REV LIMITER

I have a 1995 240 sx se and i am going to put some wild cams in it what is the highest RPM that i should set my rev-limter at and be safe?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'> also what product will give the most HP to this engine. (excluding NOS and turbo). And what is the most i can advance my ignition timing?

[jay]

I know the JWT ecu ups your rev limit to 7k, so my guess would be that is the safest you can go. As for HP add-on, get a cat-back exhaust, intake, headers, increase the compression, port + pollish, cams, JWT ecu etc. Remember not one product will yeild the most HP, they all work together to produce power, especially the header, intake and exhaust. We had a good thread about N/A tuning here: http://www.zilvia.net/forums/cgi-bin/topic.cgi?forum=2&amp;topic=955
That should help you out a lot.

i'm sure i read of someone having there motor rev to 10k... but yah... u can imagine whats goin on in my head..... WhoA!! <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>

[jay]

10K? Yeah for how long, that is what I am wondering

i believe he had it like that for a while then he fucked up a shift or something to that nature and ..... poof no more engine <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>

[BlankFlip]

he also had the &quot;bs flag&quot; pulled out on him though <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'> .

[jay]

I just cannot see revving our engines to 10k as being good. Yet I still would like to see how hard it would pull at 10k, it would be interesting to find out. But not on my car. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

(Edited by jay at 1<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wow.gif" border="0" valign="absmiddle" alt=':0'>2 am on Dec. 3, 2001)

does someone remember tha post? i'm 99 % sure i saw it here.... oh well if it's bs all the better he had me fooled <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>

[BlankFlip]

yeah nismos14, he never replied back once everyone had him figured out n saw that he was a liar, he's probably on w/ a different s/n by now.

LoL *woosh right over my head :confused: i fell for it :'(

[jay]

Yeah I think that 10 grand is bs too but I bet you could do it for like 5 seconds or so. I bet that is what he meant, he had it at 10k for five seconds before it blew up. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

[BlankFlip]

i guess he did it for a while when he was racing a supra....supposively. n then his engine blew, but it was all bs.

[jay]

oh well, another dumbass who couldn't back up what he said. I bet he can run a 200 shot of nos on that magical engine too.

how high could u take ur rpms and what are the benefits are the benefits only seen &nbsp;with the swap of cams?

[jay]

Please correct me if I am wrong but isn't it the long stroke of the KA that keeps it from being able to rev real high? I am not an expert but I can remember reading that somewhere. The power gain from the cams should be throughout the whole power band, once again I am just speculating.

(Edited by jay at 1:18 am on Dec. 3, 2001)

yah what allows some cars to rev so much higher and others so low?

[jay]

All I know is that hondas can rev to the moon but have no torque and we can't rev that high but we have gobs and gobs of torque. That is all I really know...

[HippoSleek]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from BlankFlip on 11:10 pm on Dec. 2, 2001
i guess he did it for a while when he was racing a supra....supposively. n then his engine blew, but it was all bs.
</td></tr></table><span id='postcolor'>
gee... I seem to remember that post. &nbsp;muhahahahaha... something about a Jun built KA...

[DSC]

Not 100% on this but....isn't it (atleast partly) because of hondas lower displacement(1.8 vs 2.4). Theres less to move...thats (again, atleast partly) why the sr can rev higher...I don't know what else affects how high you can rev. Anybody care to add anything?

what would be the purpose of revving higher in our car where our peak horsepower comes in lower n way?

[konkman]

I don't know,

But at 10K rpm's I can hear the valve springs shattering in my head. &nbsp;I'm thinking it would cause a complete engine meltdown.

[mistert]

well, stroke has alot to do with it. an RB25DET has the same cylinder width as an SR20DET, but typically readliens a few hundred RPM higher. why? because the stroke is shorter. since theres more cylinders, you can use the same width and shorten the stroke to achieve the better displacement but free-er revving. RB26dett's can go all the way to 10k (although its not recommended), and i've heard the tach on the 400r goes all the way to 12k.

however, if you want to be able to rev more...and even if you dont really wanna push it that far, but want better pickup at the high revs...I would suggest getting dual valve springs and titanium retainers. this wont even cost you a couple hundred dollars, but your engine will be much more responsible in the high RPM's. if you wan tot really push it, get newer, reinforced valves. these are also relatively cheap, and will take alot more punishment in a highly tund N/A or F/I engine. i think ferrea makes some valves for the KA? if they dont, im sure someone else does.

[whateverjames]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from nismos14 on 11:57 am on Dec. 3, 2001
what would be the purpose of revving higher in our car where our peak horsepower comes in lower n way?
</td></tr></table><span id='postcolor'>

if you raise the peak horsepower to a higher RPM, your horsepower will be more efficient. you may lose a little bit of torque, and it won't be as powerful with daily driving but #### would it pay off when racing.

[mistert]

well, horsepower is merely output(torque)xRev/5252. look at any dyno chart and work i tout for yourself. thats how hondas make power. the more you rev, then more you're going to make power

this'll give you more flexibility...you'll still have all that torque and off the line power, you'll just be able to push the engine harder, especially on the highway

(Edited by mistert at 9:18 am on Dec. 3, 2001)

[95240se]

thanks for your help.

[240racer]

there are a couple things that control the redline of an engine. &nbsp;Mostly it is stroke, piston weight, con rod strength (those things cause you to throw rods) and also valve springs and valve weight. &nbsp;The valves tend to float off the cams when the are going up and down real fast, called valve float. &nbsp;With the bottom end, the stroke determines the maximum piston speed at a given rpm. &nbsp;then the weight and speed of the piston determines how much inertia it has (mv^2) that inertia is controlled by the con rods so they have to be strong enough to handle it. &nbsp;the S2000 has a short stroke and probably very light pistons and light and strong con rods. &nbsp;Our engines have a longer stroke (which allows for more torque) so the piston is moving much faster at any given rpm that means it has mor inertia and therefore will throw a rod sooner then the S2000.

[S13Grl]

Leave it at 7K just to be on the safe side. I wouldn't shift at anything higher than 65K. Try and dyno your car and see where you peak at.

Irena

[alchemist]

IIRC the KA block has a destructive harmonic that occurs in the 8K range. &nbsp;

[fourg63]

The KA motor can handle 10K, but with proper build up.Lightened, balanced crank.Hi strength rods and pistons.Race spec head work is a must.Cams that make power up to 10K.What's the point of revving that high if you make no power after 7K, right?Jun of Japan were actually very impressed with the KA motor.They were testing its potential and according to JUN USA it made almost as much power as their &nbsp;RB26DETT and revved to 12K.Unfortunately there's not enough demand for KA race parts so JUN will probably not make any for it.

[whateverjames]

i always thought the japanese hated the KA, i used to get email from a few japanese that saw my website saying i need to get rid of that diesel engine and get an SR. hehehe.

(Edited by whateverjames at 11:39 am on Dec. 5, 2001)