Thanks for the update! Its looks amazing.
Thanks for the update! Its looks amazing.
Absolutely amazing. That is going to completely shred!
Wow! Great build and fantastic attention to detail! The dash and exhaust look amazing.
I've got to get back on my "7" build. You mentioned that you didn't want to use steel floors, what was your reason? I've been considering using bead rolled steel sheet for the floors on my build to avoid more riveting and the potential for them getting the heads ground off on bumps.
In reply to bgkast (Forum Supporter) :
Mostly aesthetic reasons really. I never see them stay flat after welding. That and the potential for oil canning/lack of stiffness. Your idea of bead rolling gets at a lot of those concerns, though, might end up pretty nice.
I guess If steel was super strong I'd be OK with the tradeoff and ease of fabrication but even a relatively thick 18g sheet steel (regular old sheetmetal, A366 or whatever) floor is weaker, heavier, and less stiff than 0.1" aluminum in 6061 or especially 7075.
I countersunk the rivets and used structural adhesive so hoping that gets around the problem of ground contact. You're exactly right that it's more work, though!
bluej (Forum Supporter) said:I love the massive shift light idea. Is that an rpi solution you have going? I see your layout of the electronics board (and some components) evolved, what was the thinking there?
It's a regular old PC in car size (ITX, I think it's called?). I pieced together a motherboard, HD, and a car specific power supply. Probably have $400 in the whole setup? Same price as a commercial gear indicator and obviously a ton more capability. I also use it for the electronic throttle control and TCS calibration, those are both in an arduino.
The main change on the electronics board was just that I screwed up and thought I needed high side drivers for the vanos. Turns out that was only for the S54 system, the N engines have plain solenoids I can drive through ground with the megasquirt directly. I remember having a handful of high side wires and holding them while staring at the front of the engine trying to figure out where I should put them. Ah crap!
I spy a Motogadget M-Unit for your body wiring. Solid choice; I've used them on motorcycles and I could see them suiting a minimalist car like this quite well. The PDM market is rapidly growing and there are more and more options to choose from.
The floating dash worked out to be an excellent design detail. Fabricating a car like this requires loads of skills, but an eye for design is often overlooked. Nice execution!
Mezzanine said:I spy a Motogadget M-Unit for your body wiring. Solid choice; I've used them on motorcycles and I could see them suiting a minimalist car like this quite well. The PDM market is rapidly growing and there are more and more options to choose from.
The floating dash worked out to be an excellent design detail. Fabricating a car like this requires loads of skills, but an eye for design is often overlooked. Nice execution!
Yeah, so far so good on the motogadget. I like the phone bluetooth proximity based ignition switch, seems pretty reliable so far. I needed another fuse box running off the 'ign on' signal from the motogadget to fill all the relay/fuse needs but that was pretty simple. I also really like the turn signal/lights/horn function, keeps me from needing a stalk on the column.
On that topic I also bought a cheap 4 channel RF transmitter system for the steering wheel controls. These are keyfobs and receivers intended for door locks, alarms, etc. Then this 3D printed steering wheel horn insert carries 4 microswitches that I soldered on to the RF transmitter board (keyfob). That whole thing clips into the steering hub where the horn switch would go. This way I have horn, lights, and signals on my wheel with no curly cable to deal with. This green part was a draft for dimensions. I need to have my 3D printer friend do a final part in black with some design tweaks to get the symbols clearer. Works great with the motogadget, a short push gives 3 signal blinks, a long push locks it on up to a calibrateable speed.
Amazing project! Def one of my favorite builds i have seen online anywhere!
Finally got the cowl and windshield on today! Now it really is done. Two things could come next: First, my cool outside rear view mirrors could arrive and I'll be ready to have it inspected or second, it could get just warm enough to back it out of the garage for a whole lot more tuning that needs to be done before the dyno. I'd like to get some tuning done before the inspection because it would lend some credibility if I could fire it up without a lot of drama. For now I guess I'm on a short pause until one of those two things happens.
That is deeply deeply sexy. Nice freakin work dude.
I just found this post today and I'm really glad I read it from start to finish. This is an awesome project.
