What is a safe redline?

[GBSilviaS15]

What is a safe redline for the KA24DE engine? Of course I know the stock 6500 is safe, but how far do you think a KA24DE can handle before it goes, KABOOM!?

My cousin has a 94 prelude, and he tuned his ecu to redline at 7200, and that's safe still for that motor. Isn't my motor just as good? His is an H23 by the way.

I'm trying to tune my ecu so that when I shift from 1st to 2nd, I stay on my sweet spot making my peak horsepower.

Thanks guys.

[TheOne]

about 6k rpm's as the hp starts falling off at 5.5k rpms, this is on a non-turbocharged engine.(or mods affecting how high the hp goes)

[bcar240]

stock I would say you should shift before 6k, like TheOne said, there isn't much power to be had past that. The stock revlimiter is around 7200, but I woulnd't want to really go that high often unless I built it up and had a reason, like a turbo.

[GBSilviaS15]

Since my power starts droping at 5600 rpm, would it be better if I shifted at 5600 rpm? Or a little after that?

Thanks guys

[Florida240sx]

Going to be a little bit after.One of the members figured it out for his MR2.Got to have spread sheets of power at specific rpms.While it drops off at 5600 if you shift at 5900 you'll lose 10hp than if you stayed for 100rpms more.because of when you go to next gear.Pretty much you run the car until it drops off to the point of that's where you are at when you sift into the next gear.hit peak at 155 drop down to 130 by say 600rpms and building back up form 130.Instead of shifting at 5600rpms(peak hp) and starting at say 110hp. I'd say probably 6400 is a good shift point. Anyone have better ideas or to say my theory is wrong.

[bcar240]

That theory makes sense. You are running out one gear a little longer so you can come into the next one higher in the powerband. Seems smart to me. Like you said though, need the charts to find the best point.

[KAKILLERS13]

When I had a KA I shifted at 7 g's every time I raced. Never lost against an all motor honda product. Ofcourse I did blow up 2 KA's in the past 6 months but it was from drifting.

[skydragoness]

The KA has nothing after 5.5k it just plateaus, going to redline or past it is absolutely pointless unless you've upgraded the cams, and made substantial changes to the compression--amongst other things. It's not a Honda motor, hence the torque.

[fatboy]

i shift at 6 and shift like a pro!

[e_c]

the theory above is good, shift higher so that the new gear shifted into is higher in the powerband... that is good but you have to remember that you also want it to be in the power band where your acceleration is better... for instance, you acceleration from 5000-5500 is probably the best acceleration in the whole power band, as it comes to hit top hp, then after top hp, you lose power, and acceleration, so if your shifting too high, the acceleration is lower than it could be in the next gear if you had shifted earlier, sorry if that doesnt make sence, i might read tomarrow and be like WTF was i thinking...

[Maverick7687]

Ok, I have driven a few different 240s and I know that power drops at around 5.5k but I just felt like saying this because there could be things that are different. Like my 240, it is different than any other I have driven, I know it is something wrong but I don't know what it is, and it still runs fine and gets me reliably where I need to go so I am not going to worry about it. The thing is when I hit about 5.5k it feels like something kicked it in the *** and the car just takes off..someone thought I was playing with them one day because we were racing and my car hit 5.5 and I just flew by them when they had a lead at frist(like VTEC....JDM tyte yo...) . No real point in this, just thought I would add it as something to think about..

Mav

[dfw240_EE]

I use this technique in every stickshift car I drove. What is said above it true, you don't shift at the power peak, because you lose more by going into a weaker gear. Remember though, the gears are not evenly spaced. According to DriftKat.com:1st 3.3212nd 1.9023rd 1.3084th 1.0005th .759

As you can see the drop is less severe the higher the gear. So I find the best method is to shift at the highest RPM for 1st to 2nd, and then for each gear bring the shift point closer to the power peak. Or for me trying to save fuel shift 1st-2nd around 3500 to 4500 or so, dropping the shift point as said above to 2000. I find the KA runs most efficiently around 2000-2500.