turbo.... Any advice appreciated

tyreburner · Post by **tyreburner** » Tue Apr 17, 2007 7:34 pm

aaaggghhhh too technical for me ..... i think i get it , are fcd's universal???? ( as celica ones are 10.00 on flea bay

) and where would i plumb one???i.e are they difficult to fit??, also can someone please tell me where to run the piping for my boost gauge please

many thanks
Mick

acqu135c3 · Post by **acqu135c3** » Tue Apr 17, 2007 11:40 pm

I beleive the fuel cut deffender for a celica is an electronic device whereby it sits between the map sensor and the ECU and modifies the electrical signal whereas i beleive the type you need for the 406 turbo engine is a pneumatic fuel cut deffender which sits between the inlet manifold and the map sensor and changes the pressure of the air getting to the map sensor. Though please correct me if i'm wrong.

acqu135c3 · Post by **acqu135c3** » Tue Apr 17, 2007 11:45 pm

One thing I have wondered with using a fuel cut deffender is given it basically fools the ecu into thinking you're running less boost than you actually are then how does that affect the fueling map? Would it not run significantly lean?

niz406 · Post by **niz406** » Wed Apr 18, 2007 9:18 am

The FCD onlt affects the higher tier of your boost threshold... normal boost and off boost conditions remain the same, you set the boost to 2 psi over the desired amount as the FCD I use has a 2psi differential where it will operate between this given pressure. if I set it to 16 psi then @ 14 the FCD will begin to operate ( 14 is the limit of the stock ECU ) although saying that I believe that the TurboSmart FCD will begin its work at 13 psi anyway, but has a range upto 30psi.

So any point after that the excess pressure will de diverted to the FCD cylinder. I believe this is what happens anyway but I will look it up later in my TS FCD hand book and get back to you.

Malachy · Post by **Malachy** » Thu Apr 19, 2007 9:53 am

niz406 wrote:
Welton wrote:But how does the ECU know what gear you're in
This is why cars have two speed sensors...

??????????
they have a single vss on the gearbox this feeds into the ecu its a 3 pin setup 1 pin is a 12v supply 1 ground 1 signal, the only other vss's are the abs ones these have nothing to do with the running of the engine

never seen a pug with 2 vss's that go into the ecu.

but basically the ecu just has an input from the vss thus being able to tell what gear your in

niz406 · Post by **niz406** » Thu Apr 19, 2007 10:32 am

OK wasn't specifically talking about the VSS...

Engines have crank / camshaft sensors which assist timing, through reading rotation and speed.. these all attribute to engine speed... and then the VSS does the road speed

Malachy · Post by **Malachy** » Thu Apr 19, 2007 10:41 am

niz406 wrote:OK wasn't specifically talking about the VSS...

Engines have crank / camshaft sensors which assist timing, through reading rotation and speed.. these all attribute to engine speed... and then the VSS does the road speed

ok but the turbo does not have a cam sensor though

you only need a cam sensor if running sequential injection or coil on plug ignition.

niz406 · Post by **niz406** » Thu Apr 19, 2007 10:48 am

Thought the cam sensor was built into the coil pack module, through some sort of trickery?

lol

Malachy · Post by **Malachy** » Thu Apr 19, 2007 10:58 am

nah the coil back is very simple :/ the only xu10 to have a cam sensor is the gti6 you can see the teeth for it on the inlet cam (which answers james post i replied too )

coil pack is just basically 2 coils, in a plastic case. that simple

the crank sensor just works out the engine timing as its a wheel with 60 teeth around it with 2 removed 120degrees BTDC crank sensor just works timing out from that however it cant work out what stroke you on (compression or exhaust) due to crank spinning 2x for each cycle. this is why the setup is wasted spark.

niz406 · Post by **niz406** » Thu Apr 19, 2007 11:36 am

Ahhhh wasted spark.... so is there wasted spark occuring then, that could result in misfire?

Explain more... this is interesting!

Malachy · Post by **Malachy** » Thu Apr 19, 2007 12:01 pm

ok you car has 2 coils built into the coil pack

the xu series of engine firing order is 1342 with cyl 1 being the gearbox end.

coil a fires spark plug 1 and spark plug 4 at the same time
coil b fires spark plug 2 and spark plug 3 at the same time

ok now lets see how an 4 stroke engine works.

Its based on the OTTO cycle this means there are four cycles (well technically there are six but we wont go into that)over 720 degrees or crank movement (or 360 of cam)

Induction stroke 0 degrees to 180 degrees crank, 0 degrees to 90 degrees cam
compression stroke 180degrees to 360 degrees crank, 90 - 180 degrees cam
power stroke 360 degrees to 540 degrees crank (so same piston position as induction), 180 - 270 degree cam
exhaust stroke 540 degrees to 720 degrees crank (same piston position as compression), 270 - 360 crank

Induction stroke is when the cylinder is at top dead centre the piston moves down and the inlet valves open allowing the engine to suck in air and fuel.

Compression stroke is when the fuel and air are compressed by the piston moving to the top of the cylinder while all the valves are closed, the spark is fired during this cycle to ignite the fuel.

