Hi Everyone,
I have a '04 Coupe, with a cat-back exhaust sytem and Callaway Honker C.A.I. It was 350hp stock and this Fridayit will be dynoed and I'll find out how much more these few mods have given me.I have considered having it S/Cd, but without long-tube headers (live in Calif) will not get the most out of the S/C. So, my question is: Does it make more sense to sell this car and buy a used C6that will come stock400 to 505 hpdepending on the model?

I really likemy vette, so am thinking of holding on to it for a bit and then buying up. Feel like time is on my side, since GM just keeps making the vettes faster and with the '08reported to be 600hp - YIKES!

It sounds wiser to buy a C6, rather than stress out my C5 by S/Cing, but need to hear from someone whom is more knowledgeable. Input will be greatly appreciated.

Thanks in advance.
RJ

 

I have debated the exact same thing a few times actually. My car of course is SCd and is putting out a bit more hp than the new Z06. I would say get the model you like whether it be staying with the c5 you have or going to a new c6. A stock car IE: C6 is easier to maintaincompared to a modded car IE: your C5. You can also take your car to any chevy dealer when it is stock and they will know how to work on it. You should have seen the look on the techs face at Burt Chevy when I opend my hood. He was calling me asking how to take the supercharger off and thats not a good feeling trust me. Now I only take my car to an actual Corvette shop to be worked on and that is a bit more expensive. I think either way you will be happy.

 

The tighter you pull the string, the sooner it starts to sag.

 

First, the '08 vette won't have 600 HP, and if and when GM brings out the "Blue Devil" -- SS or whatever they call it finally, it will be in the neighborhood of $100K, and (I'm going out on a limb here) probably edgy or a bit of a disappointment compared to expectations like the ZR1 was (it was powerful for its time but difficult to tune and not that dominating for all its high-tech and $$).

Second, a SCR will work well with short-tube headers - for that matter you can use the stock exhaust manifolds with a SCR and it will still provide a lot of more power than stock. The way to put itin perspective is that shorty headers give you about half the power gain of long tube headers - say 15 vs25 on a stock engine, and about 25 vs 45 for heavily supercharged.

The bottom line -- where your logic leads --is this: stock '08 'vettes will have 435 to 505 SAE certified HP depending on model, which means about 375-445 RWHP. You can get to the top of that range with your present car and this combination: shorty headers, the cat back, a SCR (either a Magnusen or a Procharger or Vortech centrifugal type), and an intercooler and the new injectors, etc., that come with a SCR kit, topped by a very good tune (re-programmingof the ECM). I'd add oversize cats, too, because heavy use of the SCR is likely to burn out the stock cats, but you can probably make the power you want without them. Either way you will have about 450 RWHP matching the stock top end 'vette andthe car will be dependable if you keep it in good condition and don't abuse it: I drove a Magnusen SC'd stock engine as a daily driver for two years before installing my current engine.

As to the SCr, my recommendation is the Magnusen. It costs abit more overall only because you have to replace the hood (Prochargers and Vortechs fit under the stock hood) and have it painted. Against this disadvantage, it looks better - when you open the hood to show friends, you have a gleaming big thing that looks like a SCR (rather than like a big AC compressor) right on top of your engine; it provides more low end torque, and it has a sterling reputation as easy, no hassles, and dependable as an anvil (stay below 450 RWHP on a stock engine and you should be worry free). Fuel economy will be about 1 mpg less than stock.

All of this, well done and installed by a good shop, will run you about $10K, or done on a budget, about $7.5K

Realize that you are not really done. You need wider wheels and tires to use the power well and really ought to install the Lingenfelter C5 mini-tub kit and put some 11" or 12" wide wheels and 315+ section tires on the rear to use the power. I'd recommend an upgraded dual-core high capacity radiator with a built in oil cooler, and you really ought to have the transmission output shaft replaced (or refrain from dropping the clutch, particularly if you run drag radials or racing slicks).

Total cost, to do all of this right, is probably $9-$12K depending. For that, you will have a car that is up to date or ahead of the curvepower wise, almost unique, and distinctly yours. But it will not be a new model, but with the rate GM is marching on power upgrades to the vette you will have about4-6 years before base 'vette's have power exceeding your model (probably from the present V8s but with direct injection and cylinder de-activation)

 

Well, I'm not more knowledgeable. However I am willing to share my opinions, so here goes:

Ya know, I've gone through the same thing. When I bought my Z used there was an 05 coupe on the lot with about the same mileage and price. But I went with the C5Z for just that little bit of extra performance. At the time, I liked the looks of the C6 a little better but I got the C5 anyway. Now, I like the look of the C5 just a little bit more.

After owning it for a little while I started looking into mods and asking questions on here about how much the stock LS6 could handle. It turns out that it's pretty high strung as it is. I'm concerned about both resale value and predicted longevity (which of course affects resale value). I don't want to built a time bomb.

If Chevy puts out a 600+ HP vette then the price of the 500HP Z06 will come down some. Unless they put a $100k price tag on the 600+HP version. It's hard to see into the future. The problem is, If they sell a much faster car for about the same price then the value of the older( and slower) car goes down. If they had priced the C6Zs lower, say upper 50s, then that would have killed the resale value of the C5Z.

I guess what I'm saying is: Yes your logic is sound if you want to move up to the 400 HP performance level without any issue on longevity or legality. Simply trading in on a used C6 will solve that problem. You should drive one first to make sure that it's enough of a performance gain (and not just the dealer around the block test drive). And the price difference shouldn't be huge.

If you're looking for that big power jump, like to 500+ RWHP, then the decision is a little tougher. C6Zs are still going for 70k+. It might be more cost effective to install a SC kit (like the lingenfelter) than to by a C6Z. You would end up with a little bit more power. I'm not sure about resale value. I'm also not sure about legality in CA.

Again, these are just my opinions, offer void where prohibited, your mileage may vary etc...

 

Thanks everyone for taking the time to reply.

Hey, CWB - are you a plastic surgeon? Ha, ha!

Lee
Thank you so much for explaining this in such detail. I believed the rumor about the '08, but knew I would get the straight scoop here.
This willan expensive project and I will have to seriously consider all aspects of this job.

Although doing the s/c works well for you and others whom are knowledgeable, with my limited tech experience (although I am learning all the time), I will be relying on a shop 100%. Aperformance shop was just referred to me and I will be going there tomorrow to get dynoed. If trustworthy, I'llbe more apt to do the s/c.

Glad to hear that shorties are not out of the picture. Staying street legal is paramount on the list.

Thanks again. You can be sure I will be printing outthis thread.

Hey Everyone,
Take care. Stay safe.
Have a great 4th!
RJ

 

Thanks, Riley!
Didn't read your reply until after I posted mine.
I like your logic and it is funny - I alsopreferred the looks of the C5 at the time and now like the looks of the C6. Especially like the new headlights.

This is going to be one I ruminateat some length before proceeding. I think I'll be happy in the 450 hp range, but if past experience is the teacher, my guess is once there, I will want more. Although, I will never have 100K to spend on a care, so I will have to be willing to compromise somewhere.

Oh, sigh,Why can't I be happy with a normal car like other girls.

Thanks again for taking the time to reply and sharing your experience.

Take care. Stay safe.
RJ