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Tony Hanna
06-01-2006, 02:55 PM
... as to how much boost you could safely run on a T1 (non-intercooled) mitsu setup with methanol injection? I'm just wondering if the cooling/detonation resistance from the methanol would be enough to find the limit of the mitsu turbo (I'm guessing ~22 psi without the restriction of an intercooler in the system)? I know the little Mitsu is going to be making some really hot air at that point which is why I'm asking.
Thanks,
Tony

Frank
06-01-2006, 03:35 PM
I bet you could get 25psi, but the real question is if you will make more power at 25psi as 22psi. Dyno testing is in order! LOL.


Frank

Tony Hanna
06-01-2006, 03:46 PM
Thanks Frank. I just got the exhaust worked out, and it's boost creeping like a champ now. I figured I'd do a quickie methanol injection setup and fool the map for now and just make use of the boost. When I get back to work later I'll add an intercooler and decide which turbo I want to go with.

cordes
06-01-2006, 11:07 PM
I think that 20-22 PSI would be very doable from what others have posted. Should make for a fun time.

Tony Hanna
06-02-2006, 10:04 AM
I've actually seen 20+ out of a mitsu before but that was with the wastegate shimmed completely shut, through an intercooler, and the weather conditions were ideal (cold and damp). It was enough to light the tires up in a Daytona in 1st or 2nd without any clutch abuse, but the power would fall off pretty quickly in the upper rpms. It made the car feel really quick and it was an absolute blast to drive, but in reality it wasn't very fast.
I expect this will be about the same as long as the methanol will keep detonation under control with no intercooler. It should be fun for awhile until I can get an intercooler installed and save up the coin for a turbo.

Frank
06-02-2006, 10:11 AM
If you were to use tons of methanol, it will be like an intercooler, but it will need to be injected right after the compressor and also will need to be in enough quantities that it takes care of all your fueling issues beyond stock.


Frank

Tony Hanna
06-02-2006, 11:00 AM
If you were to use tons of methanol, it will be like an intercooler, but it will need to be injected right after the compressor and also will need to be in enough quantities that it takes care of all your fueling issues beyond stock.


Frank

That's the plan :thumb: . I may even go a little further with it and blind the map at 10 or 12 psi, then take over with the methanol from there.
So, you think I should put the nozzle right after the compressor outlet? I was going to put it in the comp to tb hose spraying right into the throttlebody to lessen the chance of spraying against the hose and running back to the compressor. You're probably right, as hot as the air will be, I guess puddling won't be an issue.
My main concern right now is finding a place to mount a large enough reservoir. Since I'm going to be relying on the meth for fuel over such a large psi increase, I don't want to run out. I'd really like to have at least a 3 gallon capacity, but I don't want to put it in the trunk this time (the 6 gallon marine tank I used in the Daytona was a bit overkill). Any thoughts on what to use for a reservoir and where to mount it?
Thanks,

Frank
06-02-2006, 11:48 AM
3 gallons with a hobbs switch should be good to kick on at 8psi and over. I would then also run the hobbs switch to switch a vacuum solenoid from your normal g-valve to straight vacuum to really clamp it down tight on the wastegate.

Tony Hanna
06-02-2006, 12:48 PM
3 gallons with a hobbs switch should be good to kick on at 8psi and over. I would then also run the hobbs switch to switch a vacuum solenoid from your normal g-valve to straight vacuum to really clamp it down tight on the wastegate.

Hmmm. I've got an old vacuum reservoir off of some sort of GM laying around.
How's this sound? Use a solenoid to switch between straight manifold vacuum to the wastgate (low boost) and stored vacuum from the reservoir (high boost). That way on the high boost setting, both the spring pressure and the vacuum stored in the vacuum reservoir would be working together to hold the wastgate closed. I'm using a bleed for boost control right now, and I could even work that into the low boost side so I could go above 5 psi on low.
I'd probably still have some creep issues, but with the alky on a hobbs switch, it would keep me from doing any damage, and chances are if I'm winding it hard enough to get creep, I'll probably be on the high setting anyway.
Now I just need to figure out what to use for an alky tank and where to mount it. Since I'm keeping the ac, space is at a premium. I'm thinking in front of the core support would be ideal, but that would make it a pain to fill.
Any ideas?
Thanks,

Tony Hanna
06-02-2006, 10:08 PM
Well, it's looking like I'm going to have to go with a 2.5 qt universal coolant reservoir. The only way I could work out to mount it is to go with a smaller battery and mount it in the battery tray. There's just no room anywhere else without running clear back to the trunk. Hopefully the 2.5 qt will be big enough that I don't have to fill it more than once a day. If not I guess I'm looking at another boat tank in the trunk setup.

Whorse
06-02-2006, 10:24 PM
Is there any room for something long that would fit by your windshield wiper motor and resevoir?

cordes
06-03-2006, 03:42 PM
Some of the coolant resivours for the GM trucks are pretty big. They have the low liquid switch in them too.

