Perhaps foolish, but has anyone attempted a synthetic torque curve?

[RockinRyan]

I couldn't help but wonder, with the ability to program turbos so finely - what would happen if someone coded an actual arc into the torque output? So that it had a perceptible rise, peak and fall? (Selectable, of course. Can't lose a stop-light showdown for nostalgia!)

Is this feasible??

RR

[Deja_Vu]

...did you just sign your own post?

Also, why would you want that?

[MChat]

For traction purposes I've used programmable boost controllers to "ramp up" the boost in certain gears.

For instance in the car I just sold (N2MB controller) it would do 10psi in 1st (9psi Waste Gate Spring), start at 12psi in 2nd and then ramp up to 15psi by 6000 rpm in 2nd. (3rd and up were full boost).

I also did this previously with an AVC-R controller; actually had a dyno of the difference. Peak HP was the same, but the "ramped up" map did not have the torque spike as the turbo spooled up.

[RockinRyan]

Originally Posted by Deja_Vu

...did you just sign your own post?

If you're asking about "RR" then yes. Some people do that.

Originally Posted by Deja_Vu

Also, why would you want that?

The reason for this question is all about several people feeling like their F8X M has a feel that "lacks soul" and is less fun. I believe this is all about the lack of thrill from a bone-straight torque curve. There's no rise and fall that we experience with naturally aspirated engines. My question is - can we synthesize this feeling by mocking some of the natural curve?

When I test drove several F82 M's the car was extremely fast, but didn't feel like it. And if I'm willing to give up two tenths of a second to row my own gears, I'm clearly driving for the experience and not simple metrics. If I could have a mode that made the car feel more natural and thrilling I'd like to know about it and experiment with it.


<anonymous>

[RockinRyan]

Originally Posted by MChat

For traction purposes I've used programmable boost controllers to "ramp up" the boost in certain gears.

For instance in the car I just sold (N2MB controller) it would do 10psi in 1st (9psi Waste Gate Spring), start at 12psi in 2nd and then ramp up to 15psi by 6000 rpm in 2nd. (3rd and up were full boost).

I also did this previously with an AVC-R controller; actually had a dyno of the difference. Peak HP was the same, but the "ramped up" map did not have the torque spike as the turbo spooled up.

Thank you, Michael, this is really cool! So did the car *feel* a lot different to you under that configuration? Or do you think it could accomplish the effect that my thread is asking about?

Ryan

[MChat]

Originally Posted by RockinRyan

Thank you, Michael, this is really cool! So did the car *feel* a lot different to you under that configuration? Or do you think it could accomplish the effect that my thread is asking about?

Ryan

I'm sure with the right boost controller or custom tune anything is possible. You just need to be able to control boost by RPM (and by gear if you're doing it for traction purposes like I was).

Here is a couple of dynos of a 4th gear (closest to 1:1) pull where the boost ramped up over time (the only difference was the maximum boost target). These settings were then set for 2nd gear on the street and allowed full throttle assaults without spinning the tires. As for "feel", well it felt like the tires weren't spinning

NOTE: this was on a turbo 4 cylinder Neon SRT4

[MasterC17]

JB4 Map 5

[YMB_M3]

Never really understood the point of intentionally maiming the powerband in order to mimic a different car at the expense of being slower. Didn't you guys know that the powerband wouldn't be like a high revving v8 when you were purchasing the car?? How is more torque in the midrange something that is not desirable?

[RockinRyan]

If you feel that nothing is missing with a torque band that you can balance tea cups on, then good for you. For people who like and miss the sensation of a torque curve that has a bend in it, this is what is being considered here. I'm not saying I would track with a maimed curve, or even use it all the time - certainly not. But if it made the car feel like an E39's V8, which should probably be possible, and with an engine that has 111 more torque than its predecessor, on a daily drive situation the car could legitimately be more fun to drive.

And this is the future of sports cars. It's not like there are lots of options in this bracket. This is a question of adaptation and experimentation. Could a moderate tune with a bend feel more like the old spirited engines that many still pine for? I don't know. That's what this thread is for.

[Jeff@TopGearSolutions]

I guess everyone has their opinion and sensitivity of what feels more fun or right.

Truth is BMW and their engineers go out of their way to make the car efficient and linear because that is the ideal way of producing power.

To most, nothing feels better then having power right away and continuing to make power to red line.

Anyway, there is an easy fix if you rather build up power as RPM increases just change the boost curve.

[MChat]

Originally Posted by darge82

All you are doing is making the car slower, well unless you have traction issues....

That is the only reason I've done it... I think OP wants the car to "feel" different; the only feeling I go for is having the quickest acceleration with the tires on the edge of losing traction.

[8600RPM]

Jb4 map 5 is a linear boost which actually doesn't give linear power. I had an f80 and used jb4 map 6 to create my own linear map and it was great. Worth doing in my view. Get yourself a jb4 and use map 6

[LDSM]

I think a more helpful approach would be to adjust the throttle mapping to make it longer in sport mode, similar to what the ATS-V and CTS-V does.

Instead of having a sharp throttle in sport+, where a slight press of the gas pedal results in more throttle application, it should be the opposite. Having a longer pedal feel, would be especially helpful on the track and controlling the power output.

[RockinRyan]

Originally Posted by LDSM

I think a more helpful approach would be to adjust the throttle mapping to make it longer in sport mode, similar to what the ATS-V and CTS-V does.

Instead of having a sharp throttle in sport+, where a slight press of the gas pedal results in more throttle application, it should be the opposite. Having a longer pedal feel, would be especially helpful on the track and controlling the power output.

Perhaps THIS is the solution to the "problem" many have expressed!? I'll keep this in mind, thank you.