Archive for the Subframes Category

Ups and Downs

Posted in Delays, Subframes, Suspension on May 15, 2012 by David de Regt

It’s been an interesting month.  Soon after the last post, I decided that nothing was coming in soon enough and that I should just bring the car in to get painted.  I had Showcase Auto do it, and it came out great (for a racecar — painting carbon fiber body parts is never fantastic unless you put 20 pounds of paint and bondo on it, hence removing the point.)

I got the car back a week and a half ago, just in time to try to put all the new parts that arrived on it.  The Ciro Designs wing came in, and we fabbed up a splitter (currently in revision 1, there’ll be canards and paint later).  The control arms and delrin finally came in, and we spent days assembling the car and finally, this past weekend, had a chance to bring the car down to Packwood for what was supposed to be a 2 day event, getting a ton of runs on the car in preparation for the Lincoln mini-nationals in 2 weekends.

Unfortunately, that was not to be the case.  We took a couple runs in the car, which were pretty good, but quickly started getting some nasty rubbing making the sharp turn to get to the start line from grid.  We ignored it, planning to look into it at lunch.  A couple runs later, we started getting something acting like the car being out of gas in the middle of my dad’s run, and then shortly thereafter it gave out entirely and refused to run any more.  Some quick diagnosing led me to find that the ignition lead was shorted to an always-on battery line somewhere, and it wasn’t obvious where.  In addition, when you shorted the fuel pump on with the diagnostic connector, the circuit main relay under the dash started buzzing heavily, and was rapidly heating up (to the point that the wire insulation was melting).  So, after spending a while with it, we decided to bail and head home to diagnose with more tools and time.

Monday, my dad and I converged on the car and pulled the front wheel off, only to discover something really unfortunate.  The rubbing apparently was caused by the new front control arms pretzeling themselves under the stress of the Packwood bumps, or somethingorother.  I’m working with the EPMiata folks to try to figure out if we have a good answer, or if their arms are just not strong enough for SSM autocross duty.  However, that give us a bit of a major problem.  There’s one more weekend of events (19/20th) and then we have to hit the road Tuesday to get to the Lincoln events in time, which means we only have one more shot to test this stuff out, and it needs to be ready for this weekend.

As a result, just to have a prayer of making it to Lincoln, I’m enacting a fallback plan of using stock front UCAs.  AWR is overnighting me some delrin bushings for them, which come in Wednesday, and I’m putting the V8Roadster ball joints into them.  We’re going to bend them in a press a little bit to get the camber level we need, and run it as is for now to hopefully get some events under it before going with another custom solution of some sort.

I also pulled apart most of the electrics in the car today (pulled the dash, fuseboxes, and relay blocks) to try to figure out the problem.  The only issue I can find so far is that two of the wires in the main fusebox had melted together, which shorted the ignition (white/red) line to another fused always-on line (white/green).  I re-insulated them and separated them, and I will be moving the fusebox to somewhere with more airflow to keep it cool (the event this weekend was quite warm, and I think the splitter was keeping underhood temps higher than usual).  In addition, I should probably add some vents to the hood to let some of the air out, which will likely assist with front downforce as well.  I’m replacing the main circuit opening relay with another I had kicking around from a lower mileage car, and hoping for the best this weekend.

With any luck, I’ll have better news to relay soon.  Tomorrow I get a different used front subframe to swap mine out with (we had to drill the front UCA sleeve out to 5/8″ to use the EPMiata control arms) so I need to get another stock one to put the stock arms back onto, and the delrin bushings come in to reassemble everything.  The real DA shocks come in from Shaikh either late Thursday or early Friday, leaving me a few hours to get the car aligned for the weekend.  From there, hopefully our last minute changes here will keep it running long enough to abuse it all weekend, then head east to Lincoln a few days after that…

It’s Alive!

Posted in ABS, Engine, Subframes, Wiring Harnesses on February 20, 2012 by David de Regt

Yesterday was an important milestone: the new engine fired up in the car for the first time.  I’ve been out of town a fair bit of the last 2 weeks, but I’ve been spending a ton of time on the car, so quite a bit has occurred anyway.

As planned, on the 9th my dad came over and we tore everything remaining out of the car.  The next day, I started working on the ABS changeout.  The first step was removing the old brick, which was pretty painless.  To keep from losing too much fluid, I just threw the lines into the new brick in the right places while I figured out what to do next.  The lines happily went in with the brick facing backwards, but that wasn’t really what I wanted.  I designed the wiring harness to have the brick facing the stock direction, so I needed to fix that.

Talking to Doug, the stock lines should take the amount of abuse necessary to move everything where I needed, so I spent a while slowly massaging the lines into where I wanted them to mount and was fairly happy with the result.  After the supercharger setup is in place, and I know where everything will be in final shape, I’ll cut into the lines and shorten them to be only as long as they need to be, but for now I’ve cirlycued everything to try to keep it as compact as possible while keeping stock line lengths in case I need to move it down the line.  I took the stock 05 bracket, lopped off some unneeded tabs, drilled some new holes into the bottom to utilize some existing threaded holes in the NA chassis, and mounted it up solidly.  This should be about as secure as the stock 05 mounting.

Next, I started on the NB subframe.  I’m switching to the NB front subframe for the better suspension pickup geometry and better steering rack.  Unfortunately, I didn’t realize just how many parts are involved with this.  I had the rack and the subframe, not realizing that a ton of parts changed compatibility between the generations as well.  So, at this point, I just swapped out the subframe and ordered a bunch more parts from Panic Motorsports and moved onto the wiring harnesses.

