Hey Guys, I am new to Kei-trucks but have been a wrench turner most of my life. Gotta be honest though, my KS3 Sambar is the first carbureted motor that I have ever had to work on. Seems that upgrades would go much easier if there was a way to convert from carbed to TBI. Has anyone attempted or succeeded in this?
Yeah, I am thinking more TBI (Throttle Body Injection) which is a type of mechanical fuel injection vs a full re-wire + ECM/ECU addition to go full EFI. It's a nice middle ground that would allow for a turbocharger setup and intake modification.
fletch, Please Tell us more what you did, with pics and details! I don't remember past posts on this. Limestone
You're going to have a hell of a time with boost enrichment and boost timing retard if you're relying on a rudimentary control system. Don't be afraid of a few Here you go, it was actually quite simple. I have $855 into the conversion and have full spark and fuel control. And all the crap left over: My next step will be a little turbo with a goal of about 75hp, lets see where the weak link is in these engines. I know I can keep my timing and AFR safe, it's just a matter of what those little bitty rods can handle.
Man...that does seem pretty easy. My normal subie tuner at MZM here in Austin was recommending a Garrett GT06 or RHB31 for a turbo setup. I guess worst case, if I screw it up I can re-use the Microsquirt on the EN07Y I'll end up replacing the carbed engine with and go SC/TC on it...lol
@fletcher0780 How's your build doing? I was planning on doing a similar setup with a turbo. What's your duty cycle on the stock injector at the top end? It looks like that Honda throttle body only has a 240cc injector stock which I would think you'd be getting pretty close to the limits on, especially if you try and add a turbo. I see that you can get a 550cc aftermarket from DeatschWerks intended for the CRF450R that uses the same injector as the throttle body you have. Calculators say for 3 bar fuel, the 240cc is good for about 40hp and the 550cc would be ~75hp.
It's actually fully complete. I went a different direction and used a Holley Sniper EFI 550-552 setup. TB is good for up to 2BAR of pressure, so an AMR500 will be in its future as well. Working on a write up now, but here are a couple links for the build: https://www.facebook.com/customautoatx/posts/114147151229248 https://www.facebook.com/customautoatx/videos/543985620389341/ https://www.facebook.com/customautoatx/posts/109891818321448
That looks like it comes with a 100lb/hr (1050cc/min) injector, that should be plenty. That's not a bad setup either.
That Holley is interesting, are you using it for ignition? You're 4 cyl, but it also only shows setting it up with 4, 6, or 8 cyl, with the Daihatsu 3 cyl we could probably set it up as a V6 and just treat 4,5,6 as wasted spark I would think. The throttle looks interesting on it as well, I see in your picture you have what looks like a bent aluminum bar for a cable mount and an opposing spring connected to something on the IM? Just thinking about options, still leaning microsquirt, but I like how it simplifies a lot of things. Significantly less wiring, includes wideband and display out of the box, no 4 wire iacv controller, etc. But I also don't quite understand how it would work with the factory position sensors/timing yet for ignition.
No, still using OEM coil/distributer for ignition. Spliced into OEM coil/tach signal for timing. Yes, return spring connected to static position on intake manifold just to ensure no stuck throttle. Unsure about a 3 cylinder utilization; would probably reach out to Holley for that particular question if you went that route.
Hey @fletcher0780, did you end up chucking a hair dryer on your setup? Would love to hear how that part went!
The injector is 400cc, I haven't seen more than about 60% DC at 6500RPM and 100 kpa. I ended up buying an AMR300 supercharger that I have yet to install, but am going to aim for 10psi. The truck has been running solid on MS and the Honda TBI for over a year though, I don't miss the carb one bit.
That's excellent news, I've been collecting parts and slowly getting other projects done. I have the throttle body and a few related items, but lately been building bumpers, installing lift, and just driving it. My stock carb is still happy as can be, but it won't be with boost. A little boost would definitely wake this engine up I'd think. I don't need it to be a rocket ship, but some of the hills around here are painful.
Boost definitely helps. In the interim I have gotten both a Supercharged KV3 and a Supercharged KV4 Maleza. Running meth/water injection on the stock AMR300 with a catch can/separator just to ensure no blow-by makes it back into the intake. Looking at the possibility of a SLIGHTLY smaller pulley on the 300 to get above the 8psi level it runs. I think an AMR500 might be a bit of overkill, but it with an oversized pulley might be in the future too!
I used PLA, then painted with engine enamel, holding up so far. https://drive.google.com/file/d/117jSMh2Pi4duytDu7DNO3GGaUbr4RA3l/view?usp=sharing