This is an amazing build. It helps that I'm an N52 fan.
A couple of questions on that front:
Do you have any megasquirt tuning references for the N52? I haven't been able to find anything.
Have you put the magnesium valve cover on? Everything I've read before says they won't fit on a block with a plastic vc.
shagles said:This is an amazing build. It helps that I'm an N52 fan.
A couple of questions on that front:Do you have any megasquirt tuning references for the N52? I haven't been able to find anything.
Have you put the magnesium valve cover on? Everything I've read before says they won't fit on a block with a plastic vc.
Thanks!
I guess I'll be making a few tuning references as I go, most of the BMW megasquirt stuff out there is S54 related. I was hoping it applied but little of it does. In the end the main thing is that the vanos control is much more 'normal' than the S54 but the cam wheels are stupid. 3 very uneven big teeth are pretty tough to get MS to choke down, that's why I'm still running on batch fire. I have a few more things to try before I just break down and cut all but one tooth off both wheels. I'll happily share whatever I learn, of course!
Also, I am not using the valvetronic variable lift system. I just locked it open and am using regular ITB's. I don't think the valvetronic stuff would be that hard, it's just a stepper motor like any ETC, just one more thing to figure out and I was at my limit!
Mag valve cover fit fine and looks amazing compared to the plastic. I read the same thing you did but not sure what anyone was talking about, zero issues. Oil is still inside, air is still outside, seems like a valve cover. You have to buy new Al bolts but otherwise easy. I guess the caveat is that I'm not using the stock PCV system so maybe that was the issue, never paid attention. Here's a pic from just after I put it on.
Alex
Beautiful work. One of the nicest Seven's I have ever seen. Which iteration of N52 is this? I was poking around on hp/tq and it looks like they vary considerably.
In reply to esuvee :
Got it, anything that you learn and can pass on would be great.
That coated vc definitely looks WAY better than the plastic one. What are you doing for the pcv?
84FSP said:Beautiful work. One of the nicest Seven's I have ever seen. Which iteration of N52 is this? I was poking around on hp/tq and it looks like they vary considerably.
Thanks! All the N52's vary only in intake manifolds and ECM calibrations. There were 3 intakes, a single stage fixed geometry, a 2 stage, and a 3 stage variable runner versions. They were apparently remarkably effective as you see the power vary dramatically (100ish HP across all three, IIRC?).
Regardless, I threw all that stuff out and am running S54 ITB's and a megasquirt instead of the stock ECM (DME in BMW speak, I think?). I fully expect this to be a step back in power and torque curves relative to the certainly well engineered stock setups. But ITB's, man! My power goal is to eventually get to 300hp at the crank. That's right in line with the 3 stage stock setup. I won't be nearly as high on tq since the ITB geometry is fixed but it should be a decent power combo and it will sound wicked. There's likely a lot more in there if I could easily do cams but there's nothing on the market for the N52.
Alex
shagles said:In reply to esuvee :
Got it, anything that you learn and can pass on would be great.
That coated vc definitely looks WAY better than the plastic one. What are you doing for the pcv?
With the dry sump system I have a vented catch can on the oil tank and then a vacuum valve on the valve cover to regulate crankcase vacuum. That's the silver thing on the hose coming off the front of the valve cover. There's a decent bit of power in using the dry sump to pull a mild vacuum in the crankcase using the oversized scavenge pump so that's why you don't want it just vented.
Alex
Waiting for video/audio from the ITBs/exhaust!
These were really sweet sounding engines in the cars I had them in as they revved out.
Karacticus said:Waiting for video/audio from the ITBs/exhaust!
These were really sweet sounding engines in the cars I had them in as they revved out.
Me too! They remind me of the S52 in my E36. Loved that engine, just a touch more silky than the S54. Curious how much of that is engine architecture vs tuning knobs like ITB's. So far at a super high idle for 10 or 20 seconds I'm pretty encouraged.
Alex
Very awesome build. I remember those cam sensor being a pita, you can use the comp logger with 'log cam and crank' mode to see the wheel arrangement better. If you see the cam high/low different at different phases at a specific crank tooth, poll level triggering tends to work best.
