Maschinenbau Posted March 3, 2019 Author Report Share Posted March 3, 2019 (edited) Big little upgrade! I machined these solid aluminum shock bushings after work. I bought a 12" stick of 1.5" OD aluminum for $16 on Amazon and used 4 inches of it. So this is a $4 set of solid bushings if my Challenge budget math is correct. So here's the problem. The G35 shock bushings are designed to work with G35 shocks. G35 shocks have yoke on the bottom, centered over the bushing with a thru bolt. I don't have G35 shocks, I have used dirt track racing shocks offset from where they should be. So this whole time I've been driving with a cantilevered 1/2" bolt going through the rubber bushing, bending the bushing every bump and rebound, resulting in the most non-linear damping curve imaginable, probably. You can torque that bushing just by pulling on the bolt by hand. So my fancy redneck racing shocks probably aren't doing much. This was 4 hours. I fought valiantly and triumphed, wielding the power of parts-store bushing press, electric die grinder, and beer. The other side took way less time, especially after sleeping on it. I also filled the gap in the chassis with some shock bellows, fashioned from the Datsun's A/C ducting. Hoarding pays off, see? Nice and tidy. Now my shocks actually do something! Then I turned my attention to the front. Those fenders need help. Quick update on the sheetmetal supply. You know what, the fenders just need to go. And that's as far as I got. But there's an autocross tomorrow. So I'm just gonna duct-tape the sharp edges and send it. Edited March 3, 2019 by Maschinenbau 4 Quote Link to comment
Tedman Posted March 3, 2019 Report Share Posted March 3, 2019 Congrats on making the mag and well done placing 14th overall at the event! 3 1 Quote Link to comment
Maschinenbau Posted March 4, 2019 Author Report Share Posted March 4, 2019 I'm famous in junk car racing! I just got my issue too. It doesn't look like it, but the car has come a long way this winter. 1 Quote Link to comment
Maschinenbau Posted March 4, 2019 Author Report Share Posted March 4, 2019 Autocross Points #2 was yesterday, and I did much, much better this time relative to the field. I finished 30th out of 90+, with a 3 second spread between 5th and 30th. All cars ahead were fairly-modified STX, STU, SM, and SP classes of cars. For perspective, the car ahead of me was a crazy turbo-flutterin' STU Subaru STi and behind me was a gorgeous SP 2011 911 Carrera S. I'm pretty satisfied. Biggest takeaways: Seat and position are game changers. I can actually focus on driving now instead of leaning way back and hitting my helmet on the ceiling. Solid shock bushings are doing something incredible. My driver/autocross vocabulary is lacking, but the car just feels so much more predictable and quicker to transition between turns, especially in a slalom. The rear dampers must actually be working now and keeping it from rolling as much, because the control arms didn't clunk on the frame like last time. Night and day difference that you can feel just by leaning down on hatchback. It stiffff. Stock drivetrain still reliable as gravity and still throwing the same 7 minor engine codes. 2 Quote Link to comment
Maschinenbau Posted March 6, 2019 Author Report Share Posted March 6, 2019 More photos (pardon the fender progress). Atlanta Region SCCA has a really great photography. Once the body and paint and done I'll have to buy some prints from him. 2 Quote Link to comment
68Datsun510 Posted March 6, 2019 Report Share Posted March 6, 2019 LOL are those Jeep wheels!? Bad ass project! Quote Link to comment
Maschinenbau Posted March 6, 2019 Author Report Share Posted March 6, 2019 Thanks! And yeah $40 for a set of 15x8 is hard to beat! That's half junkyard pricing. They are the cheapest OEM 15x8 wheels with a 5x4.5(114.3) lug pattern that I can find, and I keep on finding them too, because Jeep guys love to upgrade wheels and tires. So I have an entire second set that I'll be drag racing on. I have 8 Jeep wheels in my garage for under $100 and I've never even driven a Jeep. 2 1 Quote Link to comment
Maschinenbau Posted March 13, 2019 Author Report Share Posted March 13, 2019 Cardboard fenders for lightness! No not really Update on the filing cabinet graveyard. These fenders hit them hard. I left extra along the bottoms until I figure out the air dam and rocker transition Due to the max panel size of the cabinets, each fender is actually 6 pieces stitched together very carefully. I got one side fully welded up tonight, long after taking these pictures. I also wrapped the steering wheel with some cycling handlebar tape. 9 bucks shipped and one pack is just enough for a Datsun steering wheel. I think it feels and looks much better. 5 Quote Link to comment
