DIY Wideband Lambda Controller

Another step closer to turbocharging The Dog, or to any destination point actually since it's not really related to forced induction, i just bought a DIY Wideband Lambda Controller of the net. It's the Sigma Lambda Controller, SLC DIY from 14point7.

Features as copied from the web:

• 0.01 Lambda accuracy
• 4 digit display
• Pressing the face plate button cycles between; AFR, EGT, Boost, display
• Boost reader with optional onboard boost sensor
• EGT reader with optional EGT probe
• 0-5v EGT linear output
• USB connectivity
• RPM Pickup
• Seven 0-5v analog inputs
• Real-time datalogging
• Programmable Linear Output
• Programmable Narrowband Output
• Over voltage protected
• Reverse voltage protected
• Fused design

What interests me the most is that it can read Boost and EGT apart from AFRs. Usually AFR readings are only useful on dyno runs and tuning. Once your ECU mapping is set, you don't really need AFRs anymore. With the feature aforementioned, i can still use the box to read Boost. That's why i opted to buy the Boost sensor as well. It also has an output to communicate with my Megasquirt so tuning should be easier. It works with Bosch 17014 Wideband Sensor.

It's on its way to Indonesia and hopefully will arrive by next week so i can start soldering the parts on the weekend.

High Idle RPM Solved

After installing a custom IACV blockoff plate a few weeks ago, i managed to lower my 4A-GE idle speed from 1500 to 1100 RPM. This is with the idle screw set to max, meaning there's no air coming from the idle air passage. It's still a bit too high as according to the manual, it should be around 850 RPM. Last weekend i went to check further on this problem.

Since the idle screw has been maxed, this can only mean that there's a vacuum leak somewhere on the intake manifold. Hoping that it wasn't the throttle plate needing to be replaced, i went to check the vacuum lines around the manifold. Here's how the lines look when i checked.

Keep in mind that my intake plenum was cut-n-shut to relocate the throttle body to the other side as it was for FWD originally. Notice anything wrong?

See where the PCV line from the cam cover goes? This is obviously wrong. Connecting it this way would always leak vacuum from the cam cover to the intake. Also notice the brake booster vacuum line goes to the inlet near the cold start injector. Originally, this was where the PCV line supposed to connect. I find this also suspicious. Not in a way that it would leak vacuum, but exactly the other way around, it might not even have vacuum. Originally, that inlet has an air passage that goes to the throttle body and channeled out to just before the throttle plate, like so..

With an aluminum plate now in place of where the TB was, this hole might be blocked. Well, you tend to start doubting your engine swap workshop's capability if you find out that they connected the PCV line that way. It was easy to check if they made a channel on the aluminum plate so that vacuum remains. Run the engine, unplug the brake booster line, check for vacuum using your finger. Vacuum's there. Good, they didn't screw up there, at least. I then just need to take the PCV line off the intake runner.

Taking the PCV line off means that i need to get some form of oil container. Commonly known as oil catch tank, this ensures that oil coming out from the PCV line won't mess the engine bay. Failing to find any container to use, i temporarily wrapped it with sponge. My friend Stanley used an aluminum water bottle, didn't you Stan? I think i'll be following your steps soon. With the PCV line off the intake runner, I decided to move the brake booster vacuum line there, hoping it would make bigger vacuum so that it helps on braking with those 4-pot RX7 calipers. Hence, it was the vacuum inlet on the intake plenum that needed to be plugged. I used a braided rubber hose and plugged it with whatever my hands could reach that time, which turned out to be a ziptie and 12mm bolt. Another ziptie to secure the brake vacuum line in place and here's the final result.

Loosen the idle screw a bit, crank the engine, check the idle RPM, adjust the idle screw and there you go, i'm idling at 850 RPM now! Idle speed adjusting screw is now working and I'm really glad vacuum wasn't leaking from my throttle plate. It would be more difficult to solve obviously!

Drama on The Dog's First DCC Gathering

After two years since the project started on Mar 9th 2008, The Dog can finally come with me for her first gathering with fellow Daihatsu Charmant Community members! The gathering was held on a sunny Sunday, Mar 20th 2011 on Senayan Parking area. This was actually a small gathering to discuss the plans for DCC's 5th anniversary next month.

To be honest, The Dog seemed reluctant to join the gathering. She gave me all sorts of drama during the day. First, she refused to start after i stopped by an ATM. Starter motor seemed struggling hard to crank the engine. At first, i thought it was heat soak from the exhaust manifolds so i waited for it to cool off a bit. Crank it again, still struggling. Ffffffuu... Okay, this won't work. I won't bring The Dog to the gathering like this. I have to solve this first. Got a help from a few guys to push The Dog, shift to first gear with clutch on and once she had enough momentum, off with the clutch and there she goes. Definitely something with the power supply to the starter motor.

