well, i went to the dyno for the first time. My car stats are: 03 GT 2V, 5-speed, 53k miles, no engine mods, flowmaster cat back. with that said i put down 236rwhp, i was amazed. I talked with the guy and we figured a 15% frictional loss. that puts me around 280 at the crank..hmmmm. the only thing I have done lately is change my plugs (AGSF32C, coppers) and I run amsoil oil. so maybe i have factory freak....

here is the dyno sheet

 

Those are STD #'s which arent corrected. SAE #'s are corrected and are a little lower.

Stock 01-04 GT's usually put down 220- 230rwhp.

 

boy o boy talk about shitting in someone's corn flakes....lol im just kidding. so what would SAE #'s look like. this was my 1st time ever at a dyno so i didnt know what questions to really ask. i am still pumped though, i was expecting more along the lines of 200-210 wrhp...so anything over 225 is nice. this was done to get a baseline. my car will not be my daily driver within a year, and thats when the fun stuff begins.

 

hp talk is fun and it allows for good baseline comparison. But, when you loose a race to a lesser powered car, saying you have more hp won't mean jack.

hp sells cars and is good for bragging rights, but that is about it.

But, it is sure fun to talk about.

 

From the looks of the torque curve, a good tune would pick it up a bunch from 3500 RPM on down. There's a pretty long open loop fuel delay on these; should be making 250 lb/ft or so right off the bat.

 

I know that, power is only one part of a fairly large equation. I just want a fast streetable car, I pretty sure im going to stay N/A. I realy dont want to get into the 400+ range really with this car. Proly a stroker kit, heads, cams and the usual bolt ons.

 

tuning is in thatcards for sure, Im going to get tuner when I put gears in. I just have to sit tight for a while this is my only car so Im not going to tear into it until its not my only car.

 

one more thing, the guy setting me up asked if I had aftermarket injectors. which I said no to, they are pink, but they have been on the car since day I bought it(brand new). I believe 19 lb is the stock injector, are those pink?

 

Hey man those are good numbers for us poor little 2v guys. Be PROUD !!!

 

+1 and a tune will make your shifts faster and seem like your faster!! lol i need a tune. i have an 03 manual and pushed 241 on a 94* day and 89% humidity stock

and what waterdr says is true. buddy of mine has a tt that pushes 215hp and would win any race against me (without my tune). lol.

 

Your pinks are the stock 22#. The 03-04 GT's had a compression bump so they used a larger fuel inj. compared to the orange 19# of previous years.

 

I've dyno'd probably 2 dozen bone stock and mild bolt on 02-04 GT's... pretty much all of them pounded out 220-240rwhp. Get a little more aggressive with the bolt ons and you get a little more hp.

You should be able to get a tq curve like this:
http://www.squarerootofone.com/images/dyno/dyno.jpg

That's a bone stock untuned 03 4.6 2v.

Here's the baseline on my untuned 5.4 2v:
http://i56.photobucket.com/albums/g1...graph-only.jpg

 

Have you ever dynoed a stock Cobalt SS or one with a Stage 2 upgrade?

 

Read this guys post:

The original version indeed was very quick downshifting to 2nd below speeds of 55 mph and punching it, faster than anything I ran into. Going 65 mph you could also downshift into 3rd and get something out of it, but nothing like the Stage 2 which would blow the doors off the original because of the increased torque and hp through all 5 gears. I got the impression it was somewhat of a half-hearted effort by Chevy to release something competitive with Honda Civic SI and Mitsubishi Lancers, but the specs are the old 200+ hp 4 cylinder specs that were current until this year. Now everything (aka Sun and Solstice) seems to be at 260 hp, the new rating of the Stage 2. Of course, Chevy under rates their horses and always has (remember those 1990 RS's that had the old 300+ cu inch Z28 engine? 270 HP? No, a lot more than that for those of us who had one), so I'd really rate the Stage 2 at 330 hp with the power ot weight ratio, of course any car rated at 260 hp bench would be over 300 if it were under or close to 3,000 pounds.

 

nope... but I'd bet it pushes out 20% less to the wheels than the factory rates it at at the crank.

EDIT: Did a little searching and found a 07 cobalt ss with a few bolt-ons and a helluva lot of tuning running 16 1/2 lbs of boost making a laughable 214/237. Sorry but while they're feeding the fuel for 300hp, they're not quite there. Closer to making the 260bhp that it was advertised at.

Found another with the GMPP stage 2 set and a tune and bolt ons making 249/224

These cars are weak sauce. If you have to put 16lbs of boost into a motor to make 220-240hp you're wasting your time. The car weighs about as much as a mustang (a couple hundred lbs diff) too so you end up with those barely-pump-gas drinkin 4 bangers turning in 13.9-14.1 second time slips.

 

Dead wrong. STD is a correction factor just like SAE is, the difference is that STD corrects to slightly more ideal conditions than the SAE correction factor does.

Uncorrected numbers can be either higher OR lower than corrected numbers, be it STD, SAE, EEC, DIN, or JIS correction factor, depending on the weather conditions seen during the dyno pull.

 

the SAE's would probably be like 231rwhp. Mine put down 271 STD, and 266 SAE. So subtract about 5.

 

231rwhp SAE was with a catback so you minus 7rwhp for the catback and that puts him in the low 220's rwhp. i am guessing the catback would atleast be worth 7rwhp.

so everything seems right to me. gratz on numbers.

200-210rwhp you were expecting might have been closer with a 5.0 motor from the fox's but most 99-04 gt's are in the 220's rwhp stock.

 

FYI. the 4.6 motors in general are not worth stroking. the best bang for the buck with them is Forced induction. a blower on them will hit 380-400rwhp. build the motor up N/A and you might hit 350rwhp or around there and spend more money doing it.

4.6's need FI.

 

I doubt the flowmaster catback gave him 7 rwhp. Maybe 2 or 3 rwhp.

 

my friends bullitt gained alot mroe than that. went from 240rwhp to 250rwhp by adding a SLP catback.

2-3rwhp seems low to me on a GT for a catback exhaust. maybe a v6 mustang.

 

That I believe. SLP is a straight through muffler just like Borla and Magnaflow. Stock mufflers, Flowmaster, and Mac are chambered mufflers. A straight through muffler flows better and will show better gains than a chambered. People get chambered mufflers to have that muscle car sound, but they will only give you a few rwhp over stock. My buddies SS Camaro gained 20rwhp by going from a stock catback to SLP.

 

true.

 

holy thread from the dead batman.....I just fell on this thing. I haven't post in the tread for months...LOL. Well as an update gears are in and SCT tune is on. I haven't made it back to the dyno, but I will over the summer.

 

when my gt was stock with only midpipe and catback it ran 244rwhp and 268rwtq...so 03DSG those numbers are good because of the slowmasters