RC F Dyno Procedures
Lead Lap
Joined: Feb 2016
Posts: 410
Likes: 23
From: Houston, TX
Wanted to share some of my dyno results. A couple of things. First, I will say that I am a little disappointed in the results but, I DO NOT regret any of my performance mods/adds ($ value) and am not seeking to disparage anyone’s product. In one form or another they have provided me value. I will likely continue to add things to the car and try to measure impact as I go along. I may also get a logging cable and software to see if there are things that I can do to enhance my results, although I want to be careful not to do anything that only impacts dyno results and is not something that is repeatable in day-to-day driving/real world experience. I’ve been following the IS-F ECU flashing threads and there has been a lot of reference to Knock Correction Learning Value (KCLV) stored in the ECU and how it impacts performance. There are supposedly things you can do to get it up but, I am unclear if once you get it up (no pun intended) will it stay there or does it revert back over time based on various factors. Second, overall the results seem a little odd and not what one would have anticipated. I am really focusing on the deltas here as I know dyno results can vary from car to car, dyno to dyno, and even day to day based on conditions. I did try to keep most variables consistent. Used the same dyno, I operated the car, and made the same adjustments as listed in this thread. Conditions (temp and humidity) was fairly consistent in the dyno building on the different days. Car was not driven overly hard or heat soaked in getting to dyno location (10-15 minutes of cool down as car was getting set up on the dyno). Any and all input or comments are welcome. I will try to answer questions as best I can. I will say that the dyno operator was surprised and complimentary of these results as he wasn’t familiar with Lexus’ F brand and thought the car performed and sounded awesome, especially for a NA 5 liter v8 with no modified ECU parameters. He’s primarily a GM LS guy.
Baseline – All stock, ~2500 mi on car, 3 runs w/best results:
377 rwhp/349 lb/ft TQ – SAE
387 rwhp/359 lb/ft TQ – STD
Apexi Intake system (silicone tube/drop-in filter) – same day as baseline, 10 minute cool down for install of intake, 2 runs w/best results:
390 rwhp/348 lb/ft TQ – SAE
401 rwhp/358 lb/ft TQ – STD
Delta – (+13 rwhp/+0 lb/ft TQ)
Meisterschaft GTC exhaust & Apexi intake system – 2mos after baseline (1 mo after exhaust install), ~3K mi on car, 5 runs w/best results:
391 rwhp/365 lb/ft TQ – SAE
400 rwhp/365 lb/ft TQ – STD (think there may have been a hiccup here as there seems to be about a gap of 10 between both hp and tq when comparing SAE to STD readings on this dyno)
Deltas:
Vs Intake runs – (+0 rwhp/+17 lb/ft TQ)
Vs Baseline runs – (+13 rwhp/+17 lb/ft TQ)
Baseline – All stock, ~2500 mi on car, 3 runs w/best results:
377 rwhp/349 lb/ft TQ – SAE
387 rwhp/359 lb/ft TQ – STD
Apexi Intake system (silicone tube/drop-in filter) – same day as baseline, 10 minute cool down for install of intake, 2 runs w/best results:
390 rwhp/348 lb/ft TQ – SAE
401 rwhp/358 lb/ft TQ – STD
Delta – (+13 rwhp/+0 lb/ft TQ)
Meisterschaft GTC exhaust & Apexi intake system – 2mos after baseline (1 mo after exhaust install), ~3K mi on car, 5 runs w/best results:
391 rwhp/365 lb/ft TQ – SAE
400 rwhp/365 lb/ft TQ – STD (think there may have been a hiccup here as there seems to be about a gap of 10 between both hp and tq when comparing SAE to STD readings on this dyno)
Deltas:
Vs Intake runs – (+0 rwhp/+17 lb/ft TQ)
Vs Baseline runs – (+13 rwhp/+17 lb/ft TQ)
An intake that net 13 rwhp is surprising as well.
Anyone else experience this?
I did say that I found the results odd. Yes, no hp gain with exhaust but, there was tq gain. I'd also like to see if I can get the dyno operator to do a better job with the graphs and see if I can overlay some of the runs to see how the area under the curve compares.