Maschinenbau Posted March 14, 2019 Author Report Share Posted March 14, 2019 Got the fenders all welded up This thicker stuff didn't warp as much as the rears. Also I suck less this time. I left extra material along the bottom and still need to form the transition to the rockers a little better. But that leaves us at the front fascia. All I have from the Datsun is the heavy ugly 80s chrome bumper, so I'm basically starting from scratch. This is a racecar, so a decent air dam and undertray may help in the drags. I don't want a splitter or front spoiler (or at least not a crazy big one) because I would rather reduce drag than improve front downforce, and anything strong enough to support downforce will likely be heavier and more complicated than a simple air dam. So to recap, goals for front are: Cheap/free Reduce drag Downforce neutral Aesthetic Removable for towing Over the past few months I have been gathering inspiration from everything from land speed racers to eco-modders. The eco-modders have extensively documented very cheap, very DIY-friendly ways to reduce drag. Just google image search "ecomodders aero" and take a dive down that rabbit hole. One of their preferred materials is coroplast, a lightweight yet stiff corrugated sheet of polypropylene. The same stuff all those election yard signs are made from. You can get this stuff for free after any election or by walking along the ditch of a nearby highway and gathering all the tipped-over or blown-away ads. AND benefit your community and the environment by upcycling this material. Polypropylene unfortunately is not very recyclable, so the majority of it ends up in landfills. Unless, of course, it ends up on a car... It forms decently too. And the little metal rods can be modified to stake several sheets together and add stiffness. I enjoyed the irony of a "Cash for Junk Cars" sign in my garage, and the appropriate shamrock for this weekend. I could really use some feedback on design. Nothing is set in stone (or hot glue) yet. How do we feel about the shape? Stay flat or bulge out forward more? Angle of attack? Does it need a small bumper-like feature? Am I going insane for screwing yard signs to my racecar? 3 Quote Link to comment
]2eDeYe Posted March 14, 2019 Report Share Posted March 14, 2019 Looks good, if nothing else you can call it a mockup for testing lol Quote Link to comment
Maschinenbau Posted March 15, 2019 Author Report Share Posted March 15, 2019 Here are the turn signal "eye sockets" I burned in last night. 3 Quote Link to comment
dukerollo Posted March 16, 2019 Report Share Posted March 16, 2019 I like the yard signs. Bonus points if you leave the inside unpainted so you can read what they say. I would try try to give the lower edge a little more “pout”, or maybe do a slight lip. I think aesthetically you have done pretty well so far and a plain slab on the front will detract from that. I know form>function blah blah, but still.. Quote Link to comment
Crashtd420 Posted March 16, 2019 Report Share Posted March 16, 2019 This build cracks me up and impresses me everytime .... keep it up..... On the front I would roll the bottom in some .. right now it looks way to flat .... Quote Link to comment
datsunfreak Posted March 17, 2019 Report Share Posted March 17, 2019 On 3/14/2019 at 9:16 AM, Maschinenbau said: I think the above photo fits the below statement to a T... Quote Cheap/free Reduce drag Downforce neutral Aesthetic Removable for towing Only thing I would probably change is to make it metal (or better yet fiberglass) and make it easy to unscrew. Quote Link to comment
Maschinenbau Posted March 19, 2019 Author Report Share Posted March 19, 2019 Great tips guys. Here's where we left off last time, with the eye sockets finished. Here is some broken rain gutter I have been hoarding for months. It's a bit...boxy I cut some curve into it, riveted it back together, and cut tabs into the bumper. I also cut some slots into the valence/under-grill metal piece, so it goes together really easily. Should all blend in together nicely. Also I have this piece that went under the original bumper, but not sure it has a place here. It's pretty mangled on the corner where this car was wrecked. But maybe it could work 6 Quote Link to comment
Maschinenbau Posted March 31, 2019 Author Report Share Posted March 31, 2019 Last weekend was entirely devoted to minivan deferred maintenance, so no Datsaniti fun was had. This weekend I got the air dam roadworthy and tested it out. Metal hooks attach to the radiator support bracket. Hot glue works well for holding it together. The whole bumper/air dam assembly comes off with just 4 self-tapping screws. Every other fastening feature is passive capture. You can push on it pretty hard without it caving in or deflecting. Should be stiff enough for 100+ (120+...?) mph of aero force. Went for a drive and didn't notice any floppiness. A cop pulled up next to me at a stoplight and said "Cool, but it needs an LS swap." "It's plenty fast". I don't think he knew what was under the hood. Cool cop though, and didn't seem to mind the overall level of jank I put on the road. The next morning I took it to a car show and drove on the interstate for the first time, getting up to 80 MPH with ease. It's loud, it drones, and random components hit their resonance and vibrate all at different speeds, but it drove smooth and predictable. Not saying it's daily-driver status, but maybe I don't have to tow it to autocross anymore. 25 urban miles round trip on a hot day. I took surface streets on the way back to avoid that Atlanta traffic, but it rides so better on that smooth interstate pavement. Bumps, ruts, and potholes are terrifyingly loud in this car. Kids at the show loved drawing on it with the chalk I brought. 7 Quote Link to comment
