fonque

making a car spin higher does not sacrifice any power down low if you aren't making any internal changes to the motor. e.g. just valve train, no cam changes. It will spin higher and provide a foundation to make alot more power up top since you can wind a gear out longer.
From what I have read so far over the last few days, it is safe to raise the red line up to 7300 - 7500 RPM with only a change in valve springs.

I am looking to see what can be done to get those last 500 RPM. I know this sounds like rice boy nonsense but I do have a reason why I am investigating this.

Rod Run

and just because it spins higher, doesn't mean it will produce any useable horsepower or torque at that range and yes it will sacrifice power somewhere. If it didn't, every engine builder out there would have designed engines with even torque and horsepower throughout the entire RPM range.

It sounds like you are chasing the higher RPM so you can say "my engine revs up to XXXX RPM", more than trying to find actual horsepower.

You talk a little about not going into the engine (except for maybe valve springs) and still making a good foundation for more power. Even if you did get it to rev higher, you will be out of a useable range and also making more horsepower without strengthening up the bottom end can only lead to disaster, especially since you want to make it up near the engine's limit anyway.

moonsign

A good torgue curve is what you should be shooting for, and not high RPM's. If the torgue curve is falling off at high RPM's[and it is for sure], then you're just blowing smoke, and killing the torque worse. Torque is what spins the wheels, not H.P. "Moon"

Rod Run

YUP!

As the saying goes.... horsepower lets you go fast and torque is what gets you there

XtremeSS

Are you goin big turbo? That would be the only reason you would want it to rev to past 7k, to rev out a gear longer for racing and make use of the larger late spooling turbo. Most good aftermarket turbos for our application have enough flow at 7k rpms, raising the rpm limit with the springs and cam would be HIGHLY beneficial. And yes, valve springs and ZZP cam with large fuel lobe is really all u would need to get to ~7k rpms.

hhrfreek

I'm sure your research includes using a bigger turbo. My car holds 23psi til about 5600rpm then it creeps down and falls off hard to about 19psi by 6500. There are many aftermarket turbos that can move a lot more air and hold 24psi+ through a 7500rpm redline no problem. I don't think thats in my immediate future though because e47(even on a mostly stock car) is a riot.

BTW, balance shaft delete in my experience was terrible. The engine idles pretty smooth, but as you approach 3k+ it vibrates really bad. The vibration is only made worse by using stiffer eng/trans mounts and if you're modding you will likely get performance mounts. If I do a turbo upgrade at some point, I will only do springs and be happy with a 7200 redline.

XtremeSS

My bad, I was thinking of E fueling. If your not tuning for ethanol, than you shouldn't need the cam with fuel lobe. As hhrfreak said, just need the springs. But hey as long as your working on the valve train...may as well throw in a set of cams.

fonque

when you did the balance shaft delete, did that car have an SFI damper on it?

hhrfreek

I did a bsd on a 2.4l. I did not use an aftermarket damper. I used the stock damper, though I should have used a better damper. I was spinning 7800 with a SC. The 2.4 has larger bs than the 2.0 so I'd feel more comfortable spinning those into the mid 7s. I wont be spinning higher than 7200 ever with this engine, so I will retain the factory crank pulley, bs and my only valvetrain mod will be springs and possibly cams if fuel cant keep up with a bigger turbo on e47.

foolmoon_design

all this mumbo jumbo.

plain and simple. the stock lashes, rockers, and springs are not gonna hold up after 7,500rpm. you can upgrade but then the K04 runs out of breath. then you go bigger turbo to take advantage of better head parts, and you run out of fuel. then its cam time. questions?