Tony Hanna
06-03-2006, 03:55 PM
I had thought about putting something between the ww pump and wiper motor, but that would have me building a custom tank. I think I'll try out the universal reservoir for now. It should be good to get the system set up and if it emptys too fast, I'll try to figure a way to mount something bigger like the truck coolant reservoir.
Thanks for all the help. I'll keep you guys posted on how it works out.

zin
06-06-2006, 02:11 AM
I believe it was some of the Nissan IMSA cars that were using Alky and no intercooler and making silly amounts of power. The big trick was that they were running at least 20% of the fuel needed by the engine up-stream of the throttle bodies (shortly after the turbo). This acted as their intercooler and it worked very well. I guess it's going to come down to how much you can pump into the thing without overfueling it. Sounds like it should be fun!

Mike

Tony Hanna
06-06-2006, 02:55 AM
I believe it was some of the Nissan IMSA cars that were using Alky and no intercooler and making silly amounts of power. The big trick was that they were running at least 20% of the fuel needed by the engine up-stream of the throttle bodies (shortly after the turbo). This acted as their intercooler and it worked very well. I guess it's going to come down to how much you can pump into the thing without overfueling it. Sounds like it should be fun!

Mike

That's the beauty part of it though. If it takes enough alky to cool that I'm overfueling, I'll just blind the map sensor at a lower voltage (take out some gasoline). I need to build some sort of adjustable zener diode so I can change the clamp voltage. Maybe a 3 volt zener in series with a potentiometer so I could blind the map anywhere between just below cutout down to 3 volts. That should let me pull enough fuel to get decent afr while still spraying a bunch of alky.
Any thoughts?

zin
06-07-2006, 01:46 AM
I see what you're saying, trade some Alky for some fuel. The trick way to do it would be to slope one in while the other comes out. Not real sure how to make that happen though. One way to do a simple switch would be to run a solid state relay that would be triggered by a pressure switch to cut the voltage seen by the computer via a resistor or pot. I'd suggest using the pot to allow you to fool around with it till you find what works (cut in points, etc), then maybe use a fix resistor to ensure nothing changes. The relay would need to have normally closed and normally open closed pins, that way the voltage could "pass through" on the normally closed side and give normal fueling till the Alky kicks in. It would be a good idea to hook it up to a toggle switch so you could pick and choose when to use the alky. Of course there is always 100 ways to skin a cat and this is just one.

Mike

Tony Hanna
06-07-2006, 01:00 PM
That sounds like it would work great Mike, but it's a little more complicated than what I was planning. I was just thinking of blinding the map with a zener diode and a potentiometer and then setting the pressure switch for the alky to kick on a psi or two before it starts to lean out from losing gasoline. I know it'll go pig rich for a second until the boost comes up, but as fast as the mitsu builds boost, I doubt it'll cause a problem.
Your realy idea I may run with though. If I put a relay in series with the zener diode and potentiometer, I could run it off a pressure switch in the alky line.
With a setup like that, if a problem occurred with the alky system like a pump failure or running the reservoir empty, it would throw the map back to normal operation and cause cutout instead of leaning out and doing damage. I could even build a second safety into the system and use the same pressure switch to switch a vacuum soleniod to lower the boost back into a safe range.
The only down side I could see to that would be finding a pressure switch rated at a high enough pressure (40 psi would work) that would handle methanol.

Tony Hanna
06-07-2006, 09:48 PM
Ok, I need an evaluation on this by some of you electronically literate guys.
I think I'v got the perfect little rig designed to adjust the map voltage cutoff point and act as a safety if the alky system should fail.
What do you guys think? Please excuse the crappy ms paint diagram.

zin
06-07-2006, 10:30 PM
Looks good, if I'm understanding the circuit correctly. The diode is tapped into the sensor return (variable 0-5V), in order to bleed off any "excess" map sensor voltage? The pot will allow tuning of the cut-off point. Having pin 87a (normally closed) remain open ensures the full/accurate Map voltage to the computer if the system is inactive. If the relay is activeated, then the voltage can be bled off. The activation of the relay is controlled by the pressure switch, therefore no pressure, no cut-off. Can't see why it wouldn't work as intended.

Tony Hanna
06-07-2006, 11:27 PM
Looks good, if I'm understanding the circuit correctly. The diode is tapped into the sensor return (variable 0-5V), in order to bleed off any "excess" map sensor voltage?
Right, With the pot adjusted to 0 resistance, the zener would clamp at 2.9 volts effectively stopping the computer from seeing any more by shunting the excess voltage to ground.

The pot will allow tuning of the cut-off point.
Right again, as the resistance increases by adjusting the pot, it takes more voltage to get the zener to clamp raising the voltage that the computer can see from the map. Hopefully if I got the right range pot, I should be able to adjust it all the way to cutout (4.3v) if I should want to, or anywhere between that and 2.9 depending on how much gasoline I need to pull to get the afr right with the ammount of alky I'm spraying


Having pin 87a (normally closed) remain open ensures the full/accurate Map voltage to the computer if the system is inactive. If the relay is activeated, then the voltage can be bled off. The activation of the relay is controlled by the pressure switch, therefore no pressure, no cut-off. Can't see why it wouldn't work as intended.
Hopefully, if I don't foul anything up when I assemble it.:p
On top of that, the relay I'm using is a DPDT so I've got another contact to play with. I may use it to energize a vacuum solenoid to send boost pressure straight to the wastegate can in the event of an alky system failure.
That way I'll have sort of a double safety.
I need to pick up some wire, connectors, solder, and a soldering iron tomorrow and I'll throw this mess together to see how it works.