Higher Redline . . . advisable? worth it?

[Zebrahead]

I'm planning an ECU in the future, and I've read than when you reprogram your ECU (or get a new one), you can increase your redline. But the gear ratios are still the same, so would it even be worth it with the KA? Power drops off at around 6.2K-6.4K, so if you increased the redline to 7500, would it even be worth it? Would you even have any power in thsoe higher RPMs?

Nick.

[Daunttless]

Not on a relatively stock 240, theres no point. That and the stresses from the additional rotation will damage you stock internals. The KA was not meant to rev that high, and on a stock setup you'll lose power due to the heat generation.

[Zebrahead]

I figured as much. My plan for my KA is all motor, as follows:

Intake (done)Exhaust (done)Clutch (very soon)HeaderCamsKA24E pistons (for compression)

There's not much more I can add to gain decent horsepower. Only things I can think of are Pulleys and a flywheel (which doesn't actually add any horsepower).

When that's all in, I plan to get a new ECU (from JET or something) or have JWT reprogram mine. Once I do have it reprogrammed, should I see any difference in performance?

Nick.

[Daunttless]

I'd suggest a port and polish while you're doing camwork. Also, don't go with the JET, definitely go JWT, and yes, you'll see a significant performance gain. : )

[Nismo_Freak]

Increasing the redline on the KA is simply retarded until you have it built (head, internals, etc.) for the higher rpms. You risk floating a valve which causes a free-for-all in the combustion chamber that results in FUBARed Pistons, Head, and sometimes the Rods can torque and grind the remaining piston against the block for added pleasure. High power cam profiles will open the door to higher rpm because there for one will be power up there. You will need new retainers, springs, cams, rods, and pistons for the higher RPMs and items such as a balanced or knife-edged crank and lightened flywheel will take some of the inertial load off the bearings in these before mentioned parts.

[flip240]

I heard somewhere that the KA crank isn't fully counterweighted?? Is this why the engine rocks alot when it first starts up?? And another reason why it can't rev too high?? I've worked on engines before, but haven't worked on any Nissan's yet... But I love my KA and I even love how it rocks when it starts up too

[APEXi240]

I hate when mine rocks when it starts up. I contribute some of that rocking to worn motor mounts, as mine are in desperate need of replacing.

[Daunttless]

The KA is a very vibration prone motor as is, its also only half counterweighted. : )

[flip240]

Mine rocks a bit, but u can only notice it if you are looking at it when the car starts... can't tell at all inside or out.... What was the purpose of half-counterweighting the engine?? That'd be a pain in the a** to work on that crank i bet.

[cnichols]

Going to pull my KA soon and start re-building but I don't want to make any mistakes or not do something that I might regret later.

I noticed that with the HKS 3037 Turbo there was some lag, but I think part of it was due to the fact that my #3 cylinder was gone (compression test...60!). In order to stay in boost a while longer I would like to have a higher redline.

I wouldn't mind getting the KA to rev to 7000 and still have the option to go a couple hundred higher in the event of a missed shift or other mishap so that I don't float a valve or worse. Obviously the valvetrain would need upgrading...should I go titanium or is that overkill? Also, has anyone de-stroked their KA????? Would lose some torque, but should gain some RPM's...I'd hate to do this and have it be a turd, but I assume it might help some with the roughness associated with the KA in addition to making some adjustments to the crank.