Live Thread: Prepping our 435i for SCCA Time Trials with BimmerWorld

Is this like The Price Is Right where if we are over, we automatically lose?

J.A. Ackley said:

Is this like The Price Is Right where if we are over, we automatically lose?

You can go over as long as you explain how you're going to help me make that number.

JG Pasterjak said:

J.A. Ackley said:

Is this like The Price Is Right where if we are over, we automatically lose?

You can go over as long as you explain how you're going to help me make that number.

I like that. This has got more interesting.

302. 

One under crank number, at the wheels, stock.

Bowie missed it by a whisker.

But, yeah, BMW definitely underrates all of their turbo cars. 

The soft initial curves on pulls 2 and 3 were us rolling into it really gently because it kept wanting to come out of dyno mode after the first pull and start downshifting on its own. So don't sweat those.

But man look at that absolutely tabletop of a power curve. And it seems like there's zero reason to run this thing past about 6200-6500 rpm. Going to redline just makes more noise.

I haven't had mine on the dyno to prove this, but my feel is that all the tunes just throw a bunch of low end torque at the car and don't do anything of consequence to the top end.

I ended up actually going with the "Stage 0+" tune, which is supposedly the M2 tune. It felt like it was the only one that woke the car up over 3500 rpm at all, and was repeatedly a little better doing wide RPM 2nd/3rd gear pulls to try to validate.

RacerBowie said:

I haven't had mine on the dyno to prove this, but my feel is that all the tunes just throw a bunch of low end torque at the car and don't do anything of consequence to the top end.

I ended up actually going with the "Stage 0+" tune, which is supposedly the M2 tune. It felt like it was the only one that woke the car up over 3500 rpm at all, and was repeatedly a little better doing wide RPM 2nd/3rd gear pulls to try to validate.

Not surprised here. We're going to do some tuning at some point, but I'm not expecting a miracle. The turbo is so small that you're just not even going to get the throughput that the gaudy top end power requires.

But I'm content with an unstressed engine that can deliver lots of trouble-free track miles (as long as we can keep the rod bearings happy).

The Porsche 996/7 world has a lot of these bolt in "rollbars" that attach to the stock seat belt mounts.  I'm not a fan, really all they are is pretty, heavy, harness bars that are held in place by a few bolts in shear.  Doesn't look like that "rollbar" is really any different.