Difference in HP

[Terryfied]

I installed headers, K&N Typhoon Cai and got a dyno tune that netted 380 hp on a 52k mile 2010 2SS, L99. A friend went to the same shop a year later with the same mods, same year with 60k miles and netted 423hp. The tuner used my tune on his car too! We both put in fresh plugs, he put on new wires but I didn't. The weather conditions were very similar too. Tune was done on a Mustang dyno. Why the hell would there be such a disparity in hp? The LS engine builds can't be that inconsistent can they?

[SSE 4 2SS]

Originally Posted by Terryfied

I installed headers, K&N Typhoon Cai and got a dyno tune that netted 380 hp on a 52k mile 2010 2SS, L99. A friend went to the same shop a year later with the same mods, same year with 60k miles and netted 423hp. The tuner used my tune on his car too! We both put in fresh plugs, he put on new wires but I didn't. The weather conditions were very similar too. Tune was done on a Mustang dyno. Why the hell would there be such a disparity in hp? The LS engine builds can't be that inconsistent can they?

If they are both L99 cars, with all the same other bells and whistles... take em to the track and at the same time, in opposing lanes make five or six or more passes, swapping lanes each pass and average out the times and speeds... make enough passes to toss out the high and low. Those are the numbers that matter, not what prints out on a dyno... make sure traction isn't the deciding factor either, and swap cars and do it again... remove another variable...

A dyno is a tuning tool, not a race tool... it gives a particular car a baseline... you can't compare car to car on a dyno. That's done on a track.

Have fun...

And if you eat his lunch four out of five times with "less power" so much more the bragging rights..

[rontammy0]

You are in the ball park for what an l99 will make with your mods. Maybe on the high side a bit. Regardless.....there is no way in hell your buddy is putting down those numbers with the same mods on an l99.

[SquawkVFR]

I found that the butt dyno is your only true measurement at that level. Even then, the difference is very subtle until you start cammin’ and blowin’.

[Terryfied]

Originally Posted by SSE 4 2SS

If they are both L99 cars, with all the same other bells and whistles... take em to the track and at the same time, in opposing lanes make five or six or more passes, swapping lanes each pass and average out the times and speeds... make enough passes to toss out the high and y best et is 12.7 on street tires
A dyno is a tuning tool, not a race tool... it gives a particular car a baseline... you can't compare car to car on a dyno. That's done on a track.

Have fun...

And if you eat his lunch four out of five times with "less power" so much more the bragging rights..

My thoughts too but given 40+ extra hp I could get beat handily. I ran 12.7 best run. I'm guessing he might run 12.5?

[SSE 4 2SS]

Originally Posted by Terryfied

My thoughts too but given 40+ extra hp I could get beat handily. I ran 12.7 best run. I'm guessing he might run 12.5?

That’s why you go to the track... not all is defined by the dyno. Bone stock, my Camaro ran a 12.70 something and I lost to an L-99 car that ran a 12.699, and I mph’d by 4 mph... but I lost... I made 376 RWHP according to a dyno... I couldn’t drag that POS to the track though...

You’re guessing... he can run xx.xxx. I’m simply saying, take them to a track and find out. You mentioned in the original post weather was relatively the same... was there a correction factor in the software for humidity, how close was it in temperature, were the cars tied down exactly the same or was one car on top of the rollers and the other was behind the rollers relative to car position, was fuel quality accounted for, were the air filters the same cleanliness, was the MAF on both cars the same cleanliness, were they calibrated the same... all of these factors come into play and many more...

A dyno is only a tool used for tuning. Dyno numbers are used for bench racing and bragging rights... no one will pay you for a number... unless you are in a dyno competition for fun... you can however earn money with your butt in the seat making pass after pass after pass until you know every nuance, trait, and idiosyncrasy of the car... how to get the very best it has to offer... that isn’t made with a dyno sheet, it’s made on a track... where cars are taken after the dyno days are done and the car is tuned for trials... then with seat time under your belt, you further refine the tune in both the suspension and the power plant... you use the tools to refine the car to the point it’s competitive... one car vs itself... not one car vs another a year later with relatively the same conditions...

Here’s an example... I make a pull and get a number from the dyno. I make multiple changes and do another pull, did I gain anything... those are not good odds to be choosing from... so the first pull is my baseline... or maybe I make three pulls and average them... or more... then I start making changes... one change at a time... one variable... do I make one pull and determine if it’s a pass/fail... in some cases yes, in other cases no, I’ll need to make more pulls and attain an average... to try to replicate conditions... now most tuners I know will make One pull to see the A/F ratios and some other things... then they may jump right into whole hog changes, that they have gained knowledge of through years of trial and error... sweating their asses off in hot fume riddled dyno bays... (seat time)

Then they will start making incremental changes to the peculiarities of the specific vehicle they are in... but none of that matters to any other vehicle.. passes on the track are what matter...

Hell, go have fun, wear out some tires and burn some fossil fuels... go make a bunch of passes then call him out... beat him with seat time and a ‘lesser’ car according to the dyno... then you can rag on him about being a crappy driver...just don’t lose or give up to a number on a piece of paper... I’ve never seen a dyno make a pass on a drag strip...

[pyroguy]

There's not a snowball's chance in hell that a L99 made 423rwhp with headers, a cold air intake, and tune on a properly setup dyno. Either the guy's dyno is way off or your friend is filling you with BS. Like someone else said, take them to the track and see how they do against each other.

[Smokin19]

My 14' L99 made the same as yours when dyno was done by Steve (RDP).

[jc615]

for my L99 to get to his numbers I needed a stage 2 tsp cam...take that for whats its worth

[qcman]

Originally Posted by pyroguy

There's not a snowball's chance in hell that a L99 made 423rwhp with headers, a cold air intake, and tune on a properly setup dyno. Either the guy's dyno is way off or your friend is filling you with BS. Like someone else said, take them to the track and see how they do against each other.

Totally agree not a chance.........

[Terryfied]

Delete

[Terryfied]

Originally Posted by jc615

for my L99 to get to his numbers I needed a stage 2 tsp cam...take that for whats its worth

I thought the same thing but he has a stock cam.
There's no animosity here, I was just curious.
The track will definitely settle the score.

[christianchevell]

Little things matter; like is his correction factor the same STD...inflated or SAE? is he a newer model with electric power steering? is his exhaust more free flowing? Is his intake not a heat soaking cheaper K&N? His tires the same? Headers intake and tune...should be about your numbers no real big glaring thing could be a difference, but the guy operating the software printing the data on the dyno..... tire slippage etc its all in so many things its hard to track it down but the print out helps; colder air can make a car suck much more gas making more power so a dyno run on a cold morning with denser air can make a lot more power on the same day with a little more heat …..numbers drop, correction factors can be off especially without a good weather station attached.

[rontammy0]

Originally Posted by christianchevell

Little things matter; like is his correction factor the same STD...inflated or SAE? is he a newer model with electric power steering? is his exhaust more free flowing? Is his intake not a heat soaking cheaper K&N? His tires the same? Headers intake and tune...should be about your numbers no real big glaring thing could be a difference, but the guy operating the software printing the data on the dyno..... tire slippage etc its all in so many things its hard to track it down but the print out helps; colder air can make a car suck much more gas making more power so a dyno run on a cold morning with denser air can make a lot more power on the same day with a little more heat …..numbers drop, correction factors can be off especially without a good weather station attached.

My cheap K@N cai has me right at 375 with boltons on l99. That's about average or close to it.