Harlan's Impossible turbo build.
You keep trying to re-invent the wheel 
12-03-2014, 06:50 PM
#152
Turbo is installed. WI is installed with the exception of wiring. The brain is setting on my desk. Car is leak tight and driveable with 4psi wastegate (and a very careful right foot.) Had to ditch the battery and use an ultracapacitor for starting because of fitment, as well as ditching the SOHN adapter because there was no way to make it fit with the turbo downpipe.
The whole thing looks pretty horrid, but it works. Dunno if I want to post pictures, it really is an UGLY baby. I think I'm going to scrap the whole intake/maf and just run a map converter. It's a lot more headache, but probably worth it in the end. I can't figure a way to put a decent sized maf/air filter in the bumper (to keep it away from indirect WI spray) and make it look semi decent. Also MAP is more reliable for boost/vac leaks.
Oh and the OMP sensor is a rotary encoder (similar to an old telephone). It sends out pulses that the ECU reads to determine OMP valve position. The ecu just adds the pulses in the open direction and subtracts the pulses in the closed position. This directly to the OMP table, 60 on the table is 60 pulses open. It is NOT a switch.
The whole thing looks pretty horrid, but it works. Dunno if I want to post pictures, it really is an UGLY baby. I think I'm going to scrap the whole intake/maf and just run a map converter. It's a lot more headache, but probably worth it in the end. I can't figure a way to put a decent sized maf/air filter in the bumper (to keep it away from indirect WI spray) and make it look semi decent. Also MAP is more reliable for boost/vac leaks.
Oh and the OMP sensor is a rotary encoder (similar to an old telephone). It sends out pulses that the ECU reads to determine OMP valve position. The ecu just adds the pulses in the open direction and subtracts the pulses in the closed position. This directly to the OMP table, 60 on the table is 60 pulses open. It is NOT a switch.
12-04-2014, 06:27 PM
#155
Got on the road today with the knock detection and headphones. The knock lockout isn't hooked up yet and the WI pump isn't wired or plumbed to the tank yet so I took it really easy. I did however get the wastegate to open momentarily at just under 4psi so I guess I am officially boosted. No significant det, which is good. The knock controller and boost controller are wired. I can see boost pressure as well as the voltages off my MAF and IAT from my lcd display. Need to put in the calibration tables for the MAF and the IAT so they will be readable, but no worries.
The ultracapacitor bank will start the car quite easily, and can be left for more than a day and still turn over the car. But don't go out and get one yet... If I leave the ignition on with the air blowing and the radio on it can drain down the ultracapacitor bank too low to start the car within <5minute. I'm gonna hide a deep cycle battery somewhere and set it up to charge when the ignition is on, and at all other times maintain the capacitor >=battery voltage. So for now I have a jumper pack in the trunk just in case.
Here are some pictures of the engine bay. I haven't had a chance to even clean it out yet so don't mind the leaves, they are just there to provide extra kindling if the oil line bursts and drenches the exhaust manifold.
Oh and the hemostats are there to minimize air into the oil reservoir. This keeps it at a vacuum and prevents the turbo drain piping from backing up and causing smoke. I'll be putting an orifice in there shortly.
The ultracapacitor bank will start the car quite easily, and can be left for more than a day and still turn over the car. But don't go out and get one yet... If I leave the ignition on with the air blowing and the radio on it can drain down the ultracapacitor bank too low to start the car within <5minute. I'm gonna hide a deep cycle battery somewhere and set it up to charge when the ignition is on, and at all other times maintain the capacitor >=battery voltage. So for now I have a jumper pack in the trunk just in case.
Here are some pictures of the engine bay. I haven't had a chance to even clean it out yet so don't mind the leaves, they are just there to provide extra kindling if the oil line bursts and drenches the exhaust manifold.
Oh and the hemostats are there to minimize air into the oil reservoir. This keeps it at a vacuum and prevents the turbo drain piping from backing up and causing smoke. I'll be putting an orifice in there shortly.
