Head Work and Custom Cams

[TheMAN]

good god, all that work and you ONLY got 111hp? something is wrong

I bet it has something to do with how your head was ported

and this is what I got without doing crazy s***:
http://www.clubprotege.com/forum/showthread.php?s=&threadid=2264

as promised...

explaination about the dyno graph.

ignore the flatish one. apparently it's the tractive effort or something like that. problem is the Lb reading on the right...i dont get it. esp considering torque and hp are supposed to be equal at 5252rpm or something close to that....so anyway, just focus on the power curve

as you will see. power below where the VICS kicks in has dropped, above that it has increased.

when i can get the confirmation i will order and pay for the cam gears so i can more that peak to the left. shall be interesting that's for sure!

 

[Installshield 2]

Wow your low end really suffered in the second dyno. I would like to see how the cam gears go . This is a perfect example of when they should be used...since u will be able to dial back into the low end. Most people have used them to increase their duration which ultimately did very little...here u can adjust the duration lower to reduce overlap and increase low end. i think....
later

It is so difficult to explain quickly, and the fact that I should be doing homework makes me need to keep this short...

Cam gears only change the behaviour of the cam's specs...but they do not change them altogether...With that said you still keep the same duration/lift/angles etc. as before, but you can adjust rotational periods such as overlap and when the lobes strike the tappets in relation to crank revs...You basically are able to make the valves open sooner or later in relation to the intake stroke (referring to the intake cam) and the same with the exhuast cam in relation to the exhuast stroke...that is how the powerband gets shifted...

A lot of car enthusiasts confuse cam gears with variable valve timing devices such as VVTL-i or V-TEC, which is false...A cam gear will not allow a larger cam lobe profile to be kicked in at a certain rpm (V-TEC) or progressively (VVTL-i, which is toyota's version)...The gears simply give the owner control of where the powerband is in relation to the entire rev band, by adjustments to overlap and scavenging time mostly as well as the latter stuff mentioned...

 

[Installshield 2]

good god, all that work and you ONLY got 111hp? something is wrong

I bet it has something to do with how your head was ported

and this is what I got without doing crazy s***:
http://www.clubprotege.com/forum/showthread.php?s=&threadid=2264

Ed you did notice how much more aggressive his cams where than the J-spec (which you used from what I remember) pieces?...I would tend to doubt that there is something abnormally wrong with any of the work done, and mostly that his engine can't rev high enough for those cam's specs to start singing...hence the need for the gears, or even better an ECU with a bump in rev limit...

But you could be right, I find it strange that his first dyno was in the 103whp range when he had everything you had except the intake manifold and exhuast cam...in which case you dyno'd at 110whp with 9.1:1 compression...and he made the 103whp with 9.7:1...I understand that that little of a compression increase wouldn't make much of a difference with similar fuel/spark management, but he didn't make much more than any of the North american FS's stock...

 

[twilightprotege]

edwin, what did you say on the other forum? i cant be bothered registering...

i wasnt happy with 111whp straight off. the first run got 103.5whp but that was right and i mean right at redline. on the 2nd run (the one on the graph, he got off just before redline. i dont think it's a problem with what i've done, it's a problem with the rest of the system and how they all work together. cam gears will help bring the power band down. probably will still peak at redline, but atleast before VICS kicks in it'll be better. also, a haltech ecu will help greatly.

and yep, mazda dealers are pricks (if anyone is wondering, this is in relation to a PM)

install and edwin, do you agree with me retarding both cams when i get cam gears? actually, i'll be retarding the exhaust cam and advancing the intake cam. the intake will need to open slightly earlier, and the exhaust will need to open slightly later. am i right in this?

 

[Installshield 2]

Hang on a minute...I will find the info...

 

[turboge]

I've got a haltech available if you are interested.

 

[twilightprotege]

nah, i live in haltech country (australia), thanks anyway

 

[Installshield 2]

I can't find the info on the pclub posted by Jesse along time ago...So this is all "from what I can remember"...

