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.
i have a couple options, one company has axles made by driveshaft shop that are sold exclusively through them, however a lot of people have had issues with them. the other option is using Empi offroad parts and building my own axles, which is likely the way ill go.
i have a couple options, one company has axles made by driveshaft shop that are sold exclusively through them, however a lot of people have had issues with them. the other option is using Empi offroad parts and building my own axles, which is likely the way ill go.
never heard of this. Interested to see what you come up with.
u-joint axles are inferior to cv joints. u-joints work in a driveshaft because there is generally isnt a high angle because of the length of a typical driveshaft. my axles currently is just over 21" long, once you put a yoke on either end it would end up with a driveshaft around 17-18" long, consider around 5" of total wheel travel, even if the axle was flat at ride height (its not) it would be 3" of compression, well, you can do the math on the angles. a lot of cars used to run u-joint axles (datsun z cars for example) and there is a reason people convert them to cv joints.
a 6 ball cv joint is actually very strong, angle is what caused the failure of mine. talking to a few people they figure the car squatted so hard, combined with some movement of the transaxle caused the joint to bind, breaking the cage. really better parts will likely still break (unless i end up with cv joints that allow for more angle) without stiffening up the rear suspension to keep the squat under control on a hard launch.
well, i tucked the car away for winter a week and a half ago. of coarse my last day driving it was pouring rain and i couldnt have any fun, and the since then the weather has been beautiful, and is supposed to be sunny fall weather for the next couple weeks. oh well. relaxing for a bit, then gonna start on the winter projects.
im going to build a set of axles at some point, but its not high on my list. i tossed a stock axle in and its working just fine for now. seeing as the failure was caused by how hard the car squatted im going to be putting some rear bump stops. in mid 85 when the 944 was changed to aluminum trailing arms porsche decided that the cars didnt need bump stops in the rear, the theory being with the spring rate of the torsion bars and horsepower they came with, the car couldnt squat hard enough to bind an axle. it was also thought that during a hard corner its better to have a little extra travel instead of upsetting the car by hitting the bump stop. now with triple the horsepower, its an issue. luckily the location for the bump stops is still on the car, i just have to drill and tap the trailing arms to bolt on a set of urethane super beetle units, no big deal. itll really depend on the budget if i get the axles done before spring, its about $650 in parts to build them, plus i need to buy some tooling so i can have a friend machine the axle shafts.
the biggest change over winter is going to be engine management, i have decided im ditching the microtech ecu. the lack of idle control became a huge issue in the last week of driving it, with the combination of colder weather and driving it more in the dark (headlights and defrost load the engine harder, pulling the idle too low to be stable), it was just not fun to drive. ive decided that im going to be putting a megasquirt MS3x into the car. ive had good luck with the megasquirt 2 in the past on other projects, including this very engine. in its past life it ran off an ms2, running early gm dis-4 ignition, it was the first ecotec with an ms2, quite possibly even the first full stand alone on a street driven ecotec (this happened in 2005 or 2006). i should have stuck with it, but live and learn.
ive decided to step it up a bit, ill be building a new megasquirt v3.0 mainboard, running the ms3 processor and the ms3 expansion board. the ms3x is actually a very capable stand alone, about the only thing its not capable of doing is electronic throttle, and thats something you dont get on most stand alone computers till the $2500+ price point (i think its also designed that way because of liability, megasquirt is heavily DIY based and the last thing they need is people messing up electronic throttle settings and getting sued). im planning to push the limits on what the ecm can do, ill be running my 60-2 external crank trigger wheel, i plan to build a 1x cam trigger wheel so i can run full sequential fueling and ignition, itll have a 4 bar map sensor along with an internal barometric pressure sensor (for elevation correction), closed loop stepper motor idle control, pretty basic stuff. where it gets interesting is the additional inputs i plan to add, im going to have transducers for fuel pressure and oil pressure, along with an engine oil temp sensor, this will allow me to log that data and i can have programmed max limits set to turn on a warning light or even derate the engine. im also going to add in a gearbox temp sensor to do the same, and that will allow the computer to control the fans on my trans oil cooler. ill be able to hook my vehicle speed sensor up as well, and that allows me to make use of the boost by gear, as well as set up a simple traction control system. if i added a speed input from the front wheel i could run full traction control, i may experiment with that later on as im out of speed sensor type inputs and it would require me to build my own (not too hard, but not needed right now). im also gonna add in the knock sensor module, it will allow me to use the stock ecotec knock sensor. one nice thing is the megasquirt has can bus, so adding in egt sensors is very simple (the programming allows for individual cylinder trims if you have egt), and it can run various can bus dash units like the racepack iq dash, im hoping my current microtech dash is going to still be useable.