I pretty heavily modified the transmission harness.  The stock harness runs a battery cable all the way down the PPF to the trunk.  I’m switching to a 2.5 lb LiFe EVO2 battery, and there was more than 2.5 lbs of wiring in the harness that I could eliminate by simply moving the battery up to the engine bay, and also remove the extra native resistance of the super long cable run, to maximize the starting effectiveness of the tiny battery.  As a result, I removed everything rear of the reverse sensor hookups and ran just a couple feet of the battery cable up to by where the stock fusebox goes, where I’m now mounting the battery.  I made some quick battery and ground cables and I was good to go.

Next the front harness went in.  I wasn’t sure how everything was going to line up, so at this point I just threw it in the engine bay, to make sure it lined up with the transmission harness, that it could reach the ABS unit, and that I didn’t miss anything obvious.  Surprisingly, everything seemed fine.  Wiring is everywhere, but who cares — it’s run, and, more importantly, so far everything’s happy.  I tried hooking up the ignition switch, turning the key, and everything made the appropriate relay noises it should have, and nothing blew up.  Taking that as a good sign, I moved on.

After everything was done in the car that I wanted with the motor out, I finished putting the 1.6 sensors I need (coolant temp, fan switch, oil pressure) onto the 99 motor, added the clutch and flywheel, and put it in the car.  Corky still hasn’t finished the radiator, so for now I had to ghetto rig up some radiator lines to get everything to line up temporarily.  I got that all working, hooked up all the sensors, filled all the fluids, and tried test firing the fuel pump to see if the fuel system would hold pressure.  Then I got a face full of fuel…

I’m using the M-Tuned dual feed fuel rail, anticipating vastly increased fuel flow over the itty bitty stock rail (on the supercharger setup, not right now).  It comes with a bunch of lines and fittings and adapters.  I was hoping that them being NPT would be good enough to seal, but I was very wrong.  So, on the first spot that leaked, I tried sealing it with Permatec high temp thread sealant, as suggested by several people on multiple message boards.  I let it cure for 24 hours, per the PDF on Permatec’s site, then tried firing the pump again.  That spot sealed up just fine, letting the fuel gush forth from 3 other spots simultaneously once pressure built up.  Talked to a few more people and read more online, and everything pointed to getting yellow double-density teflon tape.  Went to ACE Racing, picked up a roll of it, and re-built the entire rail setup using three full wraps of it on every fitting.  Reassembled everything and fired the fuel pump.  Everything sealed!  For about 10 seconds.  Then it started pouring forth through the spot that I sealed with the Permatec goop.  I pulled that fitting out, cleaned everything off, let it dry, and then resealed that spot with the yellow tape.  Test fired the pump again, only to realize that, now that everything was sealing, the pressure gauge on my adjustable fuel pressure regulator wasn’t moving because I had it hooked up backwards.  I hooked that back up the right way, started the fuel pump again, and was able to actually adjust my base fuel pressure to 50 psi and sit there and watch it pump.  Next.

At this point, new steering rack supplies showed up.  The weirdly sized stock M12x1.25 fine thread bolts and a hard line and power steering pump from an NB arrived from Panic Motorsports, and I quickly installed it all, hoping to put the steering issues to rest.  I got the power steering lines all hooked up and swapped the pump to the NB pump, and the whole system sealed and hooked up properly.  However, I then learned that the NB rack has a bigger steering column output pinion.  More research showed that I needed a new U-joint and a new intermediate steering shaft off the NB to go with the parts.  A call to Panic got those on the way, and, lacking any more drivetrain stuff to do, I went back to the motor.

I’m using the AEM plug and play EMS for 90-95 Miatas.  I bought it for several reasons, not least of which because Emilio touted its ability to run the 99 crank and cam angle sensors, allowing me to run sequential injection and direct fire sequential ignition.  However, it has no out of the box ability to do any of these things, as I quickly discovered.  I spent several hours saturday and sunday hunched in the driver’s side of the cabin, laptop on my lap, swearing at the internet, and periodically causing ear-splitting backfires as I tried to make the damn thing work.  Finally, sunday afternoon, after trying several combinations of things that sounded like it kind of wanted to start, I tried doubling the fuel map (I’d scaled it up from the stock injectors to my new injector sizes,) and suddenly the engine roared to life at 3000 RPMs for a second or two and shut off.  After futzing with the fuel map for a bit, I was able to get it to reliably start and idle at whatever idle value I wanted.  The next step with the motor is road tuning the fuel map, which is going to require waiting until the steering components get in this week, but I’m glad that everything is running exactly how it should.

I spent this morning cleaning up the spaghetti wiring mess, fixing the tach (required soldering in a 1k resistor between power and the tach lead), making a bracket to hold the fusebox into the corner where I want it, and generally zip tying everything down to keep it tidy and from moving.  This afternoon I’m going to work on installing the AIM EVO4 data system and getting it to talk to the AEM EMS, then replace my dash with the AIM.

The race transmission is being rebuilt as we speak at Advanced Autosport, and should ship to me by the end of the week, so I’m using the transmission that came in the car until the new one shows up.  Doug is still working on the rear end swap (putting the diff/ring+pinion in, and adding abs rings to the non-abs axles), so I’m on the stock diff (haven’t even looked to see if it’s a VLSD) until that’s done as well.  Axis Power Racing has sent the seats to the upholsterer and should be getting them back in a day or two, at which point 2 seats, a hood, and fenders will ship out to me, and I should probably end up with them early next week.  So, as things stand right now, next week is looking like when the car will take on semi final shape.  At that point, I can also take the car out on the road and see if this new ABS craziness actually works or not…