Bad30th

iTrader: (13)

Well, I'm back from the dyno ! Finally got the new build finished. Goals were CARB/smog legal, retain good street manners/drivability and make enough power to move out a 3800# vert.

Specifics :
W2W Callies forged 347ci LS6
WCCH 71cc CNC Stage 2 LS1 heads
ATI P1SC @ 8.5psi
NX MAF wet nitrous, 50 shot jets
'04 LS6 cam
dynapack dyno (bolts to the wheel lugs)
low bottle pressure, ~800psi
Continental 3400 stall/Toy Shop built 4L60E
...more details about my setup on my website (link in sig).

I was anticipating running out of fuel at the top end, which I am. 42# injectors and Walbro 340 in-tank aren't cutting it past ~6000rpm.

Results : on 8.5psi boost it made 517rwhp/628rwtq.
On 8.5psi plus the 50 shot it made 564rwhp/743rwtq

I was looking for the converter torque spike since the torque number was pretty high, but there really isn't one on the chart. It makes that much torque and then slowly drops off, there's no "converter flash" hump in the line. Supposedly this has to do with the dynapack dyno and the way it measures power.

The bottle pressure was low, ~800psi. Couldn't wait for the heater anymore, and bottle was probably about half empty, so the n2o number could probably come up a little with a 1100psi bottle. Need more fuel before I try to make any more power with either more boost or more n2o. Maybe next summer I will take the plunge with Nasty Nate's fuel setup.

Overall I'm really happy, and the car feels great ! Here's the dyno graph :



The little 50 shot made ~48rwhp and 114rwtq, haha !! Did I mention this was through CARB legal shorty headers ? I bet I could pick up about 50rwhp switching to long tubes.

Cheers !
Rob (Bad30th)

kp

iTrader: (34)

If th converter isnt locked even though you dont see the 'spike' iy will multiply torque, thats what it does. If the converter was locked then thats the torque you have

Nice numbers with a P1 and short headers, I had JBA shorties on one of my old cars and switching to LTS picked up nearly 40rwhp. Best I could get was 430ish on a stock motor with JBAs so you are doing pretty well. 500rwhp is cool no matter what,

Bad30th

iTrader: (13)

Thanks man, you were my LS6 cam inspiration, haha. Yep, the converter was unlocked for all the pulls. I guess I was expecting the "hump" that I see on dynojet printouts from the converter flash. ...and yeah, the car feels great. Really responsive and gobs of power.

Cheers,
Rob (Bad30th)

kp

iTrader: (34)

Thats pretty impressive power for an unlocked converter, even though the torque would have dropped a lot you would have picked up 30-50rwhp depending how efficient the converter is if you would have dynod locked.

Either way over 500rwhp and CARB legal is pretty cool.

LSs1Power

iTrader: (5)

Nice... Take it to another dyno... That graph looks wacky lol.

Zombie

iTrader: (2)

Take it to the track, horsepower numbers from a dyno don't mean jack.

Bad30th

iTrader: (13)

I'll be putting it on a Dynojet next month. The graph looks that way on this shop's printouts, as it graphs the values on decel as well. Dynapack dynos are supposedly used by a lot of NASCAR and high-end shops, and are "SUPPOSEDLY" accurate to within 1/10 of 1hp.

More info on Dynpack dynos : www dot dynapackusa.com/product.htm

...and yeah, new track times will be coming soon. Had to get it tuned first.

Rob (Bad30th)
Edit : modified dyno accuracy with disclaimer.

Zombie

iTrader: (2)

I'd bet money they are not that "accurate". They might be that consistant though. I've never seen an "accurate" dyno.

Dyno's are great for tuning, but horrible getting HP numbers. They might as well measure in a pretend unit of garflabs.

Frost

iTrader: (45)

Bad30th

iTrader: (13)

...just repeating what I was told. There's no tire slip, tire size error or tire PSI that enters into the reading.

As to whether it's "accurate" or not, I'll leave that to experts like you. I modified my post above with a "supposedly" so as to not mislead anyone.

Rob (Bad30th)

Zombie

iTrader: (2)

Let me just give a little dyno numbers vs track numbers example that i've experienced. I'm not bashing on your numbers, but too many people just care about a dyno number and that number really doesn't matter. It's good to get a baseline so you can see if you gained or lost when you make a change to the car.