Power stroke -once the fuel is ignited the power is generated and the piston is forced back down the cylinder creating the power that turns the crank, the exhaust valves will start to open while the piston is traveling down.there is no fuel in the cylinder now as it was burnt in the previous stroke

Exhaust stroke the exhaust valves are now fully open and as the piston travels back up they close, while the piston is traveling up it is puching the exhaust gasses out of the engine and into the exhaust pipe.

wasted spark works by one of the cylinders being on the compression/ignition stroke and the other cylinder being 180degrees (cam timing) from that and on the exhaust stroke this means there is no fuel to ignite and the "extra" spark is "wasted" this allows you to run all spark control from the crank.

wasted spark works very well in most applications, however if you have a high revving engine 12k+ rpm there can start to be problems with the spark overlapping the strokes at high rpm causing missfires/detination and uncontrollable ignition timing. this problem gets bigger the more cylinders you have due to more spark events per engine rotation.

wes1001 · Post by **wes1001** » Thu Apr 19, 2007 12:07 pm

Malachy wrote:ok you car has 2 coils built into the coil pack

the xu series of engine firing order is 1342 with cyl 1 being the gearbox end.

coil a fires spark plug 1 and spark plug 4 at the same time
coil b fires spark plug 2 and spark plug 3 at the same time

ok now lets see how an 4 stroke engine works.

Its based on the OTTO cycle this means there are four cycles (well technically there are six but we wont go into that)over 720 degrees or crank movement (or 360 of cam)

Induction stroke 0 degrees to 180 degrees crank, 0 degrees to 90 degrees cam
compression stroke 180degrees to 360 degrees crank, 90 - 180 degrees cam
power stroke 360 degrees to 540 degrees crank (so same piston position as induction), 180 - 270 degree cam
exhaust stroke 540 degrees to 720 degrees crank (same piston position as compression), 270 - 360 crank

Induction stroke is when the cylinder is at top dead centre the piston moves down and the inlet valves open allowing the engine to suck in air and fuel.

Compression stroke is when the fuel and air are compressed and the spark is fired during this cycle to ignite the fuel.all valves are closed during this cycle.

Power stroke -once the fuel is ignited the power is generated and the piston is forced back down creating the power stroke the exhaust valves will start to open while the piston is traveling down.there is no fuel in the cylinder now as it was burnt in the previous stroke

Exhaust stroke the exhaust valves are now fully open and as the piston travels back up they close, while the piston is traveling up it is puching the exhaust gasses out of the engine and into the exhaust pipe.

wasted spark works by one of the cylinders being on the compression/ignition stroke and the other cylinder being 180degrees (cam timing) from that and on the exhaust stroke this means there is no fuel to ignite and the "extra" spark is "wasted" this allows you to run all spark control from the crank.

wasted spark works very well in most applications, however if you have a high revving engine 12k+ rpm there can start to be problems with the spark overlapping the strokes at high rpm this problem gets bigger the more cylinders you have

I said GODDAMN !!!!!!

niz406 · Post by **niz406** » Thu Apr 19, 2007 1:15 pm

Malachy wrote:ok you car has 2 coils built into the coil pack

the xu series of engine firing order is 1342 with cyl 1 being the gearbox end.

coil a fires spark plug 1 and spark plug 4 at the same time
coil b fires spark plug 2 and spark plug 3 at the same time

ok now lets see how an 4 stroke engine works.

Its based on the OTTO cycle this means there are four cycles (well technically there are six but we wont go into that)over 720 degrees or crank movement (or 360 of cam)

Induction stroke 0 degrees to 180 degrees crank, 0 degrees to 90 degrees cam
compression stroke 180degrees to 360 degrees crank, 90 - 180 degrees cam
power stroke 360 degrees to 540 degrees crank (so same piston position as induction), 180 - 270 degree cam
exhaust stroke 540 degrees to 720 degrees crank (same piston position as compression), 270 - 360 crank

--------------------- snip ---------------------

wasted spark works by one of the cylinders being on the compression/ignition stroke and the other cylinder being 180degrees (cam timing) from that and on the exhaust stroke this means there is no fuel to ignite and the "extra" spark is "wasted" this allows you to run all spark control from the crank.

wasted spark works very well in most applications, however if you have a high revving engine 12k+ rpm there can start to be problems with the spark overlapping the strokes at high rpm causing missfires/detination and uncontrollable ignition timing. this problem gets bigger the more cylinders you have due to more spark events per engine rotation.

Knew that bit... but all the rest is good read... and now I know what it means by wasted spark...

yay for the return of malachy

tyreburner · Post by **tyreburner** » Fri Apr 20, 2007 6:33 am

how technical???
sorry to interrupt but can someone PPPLLLEEEAASE tell me where to plumb my loverly splitfire boost guage into please......... i can do the electrical but need know what pipe to tap into ( pic would be very nice)

Cheers
Mick

niz406 · Post by **niz406** » Fri Apr 20, 2007 8:54 am

Use the hose off the dump valve, just fit an inline restrictor to it so you don't pinch all the pressure for the guage...