Can your tuner Kill Dyno Numbers for you?

[Lethal Racing]

Not only our cam, but others out there I have seen questions asked about the power numbers members have gotten lately. Some Members are very happy while others are puzzled. I have been tuning cars 16-17years now and I can say without a doubt there are many many many many variables to tuning and dyno numbers. Dyno numbers do 2 things, Measure Power Results and Sell Parts.

When I tune cars the first thing I do is dial in drivability and fueling. This is at the end of the day what will make the customers happy with their car. Drivability, Starting on the first crank, Not dying at every red light or when the clutch gets pushed in is always the most important. Give someone back their car with the best numbers in the world and find out how much badmouthing a company gets about the rest of the car if it drives like crap. Drivability is what sets apart keyboard tooners from a tooner, and then what sets apart a tooner from a tuner.

A true tuner can actually explain to you the "WHY" as to what they are doing and will do it with direction and purpose. A tooner is someone who knows something about cars and can put together a bunch of bandaids in your car and it may all finally drive ok, but there will be issues. And a keyboard tooner is just experimenting and using your car to get there, hopefully it all works out for you.

Onto Dynoing a car. It has been said a dyno is nothing more than a tuning tool, which is true, but it is also a selling tool. After all, you to need to be able able to offer customers a reason to buy a product from your company. Good results from the dyno are always a good start. As car guys we always measure our cars by how much power they have...We need 1hp more than our buddies car!!!!

I use the dyno to dial cars in for many different things. You can tune a car for max power, reliability, road racing, drag racing. The majority of the customers want a peak dyno number so I dial the cars in for that.This is what normally gets posted online by myself and other well known companies. That is however what everyone wants to know....How much power can my car make. When This is done I will add back in the safety parameters to the car, just the same way the factory does. Using the IAT sensor, Coolant Sensors, Knock Sensors, Fueling..ETC.

I am posting this dyno graph of a Camaro SS that we finished in the shop Friday afternoon. I dynoed the car for max power and then I changed the fueling, dropped the timing and added back in the factory safety parameters. The results were that the car lost 25rwhp by doing this.

When I see guys posting results they are unhappy with it doesn't mean that the tuner doesn't know how to tune, but the conditions the car are tuned in do make a huge difference and... No... dyno correction factors do not account for this. Was there a fan in front the car keeping the coolant temps in check? Was there enough air getting to the air filter so that the car is taking in ambient air? In my opinion if the air in the shop is 100degrees and the IAT's are 150 then the dyno corrections are not a true measure of what your cars dyno numbers should be. These are things that should concern you "IF" all you want is a peak number. Also could be that the guy who is tuning your car has different beliefs about AFR and timing and where they should be based on his/her experience(tooner/tuner) or maybe you didn't buy their product and they surely don't want something else making better power/torque(Who are we kidding that would never happen in todays world)

I hope you guys can take away some good information from this post. I am basically saying there is a huge swing in what your car can dyno and why. Be mindful in asking your tuner these questions. If they can't answer these questions then find someone who can.

[WBrady]

I think blanketing tunes at 12:1 and calling them safe(r) because you overrichened the mixture is poor. If it makes more power at 13.2:1 let it eat. Certainly isnt going to hurt a n/a car. A tuner has a need to protect his business, which is understandable, so a lot of folks err on the side of caution when taking in/sending out cars in case something happens with the engine fingers dont get pointed. I suppose its all about your intentions.

"then I changed the fueling, dropped the timing and added back in the factory safety parameters. The results were that the car lost 25rwhp by doing this."
And why did you do that? Like I said above. Self-preservation "in case s___". Good informative post though, I think a lot of people view tuning as black magic... where its actually good to know why things are changed and how they do/don't benefit you.

[Lethal Racing]

The 450rwhp run was to show how much variation can go into the dyno numbers. I by no means leave the cars at 12:1. I do set the cars up to leave safe. If a car makes the same power at 12.7 as it does at 13.2 then I leave it. No need to lean it out that much if its not needed. At 12:1 you can actually run into fuel knock.

The main point is that if I am in a 150degree shop on a 100degree day without fans on the car and the car running rich with all the safety parameters(ie pulling a ton of timing due to heat) in place that it will kill your dyno numbers.

Tuners tune on the dyno differently. How they perceive tuning or the conditions they find acceptable for tuning are always different. Some take their time and some get you in out. Sometimes that depends on the customer who decides to wait and is checking their watch every five minutes and want the highest number possible, but they have somewhere to be.

