Hey Guys:
How much will HKS step one 264 cams effect the timing of my s13. I have started the car up since I installed them. Will it effect my air/fuel at all or just my ingnition timing.
If anyone has any advice let me know.
Thanks
You are going to want to have access to change both ignition timing and fuel in order to get them to idle nicely.
Ill will be able to get some sort of an air/fuel tune before I get to the dyno but I dont know too much about the timing. Will the car be drivable with the new cams or am I at risk of damaging something if I drive around like that before its tunned. Can I boost, or should I just stay out of the cams all together ?
You are going to want/need to add quite a bit of fuel at idle to get those things to behave.
I would also recomend you not pound on he car until it is properly tuned. Cams change VE, More VE means you will run lean if not controlled. Lean = no good.
Cant say for sure but id imagine youll have a slight lope at idle.
What do you mean “slight lope at idle”. Sorry im not to sure what that is. Will the cams effect at idle more or top end?
Performance wise, they’ll affect the whole powerband.
What he means by “slight lope at idle” is… You know how drag cars, or tweaked out V-8s have that sound like they’re gonna stall when they’re idling?.. That. Except not as bad, because your cams aren’t that aggressive.
Aaahh gottcha. Thanks for clearing that up. Are the cams going to cause the car to run leaner at ideal. If so can I adjust this with the innovate wideband, bikiROM and an SAFC II ?
Whats the best way to tune for these cams. Start with the idel and work my way from there, try to get the a/f to around 14.7 ?
You’ll have a tough time getting them to idle nicely at 14.7. You will probably need to bump your idle to 1000-1100 rpm.
As for 14.7, there are only a few spots in your map where you will actually want to be at 14.7 (or leaner) and that is cruise and idle. Do not attempt to tune your car to 14.7 under heavy throttle
Bump up the idel to 1000-1100 I didnt know that. Ya thats what I have been reading about having it sit around 14.7 at idel and at cruise. What do you thnk the a/f should be at when the car is under load or at heavy throttle. I only put in the 264 and I thought that they didnt need valve work done. Was I mistaken ?
…By the sounds of it, your best bet is to bring it to Dan and let him set it up for you. With an SAFC and bikiROM you should have more than enough for him to tweak it nicely.
I have this exact cam in my own car…with no addition head work other than some RAS. You don’t need any additional valve work…but that being said 264s are still a very different cam than Nissan designed for.
Im sure that lots of ppl have done this mod on this forum. Is there any advice on what is the best way to get my car to run. Thanks for all the info so far, ive learned abit of new info.
what ruins your idle characteristics more than anything else is lobe separation, essentially how many degrees of cam rotation you have between the ramp of one lobe ending, and another starting.
With a 4-cylinder, you don’t have much time between the firing of each individual cylinder, like an 8 cylinder. You end up having the ramps “overlapping” (essentially valves open at the wrong time) between pistons. This is the number of degrees where the exhaust valve is still open – on its closing ramp . . . and the intake valve is starting to open on its opening ramp.
Having the exhaust valve still open when the intake starts to open uses the exhaust “pull” out the exhaust port to help start the intake charge entering the chamber – before the piston has started down and has generated it’s own vacuum. Also, leaving the valves open longer (duration) increases the density of the intake charge and better scavenges the exhaust gasses out.
When you’re running lots of overlap, the performance of the engine at low speed will drop (less horsepower than stock in many cases), it will idle really rough but will run well at mid to full-throttle speed when getting a full intake charge and good exhaust scavenging is very important and the overall latency of moving intake and exhaust gases is more of an issue.
Adding boost to the mix throws all of that out the window. Overlap + boost is a lot worse, because the intake air is already coming in over vacuum.
My and a friend are going to try and work with the bikiROM and see how that goes. Hopefully with the help of a wideband we should be able to dial it in pretty close then bring it down to a dyno and have them work on it somemore. I’ll keep my fingers crossed.
Hey Guys:
How much will HKS step one 264 cams effect the timing of my s13. I have started the car up since I installed them. Will it effect my air/fuel at all or just my ingnition timing.
If anyone has any advice let me know.
Thanks
You are going to want to have access to change both ignition timing and fuel in order to get them to idle nicely.
Ill will be able to get some sort of an air/fuel tune before I get to the dyno but I dont know too much about the timing. Will the car be drivable with the new cams or am I at risk of damaging something if I drive around like that before its tunned. Can I boost, or should I just stay out of the cams all together ?
You are going to want/need to add quite a bit of fuel at idle to get those things to behave.
I would also recomend you not pound on he car until it is properly tuned. Cams change VE, More VE means you will run lean if not controlled. Lean = no good.