12-04-2014, 09:27 PM
#157
WI tank/pump are now plumbed in, all that's left is to power the pump and hook up a tie down for the tank. Also just finished adding the IAT cal to my display so I can now read actual IAT and boost pressure. MAF is next.
To do: (In no particular order)
Add the relay for knock lockout.
Get WI running based on MAF IAT and knock.
Put the Boost controller in service and aim for next plateau at 8psi.
Replace flexable hose with a proper charge pipe. (Maybe see if a Air/water inter cooler will fit in that empty space...)
Convert to MAP based on stock ECU with a translator.
Replace intake with something less... crappy.
Wire up and mount the IGN-1A coils.
Wire in AUX battery.
Re-wrap down pipe and re cover with foil tape.
Route wires to make them look pretty.
Clean leaves out from under the hood and all around.
Make a snazzy looking display for inside the car to tie it all together.
To do: (In no particular order)
Add the relay for knock lockout.
Get WI running based on MAF IAT and knock.
Put the Boost controller in service and aim for next plateau at 8psi.
Replace flexable hose with a proper charge pipe. (Maybe see if a Air/water inter cooler will fit in that empty space...)
Convert to MAP based on stock ECU with a translator.
Replace intake with something less... crappy.
Wire up and mount the IGN-1A coils.
Wire in AUX battery.
Re-wrap down pipe and re cover with foil tape.
Route wires to make them look pretty.
Clean leaves out from under the hood and all around.
Make a snazzy looking display for inside the car to tie it all together.
12-04-2014, 11:13 PM
#160
I've gotten just beyond napkin doodling stage on the MAP translator. So far I can read the IAT, MAP, and RPM from the engine easily. I can also create a 0-5volt signal that the stock ECU will accept as a MAF input. It's really just a few simple lines of code and then calibration. There are a few off the shelf units available, but it should be relatively easy to whip one up. (Famous last words)
Funny thing is that it doesn't even have to be that precise, especially at the high end, nor does it have to refresh that fast. It just has to give the engine a good enough signal to manage timing/fuel. >10 times per second with .02volt accuracy on the output will probably work fine and be as good as a stock MAF when VE is calibrated.
Funny thing is that it doesn't even have to be that precise, especially at the high end, nor does it have to refresh that fast. It just has to give the engine a good enough signal to manage timing/fuel. >10 times per second with .02volt accuracy on the output will probably work fine and be as good as a stock MAF when VE is calibrated.
12-05-2014, 07:51 AM
#161
SPOOLN8
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So why did you go with that capacitor rather than buy a smaller sized battery or relocate to the trunk like most top mount guys?
Also, you are going to need some kind of intercooler if you plan on pushing any sort of boost in that thing..... I see you mentioned a water-air intercooler, I don't think that is going to be enough, if i recall from the past I don't think many people have had alot of luck with them on this site and especially when you plan on mounting it next to your turbo....
Also, you are going to need some kind of intercooler if you plan on pushing any sort of boost in that thing..... I see you mentioned a water-air intercooler, I don't think that is going to be enough, if i recall from the past I don't think many people have had alot of luck with them on this site and especially when you plan on mounting it next to your turbo....
12-05-2014, 10:25 AM
#162
I went with a capacitor bank rather then a smaller battery because of the cranking amps our cars require. The battery tray is just too small to fit a properly rated battery, and just getting one close enough that would fit the size would be expensive. It just made more sense to pay a few bucks more and have something rated for the amps.
Trunk mount is another option, but then I'm running really beefy cables all the way to the trunk (through the people space). Low volts DC does not like to travel long distances, and 2kw is 170amps at 12volts. So in order to do it right you should be running at least 1AWG. Then you have to worry about either ventilating the battery or getting an AGM battery to prevent the possibility of explosions. It all starts to add up fast.
This way I just run skinny leads to a cheap sealed deep cycle battery of my choosing and don't worry about the rest. I'll probably rig up something using a couple of LiPo packs. Not a big deal.
The biggest reason I went with the ultracapacitor bank was I though it would work well while being different and fun. I was right.
