Discussion in 'Subaru Sambar' started by banzairx7, Mar 12, 2020.
Nice! is that with the stock pulley?
Yes stock pulley. Turns out the two pulleys I had waiting in the wings had the wrong bore size. They were for the AMR500 supercharger. I assumed they were the same. I have another pulley due in tomorrow that I hope I can mod to work.
Got the new pulley on tonight. New pulley is 55mm OD and the stock one was 61.3mm. Boost went from 7psi to 9psi. Power is most noticeable at low to mid throttle. Was able to buy an alternator pulley and modify it to fit. It needed a spacer to go behind and had to have a keyway cut in it. I also had to put on a shorter belt. I could put this into kit form if there was interest.
I am very interested in the complete intercooler setup as well as the tuning maps as soon as you work out the kinks! PS I have a 95 Dias with the EN07Y and I assume the engine setup is identical with the truck one
This intercooler set up is kind of complicated and I'm not sure it would fit a van. I'm into it for probably $500 + my time so not cheap. I've also found it does require a fan which I'm in the process of adding. That means I need to add some kind of control for it. I've got a pressure switch and time delay relay on the way. The time delay relay will keep the fan from cycling off and on constantly. Basically when you hit boost the fan will stay for like 10 seconds regardless of what the boost is doing.
Just out of curiosity: Why aren’t you using a thermostatic switch. Set up so that if teh temperature on the exit header of the inter cooler is however hot, the switch closes and the fan comes on. The switches are pretty inexpensive, and readily available.
I had that thought too. Problem is by the time the intercooler would be hot enough to trigger the switch I'd be behind the curve. Everything would already be hot. If I go by boost pressure I'm cooling before it gets to the point the heat starts hurting power.
Honestly I keep inching closer to ditching the stock ECU for reasons like this. If I had an aftermarket ECU I could use the air intake temp sensor(or MAP sensor for pressure) which reads really quickly to trigger the fan.
Was back at the dyno yesterday. Since my last runs I made an intake, got the intercooler fan set up working and put on the smaller supercharger pulley for ~1.5psi more boost. Results were up but a little lower than what I expected. I'm now @ 62hp at the wheels. I think either the throttle body or exhaust is a bottle neck at this point. Not that 62hp isn't great for this little guy. That means I'm making ~73hp at the engine and stock it was rated at 55hp. A 30% increase in power is pretty good.
The last few weeks I've been trying to figure out what to do with the exhaust. Where I ended up is if I'm redoing it from scratch I'm just going to replace the supercharger with a turbo. The supercharger right now is really loud so that's reason one. I'll make more power at the same boost level with a turbo. They are more efficient and I won't have the parasitic drag of the supercharger. Last thing is turbos just make super cool noises! I ordered up a RHB3 knock off turbo, it is tiny. Compressor map though shows it's a good match for this motor. At 10psi of boost and peak power @ 7k rpm I'm right in the sweet spot of the turbo.
you are a true tinker-er!
love reading your stuff & going: man thats way toooo involved for me.
10 psi of turbocharged intercooled boost would be massive.
While you're going crazy, why not go with an air to water intercooler system, and put its radiator up front where it gets max airflow? I see lots of room for one behind the grille of my '93...
Really wanted to go with an air to water but can't find an intercooler small enough. Everything is sized for "normal" engines. The ports & core are massively oversized for what is needed. Smallest I've found is 2 1/4" connections and I need more like 1 1/2". That would leave me making a custom core which I don't really have the time for.
The turbo conversion has begun! Using an RHB31 turbo. 1 1/2" up pipe to 2" exhaust. There was no room for a muffler so i'm using a magnaflow cat to quiet things down. Turbo is mounted up high to make the oil drain much easier and give me room for some kind of exhaust piping. I found an air to water intercooler from a Honda jet ski that is small enough to fit in the engine bay.
Turbo is mounted(turbo outlet isn't clocked properly yet)-
Hot side is all done minus an exhaust hanger-
Here are some shots of the intercooler and the front heat heat exchanger. The heat exchanger is actually an RX-7 oil cooler. I'm using a VW auxillary coolant pump to circulate the water.
It's wild how much space the bulky stock exhaust takes up.
This looks like a huge undertaking, I'm interested to see how much top end gain there will be once the turbo kicks in.
Looks awesome! You probably gonna killing a little horse power with that cat. Anything after turbos impedes exhaust flow adding back pressure. Turbos themselves act as mufflers so it was likely not neccessary unless you are going for completely stealth.
Lessons learned from my 900 hp TT Camaro.
theres not gonna be anything stealthy about this mini.... from the cooler out front to the turbo...
im with you he might as well just run an open pipe out the back.
I do have neighbors and I'm fine with killing a few HP for it to be quiet. I don't think I'll lose any power. The turbo outlet is only 30mm. 2" exhaust is huge for this thing and the cat is meant for a MUCH larger engine.
You will lose some how much is the question. I've done dyno runs back to back with full exhaust vs cut outs after the turbo. The turbos were more responsive and power was increased with cutouts open. But then again I'm talking about mid mounted turbos and full car length 3" exhaust.
I really wouldnt expect much sound other than turbo noises on your setup. When I had turbos +mufflers on my cammed 6.2L it was stock quiet.
Either way..awesome build you got going!
Been a few weeks without an update, weather is a bit toasty so drive way truck work is not a lot of fun. My other project car gets to live in the garage with the AC. Front mount air/water intercooler heat exchanger is in. Using an RX-7 oil cooler for this duty. Sort of guessed on what might fit and it turned out to be perfect. I did have to trim a bunch of the grill away for clearance.
This is so damn cool. I'm excited to see how the intake ducting turns out.
Ran it on the dyno today. Power isn't exactly where I wanted it but it's up. Maxed out @ 67hp at 12psi. The stock ECU is what is holding it back now. It wants A LOT more timing. The more timing I added the more power it made. I've got the distributor maxed out for advance right now. Also there is an ECU boost cut somewhere north of 13psi.
The unfortunate news is I have to move the truck along to a new owner so I won't be doing the ECU. We inherited a 1984 Corvette recently from my wife's father. My driveway and garage are over flowing now(Mazda6 Wagon, Mazda3 sedan, Lotus 7 replica, Sambar & 84 Vette). The Corvette has sentimental value so it wins out over the truck.
So here are some videos. First is on the dyno and second is accelerating from a stop to about 50mph.
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