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The peak horsepower officially comes at 7100 rpm. While driving it, one can feel it continues building the power until the cut off under 7500 rpm. This dyno graph has a rare occurrence where it peaks at 6100 rpm. There might be variables there especially airflow etc. that might have caused it, but in all of the other cases it keeps building power till redline/cut off. Even if it was, still one would shift around redline as the power is flat to redline. It also ensures in the next gear rpm falls in the meat of the powerband, which is above 5800 rpm.
If you look at the other dyno tests done to a stock RC F, the power is at 6100 RPM as well as torque. I personally believe that shifting BEFORE the redline is a good idea, because at 6700 the torque just dies. So, basically, I think it's a good idea to shift before the 'beeper' sounds, since you still get lots of torque and power. Shifting at 6500 RPM seems to be the best... could be wrong, since I don't actually have personal experience.
If you look at the other dyno tests done to a stock RC F, the power is at 6100 RPM as well as torque. I personally believe that shifting BEFORE the redline is a good idea, because at 6700 the torque just dies. So, basically, I think it's a good idea to shift before the 'beeper' sounds, since you still get lots of torque and power. Shifting at 6500 RPM seems to be the best... could be wrong, since I don't actually have personal experience.
That is not that simple and not really relevant to the case of the OP as he just cares about before/after.
This dyno is an anomaly. Lexus officially put the power at 7100 rpm (compared 416HP@6600 rpm for ISF). So, best acceleration in real life comes staying close to the highest peaks past the cross over point between HP and torque exists (5252 rpm), which is between 6000 rpm and ~7400 rpm or so. I will spare the details when it comes to multiplication of torque through gears as rpms climb since dynos are done with 1:1 gear (5th). The engine makes 95 HP/Liter of displacement and needs revs to accelerate as fast as possible as opposed to muscle car V8s that have huge 6.2 liter displacements to hit their peaks below 6000 rpm (Corvette engine, for example).
Here is SAE corrected dyno by K&N as well as AFE and peak power surges up till 6200 rpm and then slightly increases till around 7100 rpm or 7200 rpm and then it continues to stay flat till around 7400 rpm or so. The torque curve is flat all across the rev range and even near the rev cut off it is making 90% of its peak torque.
Last edited by 05RollaXRS; May 5, 2020 at 05:48 PM.
I disagree with Yri also, but my reason is simple. The rpm always drops by few hundreds to a thousand rpm when the car shifts to the next gear. Because of this you want to shift closer to 7k rpm for the next gear to start at around 6k rpm, so you're always at peak power. If you shift at 6k, the engine drops to 5k and you have to climb again.
1st to 2nd ratio spread is the widest because of how tall 2nd gear is. 1st to 2nd drop from 7300/7400 rpm is to around 5000 rpm. About a 2300 rpm drop.
Interesting. I guess it was an anomaly. I would still suppose that shifting at the absolute redline would hurt acceleration times, like shifting at 6500-6800 RPM is probably your best option. I guess my assessment was wrong. Thank you for the correction!
In for updates. I was wondering about dyno results for this fairly inexpensive exhaust.
My butt dyno cannot tell anything.
That is surprising. When I got my Invidia, I noticed a difference immediately after resetting the ECU. It revved quicker and was much easier to hit the rev limiter on full-throttle after the Inviidia in lower gears.
There is a very simple explanation of why OP's RCF is hitting the peak much earlier. Just the fact that the rear wheels/tires are removed. That is over 100 lbs of rotational mass being taken off the rear axle. With so much less mass (and corresponding inertia) to spin, the engine has to work less hard (conversely, rely more on torque) allowing it to reach the peak HP earlier.
Sikky used Dynapack as well and the dyno curve looks identical to what OP has. It is hitting peak at 6100 rpm as well.
Should i reset the ecu after the exhaust install? If so, whats the proper procedure to reset it? I also have the next dyno pull set up for this Saturday, so i’ll post the new results right after it is done.
Should i reset the ecu after the exhaust install? If so, whats the proper procedure to reset it? I also have the next dyno pull set up for this Saturday, so i’ll post the new results right after it is done.
Disconnect the negative terminal and leave it off for a 5 - 10 minutes. Reconnect and then start the car. Let it idle for a little while.
Got the exhaust installed yesterday and drove around for 3 hours straight. Holy crap, the exhaust sounds amazing!!! I had a Good amount of people giving me a thumbs up or driving up to me to hear the exhaust. The perfect sound. Not too loud at all. Sounds nice and aggressive in the low RPM with moderate acceleration, especially at 2-4k. The exhaust does not get loud unless you want it to. The sound when the gears change is also amazing. “Cold start” (80 degree) was not aggressive enough to wake the neighbors. I have 0 regrets with this exhaust!! Oh and the other parts came in too.
Invidia is a great exhaust. Glad you really like it. I have had it for 2 years and it just has the perfect balance for me. Not too loud, but very melodic and symphonic in its tone/pitch etc. Looking forward to the dyno.
