I finally got done reading this: https://www.scionlife.com/forums/viewtopic.php?t=67782

Blindly doing head work is not worth the money.
Having a local place do the P&P sounds like a bad idea unless you are only doing the exhaust side or someone publishes a winning recipe for working the 1nzfe head.
Milling should be a better option and should be okay to do locally.

Hopefully, ZPI will be backing up their head work soon and show some proof.

The above thread convinced me that something needs to be done about the ECU or else none of this other work is going to be worth the cost. The gains will be small enough without the ECU learning how to make the new components conserve fuel.

Next up: ECU madness!

 

LOL Sorry prototype xB for removing my post as you were adding yours! I thought the Compression Ratio was 11.5:1 and posted that (I'm still in my Matrix XRS world, I guess), but also stated that I wasn't sure and was going to check on it.

As it turns out, it is in fact 10.5:1 and I deleted my post that stated it was 11.5:1 before (or so I thought) anyone saw it.

Sorry prototypexB and Proctorsilex for the confusion!

 

bump

 

heh.
i'll update with some more useful information when i have it.

i've been talking with charles at gordon race engineering about doing some head work. as i recall, they will probably leave the intake alone, work on the exhaust, and install 1mm oversized valves and seats. i'm gonna get a head to send out to them soon.
they're going to look at the head to determine whether the compression can be increased by milling alone or if i should get pistons made.
http://gordonraceengineering.com/

i just got an electrical diagram of the xa from toyota. it looks like putting in a megaquirt should not be much of a problem.

this will all take a while, so i won't have any significant information for at least a couple of months.

 

i am sorry to say that i have no good news for you, but i felt that i should say something.

i have not heard from charles since june. he still has my head. as far as i know, there has been no work done on it and i have little hope of ever actually getting it.
https://www.scionlife.com/forums/vie...121&highlight=

as for the megasquirt and other power mods, they are all too time consuming for my life right now. i thought about paying a shop to do some of it, but i want to save for a house.

i really wanted to do all of this stuff last spring, but i also started to learn how to drive my car around then. since that time, i have improved a lot and my desire to make my xa more powerful has dwindled.

when you find yourself having to lay off the pedal because you are about to pass a vette at 100+ mph in a nascar turn, things really come into perspective. the cars at the pocono raceway could go faster than my xa, but the drivers were too scared. i topped out at 110, but most people did not go past 125 even if they could.
what difference does the car make if the driver sucks?

i do not remember if i mentioned that i like my fidanza flywheel and clutchmasters stage 3 clutch. the clutch took 1000 miles of HELL to break in and 3000 miles total to get it nicely smooth. it is very nice now, slips when i want it to, and grabs very well. the flywheel is FAR from being too light. for performance shifting, i still have to hesitate before pushing into gear lest i grind most embarassingly.

anyway, the most satisfying modifications that you can make to the xa/xb are also the cheapest and easiest to install.

i am sorry that i do not have any great success stories or even a sob story of failed mods at the dyno.
unfortunately, i have a story of being ripped off

 

good luck on the info gathering.......i will b lookin in on this along with others waiting to see your accomplishments

 

My humble opinion

First you whant to create a little monster that is for sure and you whant to go n/a this is what i would do if i was you .

1. Basics (Cai/Header/high flow converter / plumbing,mufler .
2. port and polish outlet valves,Tb and find some intake manifold that works
3. stroke the engine remember there is no replacement for displacement
4. use upgraded injectors bigger fuel pump an increase the compretion of pistons
5. get the clutch flywheel an pulleys
6. Do not get the echo ecu in there go for the aftermarket. echo ecu has a limit to 105 mph.
7 .put the car on a diet lose all extra stuff
8. got to ligther wheel/tire combo 16 " i recomend
9. try get some cams not to high in the angle
10. try to cut the head a litlle to increase the compretion.

That i would do to a tiny engine like that .




I hope im not talking Sh%T

 

EL_AnOrMal_Xb, your ideas generally sound fine, but the cams might need special consideration because of the VVT-i. further, the biggest limiter is the ECU. there is little point in dumping a ton of time and money into this engine without doing something about that.

anyway, read my last post; the one that bumped this thread out of oblivion.

if someone in the southeastern PA area wants to help with the megasquirt, then i might be able to make time to get back on that project again soon.

i really do not feel like dumping another $300+ for another head (before modifications) and the local shops that i have heard about really suck.