Paul_VR6 (Forum Supporter) said:Very awesome build. I remember those cam sensor being a pita, you can use the comp logger with 'log cam and crank' mode to see the wheel arrangement better. If you see the cam high/low different at different phases at a specific crank tooth, poll level triggering tends to work best.
Yeah, tried a number of configurations of polling level and with each of them always was able to get a strong, fast synch signal but it will only run on 1 and 3 when synched (flipped high to low on the polling level and it was very clear that I was on the right cycle). Batch fire is solid on all cylinders, no issue. Also, it's not just getting synch that's the problem, I also have to do VVT which requires a pretty well defined cam wheel, not just polling level. At the suggestion of some experienced forum guys I'm trying the '4 tooth wheel' profile in the VVT area as that profile is supposed to be OK with a missing tooth, However, the 3 teeth still don't seem close enough to evenly spaced to work well to me. I was also going to try a 2 tooth wheel profile with noise suppression turned on to see if it would eliminate the oddly spaced 3rd tooth. None of these seem likely to work to me so I'm betting I end up making a hardware modification. Open to ideas, though!!
With poll level it is OK to have poll for TDC on the opposite edge so you get even teeth for VVT angle detection. On the VW they have to be setup that way (falling edge for cam, rising edge for vvt) with their fast sync cam wheel (2 long teeth, 2 short teeth).
Not sure if someone else still makes this, but it's the same pattern as the VW cam wheels: https://www.turnermotorsport.com/p-2778-n51n52n52n-intake-exhaust-camshaft-sensor-triggers-for-bosch-motorsport-management-systems/
I've been out of town for a bit but a fun part showed up while I was gone. I needed a block off plate for the removed valvetronic actuator. As I've mentioned before I hate trying to fabricate plate aluminum parts because it's really hard to get a pro finish at home. Further, this part is right on display, no way to hide that spot. I used frontpanelexpress.com again for this part, same place that I did my dash panel.
So, $30 for a part that I didn't have to make and looks way cooler. There's no branding anywhere on the engine so this also answers a few questions if I've got the hood open.
Looking like upper 40's this weekend so hopefully get some tuning done in the driveway. I'll try to remember to get a video for sound!
Alex
Here's the first 'real' start after fixing a *minor* wiring issue. I forgot that megasquirt is stupid and requires you to wire cyl A, B, C...F in firing order, not cylinder order. You would think I'd remember this from my last project but it's confusing because you also have to input your firing order in the tuning software so one could assume it was going to fire the cylinders in, you know, the firing order. I think I read the directions last time and then figured I didn't need to this time. Oh well, it runs great on full sequential now and VVT seems OK even with the odd shaped cam wheels.
Something is weird with the sound clipping on my phone, it definitely doesn't get quieter on throttle! Sounds great so far. Need to get timing sorted out (messed with that map A LOT while trying to get it to run with 4 cylinders out of order) and some basic accel enrichment, then dyno time for the bulk of the tuning.
That's also just the default dash, I don't plan on so much redundancy with the analog gauges.
Alex
First drive yesterday! No surprises, it ran great for zero tuning.
Happy with everything except brakes, I think I'm one size too big on the masters. Pedal is super high and firm but takes big effort. I'm going to wait until they're bed in but likely will need to step down.
The trans is so perfect! The rest of the car is surprisingly docile, ride is good like I remember, steering is light and fast, tons of torque, and it's pretty quiet but the trans just screams racecar! After a long time off a bike I rented a motorcycle in Phoenix a week ago and I'm glad I did just before this drive. Something about the sequential trans just keeps you involved as a driver/rider no matter what else is going on and this car is super similar in overall feel to that sport/adventure bike. It's clanky in a good way, I'm glad I put the guibo in the driveshaft and put back in the diff bushings to take the edge off the driveline bumps but I love the sounds.
So, now lots more tuning and an eventual dyno session while I wait for a title. Needed to put safety glass in, was hoping to skate through without it but no dice. It's really the only dumb Michigan law, I can't complain too much. That's ordered and easy to pop on to get through the inspection (and, I mean, certainly for the rest of the life of the car, of course...)
Alex
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