im pretty excited for this, i already have the new stim board for this unit, they are needed for building the boards and testing. i ordered these a month ago, i figured id make sure i can still do circuit board work as my hands have gotten a bit shaky over the past few years, but assembling them was a breeze so i feel confident to build the megasquirt myself. i think this is gonna transform the car, it always made great power but ive always felt i dont have good enough control over the driveability.
well, for a whole upgraded axle they are on par with other cars. the chromoly axle shafts are $250 for the pair, the cv hardened cv joints with chromoly cages are $60 each, the boots are $35 each, add in the spirolock snap rings and some new bolts, it adds up. this is to stick with a 100mm vw type 2 cv joint, if i want to go up to a the larger 108mm porsche 930 joints i need to add in some adapter rings at about $50 each. at least the price difference on the 930 style joints and shafts are about the same as the type 2 vw.
If the cost is only an additional $100 on top of how much you have spent, and it makes them even stronger, I would do it. You really don't want to do it again.
id actually need 4 adapter plates. im kinda on the fence between the type 2 vs 930 joint thing, the 930 joints are larger, stronger, and allow more angle, but the thickness of the adapter plates on each end shorten the axle about 1 1/2", and a shorter axle will have steeper angles. adapter plates are also another theoretical failure point. if i could find outer axle stubs that fit the 944 hub that have the 930 flange on them it would be a no brainer, but info on that is kinda hard to find. the other thing is axle diameter, the 930 shaft is a little larger diameter, and while that seems like a good thing, the more i think about it it may not be. the axle shafts are 4340 chromoly, they are designed to wind up to absorb some of the shock loads in the drivetrain, this helps protect the transmission. the larger 930 axle may not "wind up" as much as the smaller type 2 axle, causing it to transfer more shock load.
im still trying to sort through it, there really isnt a ton of info on upgrading axles in these cars. the old school mentality of "the axle is a fuse" seems to be the norm, so most people just toss another stock axle in.
they do, but they are sold exclusively through another company. the level 1 axles, which are based on the vw type 2 design are $600 per axle, and the level 2 are based on the 930 cv are $750 per axle. about the only thing different with these over what ive been pricing out is these use a chromoly inner race where the empi joints are just hardened steel.
i could, but that also means i gotta cut the tunnel out and buy a transmission to put in the front. seems more cost effective to just buy some cv axles lol.
havent had much time to work on the car of late, but i have gotten some stuff done. i pulled the trans out, pulled it apart and changed the final drive. after waiting a month for gaskets in the mail (stupid canada post strike) i got it all back together and it had a noise in 3rd gear, so i pulled it all back apart to find absolutely nothing wrong. its been sitting like that for close to a month, just had no time or the drive to put it back together.
i did end up pulling the trigger on the megasquirt 3x. it was another thing i ordered that got caught up in the postal strike, it took well over a month to get, and im finally just getting to it now.
so if you have never seen a megasquirt before, here is what you get
looks pretty intimidating but it really isnt. all components are packages in their own ziplock bags with locations where they go, really as long as you can solder you could build one of these things. ive got 4 or 5 hours into it so far, here is what it looks like
basicly ive gotten through installing most of the resistors, diodes and capacitors. the manual takes you through all the steps that every install will use, then takes you through the options for certain things, such as ignition input (weather your picking up a signal from a coil, ignition module or running a trigger wheel) and ignition outputs, idle control type, etc. im getting close to the point where i can do the first tests on it, but ive got a lot of hours to go on it. i also have to figure out and build my own circuit for an additional temp sensor ill be using for oil temp.
That is a big undertaking, but I'm sure it will be worth it in the end. I know you are up to the task. What do you think was causing the noise in 3rd gear?
ive got no idea on the noise, im completely baffled. its a noise in 3rd gear only in one direction, and i can make the noise spinning it by hand with a ratchet. i expected an assembly error, cant find anything wrong. im planning to put it back together and toss it in regardless, not much i can do. i never tried spinning it like that before i disassembled it, so i dont know that it didnt have that noise before i started, id just expect the noise im having now would be terrible driving down the road.
the computer, yea its a big undertaking, but nothing i havent done before. it actually seems kind of simple compared the the harness i just finished building. at the shop we are building a 65 impala with a maserati 4.2l dry sump engine with a single efr 9180 on it. i had to sort out how to make it actually run. the biggest thing is its a vvt engine and there is no info whatsoever available on the internet, wiring diagrams dont exist outside maserati.
i spent new years working on the ecm, im pretty well done now.
the main board near complete.
an additional temp sensor input circuit
all the jumpers on the bottom of the board, and the upgraded 4 bar map sensor (max of 44 psi). it also has a barometric pressure sensor for real time altitude correction
the white board is the processor daughterboard, the little green board on top of it (under the ribbon cable) is the knock module, this allows inputs for 2 broadband knock sensors. the green board to the right is the ms3x expansion board, this where all the extra inputs and outputs are.
