Happy Birthday to me (280z build)

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Rabbit Farmer
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Re: Happy Birthday to me

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I like vems for engine mang system.
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drummingpariah
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Re: Happy Birthday to me

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walterclark wrote:You are probably already looking at the MS2 versus MS3 thing so I will only add this. If you can afford the price difference get the MS3. Easier build, better features...Even if you decide to go with batch mode initially, the MS3/3X can do so much more than the 2, you will find yourself adding on capability you didnt know you wanted at first.
Im really just shooting for something that can spit enough fuel and spark into the turbo 2.8 to make more than 100whp so i can participate for a season and shake out all the other issues that im sure ill uncover. In reality, ms1 should fit the bill fine ... but the price difference between the three isnt really worth mentioning. Including the relay board, harnesses, and prebuilt ecu, its still cheaper than the install and the first few dyno sessions will cost. Your advice is definitely well received, and ms3 is looking like the winner right now.
Rabbit Farmer wrote:I like vems for engine mang system.
Ive been hearing that a lot, but not from anyone i know who races datsuns (they tend toward wolf efi). I imagine its just like choosing a firearm in that there are lots of good choices, making the right choice really depends on what youre most familiar with. For me, thats megasquirt.
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Re: Happy Birthday to me

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$950 later, my MS3 (3.57 board - I really don't want to spend any time with a soldering iron in my hand at all) order is being processed. I have no idea how long DIYAutoTune takes to ship things out, but I do know that I'd love to have this thing running this month. I still need to source a ka24e TPS, as the l28et TPS is a binary switch instead of a potentiometer.

I ordered everything pre-assembled, with a relay board and harness ready to be soldered to my sensors. Installation looks really straightforward, but finding GOOD documentation has proven difficult (there's a lot of info out there, but the signal-to-noise ratio is pretty bad).

Walter, I'm probably going to have a few handfuls of questions for you. I don't know what they are yet, but I'll assume they'll be related to ignition somehow (I'm trying to stick with the l28et distributor, I just need to make sure it's sending appropriate signal to the ECU).
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walterclark
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Re: Happy Birthday to me

Post by walterclark »

Hopefully I haven't forgotten too much and should be able to help. I made a bracket for a tps and welded a tab to turn it onto the butterfly of my tb...easier than finding one and porting it.

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Re: Happy Birthday to me

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walterclark wrote:Hopefully I haven't forgotten too much and should be able to help. I made a bracket for a tps and welded a tab to turn it onto the butterfly of my tb...easier than finding one and porting it.

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Nissan makes my life a little bit easier (it sounds easier, at least): the ka24 tps supposedly hands off a ready-to-use signal to MS and practically bolts onto my current throttle body. Alternatively, I could swap in a (significantly larger) ka24 throttle body, but I'd have to convert from pushrod throttle to cable throttle for that, and routing the cable is a bit of a pain on these (I had to do that for my SBC swaps). I'll save that upgrade for when I add a blow-off valve and intercooler and push the wastegate all the way up to 8lbs (right now, it's regulated to 6.5psi of boost).
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Re: Happy Birthday to me

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I've read that a lot of people swap to the ka24 throttle body on l28et's. I did some math, and came to the conclusion that a turbocharged 2.8liter only really needs a 50mm throttle body (up until around 300hp), and I can't think of a reason to swap to a ka24 throttle body in the near future. The problem with the 50mm l28et throttle body is that it doesn't really have a throttle position sensor. I measured the resistance output from the "l28et tps" and found it to be binary, either your throttle is ~75% open or more, or it's considered "closed". Megasquirt requires a real throttle position sensor (that offers different resistance at each throttle angle), I decided to swap to the ka24de tps.
 
I immediately noticed that the ka24de tps fits the throttle shaft of the l28et throttle body, but somewhere along the lines the mounting hole locations were changed.
Image
 
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Not a huge deal, I thought. I'll just make up a little bracket to mount the ka24de tps. I grabbed some cardboard and a sharpie and started to mock up a design.
Image
 
I looked through the metal stock in my 'garage' (it's a sad, sorry excuse for a garage, but it generally works for me) and found some 1/4" steel plate that would work well enough for this little bracket. In general, you want to try to avoid putting steel against aluminum, as the materials react to all environmental conditions differently and can actually speed corrosion, but this is a small and non-precision part so it's not a big deal. I took my template and scribed the steel stock, and drilled a couple holes:
Image
 
Everything looked good at this point, so I decided to clean up the shape a little so it wasn't an awkward triangle on the throttle body.
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Unfortunately, I found a problem at this point. It's not a dealbreaker, and is easy enough to solve, but I'm pretty sure it's going to cause me to make a new copy of this part.
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The l28et throttle shaft bottoms out on the ka24 TPS, where the l28et "TPS" was a little deeper and fit flush. I'm going to take some measurements of this prototype, specify that the thickness should be doubled (1/2" thickness), and either send it off for 3d printing (a nylon printed part would be perfectly fine for this) or have it milled out of aluminum.
 
For the time being, I'm just going to keep everything as-is and stick some washers in to space it out, but I'm not happy with that as a long-term solution.
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Re: Happy Birthday to me

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Wouldnt a Dremel tool take a quarter inch off that shaft easily?
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drummingpariah
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Re: Happy Birthday to me

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walterclark wrote:Wouldnt a Dremel tool take a quarter inch off that shaft easily?
It definitely would, but this is a problem that LOTS of l28et owners complain about, and I think having 10-20 little mounting plates (that fit) on-hand would be good for everyone. I have a lead on getting a small run of them laser cut from 1/2" aluminum at a great price, so I may go for that.
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Re: Happy Birthday to me

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I took a few more measurements and realized that the center ring on the ka24 TPS has a big lip on it, as compared to the l28et TPS. I'll drill out that center ring a bit more tomorrow, and I think I'll have it fitting flush at that point. I'm still sending the dimensions off to have a few 3d printed and laser cut to see how that functions. There are already too many OEM parts that are unsourceable for these Datsuns, it'd be nice to provide another commonly-needed, commonly-available part to the masses.
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Re: Happy Birthday to me

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Tested out my hammock camping system this weekend to make sure I'm well equipped for this season (I don't want to have to worry about getting a good night's sleep), and I can say that it was a huge success. We saw -9F with freezing rain and snow coming down, with a foot of packed snow underneath, and it was a 'cozy' weekend. I'm continually impressed with hammocks for camping.
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