Maschinenbau Posted April 7, 2019 Author Report Share Posted April 7, 2019 Lots of little updates this week. I just got back from the monthly Caffeine and Octane show, which was 50 miles round trip all on urban interstates heading out before dawn. The show was crazy huge with a great variety as always. The car got tons of attention so I did my best to spread the good word of GRM and our annual pilgrimage to the Challenge. As everyone started leaving, I started my car because someone wanted to hear the engine. I revved it up juuuuust a bit and inadvertently triggered a revving war between the 350Z's I parked with (what else is similar?) and the Mustang gang that was rolling past us. I was stuck in the middle. The Z behind me REALLY overdid it and got a ticket from a cop. C&O is wild. No big issues on the drive, but the roads were still wet this morning so the spray made it hard to see without wipers on the dirtiest most pitted windshield ever. Headlights could use an adjustment too, but thankful for lots of streetlights going through downtown. The way back was much easier, though more traffic. I really want a brake booster but can't fit one. I noticed the whole chassis seems to resonant right around 3000 RPM at 70 something MPH. Also I am smelling a lot of exhaust inside the car and can't figure out how it's getting in. All the doors seal like crap, so who knows, but it's a little nauseating even with the windows down. Anyway here's what happened since last time. Fenders are DONE with the welder. Nice little lip from a piece of 1/8 round rod and some stiffening supports. Roof patch Here's a neat trick I learned from Urchfab on youtube. When welding large flat sheetmetal that looks very sensitive to warping, blow compressed air after every few tacks to keep the heat down. I keep everything cool enough to touch and that seemed to work. I am fully committed to no wipers and no HVAC, so I sealed up the cowl opening. Water has been getting into weird places, along with smells from the engine bay. Some patches made from aluminum rain gutter, seam sealer, and rivets made a quick job compared to welding. Replaced the brake master cylinder which made the pedal definitely feel better, but I still wish I had power brakes on the street. Also that wiper motor and wiper assembly are gone. 5 more pounds removed. Here's my super lame exhaust the 'meh'-looking tip and the after-thought mounting hastily welded onto the rear fascia. And here is the new and improved hater-pipe inspired God of All Rice mode exhaust. Still sounds the same, but looks way more awesomer. I might bevel the tip, or not. I love it. 4 Quote Link to comment
Lockleaf Posted April 8, 2019 Report Share Posted April 8, 2019 Have you considered hydro boost brakes? Mid 90s astro van used a compact setup that can be obtained junkyard style. Custom hoses likely required though. Quote Link to comment
Maschinenbau Posted April 9, 2019 Author Report Share Posted April 9, 2019 I've looked into hydroboost and remote booster setups like on a BMW E34. But last night I did some measuring and I might be able to squeeze it if I angle the MC upward to clear the strut tower. It's supposed to angle up anyway, just need to figure out how to do that. Quote Link to comment
datsunfreak Posted April 14, 2019 Report Share Posted April 14, 2019 On 4/7/2019 at 12:55 PM, Maschinenbau said: Also I am smelling a lot of exhaust inside the car and can't figure out how it's getting in. All the doors seal like crap, so who knows, but it's a little nauseating even with the windows down. I have owned a lot of Datsun wagons and have dealt with this issue a lot. 😄 1. Your hatch seal leaks. Due to the low pressure area behind the car, it pulls exhaust fumes in through those leaks. 2. Rolling the windows down seems to only makes it worse, not better. 3. Keeping the fresh air vents open all the time helps, (pressurizes the cabin) but you just sealed those up. 😁 4. While your new exhaust may help this issue a lot (gets the tip further away from the hatch), I found a side exit works even better. Best fix is a new hatch seal, a new window seal, and maybe plug up those vents beside the hatch. without the front flow through vents open, the rear "flow out" vents will actually suck fumes back into the car. In for a penny, in for a pound. While I do understand the reasoning behind sealing up the fresh air vents in the cowl, it is in practice a terrible idea. 😉 3 Quote Link to comment
