i have a 00 si with the following mods...
ctr cams, skunk2 cam gears, AEM fpr, and DC 4-1 header, and AEM intake.
how do u adjust the cam gears?
i've heard that u advance the intake and leave the exhaust cam but if someone can tell me how to do it, it'd be really nice.
thnx people.

 

you're best be would be taking the car to a dyno, and getting them dialed in...cuz if you just jack around w/ them on the street..you could be losing power...i say dyno is the best bet...HTH

 

yeah i know i should take it to a dyno but im asking on how to ajust it.
do you just unscrew the nuts and turn it?
also which way is advancing? turning it towards u (if you're in front of the car) or the other way?
thnx for the help guys. im gonna try to take it to a dyno next week sometime.
wish me luck.

 

the big bolt in the middle is where it attachs to the cam. It is the other little ones around the outside you loosen to adjust the cam timming. I'm not gonna tell you which way to turn them because what everyone else said is correct, you need to use a dyno. If you dont even know how to adjust them, you are certainly not going to know how to tune with them on the street.

 

qbsi,

Here are a few things I have learned. Each time I tune my car to the seat
of my pants (hehe) my car makes power on the dyno. I know my engine
VERY well. I have been learning how to tune my cams over the last 2 months
and have put alot of seat time into my GSR.

CTR Cam Tuning BASICS I have learned:

Tip#1: Crankshaft turns 360deg, once for the intake stroke, once for the
exhaust stroke per 180deg turn of the cams.
Tip #2: skunk2 gears have a +5/-5 setup, this encompasses 2 full teeth
on the gear. there are 35 teeth on the gear, 35/360= 10.28 degrees
per tooth. this yeilds 2 crank degrees per mark on the gear.
Tip#3: 28 degrees of overlap at 0,0 works best with good breathing.
if you have all stock stuff or near stock I,H,E and manifolding, you may
find good results decreasing the overlap period as much as 5 degrees.
Tip#4: If you run more than +8, -4 on crank/valve timing changes
(+4,-2 on gear) exhaust at high lift without upragded retainers and valvesprings/lighter valves BEWARE.
Tip#5: The exhaust valves are the weakness of the B Series Engine
I have destroyed two full sets this year in my trial and error misshifting
my car by accident. I have done it twice on my current setup and it
doesnt miss a beat...(getting better at the 3-4 shift at 8K)
Tip#6: I have found that setting the valve opening timing to the spark
makes the most power on the CTR intake cam.
Tip#7: cut the damn valvecover
Tip#8: do not over tension your T Belt, keep it snug with 1/2" of defection at
TDC, keep your eye on it as you make your adjustments.
Tip#9: Too much overlap can cause the valves to slam into one another and
bend em, be careful to not run more than 7-8 degrees of seperation on your
crank valve settings. This comes from Larry Widmer from Endyn.

Here are some basics you can do for some understanding on how the engine
works together as a system. Set the cams to 0,0 at TDC with the cams INDEXED and the white mark on the timing hash. Index the cams, set to TDC on #1, loosen the fasteners and spin the cam with a 14mm open ended hand wrench while
careful not to move the gear AT ALL!!! This can funk the tension on the
belt and make the car run off peak.

Exercise #1:

Set the engine to 0,0 cams
Let the engine warm up, bridge service connector
Set the ignition timing to 16 degrees BTDC
cut motor off.
set the intake cam gear to +1 on gear (+2 BTDC timing on crank pulley)
lock down the fasteners, revarify the gear setting
start the motor
CHECK the ignition timing< DO NOT MAKE A CHANGE ON DISTRIBUTOR

in a perfect world, the timing should reflect 18BTDC. The Cam at 0 opens the
intake valves at 18BTDC. +2 would reflect a 20BTDC valve opening, increasing
your overlap period to 30degrees and yeild a small bump in compression.
this I tell you to do next:

retension your throttle cable to make it taught
run the car from 2-4K rpm in first
run the car from 3-6k in first
then make a full pass, note the second gear pull WOT and in third
stop car and let idle,
bridge service connector again (very important... housed in a green
spongy socket.. a blue connector with 2 wires under the glove
box on GSR and ITR (you will see the CEL come on)
reset the Ignition timing to 19/20BTDC look at the distance on the
pulley from 16 to 18 and make the same distance after the 18 hash mark.
unbridge the connector (cel will come off)

repeat the in car test.