I quickly head off to the nearest auto-battery shop and told them the problem. They took their battery tester out, checked the voltage, told me to crank the starter, checked the voltage again and scratch their heads. "The battery's fine. Have you checked the starter?", they said. Well, it was the same starter i use on the old engine and it was fine before. So, i asked them if they have any ground cables. Luckily they do, well most battery shop has anyway, and i told them to put more ground cables to the engine block. Here's how the engine looks after.

Notice the bright green-yellow thick cables coming out from the battery? One goes attached to the front of the engine, near the cam gears cover and other one goes to the back. Once done, fingers crossed, turn the ignition key, crank and *vroom*. Wow it worked! I had been suspecting this for a while since i noticed the ground cables were too thin. I was focusing on other problems so didn't really find the time to fix it. Well, now that i have been forced to put the cables, i'm relieved that i did.

That's not the only problem she gave me. On the way to the gathering, i drove on a highway and she decided to act up again by giving me high temperature reading. This reallllyy started to piss me off as she never gave me this problem before. I tried to speed up hoping that the wind might cool off the radiator. It turned out making the matter worse. Fearing i might overheat the 4A-GE, i took the nearest exit and drove slowly to the gathering using alternate routes. Temperature refused to cool off but i decided to keep on going until i finally reached the gathering spot.

Let's stop the drama for a while and focus on the fun part, shall we? Obviously i was a bit late from the starting problem. A line up of beautiful Charmants had already parked on the gathering area. I quickly took my place and was greeted by the guys. Nourie told me to open the hood and took snapshots of my engine. "Finally you finished the car!", they said. Well, a project like this is never-ending but thanks guys! Here's some photos i took myself. Can you spot The Dog?

Quite a few interesting Charmants i saw on the gathering, some packing mods i wouldn't have thought of putting on The Dog but turned out quite well actually. Here's a taste.. How about an Autobot Police car?

or this internet/audio/GPS/Hello Kitty-packed Charmant?

I'll feature one of my favorites soon in another post.

As previously said, we discussed the plans for our next 5th anniversary next month. Some meeting spots have been selected and surveys will be done soon. Also we have some plans to make another batch of T-shirts. During the gathering, we also voted for the best Charmant in some categories like best engine, exterior, interior, etc. We aren't allowed to vote our own car so it should be fair, i guess. Winners will receive some goodies and parts for their Charmants and will be announced on the Anniversary gathering. After the discussion, we then continue to have lunch together before bidding farewell to each other.

Okay, back to the drama. During the gathering and also on the way home, the temperature remained high. I haven't installed my custom lateral rod so i decided to make a quick stop in an autoshop so that i can also check what's causing the high temperature. A quick analysis, i found out that the fan is not turning although the temperature is obviously above the thermoswitch threshold. I ruled out faulty thermoswitch as it's still new and working last week. Unplugged the cable going to the switch and the fan turned on instantly. Okay, fan is good also. Radiator is also brand new so that couldn't be the problem. Three things left to check: waterpump, faulty radiator cap and thermostat. I decided to replace the radiator cap in the shop and carry on to install the lateral rod. Here's the rod installed.

The rod went in easily so my measurements were correct after all. I didn't get to install the 4-links as the shop's about to close.

Anyway, new radiator cap. Let's see if this works. It's was only one or two kilometers drive to my house but it was definitely nerve-wrecking. Temperature's still hot! Arrived at home, turned the engine off, opened the bonnet and waited for the engine to cool off a bit. Opened the radiator cap and turned the engine on again, with ease this time thanks to the new ground cables. Peeked through the radiator cap hole and saw no water flow. Hmm.. this could be either the pump or the thermostat. Pump is less likely as it was okay last week. Decided to open up my remote thermostat housing, 10mm wrench should do it, and took the thermostat off. Went inside the house, mom helped me boil some water over the stove, throw the thermostat in and waited. Hmm.. boiling bubbles started to appear and thermostat remained closed. Waited another minute and still the same. Gotcha! Faulty thermostat! This explains also why my fan didn't turn on. If you checked my writeup previously, you'll see that water flows like this:

radiator --> thermoswitch --> thermostat --> engine

If the thermostat refused to open, thermoswitch will always be exposed to cool water and will never turn the fan on. It's only when the thermostat opens will the switch get hot water and activate the fan!

