2018 GEN 5 Whipple 3.0 dyno results

[DTeal23]

“Same fuel as previous 805 pull, 863hp 677tq (still only seeing 20*)“

On 10 psi?

Post #3

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[TX-Ripper]

Post #3

Must be engine numbers

 

[aleccesarenriquez]

Must be engine numbers

What's happening is the elevation in Denver is depriving the car of making a ton of boost (3.5 pulley should be around 15 psi normally), but here it only made around 10 psi.

With the Dyno's correction factor coming into play, the power seems like a lot for not that much boost, but it's probably pretty accurate. In other words, the uncorrected dyno number is probably much lower and close to what the car would actually make on 10 psi, but the correction results in the higher number shown.

850+ on a Whippled Gen 3 car with high octane fuel seems pretty accurate to me. If he were to bring that same setup to a place with 0 DA, he'll make a ton more boost and the dyno will probably read something similar still.

At least that's what I think is happening here lol

 

[Mako_]

“Same fuel as previous 805 pull, 863hp 677tq (still only seeing 20*)“

On 10 psi?

yes

 

[Mako_]

What's happening is the elevation in Denver is depriving the car of making a ton of boost (3.5 pulley should be around 15 psi normally), but here it only made around 10 psi.

With the Dyno's correction factor coming into play, the power seems like a lot for not that much boost, but it's probably pretty accurate. In other words, the uncorrected dyno number is probably much lower and close to what the car would actually make on 10 psi, but the correction results in the higher number shown.

850+ on a Whippled Gen 3 car with high octane fuel seems pretty accurate to me. If he were to bring that same setup to a place with 0 DA, he'll make a ton more boost and the dyno will probably read something similar still.

At least that's what I think is happening here lol

I agree 100%

 

[sigintel]

The hp actually made is the uncorrected number.

If a correction factor for normally aspirated engines is applied to Forced Induction, then the so called “corrected” number is just a feel good silly number. You just get a “850whp” 11 second quarter mile car. Lol.

If the setup is limited by knock and cant add more air via boost, then applying a correction that tells you what hp you “could” make if you added more air is silly.

 

[TX-Ripper]

So why post the corrected number is it’s meaningless?

 

[sigintel]

So why post the corrected number is it’s meaningless?

Without posting the correction coefficient? Yes.

TLDR:
Naturally Aspirated dyno corrections assume the horsepower is LIMITED BY OXYGEN due to local air density (pressure) that the NATURALLY ASPIRATED ENGINE is UNABLE to CHANGE.

Forced Induction CAN CHANGE air density and temperature via compressor and intercooler in exchange for some output power (parasitic).

All Forced Induction aftermarket tuning typically maxes horsepower by boost increase (overcompensating for atmospheric pressure) until knock/spark timing is pulled/detonation detected: thus it is LIMITED BY FUEL CAPABILITY. Alternatively, most owners stop at a torque/hp limit where they expect mechanical damage.

NA correction such as STD(J607) or SAE(J1349, SAE J2723 (J1349 and J1995)) applied to a FI setup maxed out by knock limiting is thus meaningless.

Meaningful correction would be calculating the extra horsepower needed by the compressor to offset decreased pressure (expect 3-8%). Offsetting for humidity (0.5-1.5%) and temperature is more complicated since most FI systems are intercooled but will be significantly less than the pressure compensation.



LONG VERSION:
I used to work on repairing/tuning power plants and calculating expected power outputs using expensive software. Not saying I am an expert, but here is my thoughts on estimating (not correcting) FI numbers at sea level:


To be fair, most explanations of how to use correction numbers are written by engineers and awkward to understand.


NATURALLY ASPIRATED CORRECTIONS:
NA corrections offset for the density of the ACTUAL air(20.9% oxygen all automotive altitudes) pulled into the cylinder for combustion. The 20.9% oxygen is what combusts with the fuel.
The simple NA premise is that if you had denser air, you could have more combustion and thus more power.

That premise is impossible for FI. You cant take a car maxed on 93 oct at 16psi boost at 11.78psia ambient at 6000ft, then drive to sea level at 14.7psia ambient. You have to back the boost down by ~3psi over ambient or you end up with the equivalent of 19psi at 6000ft!
The whole point of FI is to compress the air denser than atmospheric.
At sea level, you have 14.7 psia.
At 6000 ft, you have 11.78 psia.
psia https://en.m.wikipedia.org/wiki/Pounds_per_square_inch
That is a ~3.08 psi difference or
(14.7-11.78)/(11.78)= 0.247877758913413
or ~24.8% difference going from 6000ft to sea level.
1.248 x 11.78 = 14.7

So if we tune a FI car at 6000 ft and drive to sea level, can we expect the motor to TRY to make 24.8% more power if we DONT back the boost pressure down? Simple yes, but if it couldnt survive an additional 24.8% more power at 6000ft, it wont survive at sea level either. Altitude changes the intake air pressure by 3psi. Unfortunately, the intake ABSOLUTE pressure (psia) a FI motor can handle does not care what the starting ambient pressure is before the FI compressor.