The car will never need an intercooler because the water injection will be enough. There is space for a water-air intercooler and I may use one eventually depending on how much pressure I end up running, but that's doubtful because I expect to reach the limits of the tires/drive train before I get that high.
Gotta go and finish getting the WI online. Then I can start playing at 4psi.
Trunk mount is another option, but then I'm running really beefy cables all the way to the trunk (through the people space). Low volts DC does not like to travel long distances, and 2kw is 170amps at 12volts. So in order to do it right you should be running at least 1AWG. Then you have to worry about either ventilating the battery or getting an AGM battery to prevent the possibility of explosions. It all starts to add up fast.
This way I just run skinny leads to a cheap sealed deep cycle battery of my choosing and don't worry about the rest. I'll probably rig up something using a couple of LiPo packs. Not a big deal.
The biggest reason I went with the ultracapacitor bank was I though it would work well while being different and fun. I was right.
The car will never need an intercooler because the water injection will be enough. There is space for a water-air intercooler and I may use one eventually depending on how much pressure I end up running, but that's doubtful because I expect to reach the limits of the tires/drive train before I get that high.
Gotta go and finish getting the WI online. Then I can start playing at 4psi.
12-05-2014, 10:36 AM
#163
SARX Legend
iTrader: (46)
Mad Scientist **** 
I am using a PC925 in the trunk and high quality 2AWG welding cable. With the new S2 starter it fires with barely the bump of a key. I don't drive the car often but when it is not in use it sits on a Nico tender.
I am using a PC925 in the trunk and high quality 2AWG welding cable. With the new S2 starter it fires with barely the bump of a key. I don't drive the car often but when it is not in use it sits on a Nico tender.
12-05-2014, 11:22 AM
#166
Driving my unreliable rx8
I think the air water intercooler will be fine as long as you use a big enough radiator. All the petite guys have them.
I don't think water alone will be enough to cool it. Well sure it might be enough but it will rob tons of power at the volumes you'll need alcohol in the mix i think and you'll still have a point where the loss beats the boost gain at a fairly low boost number..
I don't think water alone will be enough to cool it. Well sure it might be enough but it will rob tons of power at the volumes you'll need alcohol in the mix i think and you'll still have a point where the loss beats the boost gain at a fairly low boost number..
12-05-2014, 12:41 PM
#167
Water injection is now working, but I'm not getting the flow I expected from the injector. I'm showing about 4gph at 80% duty cycle, when I expected twice that. Might be from line losses, or maybe my math was bad somewhere, but either way I'm going to swap to the larger injector soon.
The knock cutout is on hold for a little while. I keep getting a spurious knock signal, it can happen even with the engine off. Might be that I have the sensitivity to low, or maybe there is some sort of flaw in the code that pops at random. Either way more testing is required. So for now the det phones are my safety net. Gotta get this resolved before I go further.
Yes, I will be producing less power at every pressure with WI because it's all about air density. I really couldn't care less about psi vs HP. This just means it will take more pressure to hit my goals, and that's ok. Adding alcohol does good things and bad things, I believe for most applications it's overrated. Yes there will come a point where water isn't enough, but that's beyond anything I plan on accomplishing.
On a side note though I might start running windshield washer fluid because of the chance of freezing, at least until spring.
Anyway, I gotta drive a little bit!
The knock cutout is on hold for a little while. I keep getting a spurious knock signal, it can happen even with the engine off. Might be that I have the sensitivity to low, or maybe there is some sort of flaw in the code that pops at random. Either way more testing is required. So for now the det phones are my safety net. Gotta get this resolved before I go further.
Yes, I will be producing less power at every pressure with WI because it's all about air density. I really couldn't care less about psi vs HP. This just means it will take more pressure to hit my goals, and that's ok. Adding alcohol does good things and bad things, I believe for most applications it's overrated. Yes there will come a point where water isn't enough, but that's beyond anything I plan on accomplishing.
On a side note though I might start running windshield washer fluid because of the chance of freezing, at least until spring.
