Cam Gear Adjustment Question?

[frozenwaffles]

hey guys, just quickly, when we speak of '4 deg retard' or 3 or whatever, are we talking 4 deg of cam gear adjustments notches or 4 deg of crackshatf movement? as from what i gather 1deg of cam gear movement is the equivelent of 2deg of crackshaft movement...

[Guilt-Toy]

i allways thought that you keep the gear lined up to the dot and move the cam anti clock wise 4deg....

[blind_elk]

I believe anything to do with camshaft timing is "crankshaft degs"

[frozenwaffles]

engine tuning is a science not a religion.... are you 100% sure?

[Duncan]

we are talking about o of cam movement. so 4o retarted would be 2 marks on the cam gear if it is 1 mark = 2o.

sorry I just reread the question and can't confirm whether it is crank or cam o. But for sure the measurements you hear mentioned on here are relative to the marks on the cam gear.

[frozenwaffles]

alright so just to clarify...if someone said that 4deg retard of the exh cam gera is the 'magic' number for an rb25...is that 4 marks of a cam gear or 2?

[Guilt-Toy]

depends on the cam gear.

my car gear has it written on it.

[SATO GTS]

would have to have a look at cam gears to remember

Edited May 13, 2008 by SATO GTS

[rev210]

getting individual degrees onto the cam gear would be pretty hard to do, let alone look at them properly without some magnificication.

4 degrees is generally accepted as benificial, however there are underlying assumptions about the setup. There is no substitute for testing to get it right for your car. I have done a few cars and there can be a little variation on that figure either way that has actually quite a bit of impact.

[frozenwaffles]

here is a pic of my gear....now i know that each mark = 2deg of crack as it states on the gear

what im asking is when somesays i 'retarded the cam gear by 4deg' are they talking about crack 4 deg or gear 4 deg (= crack 8 deg)???

[GeeTR]

here is a pic of my gear....now i know that each mark = 2deg of crack as it states on the gear

what im asking is when somesays i 'retarded the cam gear by 4deg' are they talking about crack 4 deg or gear 4 deg (= crack 8 deg)???

I couldnt help myself

Edit, I took it to mean, 4deg at the crank. So two marks on the cam gear.

Edited May 13, 2008 by GeeTR

[Duncan]

yeah sorry iw as too lazy to check, the car is under a cover. but the trust ones are the same I am 99% sure. 1 mark = 2o crank. So people are talking crank degrees.

BTW when setting my gears the other day we tried 8o on the intake and lost 40kw just like that. very small adjustment makes a very big difference

[rev210]

the marks are 2 degrees each. so for 4 total degrees thats 2 marks.

[frozenwaffles]

can everyone please read the question again in the first post...

we already know that 1 deg of cam timing is equal to 2 deg of crankshaft timing....it says it on the cam gear!

[depalma-bcnr33]

yes it is

[GeeTR]

can everyone please read the question again in the first post...

Its always in regards to crank not cam degree's as far as I know.

[Guilt-Toy]

hang on a minute.

Need to get to the bottom of this.

maybe someone can explain...

how do you get 4deg retard on the exaust gear?

nice lookin gear too btw

[Sydneykid]

how do you get 4deg retard on the exaust gear?

To retard the exhauits cmashaft 4 (crankshaft) degrees, you rotate the camshaft 2 slots anticlockwise, because the engine turns clockwise.

The camshaft is connected to the centre of the pulley, the cambelt is conected to the outside of the pulley.

You keep the outside of the pulley (the cambelt) still while you rotate the inside of the pulley (camshaft) anticlockwise.

Simple isn't it?

Cheers

Gary

[666DAN]

So we're saying 4 degrees retarded is way to go...."4's the key!!!"

Oh the humanity, I'll have to put it on the dyno and see, others are telling me 2 degrees advance on the Neo's :S

[666DAN]

OK I've tried the following on the exhuast cam, base timing was adjusted to 20 degrees each time (auto)

4 degrees retarded (car seemed less responsive, could dial in a fair bit of base timing though, didn't seem to drastically improve matters) Had to drop EBC gain to 20% to not go over 0.85Bar

2 degrees retarded (much the same as before, more response) Had to drop EBC gain to 30% to not go over 0.85Bar

2 degrees advanced (seems to have picked up a bit of power) Had to raise EBC gain to 40% to get 0.85Bar

Now this is the same setting as another SAU'er told me he was using and picked up about 10rwkw on the dyno.

My next thing to try is adjusting on the dyno when it's getting tuned and see the real results.