Car A. Makes 470 RWHP, 3800Lbs
Car B. Makes 500 RWHP, 4000Lbs

I'll simplify this and only go by MPH at the track since that correlates to HP. Looking at the numbers Car A and Car B should be very similar at the drag strip. The are not though.

Car A went 130 mph
Car B went 119 mph

I've seen two different 700 dynojet RWHP cars never trap better than 127mph at the track, one was a viper, the other was a vette.

Just can't trust dyno numbers

Now get that thing to the track and see what it does (if there are any tracks left in the peoples communist republic of california )

DeltaT

iTrader: (5)

What's really suspicious about your non-nitrous numbers is the torque. No one else (that I can think of) with a P1SC on a 347 is getting more torque than HP.

Jim

Bad30th

iTrader: (13)

Hmm, perhaps 'cause most of 'em are M6 cars and clutches don't multiply torque the way a torque converter does, I guess ? Or the A4 guys are locking their converters, bringing the HP up and the torque down.

All I know is that's what the printout says - and the car feels amazingly strong. As I mentioned, I will be putting it on a Dynojet next month to see how many garflabs it spits out. If you want to call the dyno shop and argue the semantics with them, here's their number :

Extreme Motorsports
818-883-8184

...or you can call Rob Barth @ Strictly Performance who tuned the car. You might remember him from a 800+ hp D1 Camaro that made the front cover of a magazine... http://www.spmotorsports.net

As a side note, I have always made more torque than HP with my setups, although not as much more as this dyno. My old heads/cam setup made 410/415, my last blower dyno was 504/512 anding the pull early with a slipping tranny.

Also, I agree, there's a lot more to ET's than HP and torque printouts from a dyno. Car setup/suspension, weight, tire, driver experience... I am just posting these numbers from the dyno (which I guess I should have known better than to do in here with all you hardcore ET freaks) since I was pretty happy with finally getting the car completed and it was finally running good.

Since this is all meaningless, stay tuned for the all-important track times coming in a few weeks, hopefully.

Rob (Bad30th)

Zombie

iTrader: (2)

WOOT! Track times!

P.S. Feel free to post how many garflabs it makes on the dynojet. It's always nice to see how different dyno's show different "horsepower".

Frost

iTrader: (45)

Zombie you have just coined a nice term for for wheel dynamometer units of measure

From this day forward they shall be known as GARFLABS!

DeltaT

iTrader: (5)

I'm suspicious because my 383 with a small solid roller put down 501rwhp/470rwt through a 4L80E with 7.2# of boost. Nothing magic in your combo so I suspect magic numbers. Also a 50-shot that yields another 118ft/lb of torque?

I'm thinking Extreme has a wicked 'Vanity' dyno.



Jim

Bad30th

iTrader: (13)

LOL. It's on the up and up, I promise. However, 501/470 from a 383 solid roller with 7psi is unusually low (and no offense intended but that's being kind), so you can't really use that to go by. Was it a Mustang dyno ?

There are stock CI cam only cars pushing mid 400's.

https://ls1tech.com/forums/dynamometer-results-comparisons/219024-cam-only-dyno-thread.html

In fact, there's one in that thread with 518rwhp.

...and yes, with a blower, nitrous is compressed along with the air, lowers IAT and makes a shitload of torque. You might consider reading up a little on it.

Rob (Bad30th)

Nickn20

Tell us more about these cars, you cant expect a street tired stick car with 700 rwhp to runs 9s right off the bat.

Zombie

iTrader: (2)

*going off topic a bit here*
I've been using the garflab as my standard unit of measure when talking about dyno numbers for a while now. I've just gotten fed up with everyone talking about dyno numbers like they are the end all be all of how fast a car is. Seems like everyone talks about how this dyno reads high or this one reads low or this brand is better than brand x, etc. Dyno's are just tools for tuning.

I tune a lot of local cars and do it on a mustang dyno, I always make sure to prepare my customers for a low number and tell them it doesn't matter what the HP says.

Frost

iTrader: (45)

Whatever.... There are plenty of stick cars that are turbo's making that power struggling to get into 10s but with high traps. 2-steps break 6-speeds.