Project 2ZR Vios, part Deux!

[remcafee]

i am fascinated the amount of effort youre going through to save 5 pounds, every bit helps for sure.

[tmontague]

Wow, I'm impressed and really appreciative if all your work looking into this.

It surprised me at how much weight you can lose when you end up removing a few piles of wire. It also makes things much simpler and straightforward today kse down the road.

In my sub 2000lb car a small amount of weight removed makes a big difference in the way the car handles corners and fast directional changes.

Do you know if the abs is run by this under dash module?

To allow my car to drive to and from the track 20 minutes away I need to keep my head and tail lights and I also prefer to keep my abs for now.

[CrankyOldMan]

Originally Posted by remcafee

i am fascinated the amount of effort youre going through to save 5 pounds, every bit helps for sure.

The irony is that I'm probably going to have to add ballast to make minimum competition weight. For the class I'm building it for, 1.8L engines are about 2400 lbs. Granted, it means I can put it where it needs to go to help with corner balance and front/rear distribution, so it's not a total loss.

I'm an engineer so this is kind of what I do. My brain needs challenges like this otherwise it gets bored and starts inventing problems to solve. =)

[CrankyOldMan]

Originally Posted by tmontague

Wow, I'm impressed and really appreciative if all your work looking into this.

It's my obsessive-impulsive disorder. =D

Do you know if the abs is run by this under dash module?

As far as I know it's all controlled by the ABS actuator in the engine bay.

[remcafee]

yes, the abs actuator is the ecu as well for abs, very neat system, keeps it packaged nicely and responds to brake upgrades very well as it has electronic brake force distribution for each wheel

[Neinris]

OMG! I had another thread confused with this one!

[thebarber]

lawd!

[CrankyOldMan]

Finally got off my arse and installed the roll hoop. With the seat slid all the way back, the bar is only 4-5 inches away and is just the right height for horizontal/upward angle of the shoulder straps.

Next challenge for safety gear is the mounting points for lap and anti-sub belts. The outboard OEM belt attachment point is too close to the seat to allow the lap belt to sit at ~45° and the inboard belt point was part of the seat itself. Looks like I need to put the mounting points into the floor. I'm looking at eye bolts with clips vs bolts with plates and haven't found a clear answer of which is "right". The SCCA rules only specify hardened (minimum grade 5/metric 8.8) fasteners, attaching directly to the roll cage, or using the harness manufacturer's hardware. Lots of conflicting opinions out there about how to prevent pull-through from insufficient reinforcement of bolts through the floor, bending moment loads on eye bolts vs shear loads on plates. Seems like there's too many ways to do it and not enough clear direction from the sanctioning bodies. Maybe there's just too many variables (and too much liability) for any organization to make a definitive statement?

[tmontague]

Love it, hoping to one day fabricate something similar. I'd like to attempt a DIY but it isn't a small undertaking.

[CrankyOldMan]

Thanks, I definitely don't have the tools or skills to do the welding fab myself. Fortunately I have a friend with the gear, time and reasonable prices. He's also interested in driving it so he has a vested interest in doing it right. =)

[Jason@SportsCar]

I have always used the stock outer mount. On the inside both the square plate and round washer kits will work, it just comes down to which fits in the place you are drilling.

[CrankyOldMan]

Originally Posted by Jason@SportsCar

I have always used the stock outer mount. On the inside both the square plate and round washer kits will work, it just comes down to which fits in the place you are drilling.

I moved the seat forward until my extended arms met the top of the wheel at the wrists (someone suggested that for a more comfortable arm position) and it looks like I can probably use the outer mount point from that far forward. Does the bracket need to be free to pivot? The OEM hardware is too large above the shoulder to fit into the opening and I can't find a shoulder bolt that's 7/16-20 thread with a 0.500 shoulder. An eye bolt and clip would allow it to move freely at the expense of a longer bending moment. Hmm...

I've read that the belt should ideally be mounted equally on both sides of the seat, so that puts the inboard mounting point right about where the e-brake cables come through the floor pan (the white rod in the picture from the center). There's probably just barely enough room on the "tunnel" for a backing plate but it would have to be welded to give me confidence in its structural integrity. Otherwise I can use the floor pan next to it, assuming there are no reinforcements or other obstructions directly below.

[CrankyOldMan]

Remember that 5 lbs of weight that I mentioned losing elsewhere? I found a good place to get a few of those. Since this is going to be track-only, there's zero reason for headlights. I already removed the headlight wire harness and figured I could add a little bit of lightness by gutting the headlight bodies. An oscillating tool and a file took care of most of it. Plastic razor blades took off the vinyl letters.

My first plan was to just paint them black and call it a day. Started with a can of Krylon Fusion since it works on plastic. There's some kind of film on the lenses. Not sure if that's from the factory or not but it's discolored at the top, possibly from heat/being under a tarp. No problems with adhesion. The orange peel was pretty awful and a grey Scotchbrite pad didn't do much for it.

I grabbed a can of Duplicolor Perfect Match (Black Sand) to see how well it works. Goes on OK, had a lot of clouding and splotches. Might have been my technique, might have been the humidity in the open garage. For science, I decided to try wet sanding. Started with 1000 grit, then 1500, finished with 2000. Still pretty bad orange peel, so I went back to 1000 for a little more deliberate scrubbing. It looked great wet, so I didn't go back up to 2000. Got a can of clear acrylic lacquer and gave it the beans. Turned out pretty "meh" if I say so myself. The pictures don't do justice to just how amateur my rattle can skills are. ;) I was going to worry about it but then remembered that these will be eating a LOT of bugs, grit, tire boogers and exhaust fumes so they don't have to be showroom quality. Done.

