I just got my computer for my minime swap.
It has the following specs:
Hot Rev Limit: 7800 RPM
Cold Rev Limit: 6800 RPM
VTEC Activation: 4800 RPM
Can the stock valve springs safely handle consistent revs at 7800 rpms?
If not, what springs and retainers would you recommend?

I guess if it can't safely handle 7800 rpms, I'll just have to watch my revs and not go over 7200 rpms..

 

7800, thats a lot for a stock sohc.

 

I know. It sounds a bit much to me too.. but aren't the real redline's much higher than the stock rev limit?

I thought the stock Y8 head revs to 7200. Will 600 more matter much?
I'm not sure since this is my first time doing something like this..

 

well, to be honest, i would be more conecerned about revving a stock d16 botom end that high. i dunno how harmful it is or could potentially be to ur car b/c i know squat about single cams. i do have a question tho, if the motor is stock why rev it that high? i can't imagine you making any kind of good power past 7k.

 

i always go to 6000rpm in my stock d15b2 all stock some times it goes to the cut off at 6500rpm
pasing the red line t0 7000rpm i never blew out an engine and is daily driven car

 

Good question.. and the answer is. Its supposedly a dealer tune, with the correct fuel curves, etc.. I'll have no idea how much power it makes in the upper RPMs until I put it on a dyno. My best guess is that the rev limit is that high so that the next shift will still be in the VTEC range.

 

its a d15b2 soch non vtec engine the engine is new the old man that sold me the civic change it a month before i bout the car .....i think the engine has 97hp + intake from 5000rpm to 6000rpm i feel the engine power

i need more hp

 

why would you want to rev a stock motor (doesn't matter what computer or bolt ons you have) your motor is internally stock and WILL NOT make any power above the y8's redline. bottom line is when you go past 7000 and it feels flat your losing power...shift at 7k

 

Well said. I guess I'll just have to see where the power feels like its just flat and figure out what RPM to shift at to keep me in the power band.

But the question still remains. Is it safe to rev the stock engine to 7800 rpms?
Here's a situation :
For example, if I'm autocrossing and I'm in 1st gear, I wouldn't have time to look down at the tach to see what rpms I'm at. The best I could do is listen the engine. If I'm wrong and I'm running at 7800 rpms, would the valves start floating with the stock springs?

 

its possible that, at 7800 rpm you could do some serious damage to the motor. my advice is to either

a: build the motor
b: get your ecu rechipped or get an msd and cut that limitter back.

and damn you guys sure did quote me a lot in this thread...

 

you can rev to 7800 rpm, but no power after 7100-7200 rpm. My Z6 has seen 8500 rpm, but power is weak. Shift at 7100-7200 NA on a GOOD tack.

 

What kind of tachs do you recommend? I just installed the computer tonight. So I have to be careful when I'm doing some spirited driving.
I'm going to be doing the Y8 swap next weekend, so wish me luck.

If I do decide to upgrade the cam, valve springs and retainers, which ones would you recommend for the engine? I've heard Zex for the cam, but haven't heard anything concerning the valve springs.

 

Yeah, but I bet that 8500 rpm wasn't on stock head internals, right?

 

what computer are you using? and why do you want to rev that high? there is no power up in those rpms without some work on the motor. also why do you need a tach isnt your car an si, you should already have a tach.

 

I'm using a modified PM6 computer. I don't want to rev that high right now because the Y8 head is still stock. Perhaps if I get a new camshaft, i'll want to rev that high if it makes any power in the higher rpms.
Why do I need a tach? Because we all know that the stock tachs aren't that accurate in the higher rpms. (Type R tachs read around 9000 rpms when its really around 8400 rpms) With the higher rev limit, it'll be more critical for me to know what the true rpms are (and shift at 7200 rpms) especially if the stock head can't handle the the high revs at 7200+ rpms.

 

my apologizes. where did you get the pm6 modified at? and how much did it cost?

 

I bought it from Zdyne. Its the D16Y8 One Wire Vtec Conversion. It cost $320.. I figured I'd save myself the aggravation of 1) wiring up a P28 ECU to my Stock SI harness or 2) wiring up a decent VTEC activation switch and Fields controller, FPR,etc..
At least with this ECU it has the correct timing and fuel mapping for the D16Y8 and I can just run 1 wire from the ECU directly to the VTEC solenoid. The install of the new ECU only took about 10 minutes. I was going to have the computer specs at hot rev limit: 7200 rpm , cold rev limit 6700 rpm, and vtec activation at 4500 rpm, but the person I spoke to at Zdyne said that they never sent an ECU out with stock specs before. He suggested the "dealer tune". Without thinking, I told him to just send me the chip with the "dealer tune". I didn't expect the rev limit to be 7800 rpm. I thought at most it would be 7500 rpm.
I guess its good in a way if I decide to upgrade the cam and springs later.

 

BONE STOCK motor with a Locash ECU. Either Mugen, LCR, or XS program.
No power up there or past 7100 rpm on stock cam. Right now I have a 7800 rpm chip in the MSD to kill ignition when using NOS.

I still shift at 7000-7100 rpm though.

 

Thanks Mista Bone!
That gives me a little piece of mind..

 

My civic manual D16Y8, is not limiting to 7,000 RPM, I have to make the change to 3,000 RPM, with the P2P ECU, and I don't know what to do, since I tried everything, some recommendation.

-Check the V-TECH valve and it works ready.