dmcantrell

Hello, I just recently fulfilled a teenage dream and bought a brand new C5 convertible. Of course, the leftover teenage testosterone coarsing through my veins has persuaded me to start looking at performance modifications. This being a 2003, I am concerned about warranty and keeping it somewhat factory in case I still own it in 20 years. So here is my question:

Can any of you suggest any (relatively) inexpensive mods that will boost performance?? I'm not asking for 100hp for $20 or anything, don't get me wrong. I have been reading alot of posts in here and many of you lilst the Blackwing as a filter enhancement. I also read about the Halltech system. I see alot of claims from these(and other) 'bolt-ons' about adding 20hp, but I am skeptical.

Any suggestions?? MAF?? Plugs/wires?? FIlter kits?? Intercoolers?? anything else??

Thank you in advance and Hello to you all!

--dc.

c5 devil

Welcome to the corvette family....As you said airintake system is the way to start...i have the blackwing and i love it ....it well not effect the warranty...to help you any more we need to know how much power you want and how much money you have to get it??
Gool Luck

SteveL2

David -- congrats on the purchase and the fulfillment of a dream! :cheers: Warranty issues are a sliding scale. The more HP you add, the more you raise the chance that GM will claim that if damage occurs to your drivetrain, then the added HP caused the damage, thereby removing the warranty from that particular damage. So, there's no bright line test for what will and will not hurt you, and some dealers are more liberal than others.

That said, to start with, you're in the right direction on something to change the stock air filter system. There are a handful out there, and you can find lots of folks disputing which is the best. I have the Vortex one on my car, and for the price, I like it. Several of them, including mine, require a hole to be cut in the shroud, thereby increasing the chances that the car can ingest water into the intake, which of course is terrible. Not surprisingly, however, these also gather more access to cooler air, so there is perceived to be a little bit better performance with them. This said, you'll find folks here who want to avoid this chance altogether, so they keep their system stock, or they go with one like the Donaldson, which I believe doesn't require any cutting of the shroud.

Many of the other "bolt-ons" give pretty small incremental gains, and you are right to be skeptical about the individual HP claims of each piece alone because some are outright exaggerated and some are hard to pinpoint since they often are combined with others. However, if you are willing to combine some of these, then you will get some reasonable numbers, and some of these items would include long tube headers and an underdrive pulley (although the cost of install of that alone is considered not worth it, while better combined with a cam install). Also, changing your rear gears to 3.73s, 3.90's, or even 4.10's will give you much more of a kick in the pants. I opted to do this early on to improve the pull while not risking any engine work so as to try to maintain the integrity of my drivetrain warranty. However, if you're like me and many others here, beware, because we had your same attitude when we bought our cars, but since you already acknowledge your weakness, it could be the beginning to a deep slide into mod oblivion. It's a bit scary at first, but it becomes quite a fun ride. :reddevil

dmcantrell

Well, I'm not sure. I would like to be able to beat a stock Vette for sure, and maybe give a good race to some of the more modified ones, and one day perhaps smoke a Viper. This is my train of thought so far:

I've been looking at ATI Prochargers. I can afford one but the car is so new and ATI told me that they don't have all the details worked out for the 2003 yet. I don't know how this could be, but the ATI representative was hesitant to quote me a part number for one of their products. So I'll wait on that one.

I have been conversing with Lingenfelter Perfromance Engineering, but the idea of driving up there doesn't appeal to me, and LPE was balking at quotes for 2003 as well.

So I am looking for things I can do in my garage for under $1000 a pop. But everything I read claims to add 'up to XX HP' without any real proof (dyno results before and after with just one mod added). I would like to stay out of the motor if I can help it. I know exhaust is a big deal, intake, timing, fuel/air mixture, ignition, thermostat, etc. But I'm having a hard time sifting through the hype of all these different vendors.

I noticed most of you list the Donaldson Blackwing as a mod, but the guy at the dyno shop I went to said he's never heard of it and recommended this 'Granatelli kit' for $500+. So now I am confused again.

I hope I answered your question.

--dc.

SteveL2

Wow, have I got great news for you, I think. Lingenfelter has an authorized shop right here in your backyard!! Yep, 21st Century Muscle Cars is located in Dallas, and they install Lingenfelter systems of various flavors. Here's their website: http://www.21stcenturymusclecars.com/home.asp. Yep, I'm biased, as these guys installed my supercharger, and did a darn fine job at that. :D

Of course, now you're opening the door for all kinds of variations in performance options. I'm not sure where 21st Century/LPE are on 2003 models yet, but once they get there, I'm betting they'll be fun.