I was afraid that i have bent my cylinder head from overheating but seeing that there was no water bubbles coming from cylinder compression after i run the engine with no thermostat, it seems my 4A-GE is doing okay. This just goes to show how reliable 4A-GEs are. It ran for a day under high temperature and yet still smiling. I don't want to speak too soon so let's see later if it's still running well.

RX7 Brake Upgrade and Short Stroke Conversion Completed

Took a chance last weekend to fit all the stuff i've been fabricating for the last two weeks. Took only about three hours to fit them in as that's all the time i have. I did the conversion on Saturday and with my bus arriving in Jakarta late, the work's done in the afternoon. Sunday is out of the question as i had to bring The Dog to her very first gathering with Daihatsu Charmant Community members!

Everything went smoothly as planned. The only minor setback came from the short stroke strut hubs that was decided to be replaced with the old ones from the car. Since the short stroke hubs had already been machined fit the Civic rotor, the old hubs underwent the same treatment.

Some pics of the work in progress.. Comparison of the rear dampers..

Fitment of the rear RS*R springs and KYB Gas-A-Just dampers.

Preparing the "HKS purple" front struts for installation.

Installed.. You can reuse your old brake lines for the RX7 calipers. I will find time to upgrade the lines to steel braided ones later.

This one shows you how the spacers will later help clear the wheels from fouling the calipers.

Who's hiding in there.. Oh it's just you, my silly awesome FD caliper!

The 80 series Land Cruiser brake master cylinder upgrade comes next. Bench-bleed the BMC, bend some brake lines, check for air in the brake lines and you're done. This pic should give you an idea of how to bend the lines.

As you can see, you need to bend them quite a bit. Also, although the fluid reservoir is bigger than stock, you don't have to worry about space as the LC BMC is shorter. This will help you give the needed space to clear the strut tower. Here's the finished work. Looks sweet paired with my T3 camber plates.

Money shot. Comparison of the stance, before..

and after..

Sorry for the muddy tires but that's around 30-40mm lower. Not really shakotan-low but just perfect for me.

Comments after conversion? First thing i'd like to point out is the ride stiffness. I'm running 6kg front springs and 4.5kg rears and it's already stiff. I can't imagine how it feels for guys running higher combination like 8/6 or even 9/6. You guys must have kidneys made of steel! Anyway, let's see later how my combination serves my purpose.

As for the brake, they felt great. I'm not experiencing any off-balance between front and rear, squishy pedal nor unpredictability from it. It does feel a bit like the brake booster needs to be upgraded to cope with the larger cylinder diameter but it'll hold just fine for now.

With that done, The Dog has officially been pimped by..

LoL, i think i'm the first guy running Techno Toy Tuning parts here in Indonesia. Am i Gabe?

Custom 4-Links

Measurements will be shared later once i'm sure they fit. Being made from steel, i believe they're heavier than your aftermarket products but should do the job fine.

Spray-painting The Front Struts

Front struts + Metallic Violet Blue + Sandpaper + Bunch of help from co-workers = Instant sweet-looking suspension setup..

Pics don't do judge on how awesome my struts look now! Thanks guys!

I decided not to paint the calipers. Too risky. Might go with one of these poser covers instead.

or not..

Cut Springs and Spring Rate

This has been bugging me for quite a while:

"What happens to the spring rate when you cut it shorter?"

Since i'm a metric guy, spring rate is measured in kg/mm. A 5 kg/mm spring will be one mm shorter if a 5 kg weight is put on top of it while it's still on planet Earth. Stuff tends to behave differently if you measure it extra-terrestrially. Put 10 kg over it and it'll be two mm shorter from its free-weight length. Also we're talking about linear-rate springs here. Progressive-rate springs complicate matters.

My puny logic first thought that spring rate should remain the same as you don't change the spring material when you cut it. Turns out i was wrong. The spring rate increases when you cut it shorter. Googled about this problem last night and found this link. It's an online calculator which tells you the spring rate with some input variables like the number of coils, spring diameter, wire diameter, etc. The formula is below:

K=(G*d)/(8*C³*N)
Where,
K = Spring Rate
d = Wire Diameter
N = Number Of Active Coils
G = Modulus of Rigidity
C =Spring Index, a ratio of Spring Diameter (D) divided by the Wire Diameter (d)

We can see from the formula above that Spring Rate is inversely proportional to the Number of Active Coils (K ~ 1/N). Since cutting a spring basically reduces N, Spring Rate would increase with the same proportion! Example, my Ground Control coilover spring is 6 kg/mm and has 200mm free length. If i cut it 25% shorter to 150mm, i'd also increase the spring rate by 25% to 8 kg/mm.