These are just a few of the factors that contribute to the difference between numbers you may like to see and numbers that leave you puzzled.

Other factors are always the combination chosen as well. Cheap Intake, Spark plugs, Ebay headers, Valvetrain not setup properly will all hinder numbers and performance over the packages we suggest.

[PfadtRacing]

Originally Posted by Lethal Racing

The 450rwhp run was to show how much variation can go into the dyno numbers. I by no means leave the cars at 12:1. I do set the cars up to leave safe. If a car makes the same power at 12.7 as it does at 13.2 then I leave it. No need to lean it out that much if its not needed. At 12:1 you can actually run into fuel knock.

The main point is that if I am in a 150degree shop on a 100degree day without fans on the car and the car running rich with all the safety parameters(ie pulling a ton of timing due to heat) in place that it will kill your dyno numbers.

Tuners tune on the dyno differently. How they perceive tuning or the conditions they find acceptable for tuning are always different. Some take their time and some get you in out. Sometimes that depends on the customer who decides to wait and is checking their watch every five minutes and want the highest number possible, but they have somewhere to be.

These are just a few of the factors that contribute to the difference between numbers you may like to see and numbers that leave you puzzled.

Other factors are always the combination chosen as well. Cheap Intake, Spark plugs, Ebay headers, Valvetrain not setup properly will all hinder numbers and performance over the packages we suggest.

Fantastic thread. Different tuners will get different results- even on the same car, for the same parts. Its not to say one tune is safe, and the other isn't, its a combination of factors that contribute to that difference. If your tuner is trying to dial in your timing on a 150 degree dyno session, chances are he will see KR and have a real tough time dialing in your timing. The result: Easily a 25HP drop.

On a good day, the dyno is a fantastic before and after comparison tool for hardware and software changes.

[Rhino79]

I will not disable knock completely just for a power number, and if I think we are seeing false knock ill hook up our external knock sensor kit. I like to tune them to make as much power as possible with no knock, and that's how they leave the dyno cell. From there it will make pulls on the road to verify that no knock is present in the higher gears.

I think a lot of people get hung up on specific Afr numbers and certain timing figures for all ls engines, but in the end the motor will tell ya what it's happy with, whether it be 12.2 or 13.2 or 26* or 30* of timing.

I do agree it is good practice to dial in the tune with reasonable iat and ect to ensure that the base tables are good without any modifiers pulling away from them.

[Avenging Orange]

Great info. I apreciate someone explaining that its not all about big numbers, though thats what sells. For me, its all about gathering the the proper combination of parts to hopfully achieve "my" goal and then have it tuned to make everything work in unison. Only numbers that matter to me are whats going on in each parameter.

[dekan513]

great to see tuners talk and go on about stuff like this . love reading stuff like this.

[Lethal Racing]

Originally Posted by Rhino79

I will not disable knock completely just for a power number, and if I think we are seeing false knock ill hook up our external knock sensor kit. I like to tune them to make as much power as possible with no knock, and that's how they leave the dyno cell. From there it will make pulls on the road to verify that no knock is present in the higher gears.

I think a lot of people get hung up on specific Afr numbers and certain timing figures for all ls engines, but in the end the motor will tell ya what it's happy with, whether it be 12.2 or 13.2 or 26* or 30* of timing.

I do agree it is good practice to dial in the tune with reasonable iat and ect to ensure that the base tables are good without any modifiers pulling away from them.

Nope I never disable knock retard at any time. That is just plain foolish in my opinion. I agree with the rest of your statement.

[TBone]

Preach it boys..... and Hallelujah!!!!!!

T.

[litle88]

Rhino or Shawn will the knock sensors detect false knock with big cams? If so how do you go around that?

Thanks

[Rhino79]

Increased notice from valve train, forged pistons, and even headers can trip false knock. The knock sensitivity can be turned down to remedy that. You have to be careful though.

We have a knock monitoring kit the uses 2 sensors, and it is very accurate and helpful in actually hearing and logging knock with the devices own software. Cranskase pressure logging will show u detonation as well.

Knock sensitivity or knock threshold tables vary from one operating system to the next. Some are good to start with and some just suck.

[Rhino79]

Exhaust rattles and rubbing can pull timing falsely as well.

[litle88]

Thanks bud! I appreciate that.

[SolomonAKOO]

some good info here!