Roman

Yeah most are single wire because they just earth to the block. Which makes sense, but to use with headphones etc I think you need the earth coming back with the main wire. Using this one: http://www.aliexpress.com/item/GM-Knock-Sensor-Ignition-Knock-Detonation-Sensor-for-2013-Chevrolet-Malibu-12623095/1738801957.html I dont have it bolted on the motor yet, but it pretty much works like a stethescope when you put it up against things. It's Interesting to hear the injectors fire or you can hear the intake sucking through the side of the plenum and things like that. Most of those noises couldnt be heard from the side of the block where the knock sensor normally goes, which is a good thing I guess!

Hey thanks, Yes I saw those but problem is that I want to make sure my engine isnt knocking before Nats trackday and possibly Trackday this weekend too. So didnt really have time to wait for Ebay stuff. I had a scout at Zebra, but even if there were any there, knock sensors are the worst thing possible to try and get at haha. So I depinned a factory loom plug that slotted onto the pins, then epoxied the bejezus out of the whole lot. Just like a bought one... Hah. Stoked that I've got a way to check for knock now though, I can have a bit more of a play with the timing as it's been on the conservative side.

Quick question about shielded earths, Since the standard knock sensor normally has a shielded wire, but is only single wire and new knock sensor is 2 wire. I'm using a spare loom's crank angle sensor wiring instead, as that's two wires shielded. However what do I do with the shielded earth, do I just earth it to the chassis somewhere? Not sure if they need something special.

Haha! Yeah it is awesome, thanks for the suggestion. My laptop cant charge from the car so no worries there.

Ahhh so I bought a cheap GM style wideband knock sensor. However it needs a PITA plug (not included, damn you) that you can only find on a late model LS2 or something, bugger. Just going to epoxy some crimped ends in and run a remote plug end on it. However I bodge wired it up to a Mic jack into the laptop, then as suggested used Audacity to crank it up a bit and output to Headphones. Works brilliantly! It's even better than just using knock sensor > amplifier > headphones, because this way I can record the whole lot as a WAV file and compare notes with the datalogging timestamps once I've filtered the results for the knock frequency. Tapping the knock sensor with a fork outputs a really clear sounding sound of... Well, a fork. So it shouldnt be too much interpretation required to figure out when it's knocking.

Awww damn could be keen for a pre nats shakedown at Meremere as well! Details, giz ze details!

The main thing to consider, is can you get away with widening your front track. If yes, then convert to discs running over the front face of the hub, like the bluebird ones. This will make your life sooo much easier as it adds the thickness of the top hat to the amount of room you have to fit everything. And there's a wider variety of potential matches for a disc that suits, like the bluebird ones. I've got some spare facelift SW20 calipers here if you want to test fit them. Although these are the bigger brakes compared to non facelift, it might suit you better getting the earlier / smaller / more common calipers.

You can get some nice small Wilwoods though. I'm running smallest of the Nissan 4 pots and it really limits my wheel choice because of spoke clearance. Bit of a pain.

Slightly different car, but I've had a few different brake setups in the front of my car. -Factory AA63 Celica struts/discs/calipers (Vented disc + single pot) -Same struts with SW20 twin pots and a thicker disc -Same struts with Nissan 4 pots and same disc After all that, my opinion... Look at the price and availability of consumables, and how easy it will be to maintain your car as the primary factors. Going to a wilwood 4 pot or Nissan 4 pot gives you HEAPS of brakepad options, they're about half the weight of cast steel twin pots, and are a zillion times quicker and easier to change brake pads on. It also gave a much more progressive braking feel, the single pot or twin pots gave a comparitively on/off sort of feel. On paper going to something like AE86 struts or Cressida struts with factory vented discs etc seems like an easy option but it can be difficult to get consumables for. It's a struggle to get GX61 front discs anymore I think. SW20 calipers are a bit better for consumables, can get some decent pad options. But dont expect people to have things readily in stock at the drop of a hat, if you need some new pads at the 11th hour... Like you can with most of the popular 4 pot options. Depending on your wheel choice, a Wilwood or similar 4 pot is probably the best option for a variety of reasons. But expensive too. Basically you need to decide, in this order: -Which strut you are going to run (Starlet size, AE86 size, Cressida size. All have pros and cons) -Which caliper you are going to run (Pick this first, make a bracket for it and then find a disc that fits available space) -Either way, you'll need to make a caliper bracket to fit anything decent... So if it's 90% the same amount of work to fit any of the options then you might as well start with something good I reckon, that will pay dividends in the long run with pad availability / choices / etc. Pretty hard to go past Wilwood or the likes.

