JPope417

Hi everyone, Im new here just posted in the new member area. Long story short have had my 2009 C6A6 for about 5 months. It was in stock form when I bought it. I spend some decent money ordering parts from Texas speed, installed everything then took it to a local tuner. It made good numbers for a mild cam(stock converter) but I honestly was expecting some more power out of here. Below is my list of mods, and my best run of the night this past Friday. Is the stock converter holding me back that much ?? Also I must say I kick my self now for not driving a few more hours to RPM in NC to have them tune my car. I suspect my tune is not the best.... Makes good power but the drivability sucks.... surging, occasional stalling, misfire codes every few days etc. I just recently got HP Tuners MVPI Pro, I am not planning on trying to fix the tune if it is messed up on my own, just want to datalog and get to know the ins and outs of LS Based Motors. I bought GMEFI tuning guide by Donald LaSota. and have started to dig in to it to learn as much as possible. Anyways below is my Mods, my dyno # and 1/4 mile numbers. Let me know what you guys think.

2009 C6A6 35.xxx miles
Texas Speed cam 225/230 114 lsa .618 .613 lift
Texas Speed double spring and retainer kit with pushrods
High pressure oil pump
C5r timing chain
160 degree thermostat
Stock Stall
SLP CAI
JBA 1 3/4 Headers with 3 inch collectors
Z06 Hpipe
Z06 NPP with Muffler mod (had to modify passenger side
Mild to wild
Tune
Nitto Invo's
Does not spin off the line at all with Comp mode on, Car leaves like a turd but then feels like its flying.

Made 435hp on the dyno, can't find my sheet for the torque..... sorry

!/4 mile best pass of the night

60ft 1.97
330ft 5.49
1/8 ET 7.9928
1/8 Mph 91.81
1/4 ET 12.1287
1/4 Mph 119.10 (did run 120.28 on a slower time)

BlackFya

I'm no expert bro but something is not right. Those numbers seem about right for almost bone stock ls3's....check out the fast list. I can vouch for RPM as they tuned my car with lg headers, halltech kb and borla stingers. I put down 406/412 and the car drives perfect! I wouldn't do any more hard runs or tuning....take it to RPM or Tick. I have heard good things about both.

5knives

Without knowing your racing technique and ability it's hard to say if your numbers are off. However, based on the issues you say you are having, I'd take the few hour drive and have a real tuner fix those for you. Granted it may only be the drivability that is of a concern but who knows how the rest of the tune is. You don't want to be beating on your car if the tune is that far off.

JPope417

Ive been racing in a 275 radial class for 5 years. Just always been on the SBF carb side of the fence. I tried bringing the rpms up on the foot brake till just before it started to push, I tried flashing the converter from 900 1100 and 1500. Nothing really changed just leaves really slow in first. Like I said no real wheel spin.

C6David

Converter is going to do a worlds difference for our cars. My cam only ls3 with 21k miles put down 452whp/412wtq with a 231/238 .617/.615 112lsa. I initially had a 3600 stall in it and my best time was an 11.3@121 my first night out. My 60' were only mid 1.6's and i wasnt too happy with that as I was shooting for 10s. I swapped that converter out for a 4000. And could only best a 11.2 trying to figure out traction issues and shifting problems. Finally after some tweaking and learning I was able to get the car down to a 10.7@126 with a 1.46 60' o to answer your question on will a converter make a difference in these car...Yes that they will. My car has a stock motor now and just adding the converter on street tires took off 6 tenths

HOXXOH

Depending on how quick you want to go, a 3200, 3600, or 4000 Yank will get you there. If you do your own install, then drive to RPM. Otherwise arrange for RPM to do it. You'll want the converter in before the tune.

You will need DR's for the track to get below about 11.2. I've been to 11.44 on Invos with a 3600 and bolt-ons, but it's not easy. You'll also need a rollbar, 5 point harness, fire jacket, or a track that just wants the money.

CMY SIX

so you build it for more HP and some how it makes you a better driver, no wonder John Force is so good he's got 8000 HP. I can hardly wait to add more HP to mine. I will instantly become a better driver and I didn't even stay at a Holiday inn express last night.

HEATWAVE

I'm running 11.3 at 120 mph in 4000 DA
My 60s are 1.5X tho

dennis50nj

The 60 ft is killing you. But even stock converter it should be better but cam could be killing that also. If the tuner isn't really that good they could have left the TM settings stock

JPope417

Never said anything about driving skill, was asking if someone had close to the same set up and what their experience and et/mph was. Thanks for an absolutely useless response.

Tommy D

The issue is here:

"the drivability sucks.... surging, occasional stalling, misfire codes every few days etc"

Before doing anything else, you need to address these issues. Regardless of modifications if a car has issues, you are not going to get good performance.

Check the codes and see where that leads you....... bad coil, wires, cam/crank sensor and the list can go on....... good luck

HOXXOH

Wow. Good job spotting that Tommy. I missed it completely.

To the OP: Try putting the OEM air inlet/filter back on to see if that helps smooth things out again.

Batman 357

Yes, something is wrong. My 2008 is bone stock at 13 flat with 109 trap speed.

68/70Vette

My stone stock 08 has no modifications other than an A&A centrifugal supercharger. 580 rear wheel horsepower on the dyno at 6500 rpm...It produces 300 rear wheel horsepower at 3000 rpms. It is compliant with California emissions controls; i.e I can get it smogged and passed..which I have already done once. There was no hassle with the smog test, since the A&A supercharger comes with a California Air Resources Board (CARB) certificate on the blower housing.

.....Actually, I'm not really sure the guy that did the smog test even knew that it had a supercharger! The installation looks very factory. At a quick first glance look..for the naive, it actually looks like an AC compressor!! There is a large duct going into the front of the blower, and another underneath the blower that is somewhat out of sight.

SlayerRX8

That cam isn't exactly tiny. It's not huge either, but without a converter you're asking for driveability issues. A converter and a good tune should fix the problem.

CMY SIX

driver skill IS DIRECTLY PROPORTIONAL TO ET/MPH. or am I missing something? oh sorry reaction time has to do with it too in drag racing but even that means nothing if you slow down after tripping the lights

JPope417

Haha, Just noticed something...... you were a 1371. Now I see why you have the need to say pointless bs. Im a 2336, have a nice day.

Crabs over Castles

Tommy D

Hey Tom,

Yup I looked at the numbers first and then looked again & caught that sentence.

To the Op

So what have you found ???