dangero

Thanks Kris, I have the option of moving the trigger wheel so will do as suggested. I have come across another issue I need some help with. As this was the first time I have wired a car from scratch I assumed the analogue outputs on the ECU would have enough current and voltage to switch an automotive relay as a high active. Unfortunately I have wired and loomed everything. every sensor is in an calibrated, injectors and ignition all works under test but the fuel pump and fan are wired to switch on with a 12v signal applied to the relay. I set the outputs to Hi but the ECU output does not have enough current to drive the relay. Reading the manual it appears the recommended way to wire outputs is to pull low to trigger relays. MY fuse box has a common earth and common power to all relays so unless i rip it all out and start from scratch I need to come up with a solution. When I test the output from AUX on the ECU when switching High, I am getting 11.5V and only a few milliamps. I am thinking it will be easier to build a relay driver for the two circuits I need rather than rewire the whole fuse box. Will the following work? NPN Transistor, like a 2N3094 1N4001 diode used as a flyback Resistor providing limited current to the transistor. (1k should do) I only need 150ma to trigger the relay so shouldn't need to stack transistors.

Oops, just reread your post Adam. I am not using a harmonic balancer with a mark that references the crank position so have done the following: Set crank to TDC by removing spark plug on CYL#1, set up dial indicator to touch piston just before TDC, wind crank through backwards and forwards watching the indicator and marked the position where the indicator changes direction. This referenced TDC perfectly, then set cams using degree wheel so cams and crank are now both in sync perfectly and I know where TDC is. Now for the mistake! I removed the tooth that is exactly inline with the hall sensor at TDC! Can I offset this in the ECU?

Thanks Adam, its a 36 tooth wheel without a tooth removed from MRP. https://www.mrpltd.co.nz/product/trigger-wheel-setup/ (24 tooth pictured but 36 tooth the same)

I decided to run a crank trigger based on the excellent explanation above. I have fitted a 36-1 wheel and sensor that as the following wires: Shield/gnd on ECU - Sensor signal ground +5V on ECU - Sensor +Ve Trig1 on ECU - Sensor signal output I assume I will need to remove a single tooth at the home position, Is this best to point to TDC on the crank? Do I need to use Trig2 for anything? Have I got the process correct? Thanks!

Sorry, should have clarified 400 HP at the crank. Bit of an update. Manifold, exhaust housing ceramic coated V band front section of exhaust fabricated Intercooler piping and BOV completed Turbo lines made and plumbed in Cam covers milled and painted Plenum & TB decluttered and painted Everything mechanical is now complete and awaiting the ECU and loom to arrive. I don't like the angle of the throttle I/C piping and will buy a few more bends and fabricate a better solution. the piping is lipped and will not blow off but it looks ugly. Still need to fabricate cold air intake. Bodywork will be mint green (see bit of bonnet in corner of pic) Corner weighted everything and we are at 486KG. Still have to add Loom, ECU, Battery. Will be heavier than initial estimate of 490 KG. At a guess I have about 25KG of stuff to add. Still should be about 500 BHP/Tonne.

ordered some 800cc denso injectors as it was cheaper than servicing the 440's I already have. Just future proofing as I will most likely need to go up in turbo size. Current turbo is maxed out at 270hp. and will be pushing lots of hot air at more than 1 bar past 6000rpm. I can keep the same exhaust housing and just go up a size on the compressor and cover by replacing the CHRA for a GTX2560 or replace the turbo for GTX28XX frame. I wont know if the turbo is suitable for the track it has been built for till I have done a tune and testing. If its too small I will replace it. The new injectors will support 400hp on E85 if I ever want to go that way. although that will break the T50 gearbox and escort diff...

