Ok as far as I know the s13 and s14 KA24DEs are the same except the cams, minor differences in the intake manifold, and OBDII... then why do S13s have a 6900 redline and the s14s have a 6400 redline??? I was told that if the s14 motor would not survive being taken to 7000... but if it's pratically the same as the s13... then why can't we take it to 7000?

The reason for my asking is because I am going to install aftermarket cams (most likely the nissan motosports ones) that will pull nicely tor edline and even a coupla hundred RPMs beyond... I am thinking of getting an APEXi rev limiter and resetting the redline to maybe 6800-7000 from the stock 6400.

Now I know there are head work to worry about, so basically my options are to:
1. keep stock springs/retainers - which I don't think is very wise
2. get new stock springs/retainers - maybe, I am not sure if they will handle at 7000 rpm redline, BUT then again, the s13s can handle up to 6900 rpm
3. ferrea titanium springs/retainer kit... which is around $500


Any input/advice is greaty appreciated, thanks!

 

i know there are a few other companies that makes a high rev spring for the ka series.
not sure off the top of my head..but just read through some SS and SCC mags.
then rock them cams and rev to where you want to be.