Hey hey everyone. Names Aaron. Just found this forum. I’m a newbie to Corvettes.

I have a question on Dyno testing the 6 speed LS3's. I have a 2008 z51 6speed Manual LS3. We shut off the traction control via the button. But the dash still lit up like a Christmas tree once we started rolling on the dyno. And the car put down some lower numbers than we were expecting. 311TQ and 319HP in 3rd gear.

The question is, is this normal? Or was there something else we needed to dis-engage or a fuse to unplug maybe. Was it this low because the car didn’t like being on the dyno or is it normal for a stock car.

The dyno was a mustang dyno. We tried both 3rd and 4th gears and they were pretty close to identical. Only odd thing which I was told was perfectly fine with the mustang was we didn’t use a tach signal. He set it via wheel RPM (I held it in the test gear at 3500RPM and he synched that with the dyno).

Any help/insight would be greatly appreciated.

THANKS!

Aaron Victor

 

I've heard of heart breaker dynos but...really though that is a very low number. Something is up with your car or the dyno and mentioning the dash lighting up I would look at the car first since. That is something which has not be mentioned here before when cars have been on the dyno. Has anyone done a tune on the car or attempted to do so?

 

To my knowledge no one has tuned the car before. I bought it from the original owner with 20k miles on it. It was completely stock.

When I say the dash lit up like a Christmas tree let ne clearify. It was everything having to do with ABS or wheel sensors. Brake light. Check engine light. Traction control. Stability control. And another one I can't remember.

We were sure to switch to traction control full off. We were not in competitive driving mode.

Anyone have special specific mustang dyno expierence?

Thanks for the help!

Aaron.

 

Since you are here looking for answers then it is safe to assume the shop didn’t have any answers for you.

Did they even attempt to explain/troubleshoot the low numbers or address your concerns? Did they even realize how low that was for a LS3 M6? With the varation on dynos M6 LS3's putting down less than 360rwhp start to raise a eyebrow.

If not...ask here for shop recommendations in your area and move on.

It sounds like you may be ready to start modding…here is a little advise…I’ve been here awhile and researched mods and found a reputable shop. I and many others can attest to the many people who come on here with botched cars. They are looking for answers after spending thousands of dollars in mods only to have a car which barely runs and on the edge of blowing from a bad tune. If you have deep pockets and willing to ride it out in faith go ahead. If not and this is a one shot deal then do it right with a well established and recommended Corvette shop. Don’t let someone learn on your dime!

 

Where was this dyno?
4th gear is the correct gear not 3rd. Don't think they were quite the identical either. Plus you need the tach signal.

Plus you need the instructions for the dyno. Since the operator has no idea! I'd head for new tuner/shop quickly!

 

You didn't say you turned off active handling which you should have with same switch as traction control. Push once for turning off TC and then push and hold until it turns off AH, then try it. If it doesn't turn off you may have a tire pressure sensor bad or not adjusted to that tire/wheel position, if that's the case you will never be able to turn off AH. That and it should be dynoed in 4th.

 

OK this is VERY helpful post. OK so there is an additional procedure than just turning TC to off. So having active handeling on would possible affect the numbers. Ill try when I get home to see if I can shut off active handeling.

Thanks!

Aaron victor

 

You'll have to push (& hold) the button down for 5 seconds for TC/AH off. Once you turn the car off, you'll have to do it everytime as it defaults to TC/AH on, on start up.

Here's a thought...maybe your tires were slipping on the rollers? Did they tie your car down REALLY good?

 

OK. Just made it home.

I am absolutly able to turn off both TC and AH. SO that works fine. We did NOT do that. We only had TC off.

So can we say there is a general consenses that by not having both TC and AH off, that the car would have reduced measurable power? Is it worth heading back to the dyno to try again? Does anyone have any previous expierence with side by side runs of a car with only TC off verses a car with TC and AH off?

Also, anyone have any first hand expierence with Mustang dynos and not using a seperate tach signal? I know someone said that "you should use a seperate tach signal" but is there anyone who has seen that the wheel speed tach approach is not viable on mustang dynos?

Thanks for all the help guys. Thanks espically to 97CoupChuck for catching the AH still being on!!!

