[jag3er]

Which gear at what RPM gives the best acceleration push? I can't find this info anywhere after searching. Is there a chart somewhere with this rev2 tq/rpm? Or personal experiences? I was out of country for 2 weeks and can't wait to go back and drive later today when my flight is over.

[ArmyBimmerDude]

Why not go out, drive, and find out?

[jag3er]

Originally Posted by ArmyBimmerDude

Why not go out, drive, and find out?

I've been doing that since March, don't have that much casual time to test all shift points. Would be nice though.

[lucassilva]

Even when you do get an answer it might not be the best for your engine. Even with these engines being mass produced if you are really looking for that edge you need to find your own timing.

[StarrDlux]

get the g-tech meter. the fastest run would be shifting past peak whp (6000?) dropping you exactly back into the lowest of peak whp on the next gear (based on how fast you can shift).

Basically pretty low revving is required due to the fact the turbo's lose their oomph.

same as my audi. would trade it in an instant for a laggy big turbo that pulled to 7000rpm.

trust me if you are shifting near redline you are going much slower.

the g-tech will log your runs and show you the log if your g-forces drop.

if you have a bmw datalogger you can access the accelerometer to log g-forces as well to determine best time to shift.

[skim7x]

Forward: This only applies to Stage II rev 1... but just thought I'd add... I know there are Dyno's of the rev2... just look around a bit

Here's the dyno I just did this morning:



So, since horsepower tops out around 6k RPM, I see no reason to go beyond that... The only possible reason is if shifting up to the next gear up will drop the RPMs lower than, say, 4.75k RPMs, in which case you might want to go over 6k and then drop your revs in the next gear... but from what I recall, I don't think any gears drop more than 1.25k RPMs from one to the next.

[Dan335i]

I would go 62-6400 rpm,s,no higher than that or you just making noise.

[StarrDlux]

when you shift at 6200-6400 tell us where your rpm drop is to. this would be based upon gear and your ability to shift (fast).

based on that dyno you would want to land at no lower than 5000rpm on each successive shift.

when i programmed automatic transmissions i'd try to target the least possible rpm past the peak whp to hit the highest peak whp in the next gear. this yielded the fastest (1/4 mile) time. but since i was programming the transmission it was very aggressive shifting (but this is also better for the transmission).

Manuals no different if you can flat shift more power to you.

i really was hoping we'd get more rpm out of the turbo's but i guess we can wait for a BT. i'd guess you'd probably see 500+ whp if you could get a turbo that would hold boost to 7000rpm.

I've found motors that make alot of power (high compression direct injection) with zero boost you can foresake the low end torque which lends itself to wheelspin and still have plenty of power for putzing around but you'd really enjoy being able to take it to redline without losing power.

instead of having 5000 to 6000 you'd probably have a bit more lag but a wider top end like 4500-7000, 2500rpm of peak power is hella lot more fun than 1000rpm narrow power band.

Probably need two GT28's to do that. I can't wait to see someone do a BT/Fuel pump kit to see what the motor can really put out.

I wish dinan would offer steptronic folks a tune to the ecu to short shift to maximize power for the stage. It totally sucks to have your car shift near 6800rpm or downshift to 6000rpm and then rev to 6800 which pretty much skips over the powerband. I'd pay extra to have my steptronic shortshift at 6000rpm and drop back down to 5000rpm in drive.

Once you pass peak whp your egt's get so hot the car starts dumping mad fuel to keep the pistons/turbo/cat(s) from melting down. its just punishing the motor so whats the point?

[masteblaster]

You can use the application from www.perfectshifting.com to approximate the acceleration of a car and the optimal shifting points.
The shifting points are usually very close to the red line in low gears and very close to the rpm where you have the max power for the higher gears.

[O-cha]

Originally Posted by jag3er

Which gear at what RPM gives the best acceleration push? I can't find this info anywhere after searching. Is there a chart somewhere with this rev2 tq/rpm? Or personal experiences? I was out of country for 2 weeks and can't wait to go back and drive later today when my flight is over.

If you give me a dyno I can run it through a program and give you your best shift points and a graph that shows the visual representation of where and why they are the best shift points.

But based off Dinans huge top end roll off I'm guessing you'll be short shifting into 4th if not into third by a few hundred RPMs.

[Mr. 5]

I've always felt that shifting at 6500 is the best for the way that this car is geared.
I shifted at aproximately 6500 in every gear when I ran the 12.3.

[skim7x]

Originally Posted by O-cha

If you give me a dyno I can run it through a program and give you your best shift points and a graph that shows the visual representation of where and why they are the best shift points.

But based off Dinans huge top end roll off I'm guessing you'll be short shifting into 4th if not into third by a few hundred RPMs.

Would you need a dyno of every gear then? Or can you use the one i posted above?

[sleepdoc]

Originally Posted by Mr. 5

I've always felt that shifting at 6500 is the best for the way that this car is geared.
I shifted at aproximately 6500 in every gear when I ran the 12.3.

I agree.

[O-cha]

Originally Posted by skim7x

Would you need a dyno of every gear then? Or can you use the one i posted above?

You only need a single dyno to do the math, what gear has nothing to do with it, hell the numbers don't even have anything to do with it, just their relation to each other as the RPMs go down and up.