Thanks Glenn! Good to know, my basemap looks to be 2-3 degrees advance behind all of that. Once I've got my knock monitoring stuff I'll set it to those figures and see how it goes.

Okay cool thanks, I'm guessing that minimal ignition timing at WOT happens at 6000rpm or there abouts (looks to be peak torque) and then tapers off a bit either side of that? One thing I dont get is that ignition timing doesnt seem to advance relative to rpm by very much. For example 6000rpm doesnt have twice as much advance as 3000rpm, so it's only got half of the time to ignite etc.

Got any pics of what the decepticon front end looks like on a finished car? Not overly sold at this point / holy scope creep batman / get 'er done

Oooohhh aahhhh EDIT: Ahh shitballs I just remembered I'm going to Coro for the weekend. 1st world problems

Ahhh okay thanks Glenn. Yeah I've got 8 injector drivers. What do you mean by ignition test advance? You mean ignition advance at full throttle? Mine is currently 22 degrees across the board from 3500rpm up, because I dont have a good way to monitor knock yet (some stuff is on the way)

I dont actually know to be honest. I did a bit of reading up previously which suggested that a single pintle design generally has a very narrow spray pattern compared to other designs (which is crappy for when you've got them right by the head, but good for things like this) However yeah, perhaps I need to bench test them and actually have a look. Might be that the spray pattern is way wider than expected. Come to the Nats trackday KPR!!

So I got all that finished, wired it all up and took it for a spin. After an extended amount of fluffing around it just doesnt quite seem to run right. When I reverted to the previous fuel map using just the main injectors, it ran a hell of a lot better instantly. It's possible that it's flowing unevenly between cylinders, or that I need to spend more time tweaking the injector ratios / timing to get it working as best as it can. Or I just need to figure out a tune using 100% outboard ones for starters and then work on blending them together. But I dont think I can really get this right without a dyno, and having a way to check individual cylinders for running rich/lean. Not too keen to blow up a cylinder just before Nats / trackday so I'm going to go back to the standard setup for the moment. A bit dissapointing, but I'll give it another try in another month or two when I've sorted out a few other niggles. Also, since I no longer need the MAF, and the MAP sensor was showing a 2KPA pressure drop from 6000rpm onwards, indicating a restriction. I experimented with fitting a velocity stack straight on the plenum, with and without a pod filter on top of it. Doing this reduced the pressure drop to 1KPA, which initially seemed like a good thing. But I had to pull fuel out right across the board, because even though there's less of a pressure drop it's consuming hot air which is less dense, and less air in total. Haha lame! Just goes to show how much of a difference cold air actually seems to make, even when you've removed the entirety of pre throttle body restriction.

Got my 2nd lot of injectors fitted and all sorted with no leaks - hoorah! A fuel line from a 20v 4age was the right length for between the rails. I've set it so the second injectors only activate at 4500rpm onwards, and for starters set it to 90% using outside set of injectors. Took it for a quick run and bodged some numbers around so it was 13:1 AFR across the board... But then my fuel map looks whack! I think the peaks and troughs are because there are resonances pushing some of the fuel back out of the runners at those rpms. So I had a look at the injector timing. It was setup so that the end of the injection event is 400 degrees before TDC combustion, for everything. The first problem with having this set statically is that the intake cam advances or retards 45 degrees, so depending on the VVTI it would make sense that this number should be up to another 45 degrees advanced to match the closing of intake valve. This doesnt matter too much with low cc injectors close to the head, because they're spraying most of the time on closed valves anyway. But for this it needs to match the injector spraying with the induction event. so I setup an rpm vs map injection timing table, and added more advance for when the cam advances. This looks to have smoothed out the peaks and troughs with the fuelling back to normal, so that was probably the issue. Jury's out though on whether these extra injectors will actually help make any more power. There's no point in tuning it any further until my IAT sensor arrives though, it falls off tune each time I drive it currently. They're a 1000cc single pintle and make a racket when they are running so it sounds pretty cool. Hah.

When I had the OBD 2 meter there were two types of reading. Instant values - Your fuel economy at that instant, so it changes all over the show. And averaged over a minute, or accumulating over your trip. So one thing to consider is that if you're using the same amount of fuel but going faster, you get better liters per km. So for instantaneous feedback it would be injector pulsewidth / vehicle speed So something like (injector pulsewidth average over trip) / vehicle speed would show you the fuel economy over the span of the trip. Would give you a number that you could bodge into Litres per km or whatever.

Yeah you just need three pins connected to obd reader. 12V earth and the SIL pin. Engines of that era may not be completely obd2 spec though so sometimes needs a custom start up command to work.