Aaron Victor

P.S.
Norty, no wheel spin. Car was strapped down properly and no unusual data conflictions between car tach/spedo and dyno tach/spedo

 

4th is the only gear 1 to 1 therefore anything else is not going to give you true reading.....

 

hope you get another run. as a comparison, my 2001 TA 6 speed stock with LS1 made 326 rwhp and 318rw torque.

 

I know on the 500 series mustang units they use a single pickup that can be put on any of the plug wires.... Other then that its just setting up the program for the specific vehicle. Corvettes can be a bitch to tie down, but at stock power it shouldnt have really had a slippage issue. Can you post copies of the dyno graph?

 

2010 LS3 here made 382/374... people posted that that was high for an LS3 car on another post? Car only had 600mi

Dirty air filter? Bad plug wire(s)? All the other lights I would not be concerned with as my car gave me some ABS lights but the check engine light should not have come on.

 

OK. here is the graph. This was the 3rd gear pull. The 4th gear was near identical, but maybe peak HP was a couple less and the MPH view obviously went out a lot further but basicly both said the same thing.

Air Fuel was 12.1 at the biginning and about 11.8 on the 6000RPM side.

DAMNIT! OK I cant embed it. youll have to follow the link guys sorry.

http://picasaweb.google.com/lh/photo...eat=directlink

 

My car ran about 11.9:1 so you are ok there...
I would certainly be leary of the whole process if he had you make a pull in 3rd

 

Ha-ha. It is so funny to see the same mentality of import car punks follows into the corvette crowd. I just want to make a FTR post on all this.

***FTR!!!***

If you want to help and participate in the discussion, awesome, come on in.

Keep your shop prejudices to your self, this especially includes other shops.

Things like "you need to pick a better shop" "why did he have you do it in 3rd" etc... Your not moving the discussion along, your only adding fluff, this isn’t FOX news this is a discussion board.

For the record, this is not a tuner shop. It is only a dyno shop. There are simple questions interjected here and that’s what’s being discussed. We did both 3rd and 4th. 3rd is printed because it made 2 more HP than 4th did. We were both surprised by that hence the whole discussion of if there was something holding the corvette back from making the power it was suppose to.

So let’s keep the discussion on track, and keep our penises in our pants ha-ha

THANKS!

Aaron

 

I appologize if you took offense, it wasn't meant that way. Sometimes they can be dyno malfunctions with weather/altitude corrections. Before you throw 100% of the blame on your car there are other things to be concerned about... that was my point.

 

Sorry, but they had some good points.

 

OK. Just got back from the dyno...

Nominally better, but nothing to make me do back flips.

So TC and AH were both verified off this time. Dash still didn’t like it, as we climbed above 4000RPM brake light and abs light on dash came on, and the digital readout started flashing back and forth with "Service ABS System, Service Active Handling System"

We did get a tad better number at first, but after 3 runs, finished lower than yesterday.

Car made:

Run #1 - 325TQ and 324HP in 4th
Run #2 - 315TQ and 317HP in 3rd
Run #3 - 309TQ and 307HP in 4th

We did notice a drop off in the power curve at 5000RPM that we attributed to getting hot, ecu pulling timing etc... But the curve was not destined anywhere near the 350+ range anyways.

So long and short, initial run with TC and AH off made about 10 more HP and TQ than yesterday. We thought to maybe come back with a new Air Filter, and a couple tanks later with better fuel (local station may be selling crap fuel) so I'm going to run a couple tanks from Exxon or Shell vs. the AM/PM brand fuel I have been feeding her.

Ill get the dyno sheet scanned in and up. We only printed out the high 325/324 run.

Where is my power I may swing by a dynojet too. Just for a comparison. *shrug*

Aaron "Down on Power" Victor

Dyno sheet #1 - http://picasaweb.google.com/aaron.m....79376345843410

Dyno sheet #2 - http://picasaweb.google.com/aaron.m....79384753602194

Dyno sheet 1 is the best pull from day #1, 3rd gear, TC off AH on
Dyno sheet 2 is the best pull from day #2, 4th gear, TC off AH off

 

Im chalking this one up to operator error at this point. Something is definitly not right. Care to share where your taking the car currently to be dynoed? But i have seen the dash light up like a christmas tree on a vette more then once while it was on the dyno. Since your in Vegas, perhaps you should go see Jeff over at Total Performance Engineering, im sure he can help you out.