[Leegamer]

Oh man, that is so sick.

[tmontague]

That looks great, well done Sam.

A true track car looks great from far but is far from great. It isn't supposed to be pretty, just fast.

Have you ever though about cutting a vent in the bumper below the left headlight for a direct fresh air flow for the intake? I did that on mine a while back and it seems to keep the intake air temps within reason in the middle of summer.

[CrankyOldMan]

Originally Posted by Leegamer

Oh man, that is so sick.

Thanks, it's an interesting look for sure.

Originally Posted by tmontague

That looks great, well done Sam.

A true track car looks great from far but is far from great. It isn't supposed to be pretty, just fast.

Have you ever though about cutting a vent in the bumper below the left headlight for a direct fresh air flow for the intake? I did that on mine a while back and it seems to keep the intake air temps within reason in the middle of summer.

It's definitely not pretty up close. I've learned that lesson at the track when I do flags and communication for the SCCA and VSCDA--looks pretty on the track, looks sketchy in the pits. =)

There's specific rules about where you can put openings and where you can direct air. In some classes you can remove a (round) headlight and directly install an intake duct. Older cars benefit more from that because they had standardized headlights. I can use fog light openings for brake ducts but that's about it.

[CrankyOldMan]

One of the goals with the wiring reduction is to simplify as much of the harness as possible. I'm tracking down every wire, module, connector and device to see what's necessary to make the engine run and comply with the class rules.

The ignition switch is first on the chopping block. I'm required to remove/disable the steering wheel lock and I have zero need for a key, so there's not much point in keeping the lock tumbler. I'll do a separate post about the steering column that includes the quick release hub and the racing wheel.

The ignition switch is essentially a double-pole triple-throw (DP3T) configuration but is actually a rotary switch with the ability to connect multiple outputs on a single armature. That means two inputs, each with three outputs. Each key position has unique connections for each armature: OFF is no connection on either; ACC is armature 1 (AM1) to Accessory Power (ACC) only; ON is AM1 to ignition 1 (IG1) and ACC, armature 2 (AM2) to Ignition 2 (IG2); START is AM1 to IG1, AM2 to IG2 and Start 2 (ST2). It's all shown in the attached PDF.

When you turn the key to ACC, you get power to the shift lock ECU, radio, power mirrors, cigarette lighter/outlet and a signal to the main body ECU so you can use power windows. When you turn it to ON, ACC is still connected and IG1 and IG2 circuits get power. That's pretty much everything in the car. To maximize power to the starter, anything on the ACC power circuit doesn't get power when you turn the key to START. That's why your radio goes off when you crank the engine.

Turning the key to START is fairly straightforward: send a signal to the ECU (STSW) and initiate closing the contact on the ST Relay, which fires the starter solenoid and closes the motor contacts in the starter. For M/T, the clutch must be fully depressed to keep the relay coil energized; for A/T, the transmission must be in Park or Neutral. I'm not 100% on how the ECU keeps the coil energized for the "key once and it cranks until it starts or times out" but it has a separate output (STAR) that connects to the coil and an input on the other side of the clutch or Park/Neutral switch to know if those contacts are closed or not.

The IG1 and IG2 outputs give power to pretty much everything else in the car that isn't hooked directly to the battery, either directly or through a relay. Lots of spaghetti to untangle on those two circuits but I'm making progress. Fortunately, a lot of those wires are contained in the main engine harness so there's not much to be done with that one. The big mess will be all the stuff that goes back into the cabin.

I don't/won't have any of the things on the ACC circuit in the car, so that means one whole position on the switch can be eliminated! The IG1 and IG2 positions can be done with a double-pole, single-throw switch (DPST) and the START switch can be a momentary toggle or pushbutton. How's that for race car? =)

[CrankyOldMan]

I did this one a while back, just now getting around to documenting it.

The car came with a Sparco wheel and hub adapter. The wheel is a Sparco R375, I think. It's pretty nice. It also had the basic Sparco hub adapter but I wanted a quick release to make it easier to get in/out when the cage goes in. I went with the NRG 2.0 SFI-rated hub (SRK-200-1BK) and got a short hub adapter (SRK-R120H) to reduce the stick-out distance of the wheel. I may go back to the Sparco hub to get a better combination of arm and leg position but for now it's got the short hub in it.

The NRG SFI-rated quick release doesn't have the bits for a horn button and doesn't have the release button that their standard models do. It's genuinely one-handed operation, which is nice in the event of an urgent exit.

The SCCA rules require that the steering wheel lock is removed/disabled to prevent it accidentally engaging. It's integrated into the key switch mechanism so that needs to be disconnected first. The bolts that hold it on are designed to shear off the head when installed as a security measure. The easiest way to get them out is with a cutoff wheel and a flat head screwdriver. In my case, it's not going back on so I wasn't careful about damaging the raised part of the clamp/bracket.

The lock has a spring loaded "tang" that engages the steering column at certain points. The lighting wasn't great so you can't really see where it goes, but somewhere in that hole is a slot that it engages. It could theoretically be removed from the key switch assembly but this is a spare column that I dissected and I don't have the keys for it (you need to unlock the tumbler to remove it from the casing). When I do this on the one still in the car I will try and remember to document that process.