Cam Angel Sensor C.a.s

[rich flavour]

hello all,

how much power can u gain by advancing C.A.S from center position??

reason i ask is because i had my c.a.s advanced now i have put it more back to the center position because im working on fuel consuption thourght it might help but i have seemed to have lost power so if anyone knows how much power your playing with by adjusting c.a.s would be a great help...

Edited April 8, 2008 by rich flavour

[**RB2530**]

hello all,

how much power can u gain by advancing C.A.S from center position??

reason i ask is because i had my c.a.s advanced now i have put it more back to the center position because im working on fuel consuption thourght it might help but i have seemed to have lost power so if anyone knows how much power your playing with by adjusting c.a.s would be a great help...

Your question cannot be answered in a direct sense..ie how much power am I playing with...There is an optimal ignition advance and it is based on so many things...some of theses things are fuel RON, compression ratio, afr, inlet charge temp and combustion chamber design...

If you retard ignition timing you do not yield as much energy from the fuel...if you advance the timing too much you yield all of the energy from the fuel but because the peak occurs prior to TDC and some or most of that energy is wasted in trying to force the piston down too early. If you do this you are trying to rotate the engine backwards...In reality this doesn't happen due to inertia of the engine but you still do mechanical damage in the process..

Bottom line is if you are running a stock setup, run stock base timing...It is an optimised compromise of power, economy and safety...

[Guilt-Toy]

the mechanical damage he is talking about is detonation

[rich flavour]

standed timming spot didnt seem to pull any where near as hard as when it was advanced i cant go back as it seems slow

also can some explain what happens when the enhine detonates?

Edited April 9, 2008 by rich flavour

[**RB2530**]

standed timming spot didnt seem to pull any where near as hard as when it was advanced i cant go back as it seems slow

also can some explain what happens when the enhine detonates?

As I said ignition advance is a compromise...If you want to trade off safety run more of it and get more power...but you are closer to detonation or pinging as some say...With stock ECU detonation is your enemy as well because if the knock sensors pick up detonation it goes into rich and retard mode...so you dont win...

At low power levels detonation will f**k the engine over time...It damaged piston crowns and combustion chamber surfaces...it also roots your spark plugs...other not so visible signs are shortening life of gudgeons pins and conrods etc etc

At high power levels detonation can f**k up your engine in an instant!!! Bang... broken piston, gudgeon pin, conrod and holes in the block as well as bent valves...

[R338OY]

There is an optimal ignition advance and it is based on so many things...some of theses things are fuel RON, compression ratio, afr, inlet charge temp and combustion chamber design...

had my CAS adjusted (on dyno) with ghey fuel (98 vortex, but drove like 95). I hope that doesn't hurt the engine. i've been using awesome Ultimate recently (last couple of months fuel has been scarce and crap quality) and i'm wondering if it'll affect the current ignition advance setup...

sorry to hijack

Edited April 9, 2008 by R338OY

[rich flavour]

well the cas on my car has been advanced since i have had it, dont think i have ever had detonation before.

rich and retard mode how will the car run during this mode???

[R338OY]

well the cas on my car has been advanced since i have had it, dont think i have ever had detonation before.

rich and retard mode how will the car run during this mode???

Reminds me of the rev limiter

Sometimes it just feels flat too

Edited April 9, 2008 by R338OY

[rich flavour]

so the car wont go anywhere like wont drive normaly exceleration lost?

is it safe to keep it how it was in the advanced spot if im having no problems?

Edited April 9, 2008 by rich flavour

[dangerman4]

asuming your running a standard ecu,

get a timing light and set your timing at idle to 15degrees BTDC

then leave the thing alone.

you will only cause yourself issues by playing with it.

different parts of the ignition map need different amounts of timing, so playing with the cas is a bad idea.

if you wind it up to 20 degrees base timing you might think wow this pulls well at lower revs, and seems to go much better.

but your whole timing map has been changed 5 degrees.

when your on full boost as little as 1 degree can cause it to ping in certain spots of the map. and unless you have a aftermarket ecu showing you that its pinging you may never here it.