If you want to see how an LPE supercharger runs on a 2001, shoot me an e-mail and maybe we can get together some time. My car will hang with stock and lightly modded Vipers. "Smoking" them, on the other hand, will take a much bigger package. Good luck. :seeya

vstella

WELCOME ... :seeya

While I can appreciate that you wish to keep your warranty in tact..that will be up to the dealer and the service advisor that you a dealing with.. :yesnod: My suggestion is to build a good relationship with the advisor and tell him of your plans...If he's OK with it your home free.

For instance My engine ..transmission..exhaust..ssupension and PCM programming has literally NO stock features or parts to it..completely modified..BUT..they have warranteed sevral other stock parts over the last 3 years with NO hassles at all... :thumbs:

My suggestion is to start with the Intake and then the exhaust..Let's see where you are then..If you still need more then we can go tyo PCM programming and rear gears..Just my .02:D Good Luck!

SteveL2

No offense to the guy, but if he has not heard of the Blackwing, then he doesn't know enough about C5 aftermarket mods to be giving you good advice. My guess is the Granatelli kit includes some type of circuitry (e.g., MAF translator) to try to adjust your car's computer, and they have proven rudimentary and unpredictable on earlier C5's, so I'd bet they're no better, and possibly worse, on the 2003s. Indeed, I'll subject myself to flames to say this is exactly one of the hyped products you might be fearing. Here are some reviews on this Forum for them, and these seem positive: https://www.corvetteforum.com/review...167&TopicID=13.

Just keep reading the Forum, and pretty soon you'll know more than you could ever imagine. Then you can decide how deep you want to go into this hole. :reddevil


[Modified by SteveL2, 3:01 PM 5/21/2003]

6SPD98

________________________________________ ________________________
Any suggestions?? MAF?? Plugs/wires?? FIlter kits?? Intercoolers?? anything else??
________________________________________ ________________________
Welcome to the Forum......You have a guestion? The forum has a suggestion.
My suggestion is look into changing the rear gears.
I went to 4:11's with a 6 speed. It really changed the whole car, there is no more strain in the drive train. It really doesn't hurt Highway driving either.
Before... 6th. gear-2000 RPM----90 MPH
After... 6th. gear-2000 RPM----75 MPH
Drive It Like You Stole It

dmcantrell

Wow -- OK how do I send you an e-mail?? What I **didn't** like about the LPE stuff is that they are insistent on using the roots-style huffer (Magnusson I think) that requires a different hood. I like my hood the way it is. They would not even talk to me about doing work with an ATI unit. But I think that a supercharger is something for the future for me -- baby steps.

Thanks for the link to the previous thread -- I read the reviews and the unit (LoneStar Performance, BTW) that this guy quoted me was the Granatelli Super Ram Cold Air Induction System -- not the MAF sensor itself. [http://www.granatellimotorsports.com/gmsuperram.htm] Has anyone ever heard of this??

This brings up another question -- that siteI just quoted has a dyno graph of a 2001 stock LS1 before and after the installation of this thing. It's showing a stock HP of 342!! How can this be?? The only thing I can figure is the 'SAE' vs. 'SAE corrected'. Does anyone know how to figure this out?? It has to do with atmospheric conditions, right? My run today was 306.6 SAE, but it was humid, 65 degress, and drizzly. Now I'm really confused. But nonetheless, this graph with their product shows a dramatic improvement over the stock air intake system.

ICULUKN-C5

welcome to the addiction...

I would start with intake, exhaust, and maybe long tube headers. These wont void your warranty.

You should get around 40 RWHP doing these mods

Avanti

Main recommendations?

Have FUN and remember you probably aren't Mario Andretti, even if you now sometimes drive the same car. Be careful, it can bite the uninitiated. A midlle-aged local bought one and immediately blasted off an on-ramp and wrapped it around a tree!

Enjoy the ride (even if it ain't a Nissan!)! :yesnod: :lol:

SteveL2

steve@all-ip.com. For future reference to send mail to others, if you click on the forum name of someone who posts, it will take you to part of their "profile," which lists, among other things, their e-mail address.

I think you're right, they only do the Magnuson. However, there's lots of tuners here in Texas if you want to go another route. Or, if you change your mind and go into the engine, then 21CMC/LPE as well as others also have various head/cam packages as well.

My guess is that's flywheel HP, not rear HP. A lot of folks assume that the 6-speed has a 15% drivetrain loss (20% for the auto). So, they measure rear wheel HP, then add 15% back to it and assume that the larger value is what is produced at the flywheel. Even with variations among cars and years, I don't think there's any way you'll find a stock C5, non-Z06, with 342 REAR HP.