3tc conversion to efi + turbo + rebuild

[pope]

Engine is in and wiring is nearly done.

Megajolt went bang, so i decided to ditch the wolf as well and run a megasquirt.

Megasquirt relay and stimulator purchased and built. Just need to buy the megasquirt, build in and then plug it in.

Things to do:
Buy 7mgte injectors and leads.
Buy a few fuses.
Get new 3" exhaust done from dump to in front of rear left wheel + O2 bung.
Buy megasquirt, air temp sensor, relay cable.
Get intercooler piping made up.
Find bolt to hold crank pully on.
Tighten, test and tune.

[gearb0x]

thumbs up for the surge tank layout, i liked it so much i borrowed your idea for my car

http://gb.detonated.org/gallery/POOCAR-20V/PB240269

[pope]

Things to do:
Buy 7mgte injectors and leads.
Buy a few fuses. Done
Get new 3" exhaust done from dump to in front of rear left wheel + O2 bung.
Buy megasquirt, air temp sensor, relay cable. Done
Get intercooler piping made up.
Find bolt to hold crank pully on.
Tighten, test and tune.

Engine idles but the 2tgeu injectors are on the way out. Had to hit them with a hammer to unstick them.

Need to look at 7mgte 440cc or rx7 550cc injectors as i think they both fit.

[gerald1]

Heya,

I could be well off the mark here but...

I've got some 3t-eu gear (only fuel injected stuff for single cam T series engines) and the injectors that people use in all T series stuff are single point injectors? and the M series engines use multi point? Now I know that the injectors position between your set up and the 3t-eu stuff is different. mine seems to inject it straight into the port, but yours are into the runners? Im not sure if this makes a difference, but i was told to stick to the older style injectors. I think the biggest of the older ones I can use are the 3tgte injectors.

so yeah, not sure if that affects you or not. but thats what I recall reading.


besides that I love this and its pretty close to where I wanna go in the future

catchyas
gerald

[thechuckster]

pope - if you are running the MSefi ECU stock, then consider grabbing the resistor pack from a 5me/ge cresidda/supra. Feed power via the resistor pack to the injectors so you run them as hi-Z injectors (and don't have to worry about PWM tuning them). When you feel confident about your tune, remove the resistor pack and then tune your low-Z-specific settings.

Also, driving 3 low-Z injectors on one channel might be a bit too much for the standard ECU - consider getting a daughter board that has a bunch of PWM drivers on it. http://www.jbperf.com/ has a neat little card with 4 drivers on it.

[pope]

Heya,

I could be well off the mark here but...

I've got some 3t-eu gear (only fuel injected stuff for single cam T series engines) and the injectors that people use in all T series stuff are single point injectors? and the M series engines use multi point? Now I know that the injectors position between your set up and the 3t-eu stuff is different. mine seems to inject it straight into the port, but yours are into the runners? Im not sure if this makes a difference, but i was told to stick to the older style injectors. I think the biggest of the older ones I can use are the 3tgte injectors.

so yeah, not sure if that affects you or not. but thats what I recall reading.


besides that I love this and its pretty close to where I wanna go in the future

catchyas
gerald

The 2tgeu injectors have a horrible spray pattern i.e. a single jet.

Atomisation would be via the stream hitting air and splash from hitting the runner. I cant imagine any reason for not using an injector with a cone type spray pattern, other than possibly a wider area of runner that would be wetted.

I'd like to hear others thoughts on this?

[pope]

pope - if you are running the MSefi ECU stock, then consider grabbing the resistor pack from a 5me/ge cresidda/supra. Feed power via the resistor pack to the injectors so you run them as hi-Z injectors (and don't have to worry about PWM tuning them). When you feel confident about your tune, remove the resistor pack and then tune your low-Z-specific settings.

Also, driving 3 low-Z injectors on one channel might be a bit too much for the standard ECU - consider getting a daughter board that has a bunch of PWM drivers on it. http://www.jbperf.com/ has a neat little card with 4 drivers on it.

AS far as my understanding goes i'm driving 2 injectors on one channel and 2 on the other. I've already tuned the PWM values for them and they seem ok. Managed to get the engine revving nicely today and temps on injectors and msII seemed ok.

Whatever injectors i get in the not too distant future will be high resistance just to play it safe.

Cheers for the link too. Interesting stuff there.

[Hurricane]

Hey just a question, have you looked into cranking pressure or dynamic compression ratio's with the cam and compression ratio your running?