[sl33py]

WTF does advancing a CAS mean??? I thought it either worked or didnt. Is it the equivalent of electrically fooling the engine into advancing the timing, but seems like the mod would be permanent. Is it literally just changing the angle the CAS is attached to the engine? Sounds like a pretty dodgy mod hahah

[R338OY]

Sounds like a pretty dodgy mod hahah

On a dyno it's a reliable way to see how a modified engine reacts to timing advance. Obviously a stock car needs stock timing. But with some mods and esp. ECU mods, advance = powah.

Doing a guess job in the backyard after a few beers. That's dodgy.

[R338OY]

WTF does advancing a CAS mean???

Ingition Advance 101:

http://en.wikipedia.org/wiki/Ignition_timi...ignition_timing

[rich flavour]

On a dyno it's a reliable way to see how a modified engine reacts to timing advance. Obviously a stock car needs stock timing. But with some mods and esp. ECU mods, advance = powah.

Doing a guess job in the backyard after a few beers. That's dodgy.

there was no guess job i bought the car like this i went back to a more center position because im trying to get more fuel out of a tank but i lost power so this is why i ask....

[R338OY]

there was no guess job i bought the car like this i went back to a more center position because im trying to get more fuel out of a tank but i lost power so this is why i ask....

Putting it back is what caused the power loss. You should see more mileage, as a tradeoff for less power. My car was sluggish until i advanced my timing. Now i use more fuel

[**RB2530**]

so the car wont go anywhere like wont drive normaly exceleration lost?

is it safe to keep it how it was in the advanced spot if im having no problems?

Rich and retard is from what I have experienced, only subtle. The car just feels flat...

The CAS position for stock base timing (15btdc) varies from engine to engine...That is why it is adjustable...For stock engine with new cam belt and no adjustable cam pulley etc 15 deg btdc would be close to the middle of the adjustment slot..

You need to become familiar with what pinging sounds like...If you know what it sounds like you can advance until pinging occurs and then retard it 2-3 deg to be safe...If you dont know what pinging sounds like (it harder to hear with loud exhaust) get it set by a workshop...You can do it yourself with timing light...there are many threads on how to do this...

[sl33py]

OK, so its literally the angle it attaches to the engine. Thanks Rb2530, that's what I was after.

Edited April 9, 2008 by sl33py

[dangerman4]

there was no guess job i bought the car like this i went back to a more center position because im trying to get more fuel out of a tank but i lost power so this is why i ask....

if you didnt use a timing light then you guessed.

as i said get a light, set it at 15 btdc and leave it alone.

if your worried about economy get it checked on a dyno,

if you cant afford the fuel bill then sell your car and get a prius

but dont just start turning the cas at random to try and increase anything.

pinging = broken ringlands = rebuild

[sl33py]

^^^^^ This is what I was thinking Seems like a hit n miss method if u can't afford cams or shafts.

[rich flavour]

i found this at the top of forced induction profromace in sticky (quick ref guide)......

OBJECTIVE : Do mid 13's(possibly lower) all day with the standard ecu, intercooler and turbo retained on your R33 gtst.

I used:

A 1995 manual R33 gtst with 93k on the clock.

With the following Modifications:

* K&N panel filter inside stock airbox

* 3inch FGK cat-back exhaust (very quiet and probably more restrictive than some exhausts)

* 3 inch stainless dump pipe off the turbo 'wrapped' with DEI thermal tape to the cat. This dump does not have a sepparate wastegate screamer or feed pipe.

* Diff Cradle kit or 'pineapples' , the Whiteline kit No. KCA349.

* Ogura Lightwieght flywheel 4.8kgs.

* Ceramic puck sprung clutch and stock pressure plate

* Wrapped turbo to intercooler pipe (DEI thermal tape).

* Removed panel behind stock intercooler.

* Timing set around 20+degrees advance.

* disable the carbon canister fume feeds to the intake.

* Turbo smart bleed valve (cheap one) set to 10psi boost

* Simex 205/50 16 inch rear tyres. let them down to 19psi.

* NGK coppers ...6ES gapped to 0.7mm.

no one has said it was a bad thing to advance timing 20+ degrees, has he done the same thing that someone did to my car??

Edited April 9, 2008 by rich flavour