When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
99% of “tuners” won’t touch that table on a customers car, and 99% of customers wouldn’t want to pay for the time involved to get a real tune. There’s ALOT of stuff that can be done, on that note most people’s tunes that pay for them leave a lot on the table as it’s the nature of the beast. Unless someone tunes themselves I don’t expect this statement to be understood fully.
Here's the tricky part. I've been looking around at companies that would be able to Xray the heads so I can figure out where to tap the transducer
Find a damaged head cheap. Take it to a machine shop and have them slice it up with a bandsaw. There will be some variations in castings but you should be able to figure something out.
Hey all,
I'm not dead and don't intend to leave this thread hanging. Lots going on, too busy to update currently.
Sparknotes:
1 - I gave up on the X ray method and used a more primitive approach (bandsaw)...GM was super nice and left a boss directly behind one of the tapped holes in the rear of the head that will work perfectly for the cylinder pressure transducer. If drilled entirely through, counterbored 1.000" and tapped, it's flush with the combustion chamber.
2 - Junkyard 6.0 has been pulled and is being built (forged rotating assembly). Might be going back to pull an 80E this weekend to rebuild, rollerize, and dual feed.
3 - 3D printer has been working overtime (custom TPU firewall grommet for all of the electronics I'll be passing through, 12V busbars and power distribution modules, misc hose retaining clips, pre-turbo charge piping protos, etc)
4 - Electronics design has been coming along slowly but surely - PCB's (circuit boards) will be on the way soon for the turbo analyzer module and fuel system controller (16 injector drives, dual level, triple pressure, fuel temp). Individual spark and fuel trim modules, ionization current sensing, knock monitor, fuel pump PWM driver, additional power distribution modules, and fresh air anti-lag are all planned and in process. Setting up the microcontrollers to work the way I want them to will be a different story entirely. Will need back-in-school doses of caffeine to complete them, I imagine.
Let me know if you guys are interested in any of the modules and I can dive into some detail on how they work and what data they're each collecting and why it's important.
Here's a couple quick pics I grabbed of the 3D printed stuff and the chopped head. Ignore the markings on the head; the counterbore needs to be 1.000" . I'll post up some pics of the transducer actually installed in a 317 when I can find a mill with enough vertical travel to put a head in there lengthwise.
Also, for reference, the 3D printed parts are, left to right,
Left: Pre turbo intake piping with a built in Bosch TMAP mount.
2nd Left: Routing clip to connect wires/vacuum lines to the upper radiator hose.
Top left: TPU (flexible) firewall grommet for all of the wires running through (w/ pressure transducer attached)
Top right: aluminum bus bar with lid. Need to tap for M6 mounting posts soon.
Right: More routing clips that attach to the AC lines to keep the wideband sensor wires from touching the exhaust.
-Cal
4 - Electronics design has been coming along slowly but surely - PCB's (circuit boards) will be on the way soon for the turbo analyzer module and fuel system controller (16 injector drives, dual level, triple pressure, fuel temp)......
Decided to make a small architecture change to the fuel system controller. Instead of the single giant system, I'm in the process of making it a bit more modular. Now it's decomposed a bit into the stuff that will generate heat and the heat sensitive stuff. The injector drivers (MOSFETS, which are basically solid state switches that can handle a bunch of current) will be in their own separate module and trigger harnesses will be routed from the main controller to the drive modules. Pics attached below of the PCB's; will be going off to fab shortly. Injector Driver Top Injector Driver bottom
There's also a couple modules that will be included in the same order that act as inline current sensors and voltage meters for the injector. This should allow me to characterize opening/closing time for the injectors, determine if what I'm commanding is actually happening, and will act as a trigger for the controller so that I don't have to keep track of a crankshaft signal to get injection timing correct. Pics below. Injector V and I Sense top Injector V and I Sense bottom
I figured that as long as I was working with PCB's, I might as well take care of the lambda sensor situation as it's a bit messy with all of the inline fuses and additional wiring to tie everything together. Pic attached of that one as well.
Lambda board organizer
I'll throw it out there as well: If anyone has the soldering ability and wants to build one of these boards, I'll send off a PCB to you for the cost of the board+a stamp. Should be less than a couple bucks for it to get to your door. I'll be ordering a couple extras, so just shoot me a message if you'd like to give it a shot!
I'll be back in a couple mins to discuss some of the root of why I'm pushing on the cylinder pressure thing quite a bit. I realized that I really hadn't touched on it yet in this thread and think that it would be helpful to explain some of what's going on.
I should also mention that this PCB stuff I'm doing is all based on KiCad, which is free. I've also started with minimal knowledge on electrical stuff but have been able to progress to this point just by reading and researching stuff on the interwebs. Anyone can start this stuff from scratch with a bit of effort!
I don't understand what you will use for injector timing if not crankshaft position.
The driver boards above are auxiliary driver boards. I'll be piggybacking off of individual cylinder injections to trigger the alternate injection (known from the calibration, I think. I'd have to check off the top of my head if it's available in HPT) and time the actual injection events. Once I get two consecutive injections I can get an estimate of crank speed variation between injections to roughly estimate for the start of injection angle that is advanced from stock injection location, otherwise I can just retard the pulse from the known injection by a given amount of time for a later injection angle that I can figure out from the current engine speed and rate of change. After that I should be able to take a moving average of engine speed between injection events to see if the engine's steady state or not.
At least that's my current logic. I still have to test it but it seems possible at the moment. It seems I might have a bit of difficulty storing the variables in the onboard memory of the microcontroller due to the size of everything, so I might have to add in some extra storage at some point.
Kind of a long winded response to your question, but at the end of the day it's still based on crank angle. Just not directly reading from the crank position or cam position sensor.
10-12-2019, 11:44 AM