With a low rod ratio "all motor" engine such as the FS, you want to dial in as little overlap as you can...Not completely illiminate it becuase you can still get decent scaveging effects in higher revs...But little amounts of overlap can in turn create large amounts of compression lost becuase of the dastardly low levels of "dwell" time...So with the FS overlap times in degrees are very touchy...too big will quickly hurt power, and too little will also hurt power albeit not as much...

With your duration I would first try messing with retarding the intake cam only...I can't remember your ramp angles, so if the lobes are steep enough it won't take much "retarding" to close off overlap signifcantly, so I would bet advancing the exhuast cam would lessen the overlap even more...So this is beyond me, if you could post your cam specs again that would help...also what amounts of overlap do you have currently?

Theoretically you could retard both the intake and exhuast cams to keep the overlap at what it is now, and I am guessing lower the power band...although I need that tech article to freshen up on this subject...

 

[twilightprotege]

my cam specs (both intake and exhaust) :
gross lift 0.3512"
cam durations @
.010 - 272.5deg
.020 - 250.2deg
.050 - 225.9deg
.100 - 199.4deg
.200 - 147.4deg
.300 - 82.7deg

my current overlap, not 100% sure, but i think i remember the cam guy saying 8-10 degrees or something. so quite high

 

[Installshield 2]

my cam specs (both intake and exhaust) :
gross lift 0.3512"
cam durations @
.010 - 272.5deg
.020 - 250.2deg
.050 - 225.9deg
.100 - 199.4deg
.200 - 147.4deg
.300 - 82.7deg

my current overlap, not 100% sure, but i think i remember the cam guy saying 8-10 degrees or something. so quite high

Woah, yeah very high for an FS I would imagine...That in itself could be most of the problem...With that much overlap you probably have pretty inconsistent exhuast pulse flow rates (the intake stroke begins while the exhuast valves are still significantly open)...Get the gears and pull back both while pulling the exhuast cam back 3-4 degrees more than the intake cam...From there you could make more accurate adjustments...

 

[twilightprotege]

yeah it's going to be play play play to find a suitable setting. just need a day dyno tuning

 

[akhilleus]

I think u will tune that engine really well. Where u could see impressive gains. good luck

 

[twilightprotege]

thanks man. might give you some ideas hey???

 

[Mike R]

Why not have the VICS open earlier or just have them open the whole time? It's just vacuum operated anyway, right? I don't know if it'd help, but you could try it......it's not my money for the dyno

 

[twilightprotege]

well my vics opens at around 5500rpm. i think you yanks cars open earlier. correct me if i'm wrong...

but i've continually thought about having it open earlier, but am not sure how to go about it. edwin maybe you can help. maybe bigger tubing or something???

i was under the impression it used vacuum pressure to work, but is electronically control. anyone, is this right?

ideally i'd like vics to open at about 4500rpm. that way at all changes of gear, the VICS is active. it's a little bit of a pain that it opens, i change gears, it closes then opens again. that dip in power when it does kick in really sucks.

 

[Mike R]

Hmm, ours kicks in at 4500. I think it's a vacuum motor, but is electronically controlled.

OK, went and looked at the shop manual. There are two ways to try it out on the dyno, apply 12 volts to the solenoid or apply vacuum to the vacuum actuator. The only ways I could think of to get it to kick in at 4500 would be to get a US ECU or get an RPM activated switch that is connected seperate from the ECU. If you go stand alone its really easy...

 

[twilightprotege]

yeah i thought that's how it worked...no matter how much vacuum you have, it'll only open when the ecu allows it to do so.

if there are any auto electricians out there, would there be a way to have it open earlier with putting in some sorta relay etc?

 

[Mike R]

Yeah, and RPM acticated switch, there are lots of those out there. They are usually used for nitrous, shift lites, etc...



MSD SWITCH

 

[MPNick]

Yeah, and RPM acticated switch, there are lots of those out there. They are usually used for nitrous, shift lites, etc...



MSD SWITCH

I think he said that he lives near Haltech. If you are going with that system you should just wait untill you get that system. I think if you add timing along with sooner VICs you may find better power at the mid range.


Thanks again


Later..........Nick

 

[twilightprotege]

arh...i c! might have to think about that.

will try a dyno run with the VICS active (running normal) and the vics in the closed (high rpm) mode to see how they go and then i'll be able to decide what's the best option