You said you'd chose 7.5:1 pistons with a 77ABDC, with that setup you'd only be getting something like 95psi dynamic cranking pressure (sweet FA).
According to some reading I've been doing, you need at least 165psi + for a decent responsive motor (std is 167psi 2tc and 174psi 2tb).
With a ABDC like that maybe the motor would respond better with a little more compression?

Also your dynamic compression ratio would be VERY low 5.45:1, from what I've been reading an engine with a DCR of 7.5:1-8.8:1 is perfect for 92-98 octane fuel and anything over that 8.8:1-9.1:1 is for High octane fuel only.
Two articles
http://www.chevyhiperformance.com/te...ion/index.html - Cranking Pressure
http://www.empirenet.com/pkelley2/DynamicCR.html - Dynamic CR

(Again all from what I've been reading, so sorry if I've buggered up some information )

my turbo 3tc is running stock 9 -1 comp, with only 95 -98 octane and ive never had trouble running upto 20psi even.

[Radar]

Hurricane just had a look at your build thread, if your using a 290 degree cam, with an ABDC of 40 @.050 then your motor is actually only seeing 8.4:1 so 20psi with an intercooler and premium unleaded fuel should be doable

[thechuckster]

pope: my bad - not sure why i thought you'd be driving 3 inj per channel

but - seeing as you've started on PWM tuning then i wouldn't bother with a hiZ setup. However, just keep an eye on the temp of the flyback circuit. If you start doing a lot of hard driving (e.g. fairly high duty cycle) then consider one of the PWM boards to give you one driver per injector.

btw - good to rear about another MS success story.

btw: i used 4agze injectors is a really poor position (90 degrees to airflow). I think the better spray pattern helped overcome the positioning. I'd go with the newer injectors but if you find your duty cycles are fairly low or you have problems with opening times at idle, drop back from the rx7 to 7mgte.

[pope]

pope: my bad - not sure why i thought you'd be driving 3 inj per channel

but - seeing as you've started on PWM tuning then i wouldn't bother with a hiZ setup. However, just keep an eye on the temp of the flyback circuit. If you start doing a lot of hard driving (e.g. fairly high duty cycle) then consider one of the PWM boards to give you one driver per injector.

btw - good to rear about another MS success story.

btw: i used 4agze injectors is a really poor position (90 degrees to airflow). I think the better spray pattern helped overcome the positioning. I'd go with the newer injectors but if you find your duty cycles are fairly low or you have problems with opening times at idle, drop back from the rx7 to 7mgte.

Yeah thanks for that.

Want to go hiZ just for peace of mind, plus i will have to retune for bigger injectors anyway.

I had heard about the rx7 idle metering issues but would really like to go 550cc just to keep a little headroom. Will probably take whatever is available tho.

[chris_rg]

hey pope,

Great to see you using MS. Let me know if you need a hand with setup or tuning.

I have tuned a couple of engines with MS now. Do you have a wide band o2?

My car is off the road again currently, broke two teeth off the diff pinion gear. Damn T series diffs are weak as piss. Currently trying to get an F series together.

Cheers
Chris

[pope]

hey pope,

Great to see you using MS. Let me know if you need a hand with setup or tuning.

I have tuned a couple of engines with MS now. Do you have a wide band o2?

My car is off the road again currently, broke two teeth off the diff pinion gear. Damn T series diffs are weak as piss. Currently trying to get an F series together.

Cheers
Chris

Hey Chris thanks man.

I've got a techedge 2j1 but i think it may be stuffed as it only reads sporadically in the megatune software. Will confirm this weekend.

Sucks to hear about your car. I've got an F series that i need to get some mounts welded onto. Just need to get an oxy to cut the mounts off of my stock diff.

On a related note, after a bit more fiddling.

http://www.youtube.com/watch?v=aqDIQETPGC4

[chris_rg]

yeah, i have a mx13 diff which I have cut the mounts off. I plan to put rt142 rear disks on it (haven't managed to source any yet though) and use a truetrac LSD centre.

Are you planning to make a jig to weld the mounts on? I was hoping that TIGing them on carefully would reduce the chance of any warping of the housing.

I have a techedge 2Y diy sensor. Works well now after fixing some bad solder joints.

nice video!, well done. always feels good when you get them started the first time

Chris

[thechuckster]

Pope: where have you mounted the wideband sensor? if it's too close to the turbo, it'll get too hot and shutdown randomly.

O/T - Chris: fwiw a guy up here with an RA40 grafted nissan pintara disks (wagon i think) onto the diff - before transplanting an entire Corona B/W diff into the same car and carried over the same brakes. Those brakes are lighter than the RT142 as the handbrake acts on the caliper rather than an internal drum.