LIVERNOIS MOTORSPORTS

FOund it on the weby....

discuss~

http://www.youtube.com/watch?v=PN2GGzlX0QE

 

Very good numbers that's just under 15% driveline loss going through an IRS unit. I'm curious how broken in the engine was for that test but if it's green it's quite impressive.

 

Seems a little low for a 3900lb car that traps 111mph. Might be the dyno reads low or this car just isn't broken in yet.

 

That could be in the 380's on a DynoJet. I believe Livernois only uses Mustang brand chassis dynos.

 

it was a dynojet

 

It's missing about 11 rwhp.

 

Lower than I thought. Then again, I didn't expect it to put out vette numbers (~380-390IIRC), with it most likely de-turned with more restrictive exhaust/intake.

 

Anyone seen Livernois post numbers of a bone stock LS3 Vette? Those numbers seem slightly low but maybe their dyno isn't one of the ones spitting out 390+ rwhp readings for stock LS3 Vettes... The M6 Camaro should only be down at most 5-10 hp from the Vettes if both crank ratings are accurate...

 

375/.88 = 426hp

These things should be putting out 375rwhp on a correctly set up dynojet.

 

Correction factor should be 15% for a manual tranny car and 17-18% for auto. You're using 12%. If you take the 15% correction factor for converting to wheel dyno numbers then you get 426 hp converting to 362 rwhp (426*.85=362.1). So it looks like it's pretty much dead on the factory rating. Will only get better at the 5000-6000 mile mark (like all of the other LSX's) when they loosen up. That dyno isn't one of the happy ones that spits out 380-390 rwhp LS3 vettes. Livernois doesn't really play the dyno numbers race game. Those are solid realistic numbers.

 

Dyno pass discussions are pretty pointless without all the info.

I don't see the numbers quoted as being dead on enough to be accurate.

WHY?

The torque number quoted was 371LbsFt... and 363HP.

Anyone other than myself find it a bit strange that an NA motor which is stock, and not a diesel, is showing a higher torque number than HP on a dyno pass.

The LS3 for the SS is rated at 426HP@420Lbsft.

A 371 LBSft is next to dead on for a 12% driveline loss... Good for a 13% loss. Better at 14%, Even better still at 15%.

Roller dynos calculate hp by extrapolating torque. They read torque and calculate HP through software.

I think its great someone strapped the car down and spun the Dynojet with it.

I don't infer the numbers are fudged, or meant to get folks going.

Folks taking a dyno that looks a bit odd on it's face, and getting worked up as if it were gospel is not founded.

HOWEVER... 364HP@371 torque is not what would be expected, regardless of drivetrain loss percentage. Now, reverse the numbers for torque and HP and it would make more sense.

 

My 88 305 Formula dynoed 194/267 when I had it and my Firehawk dynoed 294/343 the last time it was out.

FWIW, it doesn't matter what it dynos, take it to the track for REAL numbers.

 

yeah they do. i had my trans am tuned there. 360+ isnt too bad i guess. i wasnt expecting as much of a loss but, ill just have to do a little more work to get to the numbers im wanting.
my 99 trans am pulled 420 on that dyno with a vortech supercharger on it. i gotta get this camaro around 475-500whp atleast.

 

Concerning the 364 HP vs 371 Tq....take a look at the graph near the end of the video. Peak torque appears to have occured during a small 'spike' in the run (also shows up in the HP curve, of course). It is likely that with a different smoothing algorithm, the peak torque number would have been somewhat less, and thus bring the HP to Tq relationship closer to what GM claims.

FWIW...I've done a lot of chassis dyno testing. One thing I have noticed is that low-mid rpm torque readings tend to vary quite a bit with no changes to the car/engine. Near the car's HP peak, those changes tend to be much smaller. Please note that HP = torque * rpm / 5252.

Engines and dynos both vary somewhat. Type of dyno, calibration, accuracy of weather instruments, the weather, type correction factor used (if corrected at all), engine temp, etc will all contribute to different numbers on different days from different dynos and different cars. It is likely we'll see from 365-ish up to 385-ish RWHP on 100% bone stock LS3 Camaros. Some will get all excited that they got a "good one", while others might be disappointed that they got one that was a "little off". In reality, I'd bet a paycheck that the motors are all within 5 RWHP of each other (up/down), and the variance is elsewhere (I don't believe in 'factory freaks).

FWIW...using a popular HP formula....111 mph @ 4050 lb (raceweight, with driver) calculates to 432 HP.

 

An inertial dyno like the Dynojet measures the power and then calculates the torque based on the engine RPM. Brake dynos measure power and then calculate the torque.