Performing Honda K24a3/AST5 6spd Conversion

lookforjoe said:
Unfortunately, with the 4.7:1 (!!) diff, it taps out long before :(

I don't understand why on earth it would be geared that way. Our car is so light, we just don't need that tall gearing.
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Is your drivetrain JDM or USA? I think I remember Matt telling me that the JDM stuff was geared very high. I am assuming that is because of tight, windy mountain roads in Japan, and probably draconian speed limits, but I don't know.
 
Pete Whitstone said:
Is your drivetrain JDM or USA? I think I remember Matt telling me that the JDM stuff was geared very high. I am assuming that is because of tight, windy mountain roads in Japan, and probably draconian speed limits, but I don't know.
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JDM. US is a little lower, but still (EDIT) 4.7:1 (!), I believe. 4.10:1 or 3.98:1 would be preferable. I mean, it's not the end of the world since I have no reason to be driving well over 100 anyway. 100 is still ok in terms of rpm's in 6th :D
 
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More wiring....

Keyless entry wired, stereo & BT microphone wired.

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All switches from '80 style wired in, adding a (round) switch on either side of the console for my heater valve and cooling fan override (one hole drilled on right).

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Only one of the AC fittings arrived - the rest of the order is MIA, and of course the vendor is closed on Fridays after noon.

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Had to remake the glovebox insert - the older one I cut up (from the parts car) was missing the locating tabs underneath - without them, the base bows upward,and the lock does not release.

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Dash & switches done for now.

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Remade the low side(#10) hose. 135º fitting at compressor, #12 MOR, welded to #10 beadlock hose barb. Nice & relaxed fit now.

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It's clear of the bulkhead - just looks like it's close

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Made a modified #8 elbow fitting - didn't need to remake the hose with this.

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Hopefully it holds vacuum now.
 
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Can't find the source of the vacuum leak in my AC system. Can't see any oil residue on any of the fittings I made, which would to me be indicative of a leak. The only obvious leak has been the short hose to the condenser. I recrimped the line fittings with the #6 die following Tony's suggestion.

Not sure I didn't over do it :D

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Hussein, The crimp looks good. I have crimped them tighter than that. Do you have a gas bottle? I made an adapter from my Argon bottle to the AC manifold and put 300 PSI on the entire system. Then spray all of the connections with Fantastic house hold cleaner. Small leaks will appear like aluminium corrosion and big leaks will make big bubbles. Stop messing with the vacuum all you will do is draw more moisture into the system.

TonyK.

Grimsby Ontario Canada.
 
TonyK said:
Hussein, let's look at this a bit more. When the accumulator was frosted like in the picture was the expansion valve picture taken at the same time? I know now that you have an expansion tube, but frost should be starting there. Two things come to mind. If the frost is from the expansion tube to the accumulator then you do not have enough air flow over the evaporator. If the frost is not at the evaporator lines but is at the accumulator, you have too much charge in the system and the bulk of the expansion of the gas is happening after the evaporator in the return lines and accumulator. Keep in mind that the ambient air temperature will have some affect on all of this as well.

Just one other thing that I have noticed with bead lock crimps, from time to time you may see one leak at the hose crimp, install the next smaller die in the crimp set and give it a bit more crimp. some of the hoses and some of the fittings have just a bit different diameter and the crimp needs just a bit more on it to get a correct seal. I have had this happen a few times and recrimping with a smaller die has solved the problems.


TonyK.

Grimsby Ontario Canada.
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Hey Tony - I could use your input.

I reinstalled the re-crimped hose, and the system held vacuum (drew down for an hour, left for another hour), so I charged it again -added about 20oz of R134a. With the system operating, I had even temps on both sides of the evaporator, equal to the frost I had on the accumulator.

Duct temp is 30º below ambient.

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ambient temps in the 50's

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The thing is, I kept thinking the freon was leaking as the compressor wouldn't kick in after I shut the engine down & then restarted & turned the AC back on. I had the same problem when charging - I had to bypass the low pressure switch to start the compressor. Now, if I bypass the low pressure switch, the compressor will run. If I then reconnect the pressure switch, the compressor will continue to run until it is turned off, and then the same thing happens. Is it likely I just have a flaky low pressure switch (using the factory Fiat-supplied switch) ?

EDIT - looking for a generic AC binary switch that will thread on to the Four Seasons 33176 accumulator schraeder valve fitting - those don't need the system evacuated like the Fiat one...
 
