Random Question about Power Curves with Tunes

[JoeyBananas]

Quick Question. I came from a 9 second S2000 that had 2.2L and a single GT35r Turbo. I always had to go to Redline to get the most out of it. Being these motors are larger and Turbos are Smaller, say I went with a BPM Stage 2 tune, if I were to do a highway pull or 1/2 event or even 1/4 etc, am I going to want to start these pulls at 5,000+ RPMS, or do I want to start lower and even shift before redline? (which sounds so odd to me, lol).

Thanks guys.

[chewbakam4]

Are you serious? 1500 posts and an S2k owner with a 35R turbo asking where to shift? I have now seen it all.

/thread

Just kidding dude

[Mike@N54Tuning.com]

Originally Posted by JoeyBananas

Quick Question. I came from a 9 second S2000 that had 2.2L and a single GT35r Turbo. I always had to go to Redline to get the most out of it. Being these motors are larger and Turbos are Smaller, say I went with a BPM Stage 2 tune, if I were to do a highway pull or 1/2 event or even 1/4 etc, am I going to want to start these pulls at 5,000+ RPMS, or do I want to start lower and even shift before redline? (which sounds so odd to me, lol).

Thanks guys.

Just pull a dyno graph of whatever tune / map you are going to run and you will see the power curve.

For example with a JB4 you would shift at 6/6.5 as the power curve starts to taper at that point..



This is with stock turbos, but if you had upgraded turbos you could go to red line as the turbos don't loose steam.. All depends on tuning and your mods essentially.

[JoeyBananas]

Originally Posted by chewbakam4

Are you serious? 1500 posts and an S2k owner with a 35R turbo asking where to shift? I have now seen it all.

/thread

Just kidding dude

Lol well it always made sense to me, ya shift at redline, now I read about power falling off etc and doesnt seem so clear, lol

[BMWcurious]

Assuming a typical single peak, change gear when the power at the drop in point in the next gear is higher than remaining in the present gear. This will vary with each gear change.

[F80Paul]

Mike is right, you want to stay in the power curve, which can vary depending on your hardware, octane available(assuming your tune takes advantage of it), and tune. Dyno your car If you want to know for sure. Otherwise if you have a lot of experience you can use your butt dyno and test different shift points with a Vbox or draggy. Generally speaking with stock turbos you are going to want to shift by 6500rpm. High altitide cars should shift even sooner. Upgraded turbo cars will be happy shifting around 7k.

[mike@x-ph.com]

Originally Posted by JoeyBananas

Quick Question. I came from a 9 second S2000 that had 2.2L and a single GT35r Turbo. I always had to go to Redline to get the most out of it. Being these motors are larger and Turbos are Smaller, say I went with a BPM Stage 2 tune, if I were to do a highway pull or 1/2 event or even 1/4 etc, am I going to want to start these pulls at 5,000+ RPMS, or do I want to start lower and even shift before redline? (which sounds so odd to me, lol).

Thanks guys.

Do a dyno and look at the power curve, you want to shift 500 RPM after your max power to stay in that range at all times.

[SflBimmer8484]

Based on some of the dynos in this thread this question would greatly depend on whose tune you go with.. With our stage 1 shift at redline and with our stage 2 tune I shift at 7100-redline.

STAGE 1 93 Oct

STAGE 2 93 Oct

[mike@x-ph.com]

Originally Posted by Andrew@ActiveAutowerke

With our stage 1 shift at redline and with our stage 2 tune I shift at 7kish.

[/CENTER]

With that kind of power curve i would too

[Mike@N54Tuning.com]

Originally Posted by mike@x-ph.com

With that kind of power curve i would too

Don't only look at HP but the TQ curve is also important

Mike

[AlterZgo]

Originally Posted by JoeyBananas

Lol well it always made sense to me, ya shift at redline, now I read about power falling off etc and doesnt seem so clear, lol

I’ve been running my BPM tune for about a week. While virtually all dynos for all tunes pull to about 6000 rpm and flattens out and drops, what I have found is that the power and acceleration is so much stronger than stock that it is very easy to shoot right past the power peak and hit the rev limiter in 1st and 2nd. So I would say shift at redline in 1st and 2nd. In 3rd, I’d shift at about 6.5-7k rpms to put you right back in the sweet spot of the torque curve for the next gear.

[M3anPower]

Originally Posted by Andrew@ActiveAutowerke

Based on some of the dynos in this thread this question would greatly depend on whose tune you go with.. With our stage 1 shift at redline and with our stage 2 tune I shift at 7100-redline.

STAGE 1 93 Oct

STAGE 2 93 Oct

How are you able to flat the power at high rpm?
My tuner said it's possible to do it but I'll be shortening the stock turbos life

[F80Paul]

Originally Posted by ///M1990

How are you able to flat the power at high rpm?
My tuner said it's possible to do it but I'll be shortening the stock turbos life

With stock turbos the only way to get that kind of curve is to reduce boost through the midrange. Stockers lose efficiency very quickly after 6krpm.

[Mike@N54Tuning.com]

Originally Posted by F80Paul

With stock turbos the only way to get that kind of curve is to reduce boost through the midrange. Stockers lose efficiency very quickly after 6krpm.

+1

Yes stock turbos aren't efficient towards redline.. This is one of the reasons many upgrade as upgraded turbos run strong to redline as one of the graphs I posted above show. (Pure Turbo Dyno)

Mike

[SflBimmer8484]

Originally Posted by ///M1990

How are you able to flat the power at high rpm?
My tuner said it's possible to do it but I'll be shortening the stock turbos life

Lots of time spent on the dyno. With a max boost is 21-22 on our stage 2 you wont have any decreased turbo life. I also run this file on my personal car 16k miles so far.

I have seen a lot of the base files floating around that have a very large dip towards redline so pick your "tuners" wisely.

Side Note: Its really important to know what gas was used during the dyno runs to be sure you arent comparing race gas to a 93 or 91 octane run. Higher octane will help alot with timing and keeping power up. All of our runs are done with 93 oct pump only.

[Mike@N54Tuning.com]

Originally Posted by Andrew@ActiveAutowerke

Lots of time spent on the dyno. With a max boost is 21-22 on our stage 2 you wont have any decreased turbo life. I also run this file on my personal car 16k miles so far.

I have seen a lot of the base files floating around that have a very large dip towards redline so pick your "tuners" wisely.

Side Note: Its really important to know what gas was used during the dyno runs to be sure you arent comparing race gas to a 93 or 91 octane run. Higher octane will help alot with timing and keeping power up. All of our runs are done with 93 oct pump only.

+1

Fuel is very important!

Nothing good happens on 91 octane.. LOL

Mike