Dinan re-map raising redline thoughts?

[Olly84]

Hey ya'll. I have a lil' 325i. Japanrot, 5-speed, not the fastest, but really fun to drive. Was wondering if doing the Dinan re-map to raise the redline closer to 7000 rpm would be ok with this engine. I find that for some reason, after I installed the BMW performance air intake and a Dinan exhaust, I've been unable to hit 60 mph in 2nd gear without hitting redline. I was able to before these mods...or is it all in my head...?

Anyways, I was thinking about doing the re-map mod just so I don't bounce off the revs so quickly. I do drive the car hard and I've heard something about an oil pump nut coming loose if these cars are constantly driven hard?

[RGBaker]

I can't see how a remap would change the mechanical relationship between engine rpm and wheel rotation? The rpm/speed ratio is fixed to the combination of transmission gearing and differential -- if you haven't changed those, I'd venture you could never get to 60 in 2nd ...

As for whether it's worth risking additional mechanical stress on a sixteen year old drivetrain, I'd say that's up to you. The hp peak on the stock engine is over by redline, so the only reason to consider it is to be closer to peak when you shift to 3rd. I don't know where the Dinan re-map has moved your peak to.

[Muzz258]

Your gear ratios are set. The only variable that you have to play with is the rolling radius of the wheels though wheel and tyre size changes.

Not worth the risk of increasing your redline on an old engine. Its been set there for a reason.

[jclausen]

I drive home on a very lovely windy road at a very good clip my rpms and my engine are not stressed at all. I would stay out of redline unless you really need to. The more you beat on the engine the more chances you have of something happenening to it. And if you saw a dyno chart on your engine I'm sure somewhere before redline the power falls off, which is normal so why run it up all the time

[R Shaffner]

A few months ago I was testing some intake mods on my 540 using the Testo program. I was trying to compare data from WOT runs up to redline, so I was intentionally bouncing off the rev limiter. During those runs I was surprised by a few things.

The max rpm recorded by the program varied. Sometimes it was 6,100. Other times it got as high as 6,250.

And as I was watching the tach, I realized there was a lag in it relative to what the computer actually recorded. Sometimes it seemed that I hit the rev limiter in 2nd just under 6,000, while the computer run showed that it hit 6,100+.

In short, in my car during those runs, the rev limiter wasn't real precise. So you might have hit 60 in 2nd during a few runs and not in later ones.

Of course with a higher rev limit you could perform a bit better, but for what benefit and at what cost? Not worth it with a stock engine, I bet. With a DUDMD chip and other mods it might make more sense, but perhaps at some cost to longevity.