Performance Mods

[Michael]

Hey I am considering getting my flywheel lightened and pulling off the head and getting it decked to raise the compression as well as some porting mods. Those that have ported heads, did you also port the manifolds? Is there much room for improvement in the porting?  Has anyone done any of these things? Have any problems/ advice? Was it effective?

Michael.

[Turbo3]

Yo hi there,

Porting is good, but may not be the answer for the City power plant. The computer doesn't allow enough tweaking if you start changing compression ratio etc. If you're going to do that, you'll probably need to update the ECU. If you do that, you can introduce ignition timing as well. If you do that, you may as well update the whole intake system. If you do that...hang on to wallet!!! :-/ ;D
That's the bit where I went wrong!!
Don't know if it actually work yet.
Need more money to finish it.....

Pete

[QikLude]

yeah how would you run a link or something on it?

Intake a bit messed up for normal computers or is it simple enough?

has anyone tried rasing compression?
Im about to try this myself unless someones tried and had a bad time?!

Jw

[Charles]

There is no probs porting. Works a treat specially round the short side radius and blending valve seats into port. Do not make the ports any bigger though as you lose too much charge velocity.

You can relieve the area near the valve seats to reduce shrouding.

Also cut the shafts out of the throttle body (the side that the screws do not go into) and grind down the other sides to improve airflow. Blend some sort of radius into the phenolic spacer where it opens into the intake manifold. If you have a T1 fit T2 pistons, mill block and head to raise compression.

Running higher compression with other associated mods will make the engine sparkle. Much better off boost (and on) run the same factory boost and reduce stress on components (turbo), comes on boost quicker too. Don't have to use boost cut lifter. Would recommend an adjustable cam pulley if you mill a fair bit off the head and block.

Factory ECU copes fine. Get an adjust able fuel pressure regulator and tune on a DYNO at what to set mixtures at around 11:1 to 12:1 at full boost.  Leave O2 sensor connected as it does not influence what.

[blitz_power]

Hi charles. I am thinking of installing Unichip. what do you think? Since the B20A injectors cannot bolt in. is that a hard job to custom it?

Thanks..

[Michael]

I dont want to pull out the block, how much can your raise the compression by only shaving the head? does this cause any problems as for the cam timing? Also, is that a rising rate fuel pressure regulator or just an ajustable one?

Michael.

[Charles]

If you take the head down to the machining limit (those bumps cast into the bottom of the head) should bump your compression up to about 8.2-8.7:1 only way to tell is check it out. From memory the combustion chamber volume is about 37cc so it would be easy enough to work it out.

Adjustable fuel pressure reg not a rising rate. Rising rate will make it run too rich up top and youwill lose power.

Don't fit a unichip, half your money is wasted because it controls timing and city does not have PGM timing only fuel. Get an Apexi AFC an anyone can tune it and it has some pretty funky features and a nice blue screen. It is also cheaper and can giive you a whole bunch of info.

[blitz_power]

Hi charles. I been trying up and down in perth. Most people ask me for a wiring diagram for the SAFC. ITs pretty hard to look for the wiring diagram.

[Charles]

Oh yeah. Another thing about the SAFC or any fueling product, you may find it only works either on boost or off boost. Will take a bit of playing with as you almost need one for each map sensor. Will chase it up a bit more for you though.

[QikLude]

What about milling the factory flywheel down some?

Any one done this on a T1 gearbox flywheel?

Jw

[Turbo3]

Have machined mine. Had to so the kevlar clutch plate would fit!! I'm not sure how much lighter it is now, but it's not too drastic.

Pete

[QikLude]

[quote author=Turbo3 link=board=GEN;num=1055666270;start=0#10 date=06/23/03 at 07:57:58]Have machined mine. Had to so the kevlar clutch plate would fit!! I'm not sure how much lighter it is now, but it's not too drastic.

Pete [/quote]

your is a t2 tho, so different gearbox

My prelude flywheel I butchered bigtime, but im not so sure about the city one.

Cheers

[Charles]

You can tak a big whack off it. The entire ring of weight around the edge under the ring gear can be removed. Make sure you leave enough to absord heat generated by the clutch. Let you machinist be your guide, try to avoid leving any sharp edges which can act as stress risers.

Cheers,

Charles

[blitz_power]

Thanks charles. Hope you are able to help me out.

;)

[QikLude]

Cheers charles.

My flywheel will soon come under the butchers knife

I managed to take my heavy as prelude flywheel down to around 5.8kgs which worked really well for a turbo 2ltr.

So im hoping the city will react the same way.

Cheers

Jw