UsernameProtected

Can it be done? I miss the raw power of my c6z, but I don't want to get ridiculous with engine mods that will void the warranty.

I'd like to keep the factory NPP, and the forward cats. I'd like a bit more sound with the NPP open, but I'd prefer it not be as loud as my c6z was with kooks & corsa.

It seems like ARH mid length stepped headers, an x-pipe, and a Diablo or COW tune might get me close to this...though the reversibility of the tune for warranty work is a concern.

Budget would be around $3,000.

Is this achievable, given the parameters I've outlined? Any other thoughts on other items or combinations that might work better to get where I'd like the car to be?

Thanks in advance.

EcoBrick Bob

You can probably get away with a Halltech or other CAI, a ported Throttle Body, a 170 degree Tstat and a ported intake manifold. With these mods, I turned an 11.8 in 1/4 mi with my 15' Z51 A8 on stock run flats when the temp was 78 degrees and the DA was between 1,300 and 1,500.

Another more stealth mod is to have your stock exhaust manifolds ported and ceramic coated inside. No one will ever see the work done to them.

I installed the Borla catless mid-pipe, which is almost completely covered by the Aluminum plate.

While it would take a few hours to return to stock, ( the X-pipe taking most of that time), there will be no issues with the ECM.

As for lighter wheels, one can buy Roto-forged ones from TSW/Cray for under $2,000. a set.

Bill Dearborn

Lets see the C7 LT1 has the same torque curve as the C6Z LS7 till 4K rpm. HP is just about equal until 4800 rpm. How many times will you be taking the engine above 4.8K rpm? On the street chances to do that are extremely limited. The C7 weighs about 150 lbs more than the C6Z which is where the biggest performance hit is and the one that will be felt the most driving on the street. Lightening the car will give you the most bang for the buck and will not void the warranty. The other things you are talking about may boost high rpm HP (6K) by 10% but won't do a thing for you in the stop light Gran Prix while taking weight off the car will boost the performance from idle to max rpm.

The picture below shows how close the LT1 is to the LS7 except in the higher not often used rpm ranges. Unless you are going to track the car you will rarely get into those ranges except maybe in 1st or 2nd gear. Low gear on the rev limiter in a C6Z is 60 mph and an LT1 on the rev limiter will be in the 50s. Getting to the rev limiter in 2nd on even the lowly LT1 will get you well over most speed limits. The C7 Z51 has lower gears in the first three gears than the C6Z so that helps compensate for the added weight of the C7 but taking weight out is the best bang for the buck. To get an equivalent performance boost by adding HP you would have to add a cam and other things.



Bill

dovervold

AFE, ported TB, Corsa X, and DiabLew tune really woke my car up and completely reversible. Would be a good start. Of course I got bored and just added LT's and ported intake. Car rips and sounds amazing whenever you are ready to ditch the warranty.

NinjamanZ51

Why worry about a warranty? Better you not mod your car at all if you're concerned.

dovervold

Looks good on paper, but not the real world (owned both). The real difference is C7 drive by wire is numb. My C6Z stock ripped right to 7,000 rpm all day long. Drive them and you will feel it. But, doesn't take much to wake the C7 up!!!

UsernameProtected

Thanks for the suggestions. I read a thread where someone had the exhaust manifolds ported. I might research this more. I hadn't thought of lighter wheels. I'll be buying a new set of wheels this fall probably, so that may be an option.

Good point about the mass. I knew going in the C7 was 10% down on horsepower, and about 10% up on mass (mine was one of the earlier, lighter Z06's). I've gone w.o.t. once in the C7 now and was underwhelmed at the pull from 4,000 r.p.m. on compared to my C6Z. I was so surprised at the lack of oomph, relative to my former C6Z, that I haven't gone w.o.t. since...

This car is a daily driver for me, and I want to keep the things that make it a much better daily driver than my C6Z was. I'm not interested in ripping out interior pieces to save a few pounds. Wheels and non-runflats might be an option to save not just gross weight, but also rotational mass. I don't know what is a realistic number there yet.

Thanks for your suggestion. I'll have to research what a ported throttle body can add. I hadn't looked at that option.

Well, I didn't have a warranty on my C6Z, and was comfortable with the LS7 "sword of damocles" hanging over my head. I kinda like knowing there is a warranty, plus we all paid for it when we bought our cars (new, at least). I spent $130k on a couple of airplane engines a couple of years ago, so I can handle a relatively cheap LT-1 replacement if I had to, but I just don't see the point of throwing something away that potentially has value (the warranty).

Maybe this is contributing to my lack of enthusiasm for the C7 power/mass equation. I've ordered a Vitesse throttle controller to try that out. I know it doesn't add any power, but just maybe part of the experience is lost with a slow to respond throttle system.

Don't get me wrong, I enjoy the C7 for my daily driving mission more than my former C6Z, but I really miss the raw driving experience the C6Z provided. I know the "rawness" of the C6Z, was something that detracted from the daily livability of the car, and I know I don't want to go all out to try to replicate that with the C7. I'd just like to get a little "closer" to what my experience was with the C6Z...without getting "too close" - if that makes sense.

Thanks again all. You've given me some things to think about and research.

Bill Dearborn

I know how fast the C6Z accelerated from many bouts of acceleration off turns on the track. I have also driven a stock C7 Z51 in several autocrosses and felt it had just as good of acceleration as my C6Z was on the same courses through 5K rpm. In most autocrosses it is difficult to find a straight long enough to get past that rpm level even when running in low gear.

Bill

axr6

I'm also somewhat underwhelmed by taller gear acceleration in my C7, particularly with the weight of a passenger. I also wish to keep my warranty. Thus, major mods are out. Goal is a weight reduction that is close to the weights of passengers.

I have forged wheels on order that, with stock sized non-runflats should drop 44lbs. I have carbon fiber racing seats ready to install for 70 lbs reduction. A smaller battery is - 13 lbs. The easiest weight drop is to keep fuel loads to 50% and less (-55 lbs).

I'm only adding a CAI for +10hp. Combined with the above weight reduction this will result in an approximate 6.8 lbs/he power to weight ratio, equal and better than adding 40hp to a stock Z51.

axr6

I'm also somewhat underwhelmed by taller gear acceleration in my C7, particularly with the weight of a passenger. I also wish to keep my warranty. Thus, major mods are out. Goal is a weight reduction that is close to the weights of passengers.

I have forged wheels on order that, with stock sized non-runflats should drop 44lbs. I have carbon fiber racing seats ready to install for 70 lbs reduction. A smaller battery is - 13 lbs. The easiest weight drop is to keep fuel loads to 50% and less (-55 lbs).

I'm only adding a CAI for +10hp. Combined with the above weight reduction this will result in an approximate 6.8 lbs/hp power to weight ratio, equal and better than adding 40hp to a stock Z51.

UsernameProtected

Which wheels are you using? I agree weight reduction is more beneficial than extra power, though I'm not interested in replacing my seats. The rotating mass is of interest to me.

TennisFreak

If you believe some of the vendors and manufacturers claims on this board you can get over 35rwhp with just a catback exhaust and an intake!!

No tune required.

axr6

From "Race Tech Forged" forum vendor , Track-Pac-5 model.

UsernameProtected

Thanks!