Thanks for taking the time to explain a crank trigger vs cam. I have learnt more in the last 5 min about timing than 10 years of tinkering and reading. Your post is going into my own personal wiki. Cheers,

my sentiments exactly although I am less educated on the topic. Onto another question, I had planned to use some 440cc denso injectors I have but they have been sitting for years and the cost of cleaning and servicing them is nearly the same as buying replacements. Can someone enlighten me as to what impendence I should be looking for, brands that are reliable and cost effective. Id prefer to use denso plugs as the loom I will have is from MRP and has these fitted. more capacity would be good for future tunability. The 440's I have will get me 270 crank HP at 85% duty cycle which is the limit of the turbo, i may want to go E85 or a larger turbo later so would be better going larger if replacing. Is idle tunability affected going sizes over 700ish? I had a R33 skyline with 740'ccs that was slightly touchy at idle on cold start.

Not so much that it is a hall sensor, more that its positional accuracy references the crank position perfectly. With the Dizzy, you are referencing the cam rather than the crank so the measurement is not absolute during most of the stroke. In most applications this is not an issue but when trying to precisely time spark and fuel its better to start with the best reference point you can use. it also reduces mechanical drag by not requiring energy for spinning the CAS/Dizzy meaning more potential power (0.00001kw perhaps!)

I hadn't seen the MRP crank trigger kit. I will consider it. I already modded the distributor and would like to see if I can get it working with reasonable accuracy. I have ordered all the other suggested bits and will be putting everything together in a few weeks when all the parts arrive. The entire car needs rewiring and has no electrics at all at the moment. I will be using an Eaton Busmann fuse/relay box and will make a dash panel with all required buttons. Not much is needed just lights, indicators, tail light and fuel pump relay. Still looking into dash and telemetry but both those things can be taken care of with a raspberry pi and PIcam. Lots of cleaning and fettling to do but we are underway!

Thanks Derek, A bit more reading has an answer for me. The gearbox is a Toyota T50 from an AE86 that has a mechanical speedo cable, but the ST185 Celica had the same screw in fitting with an electronic speed sensor. I will measure tonight and see if I have enough clearance. There's plenty of room in the engine bay, everything has been trial fitted and it all has to come out again to paint all the fabricated bits. Transmission tunnel is a different story! not much room there.

Thank you for the comprehensive answers Adam, all addressed. If you can point me in the right direction for teh speed sensor Id greatly appreciate it. Cheers!

I have ordered a G4X Atom X for a race car build and the car currently has no wiring at all. Car weighs 490 kg's and not aiming for the moon in terms of power. Reliability will be the key. Engine specifications are: 4AGE 16V, bigport head, forged internals, GT2554R turbo I will be running the following configuration 4AGE distributor 24/4 tooth 3 wire (will cut off 3 teeth) Denso injectors part no: 19500-2610 - 460cc Denso coilpacks part number 90919-D2239 standard bigport plenum - standard TPS I have ordered a kit from MRP that includes the ECU, prebuilt 4AGE loom and the following sensors air intake temp sensor 1/8 NPT water temp sensor 1/8 BSP 3 bar map sensor https://www.mrpltd.co.nz/product/ae86-4age-link-atomx-g4-kit/ Things I need information are as follows: Innovative MTX-L wideband, Can the analogue output be used for auto correction on the fuel tables? I would also like to implement the following can you please comment on best options/if possible? Oil pressure sensor - Id like to connect oil pressure sensor to the ECU. will any electronic sensor work? what are the best options? Knock sensor - anything easy and off the shelf? cost effective options? Boost solenoid - Can the ECU effectively control a solenoid for boost control? I will be maxing out the turbo and only shooting for 270 engine HP but may want to taper boost spool and have a low boost setting. Speed sensor - May not be required but may need to pull this data out of the ECU for a digital dash Fuel pump switching/voltage reduction - Bit of a newb question but can I use an ECU output to feed power to a solenoid to drive the fuel pump? Can I program knock timing reduction and low oil pressure cutout? CANbus to OBD2 - I have a cheap but very effective OBD2 display. I'd like to use this as a dash replacement. Is there an off the shelf CANbus to OBS2 solution? I have seen the AEM unit that appears to be what I am looking for. https://www.carmodsaustralia.com.au/obdii-can-plug-play-adaptor-harness Many thanks in advance! first new project in over 15 years and I am a bit out of the loop!