An analogy i use is to compare two steel rods of the same diameter. One is half the length of the other. The shorter one would be more rigid, right? It bends less than the longer one when given a same load transversely. Wound those rod to the make a spring of the same diameter, you'll end up with one spring half the length of the other.

If we play with the variables, we'll end up with below summary:

1. Higher Modulus of Rigidity yields higher Spring Rate

This is a matter of aluminum spring vs steel spring of the same dimension give different spring rate

2. Increasing Wire Diameter yields higher Spring Rate

You should be able to imagine this intuitively. In case you can't, from the formula above, K is directly proportional to (d/C³) where C³ is (D/d)³ and we end up with K ~ d⁴. This reads to Spring Rate increases to the power of 4 for every increment of Wire Diameter.

3. Increasing Spring Diameter yields lower Spring Rate

By logic, to increase spring diameter, you need to get longer wire. Longer wire is less rigid. Less rigid means lower Spring Rate. Enough? If you prefer the difficult way, K is inversely proportional to C³ , again, where C³ is (D/d)³ and gives us K ~ 1/D³. This reads to Spring Rate reduces by root of 3 for every increment of Spring Diameter.

and finally, back to our main discussion..

4. Reducing Number of Coils yields higher Spring Rate

See above.

This should be equally important to AE86 and Charmant owners:

- Stock OEM Spring Front: 380mm free-weight length and 1.8 kg/mm

- Stock OEM Spring Rear: 360mm free-weight length and 2.2 kg/mm

I didn't measure them myself.. I got this from an internet forum so take it with a grain of salt.

The Dog Currently

Been a while since i posted shots of The Dog. Here's how she looks currently.

I need to get better camera.. *sigh*

DIY: IACV Blockoff Plate and Electrical Radiator Fan Wiring

Did this DIY when i was back in Jakarta a few weeks ago but only got around to write about it now since i just got my Samsung Galaxy S back. The photos below are in the phone. Also the air for my lungs apparently comes from it. Nearly suffocated without my Galaxy S.

The Dog had been running electrical radiator fan since the engine conversion finished but the fan was connected directly to the battery through an engine cutoff switch. Crude solution but it was only for temporary. It was only a few weeks ago that i finally installed proper relay and wiring system for the fan.

I wrote a guide on the wiring last year, you can read about it there. Since my thermoswitch is normally-close type, i am following diagram C from the guide.

As you can see on the diagram, a 5-pin relay is needed. The shops nearby only sell the funny looking kind with some special connector needed. Luckily the pin positioning matched my relay socket.

Using a wire cutter, 5 minutes later problem solved. No cursing involved.

Couldn't also find the special round-shaped thermoswitch connector, i had to cut off the plastics around the metal pin and solder a generic wire spade to the pin.

Forgot to take pics of the installation process, but here's a video of the system in action. You can see my Suzuki Wagon R fan turning off automagically after the temperature is lowered enough. The relays are on the passenger side strut tower.

Also notice how my idle speed is a bit too high. It was around 1500 RPM even on warm engine. The idle speed reduced significantly when i shut the IACV vent hole using my finger, a sign of faulty IACV indeed. Since i am too cheap to buy another one, i decided to just ditch the IACV and replace it with a custom block off plate. Read about IACV here.

IACV is located under the throttle body or TB. It's fixed with 5 bolts. You need to pull off the water lines and some vacuum hoses and remove the throttle body before you can comfortably unscrew the 5 bolts. Here's the IACV paired with TB.

Air route follows red arrows, goes into TB inlet hole, then green arrows into the IACV body and air passage, finally goes into the engine following blue arrows. Normal IACV blocks green dashed arrow route when the engine warms up but mine obviously didn't so i had to come up with this.

Right is the custom IACV block off plate and left is the gasket i made from carton paper. Notice how the bolt hole positions match the ones on the TB. Add some silicone sealer, shorter bolts (old bolts can't be used as my block off plate is too thin) and i end up with this.

Sure as hell didn't cost me US$19.99 to make.

No more air coming into the IACV vent and I'm now idling at 1100 RPM when warm. 1100 RPM is still a tad too high as the manual said it should be around 850 RPM but it's much better. My idle screw has been set to max so no air coming from there. I'm currently suspecting the PCV air passage inside the intake manifold is leaking air from the cut-n-shut work. It could also be a split vacuum line. Will have to check it this weekend.

Here's the block off plate in action.

By the way, ditching your IACV for this block off plate will disable your PS and AC idle up. Don't forget you'll also need to loop the cooling line or block both lines off.