so aside from the usual inputs (crank sensor, coolant, tps, manifold temp, and wideband o2) ive got it set up to run a cam sensor (that will allow full sequential fuel and spark), flex fuel sensor, vehicle speed sensor (allows it to use engine states for more accurate fueling, along with boost by gear and simple traction control), oil pressure sensor, fuel pressure sensor, engine oil temp sensor, gearbox temp sensor and a clutch switch input. after some fiddling around ive been able to get it to control my trans cooler fans, my accusump oil accumulator, and a shift light (that can be programmed for different rpm in each gear). ive still got a 3 digital inputs and at least 10 outputs i can use if i can dream up more things to monitor and control. and if thats not enough i can add in 32 channels through can bus (considering the 4 channel egt module).
the cam sensor is something i have yet to sort out, seeing my engine is an early (02-06) l61, with no provisions for a cam sensor. i have a threaded body cam sensor on order, im thinking of drilling the front of the head and using the front of the cam gear as a trigger wheel. ill have to add something to act as a tooth, im hoping i can thread one of the holes and using a bolt, but im still unsure of the best route to go.
been a while again, had so much going on in the past few months and i hadnt gotten much done. i had a pretty big setback with the transmission and the 3rd gear noise i mentioned a couple posts back. i ended up taking the trans all back apart to find absolutely nothing visibly wrong. after reassembling the trans i still had the noise in 3rd, but came to the conclusion that it didnt sound too bad and maybe it was like that, so i stuck the trans back in the car. that was a mistake, just driving on the jackstands it was screaming away in 3rd gear, dead silent in every other gear. back out came the trans, pulled it apart and still nothing visible, even running a gear pattern on 3rd gear didnt show anything seriously wrong. i managed to track another 3rd driven gear, the one i had to press on and off the pinion shaft to change the ring and pinion, was a bunch more careful heating it during install, and after reassembly and install the problem is sorted out. all i can really think of is i overheated the gear during assembly and it created a high spot in a couple teeth.
seeing as it was april when i got that debacle sorted out, i was fully prepared to do a couple more of the little things on my list and get the car out as we were having great weather for early spring. i got my bump stops put in the back, hopefully that will keep the car from squatting so hard and breaking axle cages. i havent done anything with the axles as of yet, maybe later in the summer ill look at that again. i decided to forgo baffling the oil pan, the accumulator seemed to work out well and i doubt ill get it on a track this year so it will be alright. i had wanted to pull the turbo manifold off and ceramic coat it, but thats going to wait till next winter. all was good on this plan till i went to start the car after putting the trans back in, and i remembering to turn the high idle switch on, and the car running pig rich at idle (and if you lean it out one step it turns dead lean), at that point i decided i was ripping the microtech out and going ahead with the big project of installing the megasquirt.
the good news is ive had a good chunk of time this month to be able to work on the car, and im nearing completion of the megasquirt install. the biggest task is building a wiring harness from essentially scratch (well, a flying lead harness, meaning the ecm connectors with 8' of wire attached), and after a couple hours of figuring out wire lengths and how to route everything i was able to take it home and work at my desk to create a one off wiring harness. i forgot to take pics along the way, i have some during looming and some finished pics.
almost all the connectors are brand new. i built the harness so everything is terminated to connectors so it can come out of the car with no cutting, like a factory harness would. i know ill end up needing to make changes to the harness in the future and this way i should be able to unhook everything in about 10 minutes and pull it all out and make changes on the bench. this will ensure the harness always stays neat and clean, and most importantly working correctly.
i have the cam sensor thing sorted out. what i ended up doing is threading one of the holes in the cam gear and making a piece that threaded into it, and the front is shaped as a single tooth for the sensor to pick up. dont worry, the piece threaded into the gear has red loctite and the back side is peened over, so its not coming out of there. i ended up getting a threaded body hall effect sensor and drilled and tapped the valve cover to hold the sensor. simple and effective way to do it, im just hoping everything works ok with it.
not too much else to show aside from my flex fuel sensor mounted on the intake manifold. wasnt my first choice for mounting locations, but after a friend whipped up a quick billet bracket itll do just fine.
im getting pretty close to finishing it off. as of right now i have a few things to finish wiring that arent part of the main harness (fan and accusump wiring) and have to make the fuel lines to and from the flex fuel sensor and it will be ready for its first fire up. i still have to put the new head unit in, but thats a bit of a debacle in itself. the only way to put a double din deck in a 944 is to cage mount it, and the deck didnt come with a cage. i ordered a universal double din cage kit but i have no clue if that will even work.
Nice progress, that trans whine had to be a huge pita to diagnose. Nice job on the wiring, looks really good. Bet you wish you would have done that from the beginning. Been there too many times.
09-30-2018, 01:49 PM
Moderator