You cant apply a normally aspirated correction to a FI motor.


FORCED INDUCTION:
So how can we tune a car at 6000ft and get the same power as at sea level?
Easy, compress the 11.78psia air to 14.7psia and feed it in where the 14.7psia air would normally come in (at air filter, should be sealed after filter to avoid sucking in dirt of course).
If you use external power like an electric compressor or diesel compressor to compress the air, then your engine power output will be exactly the same as at sea level.

If you use the engine shaft output to compress the air(supercharger), your combustion (and thus power) are the same; however, you will be measuring shaft power minus the parasitic loss of the compressor. (Turbo parasitic increases backpressure partially). If you route the air differently say thru an intercooler, and force the air directly into the intake manifold, you would need to have the exact same intake and intake pressure (relative vacuum) as NA to reproduce the sea level NA power.
So what do you think the pure 100% efficiency parasitic power of a supercharger is for just 3psi boost?
For ~400cfm (~470hp) at 3psi at sea level its about 4.9hp.
https://www.engineeringtoolbox.com/horsepower-compressed-air-d_1363.html
The overall efficiency of various compressor types are:
Compressor Type Efficiency, η
Centrifugal 0.70 – 0.85
High Speed Reciprocating 0.72 – 0.85
Low Speed Reciprocating 0.75 – 0.90
Rotary Screw 0.65 – 0.75
http://www.jmcampbell.com/tip-of-the-month/2015/07/how-to-estimate-compressor-efficiency/

So engine at 25% efficeincy is driving a roughly 75% efficient compressor.
So 0.25 x 0.75 = 0.1875 or 19% efficiency.
So 4.9/0.19 = 26hp.

So 26hp +/- 3 hp at 470 hp FI going from 6000’ to 0’ .

Bottom line: you get to correct for pumping power losses starting from 11.78psia instead of 14.7psia. At 900hp crank, that is closer to 50hp.

Yup, 50 freakn hp.. roughly...
This does NOT take into account the ambient exhaust back pressure is 3psia lower at 6000ft, that actually gets you back some power...
Or percent difference of ratio of N2 vs O2.

WHAT ABOUT TURBOS? This is heartbreaker for Turbo guys: Turbos derive considerable power from the expansion and cooling of exhaust gas (think ~30-70% heat energy otherwise lost out exhaust, balance from increased exhaust backpressure). Lets use 50% just for example... so take that 50hp x 50% = 50 x 0.50 = 25hp. YUP! so Turbo guys would be adding even less correction vs supercharged guys....
Now a properly sized turbo setup perfectly reaching maximum efficiency at max power might be deriving 70+% of compressor power from lost exhaust heat, thus we would expect turbo setups to have considerably less parasitic crank power reduction. We see this familiar advantage with turbo and supercharger setups on the same fuel with same knock limit where the turbo setup will typically get 30-50hp more output on 93. Changing fuel to E85 and additional combustion and waste heat in exhaust may get you ~80-100+ hp 'free' advantage on a turbo vs supercharged setup in the 1000 - 1100 whp range. Turbos are thus called 'easier' on the motor for accomplishing the same power output.


BOOST PRESSURE AND HOW TO NAIL SEA LEVEL NUMBERS
Given that the FI is already compensating for the starting air pressure, HOW DO YOU GET SEA LEVEL PERFORMANCE NUMBERS?

Break it all down:
Start with boost pressure:
If you are at 16psig max boost at 6000ft (11.78psia), what is the max boost you can expect to run at sea level(14.7psia)?
16+11.78=27.78
X+14.7=27.78
27.78-14.7=13.08psig boost at sea level

Why cant you run 16psig at sea level? Same reason you cant run 19psig at 6000ft if you are maxed out at 16psig at 6000ft.
The combustion only cares about whats in the cylinder and not how it gets there. Starting with less dense air and compressing it more first does not mean you can magically start with denser air and compress it the same amount.
Look at it this way. I can take a sea level 12psig Whipple at 93 octane and drive it to 6000ft and pulley for 15psig on 93 same tune.
Why?
12psig at 14.7psia ambient is same as
15psig at 11.7 psia ambient.
So can I just magically drive back down to sea level set at 15psig boost? No freakn way.(unless you are Jesus riding a unicorn and need to sell turbo kits based on potential hp numbers cause your actual numbers at mountain elevation of your shop make marketing difficult. j/j)

So your sea level boost pressure will be 3psig lower than your 6000ft boost pressure if you are going to keep the risk to the motor equal at both elevations.

As a side note: if you attempt to use a 25% NA correction (c=1.25) on a 16psig FI motor going from 6000’ to 0’, you would have to increase the absolute cylinder intake pressure by 25% to get 25% more power. Lets try that?
At 6000’ 11.78psia + 16 psig boost =~ 27.78 psia
27.78 psia x 1.25 = 34.725 psia
At 0’ 14.7psia + X psig boost =~ 34.725 psia
34.725-14.7 = 20psig !! Booom...
It does not work.

Pumping power loss:
Lower pumping power loss at sea level will be the majority of your gains at sea level. If you take the uncorrected actual run from a dyno at 6000ft, lower the boost pressure whatever the ambient pressure difference is and add back in the pumping power losses(they scale per actual hp(cfm)), and you get your sea level curve.

Basically, at sea level, keeping the risk to motor the same and using same fuel and same air temps: expect 20-30 hp more per 500 hp actual for supercharger. Expect 10-15hp more for Turbo. Thats it.

You can check all this by looking at ACTUAL uncorrected dyno(same) graphs of same actual end boost (absolute intake pressure at intake valve) for a supercharged FI setup at sea level and at 6000ft both at max 93oct power:
1.Sea level will max out ~3 psig boost lower (cause thats actually the same absolute pressure/density).
2.There will be a near linear 25hp+/-3hp per 500hp or roughly 1.05 (+5%) correction to get the graphs to overlay near perfectly.

 

[Torinate]

Holy crap!

knowledgeable guy!

...you had me at coefficient...

that’s exactly what I was going to say...

 

[beefcake]

nice, cranking it out

 

[Aaron1085]

So, forgive me a bit but I am rather new to the FI world and the S550 platform.

I have a 2018 with a Whipple 3.0 / Stage 2 so I believe that is the larger throttle body and 3.875 pulley.

I just cruise, so I run 93 octane, stock Whipple everything.

Why are some ignoring the out of the box, Whipple tune and going wild with other tuners? Is it because you are running smaller pulleys and Whipple won't support that, is it pure user preference, ...?

I am in New England (so, not crazy elevation here). Can you give me an idea what the 'out of the box, Whipple Gen 3' is running for boost and hp/tq numbers? I have not had the car dyno'd. The previous owner did the work, it all checks out with a reputable shop and documentation. He showed me a dyno sheet where this car is putting 643whp; seems a tad low compared to some others.

Thank you, love to learn this all!

 

[DmanDmythDlegend]

So, forgive me a bit but I am rather new to the FI world and the S550 platform.

I have a 2018 with a Whipple 3.0 / Stage 2 so I believe that is the larger throttle body and 3.875 pulley.

I just cruise, so I run 93 octane, stock Whipple everything.

Why are some ignoring the out of the box, Whipple tune and going wild with other tuners? Is it because you are running smaller pulleys and Whipple won't support that, is it pure user preference, ...?

I am in New England (so, not crazy elevation here). Can you give me an idea what the 'out of the box, Whipple Gen 3' is running for boost and hp/tq numbers? I have not had the car dyno'd. The previous owner did the work, it all checks out with a reputable shop and documentation. He showed me a dyno sheet where this car is putting 643whp; seems a tad low compared to some others.

Thank you, love to learn this all!

643 is probably pretty accurate if the car is mostly stock on the whipple tune and injectors. Most go away from whipples canned tune because a 3rd party tune doesn't have to meet any federal guide lines. They tend to get more power and run smoother as they are more specific to your set up. Once you can upgrade injectors and get a custom tune it becomes much easier to break into 700+ hp

 

[Aaron1085]

643 is probably pretty accurate if the car is mostly stock on the whipple tune and injectors. Most go away from whipples canned tune because a 3rd party tune doesn't have to meet any federal guide lines. They tend to get more power and run smoother as they are more specific to your set up. Once you can upgrade injectors and get a custom tune it becomes much easier to break into 700+ hp

interesting. So, people go third party because it’ll run ‘smoother’ ?
hmmm... I guess my set up or plan rather is to just keep it steerable and keep it easy to RIP ;). Is the Whipple time ‘fine’, specifically for long term power and reliability.

When adding that much more power (injectors and tune tweaking), would likely cause more concern with our transmissions correct? (I have a 6 speed)

 

[beefcake]

nice

 

[rtg]

interesting. So, people go third party because it’ll run ‘smoother’ ?
hmmm... I guess my set up or plan rather is to just keep it steerable and keep it easy to RIP ;). Is the Whipple time ‘fine’, specifically for long term power and reliability.

When adding that much more power (injectors and tune tweaking), would likely cause more concern with our transmissions correct? (I have a 6 speed)

I have the Whipple tune primarily due to emissions requirements. If you are looking to get every possible HP then going with a different tune/setup is going to get you closer to that goal.

As far as an aftermarket tune running smoother that is subjective. The early revision tunes from Whipple were not nearly as good as the current revision. The current revision is very 'streetable' and OEM like in my opinion.

The one thing to consider either direction you go is how are you going to put that power to the ground? 750RWHP is not better than 675 RWHP if you are spinning your wheels.

So looking for that highest dyno RWHP, tracking and looking for that lowest ET then aftermarket tune, injectors, fuel system, and a track pack are going to be needed. Maybe an upgraded clutch.

Driving around and looking for better street performance, emissions legal, and arguably greater reliability then the Whipple tune is good choice.

FWIW, I have 305s on the back and they still spin ridiculously easy and I am not about bragging how much RWHP I have.

So the Whipple works well for me in a 10R80 car. Plus I would have no problem going from CT to CA and back without worrying if the engine or trans will make it.

That's my take your mileage may vary.

Rob

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