You've got to be kidding about dyno consistency across the country. You can't even get the same numbers from HotRod Harry's Mustang dyno and across the street on Billy Ray's Dynojet an hour later on the very same car.

Now the track version of power is not about ET, but MPH. Compensating calculations for weather variables have long been known and have a high degree of accuracy. Assuming there is not excessive slippage by tires or transmission or significant head/tail winds, the MPH of a similar weight C6 with the same HP will have nearly identical numbers, regardless of an average driver or a good one.

 

And don't think that going to another tuner is going to magically net you 100hp. There's not that much left in tuning for a mild NA setup like that. I would say it's the dyno and move on... or go to a dynojet if you want to feel good.

 

If a stock LS3 only put down 290 on that dyno, then your numbers don't seem off relatively speaking and the curve on your graph doesn't look bad although the torque number is high relative to the hp number for being a stock stroke motor with that size cam. Do you know the compression with the aftermarket pistons and are these uncorrected numbers at high altitude possibly? Don't get caught up in everyone's different peak dyno numbers that you have no idea of the correction or smoothing factor if it has a kick as no graph was posted

 

that cam is all wrong and it is running too hot and that is why your AFR has to be so rich. You exhaust duration is not high enough at all for that intake duration. I have no clue who the hell told you that was a good cam but get rid of it. It is just too rich but the air charge is not transferring because the air cant get out in time and there is not enough exhaust duration pure and simple. The exhaust is not discharging and it is laying doormat and that is why they had to richin it up so much to raise the air density so it doesn't ping like mad. The exhaust is so much weaker than the intake in these motors. You need to understand the flow characteristics of the heads and then cam accordingly. Also be aware that who ever ported you heads and hopefully flowed them most likely used a test pipe which is fine but it kicks up the flow a lot more than it will actually be with the headers you are running. You need to talk to someone that understands how to cam these motors properly. let me know if you want that help.

Yes that dyno is most likely crap and off by a lot but that cam is not right at all. That is close to a single pattern cam and those don't work on these motors I do not care what anyone says. I know people used to run those types back in the day but that is when they didn't know any better and how bad the exhaust ports are on the LS motors.

 

Agreed... I have always used DYNO's for tuning (Before & After mods)... not racing. It’s the difference between the two (Before & After) numbers that matter. I honestly could care less what the DYNO MAX HP says. I’ll figure that out at the track with Vehicle weight/trap speed/elapse time/distance traveled. That information will net you a more accurate indication of "ACTUAL" HP & Torque... Even with the variables at the track mentioned will not affect the overall HP/TQ numbers so greatly… And after a couple of runs you will have a good average number.

In my opinion DYNO’s are simply a tuning tool and are great for baseline runs prior to mods and then after the mods are installed. In that case, it really does not matter what the overall numbers are… it’s the difference gained or lost after the mods. Since that business alone does little to make up for the cost of the DYNO, shops use them to generate revenue.

Bottom line, its where the rubber meets the road/track that matters. I have raced guys who claimed big HP numbers on the DYNO and beat them to the end of the track with less HP figured by track times.

SPEED SAFE, AIR RAM

 

I agree with you that I won't gain much hp from a different tuner but I want to talk to a performance shop that actually knows about ls engines instead of a shop that specializes in fords and mainly work on mustangs.

 

I'm not disrespecting your answer but can you explain what you mean by running too hot? Thank you very much for your answer it was very informative!!

 

It seems a little low for the mods you had listed. I had an '08 w/a LS3. CAI, Longtubes and a tune & it was at 412hp & 402lbft ()

 

hopefully he'll chime in but i gather he means hot in the cylinders from the exhaust duration. really sounds like he has some good knowledge on your situation.

 

Great numbers!!!! You guys get these awesome numbers with intake and exhaust that's why I was expecting a little more out of mine haha

 

420rwhp and 420rwtq for my LS3 with I/E/T. With the Texas speed 229/236 cam i made 470hp and 420tq (gained tq in the band ).

Try another dyno and see what you get. If it reads low again, you have an issue.

Maybe your tires are slipping all the way through the pull. IDK.

 

I agree the cam isn't what I'd spec either and not ideal by anymeans, but I have seen a 230/234 114 in a LS3 make 75 more than what he did so I wouldn't point at the cam completely. The exhaust isn't weak on the LS3 head, it's just low relative to how well the intake flows. My problem with his graph is the hp to torque split associated with a healthy cam is pretty much non existent regardless of inefficient exhausting of the cylinder unless he didn't have headers, but states he does. I must have not seen the same graph as I didn't see any AFR readings on his, regardless too many other unknowns that we don't have proof of what's actually in the car and the beginning/end of the graph have a couple squiggly lines that make it appear as though the operator may have got his timing off hitting the start/end affecting the numbers possibly imho

OP I'd try taking it to another dyno to compare the results, also what clutch/rearend gear is in the car and wheels/tires on it? These can affect your dyno numbers as well.

 

https://www.corvetteforum.com/c6-tech-performance/3036745-2012-ls3-stock-dyno-numbers.html?styleid=140

So all of these people dyno below sea level?

 

Thank you for the great answer!! And to answer your question I have the stock clutch with the stock 3.42 rear, also I have 315/35/17 nitto nt05's in the back

 

 

Yes I do have headers

 

Hey guys sorry to bring up an old post but I was finally able to take the car to the track. I haven't touched the car since I made this thread. Keep in mind I have never been to a track before in my life and this is probably the worst 60' a vette has ever seen lol. My best that day was a 12.08@ 122mph with an astounding 3.2 sec 60'. Does that sound right for my dyno #?

 

My LS3 car put down 394rwhp on a dynojet and trapped 122. Headers & tune only, stock air filter even. Your ET certainly has a lot more in it with that 60' but trap shouldn't change much.. Something is not right on the back half of the track, should be trapping more then that but given the dyno numbers they seem right.

 

Sounds like a good launch will get you into the high 11's. Which is right where your car should be + or - a little

Can you post a pic of your track times?

 

high 11?a good launch would put this car in the 10's