Maschinenbau Posted April 16, 2019 Author Report Share Posted April 16, 2019 Sounds like a darn good excuse for a rally-style roof scoop! Makes sense about the low-pressure zone though. I don't even have a blower motor on this car, so the only positive pressure I can build in the interior will be from scoops or some kind of cabin intake system. Perhaps a pop-up vent on the cowl with a purpose-built duct that avoids all the Infiniti computers I am trying to protect. Exhaust turn-down might help too, but I'm in love that silly pipe. Back to the brakes...something about Miatas and answers? While perusing the junkyard for a replacement G35 booster, I found a non-ABS NA Miata with almost nothing left, except its brake system. The booster is single-diaphragm and 2" smaller in diameter, so it should be a good boost but not too boosty. Cleaned up the booster with a fresh coat of paint, thenI flipped the proportioning valve bracket upside down to move the valve over to the right. A little trimming and bending made it perfect. My hope is that the Miata prop valve does a good enough job that I can remove the manual bias valve if I need an extra $20 in the budget later. But for now they're both in, because burnouts. It needs to go here. But the nose of the MC hits the strut tower, no surprise there. Here's the upper control arm mount and spring perch I surgically avoided. Much hammering was had. Much more cutting and grinding after this shot too. Getting close Why does everything I do to this car devolve into CAD fab? Burned in good to add the stiffness back. Finally found another source for my coveted Rustoleum Harbor Blue spray paint. I can't find this stuff anywhere, but it's almost a perfect match to the Datsun interior. I had to run a vacuum line from the passenger side to the booster, so I formed it out of some leftover fuel line. I won't know how it works until tomorrow, when my power bleeder adapter arrives. But mashing the pedal doesn't reveal any leaks, and the running-engine vacuum test proves the booster is good. This has been a 20 hour upgrade. My thought is easier to drive = faster to drive. At previous autocrosses, braking was an all-or-nothing affair due to the massive pedal effort involved. 2 Quote Link to comment
INDY510 Posted April 16, 2019 Report Share Posted April 16, 2019 Ha. I'm doing a similar project with 2006 Miata parts and a 510. The giant brake booster and deleting the ABS system are both giving me headaches. I'm curious to see if the non-abs master helps. What all did you do to the ABS wiring? Are all the wheel sensors still hooked up and going to the ABS computer that you separated from the brake line block? I think I need the wheel sensors for the speedo to work. Quote Link to comment
Maschinenbau Posted April 16, 2019 Author Report Share Posted April 16, 2019 At first I tried integrating the Infiniti ABS block with attached module, but I couldn't get the system to bleed down properly. So I removed the ABS block and replaced it with tee fittings and a bias adjustment valve. I am using the Infiniti cluster and gauges, so I also still have the ABS computer and wheel speed sensors. I detached the ABS module from the big heavy junction block and just bolted it behind the dashboard, exposed solenoids and all, plugged into the harness. This was enough to keep a working speedometer. If your Miata system is anything like the Infiniti one, the ABS computer collects info from the wheel speed sensors, looks for the ABS module/block to be present, and sends speed info over CAN to the gauge cluster. I wasn't able to get speedometer working without this ABS module and all 4 wheel speed sensors present in the system. Hope this helps. The black ABS module is bolted behind the dash using those 4 silver screws to the left of the cluster. 2 Quote Link to comment
Tucson620 Posted April 16, 2019 Report Share Posted April 16, 2019 On 4/14/2019 at 6:46 AM, datsunfreak said: I have owned a lot of Datsun wagons and have dealt with this issue a lot. 😄 1. Your hatch seal leaks. Due to the low pressure area behind the car, it pulls exhaust fumes in through those leaks. Same with Z car - best results by sealing EVERYTHING in the back. Hatch, spare tire well grommets, antenna, etc. Hatch and tail lights were big leak spots - new rubber was cure. You can do a smoke test - rig a shop vac to pull air from sealed cabin. Wave cigarette, etc. around rear, monitor test subject in back of wagon for reaction. Quote Link to comment
Maschinenbau Posted April 16, 2019 Author Report Share Posted April 16, 2019 31 minutes ago, Tucson620 said: Same with Z car - best results by sealing EVERYTHING in the back. Hatch, spare tire well grommets, antenna, etc. Hatch and tail lights were big leak spots - new rubber was cure. You can do a smoke test - rig a shop vac to pull air from sealed cabin. Wave cigarette, etc. around rear, monitor test subject in back of wagon for reaction. So what you're saying is that giant gaping hole where I cut out the spare tire well probably isn't doing me any favors lol 3 Quote Link to comment
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