Low dyno numbers?!?!
Drifting
Joined: Dec 2012
Posts: 1,717
Likes: 28
From: O'Fallon IL
Yes we bought pistons with a larger valve relief as instructed by the performance shop, the operator did not hook up a single sensor to the car he merely drove it on the dyno did 4 pulls in a row and drove off so I can't tell you timing, the only reason I know the Afr is through the wideband I had previously installed. The engine temp held 178 through each pull
Timing can actually take power away on these engines hence the question about it. Also it must tuned quite well to only be surging below 1,500 with an aggressive cam and no street tuning. I can tell that leaning the afr should give you more hp but take her to the track and see what it does.
Safety Car
Joined: Feb 2007
Posts: 4,684
Likes: 107
From: Opelika Alabama
Safety Car
Joined: Feb 2007
Posts: 4,684
Likes: 107
From: Opelika Alabama
Thread Starter
Intermediate
Joined: Apr 2014
Posts: 45
Likes: 0
https://www.corvetteforum.com/c6-tech-performance/3036745-2012-ls3-stock-dyno-numbers.html?styleid=140
Right there good sir, that still doesn't answer my question, the common dyno # for ls3 is 380 so why would a h/c/I/e/t ls3 only make 20 more wheel hp?
Right there good sir, that still doesn't answer my question, the common dyno # for ls3 is 380 so why would a h/c/I/e/t ls3 only make 20 more wheel hp?
Instructor
Joined: Mar 2014
Posts: 196
Likes: 2
From: Internet
It's low regardless I have seen a number of bolt on LS3 cars headers/intake dyno that same number or more.
You ever get any before dyno numbers?
If you don't have before numbers does whoever owns the dyno have any comparisons between other stock LSx cars?
Also find out if there was any KR and what the max timing was
You ever get any before dyno numbers?
If you don't have before numbers does whoever owns the dyno have any comparisons between other stock LSx cars?
Also find out if there was any KR and what the max timing was
Thread Starter
Intermediate
Joined: Apr 2014
Posts: 45
Likes: 0
Do some research, there are many cam only ls3s making over 500 wheel with no headwork done to them
Former Vendor
Joined: Dec 2014
Posts: 105
Likes: 0
From: Montreal Quebec
A stock ls3 (dry sump) makes 403-415whp tuned on our dynapack dyno and a wet sump LS3 stock makes 390-410whp. Looking at the dyno chart my guess would be a combination of tuning and dyno calibration even if they are one of the top dynos.
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Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
...and regarding those that think the track is better. Just how many variables do you think that adds to the equation?! Weather (humidity, temp, altitude), track conditions, tires, car setup, not to mention the biggest variable of all.....the typical driver.
Not to mention the OP may have no baseline track data to compare to.Now answer why you see such consistency in dyno numbers from across the country. Sure, there are always a few outliers, but the consistency is way better. If not, do you really think the Federal Government would let the automakers certify the engine using a dyno?
Thread Starter
Intermediate
Joined: Apr 2014
Posts: 45
Likes: 0
Thank you everyone for the great answers!! I am going to have an appointment set up for a dyno tune and hope to see better results, the tuner that tuned this car had absolutely no idea what an ls3 was and had no past experience with ls engines or really gm engines at all, and plus its not a dyno tune on the car it's an hp tuners tune.
Thread Starter
Intermediate
Joined: Apr 2014
Posts: 45
Likes: 0
Thank you everyone for the great answers!! I am going to have an appointment set up for a dyno tune and hope to see better results, the tuner that tuned this car had absolutely no idea what an ls3 was and had no past experience with ls engines or really gm engines at all, and plus its not a dyno tune on the car it's an hp tuners tune.
Drifting
Joined: Dec 2012
Posts: 1,717
Likes: 28
From: O'Fallon IL
Platinum Supporting Vendor
Joined: Sep 2001
Posts: 3,665
Likes: 341
After that the calibration can play a huge part. What was the final timing and lambda, like I said there are allot of variables to pinpoint just a reason as to what could be wrong.
Race Director
Joined: Oct 2005
Posts: 14,999
Likes: 200
From: Bay Area Ca.
I dynoed 375 rwhp and with a tune got 400 rwhp. Added long tubes with hi flow cats and saw 422 rwhp. With a mild came I would expect to see 445-450 rwhp.
The cam mentioned was a good deal more aggressive so I was thinking maybe 50 hp cam. The heads should of add some more too. I was conservative with my 450 ish rwhp number.
My driveline power loss was closer to 12 1/2%
Huys had made around 500 rwhp with long tubes and a big cam and head work.
Not sure what you are calling into question here?
Racer
Joined: Jul 2011
Posts: 370
Likes: 0
From: Wellington FL
Your numbers are clearly low for that hardware.
Did you ever try an old school compression test? Maybe you have a leaky valve or two. Maybe rings on those new pistons not gapped right or seated in yet. Maybe need more break in.
Did you ever try an old school compression test? Maybe you have a leaky valve or two. Maybe rings on those new pistons not gapped right or seated in yet. Maybe need more break in.
