20v aftermarket ecu & head gaskit qns

[ae71 kid]

ok guys,
I have a silver top 20v in an ae 71, i am upgrading to an microtech LT8 comp for two reasons, one is that i wanna run DLI style iglition so i dont have to stick the dizzy throught the firewall, this also means i can run my heater core again... can anyone tell me weather u must completely remove the dizzy and run some sort of chop wheel to clear the heater pipes or can i use the dizzy internals?

The second reason is to do away with the restrictive afm and run trumpets and socks, what do i need ti do this, some sort of sensor im assuming, how will it be connected and does anyone have one to sell...

Now, i was hopin to get my cams ground aswell, and raise the comp ratio slightly aswell, i assumed it would be easyer and to do this via a thinner head gaskit but i fail to see how u can go much thinner that whats on there already, i thought to make any significant differece u would need to remove a fair bit, plz explain

Also the vvti system, how does it work and will i need to consider that at all when makin these changes?

Any help and positive feedback will be greatly appreciated...

cheers tim

[slide86]

http://www.club4ag.com/faq and tech_...roject 20V.htm

http://www.ae86drivingclub.com.au/fo...showtopic=2457

here is some reading to get some ideas......

1- the best thing would be to use the CAS from a 4agze. this is short and the ECU is able to read the signal easily

2- some people find it difficult to use a MAP based setup so they just use the TPS as the sensor to tell the ECU where the throttle is at. then they use load points and stuff like that to tune the ECU. apparently its a bit rough at idle, but it can be done.

3- i think the 20v engine is an "interferance" engine meaning that the pistons are able to hit the valves if things arent mickeymouse. this would give you a big problem is you try to make the headgasket thinner, seeings as they are already able to hit. it would be very close and you would have to be careful not to damage anything.

4- i am not sure if the microtech will be able to control the vvti system. it may be able to but im not sure. i know that MOTEC and high end ECU's have the provisions to run vvti and vtec systems. not sure bout the ol microtech tho

[ae71 kid]

thanks 4 the input mate... any one else got any heplful info.. maybe ppl who have done any of these things? i would specially like to hear from someone who has done any head/cam mods...
cheers tim

[Mr Revhead]

TRD do a head gasket thats 0.4mm thinner than stock

[Hen]

Check up on the interference-ness of a 20V. I was under the impression that all 4As were non-interference stock. Though I may be wrong.

You can use the internals of your 20V dizzy. Just remove the rotor button and cap and make up a plate to seal it. Apparently the bits you are left with are the same as a GZE CAS.

VVT on these engines simply switches on and off. You should be able to configure an auxilliary output of the ECU to control it. Best way is to do a dyno run with it on, then one with it off and see where the power curves cross. This should be your switching point.

Hen

[Mr Revhead]

silver top is non interferance. black top is interferance.
TRD head gasket can be run on both wiht no problems
if changing to high lift cams then id llok into it

[psychofox]

Microtech LT8s only has one ignition output standard, you will need to run a X4 unit if you want to use Direct fire coils. The Lt8s standard can only control a single coil default. I would get a Lt10s rather than an lt8s as it has 3 outputs/2 inputs vs 1in/1out if you are going microtech. lt10s can control BOTH the VVT and ISCV, but you will need to specify these before you purchase the computer otherwise it costs to get it reconfigured. As hen says it is a simple on/off for the VVT. The Dissy cap and rotor can be removed and simply used as a CAS. I would suggest making a cover over the exposed internals. However if you do this it hits the heater outlet pretty much redering it a leaking point in you water system. You CANNOT use the 4agze CAS as has been suggested above.

TRD make a Metal headgasket for the 20V engine, which is 0.8mm thick. it increases the compression by about 0.2 points ie not much. You can shave the head, etc. but really the best way to increase the compression is to put a set of aftermarket forged pistons with a higher crown height (ie wiseco, arias, etc.), It won't help much on an otherwise standard engine anyway (maybe 1-3% increase in torque). I would investigate a bit more before proceeding. 4AG 20V is not an interfrence engine, but putting aftermarket pistons and shaving the head may make it one.

If you get a microtech it uses a MAP sensor or a TPS as its main load input, thus you can run open trumpets or whatever you want infront of the throttles. No more AFM!!! One problem using a MAP sensor on the 20V is the pulsing vaccuum in the inlet manifold from the inlet ports on each mainfold runner, I measure the MAP from the Idle air ports that connect to each inlet port and has a chamber to 'average' the vaccuum pulses. It seems to work well.

[Mr Revhead]

actaully for the silvertop the best thing to do is fit it with blacktop pistons
thatll push it up to 11:1

[Dom-AE71]

Quick tip

Get a KE70 heater core, rip out the AE71 one and replace it with that, sends the outlet pipe in a dowards direction with an Anthony Khellam cap on mine it only JUST touches but its alot more user friendly.

[ae71 kid]

thanks mate... its got a ke 70 core in it as we speek... what microtech r u running? what coils and ignitors r u running, what mods ur engine got...?? jus wanna kno what other ppl have done?

[Dom-AE71]

duno about ignitors, but im using bosch HEC715 coils, LTX8, ive got a minor wiring issue so i cant get a decent signal from the TPS to tune a good idle so it idles at about 1800rpm

get a dry cell battery

anything less, is just going to piss you off. or maybe just use the proper 20v alternator if you can and not an 4ac one like mine

[Dom-AE71]

btw my car made 90rwkw with trumpets and it goes pretty good too thats stock too nothing else done to it

[ae71 kid]

already am mate... what other engine mods u got?

[ae71 kid]

nice... cant wait... so an lt8 definately wont work 4 my application? anyone know how much a new aftermarket ecu is worth? or got a second hand one thats suitable?
cheers tim
EDIT:
i just read the wiring diargam on the microtech site, it illustrates that u use the origional cas in the dizzy, use what looks like a 20v ignitor and what look like gze coils... can someone with a clue (cos im not sure when it comes to electrical stuff) take a look and let me kno if the lt8 will work with my 20v? heres the links:

http://www.microtech-efi.com/downloads/27.pdf
http://www.microtech-efi.com/downloads/28.pdf

[psychofox]

LT8s WILL work but if you want to run DLI with individual coils (as you said you don't want to cut the firewall) you will need the X4 igniter box. As I said before though, for 20V get a LT10s/X4 as you will need the extra outputs to run the VVT and Idle air.