you should feel a bump in TQ throughout the revband. If the engine feels
like it pulls hard but with no decernable bumps in power, it means you have
made no holes in your powerband. If your car pulls hard then pulls hard
again, you have either made or lost power before your second strong point.

this baseline run at (+1 on gear) +2 on crank, 20BTDC timing will let you feel a difference in power. if you would like, move the intake gear in .5 degree bumps
advancing the spark one degree on crank accordingly for every .5 advance on the gear. This will help you find peak power on the cam timing advance. I dont recommend more than +2.5 on the gear itself.

Make note as you add advance, to "feel" the VTEC crossover point at 4500RPM.
You need to be in a tall gear like 3rd and pull from 3-5K. If you cannot "feel" a dip in the power at 4500 then you have not made a hole and more than likely have made power.

I have found that advancing my Exhaust cam to (on crank) +4 and my intake cam to +2 has the best results for me on all stock manifolding. This is a Intake valve opening of 20Before TDC and an exhaust closing at 6deg After TDC. This makes an overlap period of 26 degrees, my timing set at 19/20 BTDC. The car pulls wonderfully at all places in the band now. I need to dyno again.

I have made over 12 runs manipulating my gears on the dyno and I can tell you that I wish I knew about the 2 deg per mark thing. I made a nasty hole iN VTEC when I went to +4, -2 on the actual gear which I had no idea made +8, -4 on the crank... very bad.

it went from like 122 tq at 4300 and 98 at 4500, 122 at 5K...

my best dyno pull was at +3, -1.5 on gear at 21 timing I made 121 whp/tq at 5250 and 159.8whp and 123tq on the dyno. since then my car is much faster spinning third on an upshift regularly... at +.75 intake and +2 exhaust on the gear, 20BTDC timing.

Consider the shape of the combustion by how long the overlap period is and how it is biased more toward the intake or exhaust, and consider the way your engine
breathes. If it feels really linear at 0,0 meaning it doesnt pull any diff across the entire band, then I would try and bias the intake cam over exhaust. If your engine comes on late er-go 5700 through 7400 and dies, then you should bias the exhaust cam and let the engine excavate at a slower rate. If the engine pushes out the mixture with slow manifolding less overlap will help ya. If you increase the overlap, be sure and do it slowly and have I,H,E and make note of your gains.

I hope this is helpful

I know its alot to say without showing ya, but trust me my car has been
slow and fast in the last few months... now its quick enough to suprise
some people...

Good Luck with the tuning...

Mike




[Modified by MikeSarr_GSR, 11:14 AM 6/16/2002]

 

thnx for the great info man. this helps me a lot as far as learning to tune cams.
its so detailed and thorough
im gonna make a copy of this and hold on to it to help my friends also.
thnx again man.

 

Kewl man, all in 80 days work... ugh let me know how you do,
if you have any questions, feel free to email me directly or
IM me at mikesarr21@aol.com

peece!

 

ok which one is the intake cam? let say you're standing on the side of the car. is it the one on the left or the right side?
also where do buy a timing gun??
thnx guys.

 

great info...just started tuning mine...tonnes of problems!

the intake gear is the one closest to the rear of the motor.
you should be able get a timing gun from any place that carries a good selection of automotive tools.

 

ok so the intake gear is the one to the right side (towards the throttle body) ?

 

the intake cam is closest to the intake mani , yes if your facing the gears its on your right

 

oh man. yea I think it is the one closest to the INTAKE MANIFOLD!!!

haha... just bustin *****. I have to correct myself on the theory
I took to ignition timing... if you feel a gain, its good and I did, but:

read this and proceed:

http://www.hondalife.com/articles/ig...timingtech.htm




[Modified by MikeSarr_GSR, 7:41 AM 7/3/2002]