Anyway, I gotta drive a little bit!
12-05-2014, 02:55 PM
#168
So far I've blew off an intake coupling twice. Had my wife tow me home the first time because I couldn't find it, second time I fixed it on the spot. Now I have a new clamp on the intake.
Then I blew off an exhaust coupling... Some redesign will be required, but damn the car is quickly becoming a beast.
I saw 9psi momentarily, but that was when the throttle closed. I need some good logging to know for sure what pressure is hitting with the throttle open.
Oh and here is a picture of the preturbo water injector. It's aimed for the center of the compressor wheel to prevent turbo damage.
I'll get a better picture and maybe some video the next time I have the intake off.
Then I blew off an exhaust coupling... Some redesign will be required, but damn the car is quickly becoming a beast.
I saw 9psi momentarily, but that was when the throttle closed. I need some good logging to know for sure what pressure is hitting with the throttle open.
Oh and here is a picture of the preturbo water injector. It's aimed for the center of the compressor wheel to prevent turbo damage.
I'll get a better picture and maybe some video the next time I have the intake off.
12-05-2014, 03:38 PM
#169
for those who are doubting the AI abilities to cool the charge without an intercooler should look at BDC's thread on 7club....I personally wouldn't run without an intercooler, but it is possible to do so
12-05-2014, 04:48 PM
#171
Its actually fairly well documented...
Posted From RX8Club.com Android App
Posted From RX8Club.com Android App
12-05-2014, 05:27 PM
#172
12-06-2014, 02:09 PM
#173
OK, here's an update. I hit around 10psi last night momentarily... Didn't heard any loud detonation on the det phones. The "silicone" tubing I had used for the WG reference melted, took out my signal line for MAP too since they tap off the same port. So that took out one input to WI.
I'm really glad the WI was set to trigger on IAT and det signal as well. It kept the water in and prevented serious consequences. Need to fix then detonation detection/lockout, but so far I've put in enough fail-safes to cover my butt. If it had been a sustained boost and not a momentary tap on the throttle it could have been different. It also helps that timing is very retarded and AFR is pig rich after 100%load.
MAF based WI is not enabled in the code yet... need to fix that too.
Got initial data to set up a MAP to MAF translator. Got the density vs IAT table written, now I need to figure out the math on getting a .5volt signal to correspond to 5.5g/sec. It's going to ramp up exponentially to 5 volts corresponding mass air flow at 30psi and 120degf. Then it will be all about getting a correct VE table. Pushing this idea forward right now, because if it works it will change a lot of the design of the build.
Also in the back of my mind is welding up a short piece to connect the turbo directly to the intake manifold. I originally planned it that way, but got to the point I just wanted it done and threw together what I had.
Lots to do! So much fun!
I'm really glad the WI was set to trigger on IAT and det signal as well. It kept the water in and prevented serious consequences. Need to fix then detonation detection/lockout, but so far I've put in enough fail-safes to cover my butt. If it had been a sustained boost and not a momentary tap on the throttle it could have been different. It also helps that timing is very retarded and AFR is pig rich after 100%load.
MAF based WI is not enabled in the code yet... need to fix that too.
Got initial data to set up a MAP to MAF translator. Got the density vs IAT table written, now I need to figure out the math on getting a .5volt signal to correspond to 5.5g/sec. It's going to ramp up exponentially to 5 volts corresponding mass air flow at 30psi and 120degf. Then it will be all about getting a correct VE table. Pushing this idea forward right now, because if it works it will change a lot of the design of the build.
Also in the back of my mind is welding up a short piece to connect the turbo directly to the intake manifold. I originally planned it that way, but got to the point I just wanted it done and threw together what I had.
Lots to do! So much fun!
12-06-2014, 03:06 PM
#175
Driving my unreliable rx8
I feel the same way. I so want to be done with my build, but I don't want to go back and forth doing crap over and over. So I'm aiming for everything I could ever need. A lot of it is excessive, but just trying to cover all the basses.
Keep up with it man, don't get over anxious and blow your engine.