4th Gear
Joined: Oct 2016
Posts: 4
Likes: 0
From: Texas
2016 RC F Dyno Before/After intake and exhaust
Lexus Test Driver
Joined: Mar 2015
Posts: 818
Likes: 30
From: Nashville
Wow, your numbers are super low for stock. Am I reading that correctly? We all purchased 467hp cars and it looks like Lexus is delivering 425 hp cars unless your dyno or your engine is seriously off. Candidly, an intake should never add noticeable power or torque unless there is something seriously wrong the factory intake or the design of the factory intake. Is Lexus that bad at designing intakes or is there something up with the conditions of the dyno run done over a month apart?.
I am very curious, however, about the hp. Is anyone else getting stock hp numbers this low? Has anyone gotten stock hp pulls that are close to what the manufacturer represented? If not, perhaps class action is in order for delivering something well short of what we purchased.
This is where the Japanese fall well short in the performance market. Real sport car manufacturers normally underrate hp and underestimate real world performance. Also, speaking from a whole lot of experience, adding after market intakes and bolts ons to true sports cars (German and Italian mfgs.) usually net no gain, nominal gain or gain on either hp/tq to the detriment of loss on the other. If there were real gains to be had from such simple tweaks, you can bet a good manufacturer would design those in given how competitive the performance market is today.
I am very curious, however, about the hp. Is anyone else getting stock hp numbers this low? Has anyone gotten stock hp pulls that are close to what the manufacturer represented? If not, perhaps class action is in order for delivering something well short of what we purchased.
This is where the Japanese fall well short in the performance market. Real sport car manufacturers normally underrate hp and underestimate real world performance. Also, speaking from a whole lot of experience, adding after market intakes and bolts ons to true sports cars (German and Italian mfgs.) usually net no gain, nominal gain or gain on either hp/tq to the detriment of loss on the other. If there were real gains to be had from such simple tweaks, you can bet a good manufacturer would design those in given how competitive the performance market is today.
Lexus Test Driver
Joined: Mar 2015
Posts: 818
Likes: 30
From: Nashville
Not odd. Start messing with back pressure and you may see gains in one, but losses in the other. It is also important to not look at peak gains, but overall increase in area under the curve. You could actually get a slower car that shows higher peak if total area under the curve has decreased.
Driver
Joined: Mar 2016
Posts: 126
Likes: 28
From: LA
Wow, your numbers are super low for stock. Am I reading that correctly? We all purchased 467hp cars and it looks like Lexus is delivering 425 hp cars unless your dyno or your engine is seriously off. Candidly, an intake should never add noticeable power or torque unless there is something seriously wrong the factory intake or the design of the factory intake. Is Lexus that bad at designing intakes or is there something up with the conditions of the dyno run done over a month apart?.
I am very curious, however, about the hp. Is anyone else getting stock hp numbers this low? Has anyone gotten stock hp pulls that are close to what the manufacturer represented? If not, perhaps class action is in order for delivering something well short of what we purchased.
This is where the Japanese fall well short in the performance market. Real sport car manufacturers normally underrate hp and underestimate real world performance. Also, speaking from a whole lot of experience, adding after market intakes and bolts ons to true sports cars (German and Italian mfgs.) usually net no gain, nominal gain or gain on either hp/tq to the detriment of loss on the other. If there were real gains to be had from such simple tweaks, you can bet a good manufacturer would design those in given how competitive the performance market is today.
I am very curious, however, about the hp. Is anyone else getting stock hp numbers this low? Has anyone gotten stock hp pulls that are close to what the manufacturer represented? If not, perhaps class action is in order for delivering something well short of what we purchased.
This is where the Japanese fall well short in the performance market. Real sport car manufacturers normally underrate hp and underestimate real world performance. Also, speaking from a whole lot of experience, adding after market intakes and bolts ons to true sports cars (German and Italian mfgs.) usually net no gain, nominal gain or gain on either hp/tq to the detriment of loss on the other. If there were real gains to be had from such simple tweaks, you can bet a good manufacturer would design those in given how competitive the performance market is today.
