kfede1

I take delivery on a 2012 Grand Sport Convertible soon. I have been reading all the various posts and claims for horsepower. I have been talking to various vendors as well and heard very conflicting things:

• The Vararam Cold Air induction adds up to 40 HP when moving because of ram effect
• The Grand sport already has Ram induction and cold air induction, so the aftermarket kits are redundant
• The chip tuners will add up to 30 hp
• The chip tuners make no difference
• The chip tuners are not compatible with headers
• Headers and a High Flow cats / X-pipes will give me 40 HP
• The standard exhaust was pretty good and the headers / exhaust HP improvement in minimal
• Supercharging will get me up to 550 to 600 HP and not invalidate the warranty
• Supercharging will invalidate the warranty.

Anyway, I would probably be happy with another 50 HP, but of course more is better. I don't want to buy parts and later discard them because I went another direction. I initially thought I would do the Vararam, chip tuner and headers / exhaust, but I now am doubtful I will get the HP improvements I want since it already has forced air / cold air as part of the Grand Sport Package. I talked to Vararam and their testing was never done an a Grand Sport, so there is no comparative data.

I am looking for honest informed opinions on the topic... Also, does anyone have experience with Whipple Supercharger kits? I am investigating that approach as well. I have a sales rep at autoanything gathering info for me on that. I am interested in figuring out what issues may be associated with such an upgrade and if it is the kind of thing I could accomplish myself. I am a decent mechanic, but I know that this forum probably has many or most members at a higher level of competence than I have...

haljensen

The GS does not already have ram or CAI. Wouldn't add 40 HP anyway.

Chip tuner? Computer tuning will add HP but void Warranty.

Headers, cats and a tune MIGHT give you 40HP (and void your Warranty).

Supercharging will give you the HP AND VOID the GM Warranty.

FloydSummerOf68

Get an A&A supercharger for about $5100 plus a tune and pick up 125-150rwhp and call it a day. Don't waste your time and money on putting a whipple on the car.

As said above; intake, headers and tune will pick up about 40rwhp.

kfede1

I saw several brands of supercharger ranging from the $5100 A&A you mentioned to the $6500 Whipple to Edebock at $8000+. I read the install on the edelbrock and it looked like a lot of work. Is the A&A an easier install? It looks like Whipple promises more horsepower, but truthfully, I would be happy with 150 at that price...

I have no info yet on a Whipple install, but I hope to have some soon.

FloydSummerOf68

None of them are quick installs and I doubt the whipple would produce much more. Both can easily max out what your stock motor is capable of.

LS9Drew

Handheld tuners are junk, imo its street/dyno tune or don't bother.

Motorhead-47

You might want to crosscheck the price on that Whipple...plus the cost of the required new hood plus the paint job on that hood....

I have installed A&A centris, a few Edelbrocks and a Maggie....count on a full weekend of you've never done the job before. None of it is beyond the ability of the above average shade tree/weekend grease monkey though if you can follow step-by-step instructions.

Totally agree with just stepping up and going FI and calling it a day. Best horsepower per dollar spent IMHO!

danieloneil01

Chip tuners are for hondas brah.

NORTY

OP~ How about you leave your new car unmolested for a while? Yeah, yeah, I understand Texans gotta make a lot of noise, I get that.

Here's my point~ You're getting a convertible. It makes no sense to mod it as no track will allow you to run with any kind of blower. Unless you put on a roll cage. Are you putting on a roll cage? Most don't. So, now you gotta fast car that no track will allow you on. What's the point of that? Zippo! (Unless you're into street racing...)

Chances are, the track tech won't allow you to run with H/C/I/E either.

Honestly, just drive the car and I bet you'll be surprised by it's capabilities in stock configuration.

Based on your questions, you are unfamiliar with the C6. Either way, enjoy your new car. Take some pics and post 'em up, too!

LS9Drew

You don't have to street race to enjoy a car with power on the street

kfede1

Thanks for the info.. I don't really intend to do much track, but I would have at least wanted to get a few 1/4 mile timings... You are right about my knowledge of the c6.. This would be my firtst modern vette. I have been restoring a 71 convertible LS6, but with my travel schedule, it has been slow going..

68sixspeed

new GS convertible will get thrown out at the 1/4 mile... 13.50 max et for a convertible w/o a hard top or roll bar, 11.50 for coupes. (GS is what, high 12's stock?) As others have said, drive it a bit first, it's pretty healthy and a good amount of power for an open top car. (Not to say I haven't thought of the edelbrock supercharger myself).

I'd stay away from the tune at least to start as it will void the driveline warranty. Hate to have GM not cover an issue on a new car because of a tune.

Most of all, enjoy it!

kfede1

I thank you and the others. Someone mentioned the need for a new hood for the Whipple supercharger. I was surprised because autoanything advertised it as under the stock hood. I don't want a different hood. I am going to leave it stock for a while I guess.

LS9Drew

get your info/parts from somewhere other than autoanything, way better vendors on this site

anniv88

First, check with the dealer. See which mods will and will not void your
factory warranty.

If you want a supercharger, see if your dealer is a Callaway dealer.
You can order a Callaway supercharger option from GM if your dealer
is an authorized Callaway dealer. It's pricey, but you will still have a
warranty.

kfede1

Thanks to everyone who chipped in with advice, I took the advice, waited until about 4k miles and went to ETMC. Ported throttle body, 1 7/8 LG super pro headers, 3" LG high flow cats/ x-pipe into 3" B&B fusion dual mode mufflers and an A&A supercharger. 570 RWHP at 112 degrees shop temperature. Adding methanol / water injection this week and hoping for 600 RWHP in similar extreme heat situation. Hoping for more when I get it on the dyno in winter when the inter-cooler can do something more.