even 'long-tube' headers.

Back on the old iron v-8's, headers were the best bang for the buck for increasing power since the stock cast iron manifolds were so restrictive, but on the LS6 that is no longer true and the minimal increase in power [if any] is certainly not worth the thousands of dollars headers cost.

As for the x-pipe, it will actually quiet a stock cat-back system, any power gains will be so small as to be lost in the dyno error tolerance.

The stock h-pipe for the recent Z06's has an additional restriction in the h-section so the port connecting the twin pipes is about 3/4" in diameter rather than the full 2 1/2", apparently to increase the rumble of the stock Ti cat-backs.

I had B&B Bullet 2-tips on my supercharged Z06 with the stock h-pipe, but they were VERY loud even at idle and the cabin resonance from 1900 to 2200 rpm was maddening. B&B tech support suggested an x-pipe to quiet the cat-backs, so I installed a Bassani x-pipe. It did make the cat-backs about 25% quieter but did nothing about the cabin resonance. BTW, B&B does claim they are the loudest [95db] aftermarket cat-backs allowed and I see no reason to doubt them... =;-]

I removed the B&B's and reinstalled the Ti cat-backs, leaving the x-pipe in place and found the annoying resonance was completely gone, and the sound was considerably less than the stock system alone! [The original stock system did not have any noticeable resonance, either.]

I do miss the deep sound of the stock system, but not enough to remove a $280 x-pipe and since the car is Millenium Yellow and can be seen for miles by cops, a quiet exhaust is a benefit on the street...

I cannot tell the difference in power with either system, the Vortech makes so much more power than stock any change is lost in the error rate... =;-]

The only reason to change exhaust systems on the Z06 is to make more noise; any power gains will be small over stock. It is certainly not worth the many hundreds of dollars aftermarket cat-backs cost, at least to me.

 

[Robert YellowVette]

My understanding of this issue is that there is no "low hanging fruit" to be plucked here. If one reads the MidAmerica, Ecklers, etc, there are claims of better flow, more HP, etc with exhaust and intake swaps. The problem may come when a person thinks "intake 15HP, MAF 10HP, exhaust 15HP = 40HP total". Nope. Won't happen. From what I have read, the only way to get really significant improvement in HP by improving engine breathing is to do the whole system, using long tube headers, low restriction cats, and all the pieces on both sides of the engine. The cost for that is fairly high, and it could well be possible to get more 'bang for the buck' with some other modifications. Many of the intake/exhaust mods have been dyno tested, before and after. Look in the various Corvette magazines for this. There just isn't that much to be gained. I bought a VaraRam, which seemed to me to have the best objective data supporting its use. It raised my trap speed in the 1/4 mile 3MPH. Is it worth $400 to get 3MPH? I guess that is a personal choice. After all this rambling, my point is that the stock systems are not that bad and significant gains can be made only by dealing with the whole system, not just a piece here and a piece there.

I agree, the Z06 is a very well balanced car as it comes from the factory. Significant gains can be made in power, but at substantial cost and it involves installation of a complete system and tuning by an experienced tuner on a dyno.

A supercharger on a stock Z06 is probably the best value for the money, while leaving the car docile and easy to drive until the boost comes in... =;-]

Those who think a fancy $300 air cleaner and a $800 set of cat-backs will give them significant power gains are deluded and fair prey for the after market dream vendors...

I never understood how a cold 'ram-air' intake could increase power as much as the vendors claim on a static chassis dyno, after all the car is not moving so there is no ram effect...

 

[lg78VETTE]

Ok Robert YellowVette so i got my zo6 ti mufflers this morning but my 98 is pretty much stock except for blackwing and power duct no zo6 exhaust manifold. Would long tube headers be worth it ? or should i just put on the mufflers and leave the rest alone what does anybody else think?

 

[Robert YellowVette]

Ok Robert YellowVette so i got my zo6 ti mufflers this morning but my 98 is pretty much stock except for blackwing and power duct no zo6 exhaust manifold. Would long tube headers be worth it ? or should i just put on the mufflers and leave the rest alone what does anybody else think?

Personally, I would just fit the Ti cat-backs and leave it at that, I think you will like the sound over stock. Some people drill holes in the pipes just before the cat-backs for a cheap 'ghetto-mod' to make more noise, but I doubt you will see any power gains...

If you choose the headers and a complete exhaust system you will have a good basis for later installing a head/cam package where you will see some real gains but it does get expensive pretty quick... =;-]

Like the old hot rodders used to say, "Speed costs money, how fast do you want to go?"

 

[Edmond]

Personally, I would just fit the Ti cat-backs and leave it at that, I think you will like the sound over stock. Some people drill holes in the pipes just before the cat-backs for a cheap 'ghetto-mod' to make more noise, but I doubt you will see any power gains...

:L:L:L

Like the old hot rodders used to say, "Speed costs money, how fast do you want to go?"

So what you're saying is, "How much money you got?":L

 

[RHP]

Horsepower and weight.......

HP vs. weight is everything. I think losing 20lbs off of a car is great. I'll take it.

The easy way for my bad-ass:cool Vortech SC Z06 to take off 20lbs. is for me to push away from the table!!! I'd rather boost than loose!

Honestly, IMHO, I don't think 20lbs. is a make or break difference.

 

[Pac-man]

I really don't care either bro, but for the sake of conversation, and since this is a performance section in a Corvette forum, I said that I would gladly take a 20lb weight savings. I don't even remember anymore, lighten up or I'll have to come teach you how to drive.

 

[RHP]

ouch! Bad me....

Admonishment taken......

Chevy has done a good job cutting weight, 20 pounds here and there adds up. Made us a fantastic machine. Personally....I could stand to loose 20lbs. My car makes up for it with a Vortech SC.......I probably could use driving lessons cause this is the fastest car I have ever driven! Only had it a couple weeks!

 

[ScatRat]

Curious. Why Vortech?

 

[RHP]

ScatRat:

The Z06 I purchased had the Vortech SC already installed. :cool

 

[Z06 Tom]

From the stats I've seen it really comes down to one thing. Sound. I put the borla on mine because of the agressive tone. I think the only way to gain anything on the exhaust side is to replace the headers, cats and install an x-pipe.

Yep! My six year old runs back in the house when he sees me getting in my Z. You hear me before you see me. Then you don't see me for very long:naughty:

 

[VETTEZ16]

Got to tell you my friend put shorty headers on his '02 Z and kept cat back -stock. One sweet sound at higher RPM's. Maybe in 2 years I will do the same.
Meantime, our stock sound is kick A----, so I am not suffering one bit. The General really did a good job.

 

[Z06 Tom]

Got to tell you my friend put shorty headers on his '02 Z and kept cat back -stock. One sweet sound at higher RPM's. Maybe in 2 years I will do the same.
Meantime, our stock sound is kick A----, so I am not suffering one bit. The General really did a good job.

IMHO, the stock manifolds are pretty efficient. If you're going to go to the trouble of headers, go long tube. Especially in a na application, you want as much velocity as possible. The shorties don't do much. Long tubes "scavenge" exhaust gasses helping to evacuate the gasses much faster and more efficiently. Look at the LGs or Dynatechs, now those are headers!!

Here's the LGs, I personally have the Dynatechs: