This is my first thread I have created since 2006 when I was hot on purchasing an F40. (Never did get one.) Took delivery of my 488 GTB on December 30th of 2017 from Ferrari of Seattle. (BTW, a really great bunch of guys!) It's been raining quite a bit up here so I haven't had a chance to drive the car on the street yet. Just made a few runs on my DynoJet after breaking it in. I wasn't really sure what to expect. The results are amazing! All runs are being done in 5th gear. Here is my 4th run: Image Unavailable, Please Login I use a 15.6% loss factor to convert all my numbers to flywheel horsepower. Here are all the numbers: SAE 587.82 rwhp / 696.47 flywheel hp 474.58 rwtq / 562.30 flywheel tq STD 605.11 rwhp / 716.95 flywheel hp 488.54 rwtq / 578.84 flywheel tq Uncorrected 610.34 rwhp / 723.15 flywheel hp 492.76 rwtq / 583.84 flywheel tq Maximum rwhp occurred at 6861 rpm. Maximum rwtq occurred at 5966 rpm. The conditions were as follows: Absolute pressure 29.9, air temp 59.6, humidity 42%. One thing I was unable to do was record any boost readings. I have a sensor for my DynoJet that allows it but I can't find any vacuum/pressure hoses that will actually give me a readout. I have tried a few different sources including the wastegate and nothing. If anyone has an answer I would appreciate it. The highest reading I was able to see on the dash was 14 psi. Steve
Please extrapolate (and excuse my ignorance on the subject). You said the results were amazing. How so? Were you expecting different numbers?
I really didn't know what to expect. I have made runs on many different cars and I am always concerned about having that car that doesn't quite make the numbers. As far as the results being amazing, the results speak for themselves. This engine is rated at 660 HP and I am quite happy to see that number exceeded. Steve
So many sets of numbers. SAE, Standard, RW, Flywheel, Corrected, Uncorrected.....Which ones matter/tell the story?
I guess i am guilty of giving too much info. There are explanations available on the internet that can explain things a lot better than I can. That being said, SAE seems to be most often used on dyno graphs. Steve
Those are some great numbers. Considering the gear based boost control, 5th might not give max power.
I picked 5th because it is closest to 1:1 and was told by FoS that 5th would give full power. I will try 6th gear tomorrow and see what happens. Steve
thanks for sharing! It's impressive how this engine already develops 220 WHP at 3000 RPM: means 256 FWHP at just 3000 RPM. Great power everywhere! ciao
It indeed confirms the claimed 8000 rpm for peak power does not reflect reality; btw if one looks at the power graph that Ferrari releases, they have a curve that more or less culminates at 6500 rpm, being then almost flat (horizontal) up to 8000 rpm.
Impressive numbers, thank you for sharing. I took delivery of my 488GTB this past late August and had the opportunity to put about 1,000 miles on it. I cannot believe how much more horse power and torque it has over the 458. I am still learning how to handle this power and can't wait for spring.
If you factor 10% drive train loss you are at 660. Why did you use 15%? These ares are more efficient than that.
Notwithstanding a wide range of "possible" inaccuracies (dyno accuracy and calibration, atmospheric conditions, tire to roller traction, etc.), SAE standards are most commonly used in the US. Frictional losses on a mid-engine/transaxle configuration range between 10% and 15%. By using the SAE WHP number of 587.82 and applying assumed mid-point frictional losses of 12.5%, BHP equates to 661.29. Exactly what Ferrari claims. Nice!
I actually use 15.6%. That number is based upon the differences between motors of mine that I ran on an engine dyno and then on my DynoJet on the exact same day. I realize that different drivetrains can have different losses. What are you basing your 10% drive train loss number on? Unless you have data (engine dyno vs. chassis dyno with very similar conditions) than it is a guess. I try not to get too wrapped up in trying to convert rwhp back to flywheel horsepower. I mostly use the DynoJet as a measurement tool for changes I make to my cars. Steve
You are exactly right, using 10% or 15% is a guess/estimate. I don't believe Ferrari under estimates the power though, I have seen the opposite with my cars.
You have perfectly illustrated the problem with trying to convert from rwhp to flywheel hp. The friction loss range between 10% and 15% is a huge range. Where exactly does the 488 fit? On my car this could mean a flywheel hp range between 653 and 691. That's a big range. BTW, you (and a lot of people I have seen through the years) are calculating flywheel hp incorrectly. You took the 587.82 and multiplied it by 1.125 to come up with 661.29. So if you start with BHP of 661.29(your number), a frictional loss of 12.5% equates to 82.66 which results in a WHP of 578.63. The correct calculation is to start with 587.82 and divide by .875(1.00 - .125) which results in 671.79. Steve
To me, the most impressive thing about these curves is the almost flat torque curve between 3200 rpm and 7500 rpm. That makes the car relatively easy to drive smoothly on twisty roads, and helps give it an almost NA feel with far more torque and power than NA.
There are so so many arguments all over the net about claims of Hp on dynos. I believe Ferrari as its the most accurate i.e engine dyno. Ild only use a particular dyno to see increases or decreases in Hp when one does modifications, but for absolute accurate Hp never . Close enough but that's it. BUT what I do like is the curve. Its absolutely fantastic ! That's the great work Ferrari has done in research and engineering !
I made a few dyno runs today in 6th gear as was suggested by ForeverCar. The car lost between 15 and 17 rwhp on those runs. The highest boost I saw on the dash gauge was 13 psi. That doesn't mean it wasn't higher, but if it was I didn't see it. I sure wish I could find a hose I could tap into for a boost reading that I can record. I'm surprised no one on this forum has any knowledge on this subject. Steve
Steve, you might want to look into a simple Bluetooth OBD II device. You should be able to log boost using an app. With all the intricacies involved, it’s pretty hard to do accurate engine output measurement. Turbocharged engine is particularly tricky. It depends on how much load the dyno generates, boost can vary. With the car stationary, airflow to charge coolers is probably not reflective of actual driving conditions. Since timing control is usually sensitive to intake air temperature, you might want to log IAT on the dyno vs IAT on the road/track. Timing would be another good parameter to log. At the end of it, having fun and enjoying the experience is key!
That is a great idea. I'll have to see what's out there. Does anyone out there have any recommendations? Steve
Finally figured out how to connect my DynoJet pressure sensor to the car. Here is a graph with boost pressure: Image Unavailable, Please Login Again, this run was made in 5th gear. Notice that the car picked up a few more rwhp. That number is now 595.03 rwhp. This is due to a higher water/oil temperature. The boost pressure at maximum rwhp is 15.39 psi. At maximum rwtq it is 14.37 psi. Notice that the maximum boost recorded is 16.62 psi and that was at 6528 rpm. I also made a few runs in 4th gear. The power was down about 7 rwhp but the maximum boost was higher at 18.51 psi. That's it for dyno runs for now. Time to take it off and start on a different car. Steve
