maybe your magazine was testing the diesel version of the 330i, as the current model is faster than that. I have the C&D right here in front of me, so thats all I can think of.

as for our cars being peaking by nature, this is true, however, that doesn't mean you can drill down in the 4000-7500 range and tune for better across the band power. I guess my point is 240HP at 5000 rpm is going to be a generally faster and more fun to drive car than one with 280HP at 9000. Look at the power band of an FD for example.

 

You need to tune based on where you are going to be driving most of the time. For a race car that spends most of it's time between 6500-9000 rpm's, there is no point in sacrificing power in this range in order to get more power below it. On the street however this may be a worthwhile sacrifice in a small way. Go over to the 2nd gen section of the RX-7 forum. Alot of those guys go crazy trying to get that extra hp or 2 from the extreme top end only to sacrifice where the cars are driven at most of the time. Most of them end up losing power everywhere but don't tell them that. The people that do this are slower on the street. I don't think we should necessarily try to lose top end power in order to gain more down low. I do feel that people should be spending more time trying to make better midrange power though instead of trying to be the new peak number dyno queen. I want to see mods where we can benefit from them. A 2 hp at 8000 rpm with no gain anywhere else isn't the way to do it. If we saw a product that gave us 10-15 more in the midrange but nothing extra on top, it would be worth it. In order to accelerate, you've got to get through the lower rpm's. The faster you get through them, the faster you get moving.

 

For those that are un-familiar with ECU tuning concepts, a quick Amazon search yielded some good books that delve into ECU tuning theory. Here is one that is heavily recommended, and has even been updated.

ECU Tuning Book

 

Since we're all talking about "the street" let me just lay it out

Any turbo that comes alive before 4000 rpm will simply own on the street. It will generate monstrous amounts of torque and be alive when you need it - the mid range.

As far as the FDs, I had one with a GT3540R that spooled up fully by 3000 rpm and layed your ears back all the way to 8000 rpm - it was great, and I never griped that I didn't have lots of low down torque.

 

http://www.7extrememotorsports.com/wrc/stats/

I'm not debating anything here but I just found an interesting link: Have a look at the torque numbers. The WRC cars are not allowed to produce more than 300 HP, so it looks like that they almost tried to generate flat power curves (well exaggerated), so that they're not far from maximum power even at a lower rpm.
A flat power curve is of course even better than a flat torque curve, but it doesn't make sense to design an engine like this unless the power is limited. (20 years ago some of the WRC cars were generating 600 HP with the same displacement.)

 

Guys,
Another thought. Cant compare street use to track use. No way. Also depends on what track you will be at. Some tracks you benefit from not have to shift so much, can stay in 3nd and 4th gear. But you are using the engine from 3--9k doing that. Unless you are REAL good, a lot of shifting causes oppitunities to upset the chassis, takes away any possible left foot braking that you could use and is harder on the car etc. Good example my cz with stage 2 map was a little faster this past w/e at Road Atlanta IN CERTAIN AREAs but my overall lap times where slower with the cz than without it. BECAUSE it wasnt tuned for that track. I was loosing under the curve power in more places than I was gaining power with the unit. Good discussion, just sharing a thought and an experience of mine.
olddragger
olddragger