The HP rating of the car is not RWHP. The HP rating is at the crank. So your stock car getting around 400ish to the wheels means you're losing 67ish in the drivetrain.
Second, the funky dyno graphs and power gains. I'm sure a lot of people have seen the stair-step increases between RPM ranges- this is a combination of the variable cam profiles and the ECU torque control. No amount of modifications aside from tuning will alter this behavior. If you look at the RR tune it basically removes the stair step effect to "smooth" the powerband.
Third, Expert mode is not the ideal or correct dyno mode. Expert mode (and ExpertDark) both keep driveline abuse monitoring active. This is the handy little feature that drops your car on its face when you do a burnout or make too much power on the dyno. Those of you that like to warm up the tires probably know what I speak of- 1st gear usually goes away for that run
Your correct mode for dyno or drag racing is Sport+ with pedal dance. Pedal dance turns off traction control and driveline abuse monitoring entirely for the duration of that ignition cycle. Pretty much the only thing still left is gas/brake throttle override.
4th Gear
Joined: Oct 2016
Posts: 4
Likes: 0
From: Texas
"Pedal Dance?"
Because this thread is a FAQ link, I'm going to bump it to hopefully shed some light on things. (that's my excuse and I'm sticking to it)
The HP rating of the car is not RWHP. The HP rating is at the crank. So your stock car getting around 400ish to the wheels means you're losing 67ish in the drivetrain.
Second, the funky dyno graphs and power gains. I'm sure a lot of people have seen the stair-step increases between RPM ranges- this is a combination of the variable cam profiles and the ECU torque control. No amount of modifications aside from tuning will alter this behavior. If you look at the RR tune it basically removes the stair step effect to "smooth" the powerband.
Third, Expert mode is not the ideal or correct dyno mode. Expert mode (and ExpertDark) both keep driveline abuse monitoring active. This is the handy little feature that drops your car on its face when you do a burnout or make too much power on the dyno. Those of you that like to warm up the tires probably know what I speak of- 1st gear usually goes away for that run Your correct mode for dyno or drag racing is Sport+ with pedal dance. Pedal dance turns off traction control and driveline abuse monitoring entirely for the duration of that ignition cycle. Pretty much the only thing still left is gas/brake throttle override.
The HP rating of the car is not RWHP. The HP rating is at the crank. So your stock car getting around 400ish to the wheels means you're losing 67ish in the drivetrain.
Second, the funky dyno graphs and power gains. I'm sure a lot of people have seen the stair-step increases between RPM ranges- this is a combination of the variable cam profiles and the ECU torque control. No amount of modifications aside from tuning will alter this behavior. If you look at the RR tune it basically removes the stair step effect to "smooth" the powerband.
Third, Expert mode is not the ideal or correct dyno mode. Expert mode (and ExpertDark) both keep driveline abuse monitoring active. This is the handy little feature that drops your car on its face when you do a burnout or make too much power on the dyno. Those of you that like to warm up the tires probably know what I speak of- 1st gear usually goes away for that run
Your correct mode for dyno or drag racing is Sport+ with pedal dance. Pedal dance turns off traction control and driveline abuse monitoring entirely for the duration of that ignition cycle. Pretty much the only thing still left is gas/brake throttle override.Please explain pedal dance.
Driver
Joined: Mar 2016
Posts: 126
Likes: 28
From: LA
Lexus Champion
Joined: Feb 2006
Posts: 2,170
Likes: 98
From: California
from page 1 the graph showed Dynojet. Maybe the dyno was adjusted to read low like a Mustang dyno (20%) drivetrain loss
Intermediate
Joined: Apr 2016
Posts: 498
Likes: 43
From: FL
Driver
Joined: Mar 2016
Posts: 126
Likes: 28
From: LA
Although I should disclaimer this with the fact that Pedal Dance, while not removing the PCS warning, does in fact totally disable PCS brake engagement. So where you'd normally get the car hitting the brakes for you, it won't. So drive with care. Although if you're tracking it on those rare tracks with corner walls/signs, you probably don't want the car hitting the brakes for something not in your path anyways.
Last edited by Suburbazin; May 25, 2017 at 04:22 AM.