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The FSM indicates that the low pressure lockout switch trips at 40 +/- 5 psi. Page 50-8 under the heading "Compressor clutch and minimum pressure switch check". What is the pressure in your system with the compressor not running?
 
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lookforjoe said:
Hey Tony - I could use your input.

I reinstalled the re-crimped hose, and the system held vacuum (drew down for an hour, left for another hour), so I charged it again -added about 20oz of R134a. With the system operating, I had even temps on both sides of the evaporator, equal to the frost I had on the accumulator.

Duct temp is 30º below ambient.

IMG-20200318-162657.jpg


ambient temps in the 50's

IMG-20200318-153733.jpg


The thing is, I kept thinking the freon was leaking as the compressor wouldn't kick in after I shut the engine down & then restarted & turned the AC back on. I had the same problem when charging - I had to bypass the low pressure switch to start the compressor. Now, if I bypass the low pressure switch, the compressor will run. If I then reconnect the pressure switch, the compressor will continue to run until it is turned off, and then the same thing happens. Is it likely I just have a flaky low pressure switch (using the factory Fiat-supplied switch) ?

EDIT - looking for a generic AC binary switch that will thread on to the accumulator schraeder valve fitting - those don't need the system evacuated like the Fiat one...
Click to expand...
 
ng_randolph said:
The FSM indicates that the low pressure lockout switch trips at 40 +/- 5 psi. Page 50-8 under the heading "Compressor clutch and minimum pressure switch check". What is the pressure in your system with the compressor not running?
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Rest pressure on the low side with system off is over 50psi.
 
When working on AC systems in cooler temperatures the gas bottle pressure is often below the kick in pressure of the AC min pressure switch Temperature so you have to jump the low pressure switch to get the gas to flow. Or put the bottle in a bucket of warm water. So when the air temperature is low and when filling by pressure or the use of a scale by weight the bottle pressure most likely will not force enough refrigerant into the system you are charging. By running the compressor you can draw gas into the system to get the pressures in the operating range. Since the stock Fiat pressure switch is only a low pressure protection for the compressor it will not kick out on high pressure and allow the system to work through expansion until the compressor is required to work in the cycle again. When charging after pulling a vacuum, make sure your manifold valves are both closed Then open the low to charge I have run around in circles not being able to charge the system only to find that I did not have the high side valve completely shut on the manifold. Make sure that the expansion is happening in the evaporator. If you have frost all the way back to the accumulator and in your set up it is far, then you do not have enough air flow over the evaporator and the system is really producing greater than 30 degree differential.

TonyK.

Grimsby Ontario Canada.
 
Most systems use a temperature switch to keep them from running at lower temperatures. You may be running into this.
 
TonyK said:
Sorry see above.

In other words, I think you have it, just wait for some warmer temperatures and see how it preforms.

TonyK.
Grimsby Ontario Canada.
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kmead said:
Most systems use a temperature switch to keep them from running at lower temperatures. You may be running into this.
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This must be it - it was not working earlier in the day, then when it got up around 60º, it switched OK.

Played around with the idle control for a bit - I put the idle valve back on with a restrictor in the bypass feed port, limiting the air passage. With that, the idle is around 1000-1500, which is tolerable. Trouble is, with the AC on, the load drops the idle to around 800, which would be OK if it didn't stumble when compensating. I have no system input to the IACV for the AC compensation, since that was handled via CANbus on the Honda. I need to find another way to implement an idle compensation, whioch honestly sucks.
 
lookforjoe said:
This must be it - it was not working earlier in the day, then when it got up around 60º, it switched OK.

Played around with the idle control for a bit - I put the idle valve back on with a restrictor in the bypass feed port, limiting the air passage. With that, the idle is around 1000-1500, which is tolerable. Trouble is, with the AC on, the load drops the idle to around 800, which would be OK if it didn't stumble when compensating. I have no system input to the IACV for the AC compensation, since that was handled via CANbus on the Honda. I need to find another way to implement an idle compensation, whioch honestly sucks.
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Hussein, you are so close to the answer it will hit you in the face when I tell you the solution. Abarth swap has the same issue, solution, install the X1/9 idle up AC air valve. The ECU will see the change in MAP value and adjust the injectors accordingly. Feed the solenoid valve from the clutch wire of the AC compressor. On the Abarth it works so fast that you really have to pay attention to a very small hiccup in the idle.

TonyK.

Grimsby Ontario Canada.
 
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