So I have several questions I hope to have answered.

I have a 2006 G35 Coupe, and it is stock. I want to get the uprev tuning software and modify some parameters. I will list my questions in order of importance.

1) When I remove the RPM limiter, how high do people safely rev the engines when driving?

2) When the speed limiter is removed, what speeds have you guys hit before the car ran out of steam?

3) Is navigating the Uprev Tuning mode easy enough to just do the RPM limiter removal and Speed Governor removal?

4) Do I need to do anything to remove the throttle limit? (I heard the stock ECU tuning limits the throttle position from reaching 100%)

Here are some clarifications to my questions separately.

1) It is about the rev limiter. I know it is usually soft limiting first by reducing fuel as you approach the red line, and the auto g35 has a hard limiter where it just cuts fuel and stops around 7,000rpm. I just want to be able to run it higher, and reach deeper into the power band, so the next shift is closer to the power band. But I don’t want to kill the engine right away accidentally. The engine is well taken care of and UOA shows excellent wear traits.

3) About Uprev software, I am familiar with cars and most software platforms. I don’t expect to “tune”
the car on my own. But for now, just use the software to remove speed limiter, rpm limiter and wide open throttle at any speed.

 

This sounds like an @seymore4 question but as for raising the rev limiter I would definitely not remove it entirely (not even sure you can but it can probably be edited to something absurd like 9k). I'm also not sure how it's going to help shifting since that would require editing of the TCM parameters for shifting but again, maybe Seymore can shed some light on it.

As for the second question, when I top speed tested my car it was basically falling on it's face at 150 just like I expected, rev up coupe with no mods at the time. I wasn't watching the speedometer though and I never hit an actual speed governor but it was definitely out of steam at stock power levels going that fast, I think it was like 157 when I lifted though because I hit my end cones on the runway and didn't want to end up in the sand. I'm not sure it requires any editing though since the chances of ever needing that kind of speed are infinitisimally small and the stock parameters should be just fine. Keep in mind it took basically the entire length of 1.25 miles to get to that speed and almost 1/4 mile to slow back down again. This was a 6MT coupe, not sure what your 5AT would do.

Personally you should just talk to Seymore about having HIM do the tuning remotely (e-tune) he's well qualified with an excellent reputation, has been doing this for years, and that way you know it's done right without any accidents happening.

Also, I'm pretty sure he lives over your direction so that might be an option as well.

 

Shoot me a PM when you're ready I can get you set up. Uprev is currently out of stock of cables and doesn't know when they're getting more, but I happen to have a few on hand

With stock internals I don't like to go more than a couple hundred RPM over.

Yes, Extremely simple.

Just open the "electronic throttle" tab and you will see "select electronic throttle control settings". Select your map, then "Uprev tuned throttle" and you're good to go.

There is a throttle cut that comes in slightly before the hard fuel cut

 

I've never dynoed my car but have seen charts that people posted after tuning on this site. aren't we already past the power and torque peaks before rev limiter? or are the declining power and torque curves caused by throttle and fuel cut before rev limiter? is there any point in revs above the power/torque peak?

 

Yes you are

 

The reason why you still rev the engine past peak torque/power output is because when you shift you want to be high enough up into the power band that you are still making good power, it's sort of a balancing act.

Lets say you make peak power at 6000 and your redline is 7500 but at 7500 you only lose -15% power.

Now lets say when shifting it drops your rpm -4000 from 7500 to 3500, but at 3500 you're making -40% power.

For the sake of simple math lets say these shift points nets you a total power loss of -55% (15% loss + 40% loss)

If you increased the redline to 8000 you might end up making -30% power but increasing the shift point to 4000 only reduces the power to -35%. This nets you a total of -65% loss (30% loss + 35% loss). Therefore you essentially spend more time in a lower power state at the higher redline point when you could just shift to quickly get back to the peak power. Since you "lost" -65% power compared to the previous shift points which only lost -55% power.

Now lets assume the opposite, lets say you shift right after your peak power so like 6250 so you are only making -5% less than peak power. But the -4000 rpm drop from shifting brings your rpm down to 2250 so now you're making -80% peak power so it feels sluggish and takes a lot of time to rev back up into a better part of the powerband again. This situation would have the worst performance because of the -85% loss (5% loss + 80% loss).

All these numbers are hypthetical and pulled directly from my *** but hopefully it gives you an idea of the importance of having the CORRECT redline and shift points. After a dyno pull the graph will let you actually SEE where the power is being made and you can visualize which part of the powerband would be best to use. There's a LOT of things that factor in to this, cams, intake, exhaust, any type of FI. This is one reason why track cars typically have aftermarket cams, so the power doesn't drop off at high rpm but keeps on pulling, then you can rev as high as is mechanically allowable (which gets super expensive super quick once your stock oil pump hits it's limit) and the power keeps climbing.

Cams are a tradeoff though, it doesn't really "create more power" it just shifts where the power is made across the powerband. At the end of the day it's the gasoline and air that's making the power and if you're putting the same amount of gas and air into the cylinder then it's making the same total amount of power (roughly) across it's powerband, it will make peak power at different parts of the powerband depending on the cam.

 

Hello all ,

I have a 350Z and I would like to have the wide open throttle at all speed, s I understand it is limited from factory in 1st, 2nd and 3rd gear.
Is the solution proposed below by Seymore4 sufficient to get rid of it ?
And if yes, is a uprev standard kit sufficient or do I need a tuner kit ?

Thank you for your help,

 

The tuner version is only necessary if you want to be able to access and adjust the tune yourself. If you just want it tuned correctly by a professional, then the standard version (tuned by me) is perfect. I left you a visitor message, shoot me an email I'll get you set up.