Aahh so I found that if I changed the fuel modelling from 'traditional' (which doesnt care about injector size etc) to 'modelled' then it works out fuel based on engine size, injector size, fuel pressure, blah blah. Which is what I need to do in order to access the Litres per Hour figures and other similar measures of fuel consumption. (Even though Effective pulse width is same same I guess) However it's a kick in the balls because all of the fuel values on my existing map need to drop down by like 95% for it to work. So I think I'll put that one on hold until I get my proper IAT in and configured, and map sensor calibrated properly. I'm thinking that once I've got gear detection setup, I can just filter the log files to only show values for 6th gear, TPS at say 10-20% and then have an Engine RPM vs Litres per Hour graph to compare between runs. Irony noted of using lots of gas to make car use less gas.

Yeah fuel pressure will be constant, my FPR doesnt reference manifold pressure. Yes initially I was thinking that logging injector pulse width makes sense. But then for some reason that now slips my mind it seemed like it wouldnt be accurate based on info that I had. However, I've just noticed if I change my fuel calculations from "traditional" to "modelled" it allows you to enter engine size, injector size, fuel pressure etc... Once you've filled in these things it gives you some better information about fuel consumption, estimated air/fuel consumed, etc etc. Hoorah! Either way, as per the Honda article it looks like advancing the cam 15-20 degrees and advancing timing to 35-40 degrees and 15:1 or there abouts will be the best starting point. There's not much point trying to tune any further at the moment though until my new IAT sensor turns up and I get my MAP sensor calibrated properly. Because I tune it up nice one night, then the next day its all over the show again. Needs some more accurate info to get the compensation tables working correctly I think.

I Rikey

Hey guys I'm trying to think of the best way to tune for cruising / fuel economy. I was thinking same stretch of flat straight road, do a run aiming for a constant 80kph on GPS. Datalog all the things. Adjust a variable (ignition timing, VVTI, or fuel) But then what would be the best measure of economy? A lower average throttle angle perhaps? More bang out of less air. The factory ECU seemed to want to run right to the limit of detonation, so perhaps slamming in timing right up to that point is best for this motor. Some people say running leaner is a better idea, but then others say you end up needing more throttle angle to keep the same speed if you do so. EDIT: Aahh! This article is pretty awesome on the topic. http://www.superstreetonline.com/how-to/engine/0510ht-fuel-economy-tuning/

Got the new alternator fitted, so far so good. I got called out in the fab disasters thread for some terrible wiring for the fan relay. So now have the ECU triggering a different relay and the ugly one gone. Woot! The speedo signal now works but need to setup gear detection so I can have a gear dependent rpm for the shift light. Bought some more bits to setup datalogging with: 3 fast response IAT sensors (One for intake, one for engine bay temp, third for... dunno yet) A 3 axis accellerometer that outputs x y Z axes as 0-5v each (Measure cornering speed / accelleration for tuning) A wideband knock sensor and an amplifier for tuning ignition safely with headphones. Some bits for a revised intake. Currently the intake pipe from the air filter is 2.75" but the throttle body entrance is 3". So I'm going to upsize this and see if that removes the pressure drop at 6k rpm onwards. Also with some awesome help from Dave Sentra we've started on a spare manifold for some outboard midboard injectors Still needs a bit of work and some $$$ for hoses and things, so probably wont be done before Nats trackday. But should be fun to see if it helps make any more power phasing them in at high rpm. (Helps mix the air and fuel better, apparently!) The main concern though is that it might hit the bonnet when the engine moves. So plenty of things to keep me entertained for the next while when all of this stuff turns up. The car's running really well with the new ECU, but I still need to calibrate the MAP sensor and temp sensors properly so that temperature compensation etc works properly. Everything's open loop at the moment but once I've got the map looking good I'll set it to closed loop below 4000rpm at low/mid load so it can adjust fuel as need be for good cruising economy.

Yeah to be honest I might end up going MAP anyway in the long run because I want to take some restriction out of the intake. As currently between the air filter and the throttle body it's 1/4 inch smaller pipe than the throttle body inlet pipe size. (2.75" vs 3") And the MAP sensor shows a pressure drop above 6k rpm, probably because of this. But it's been interesting seeing the difference with this, and getting a better understanding of both. The main things that suck about MAF are that an air leak ANYWHERE ruins your day, and if you change one single thing in your intake it throws its toys out of the cot. But if a 3" or 3.25" pipe with MAF bodged in works well enough after being calibrated I might stick with that because my brain can make sense of the tables a little easier. Turns out my tables can have 20 rows of resolution so it's not really an issue running out either way. Good fun though! Cant wait for next trackday.