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WaterH said:
I’m going to get some measurements and maybe one of the “cad guys” can figure How much difference an inch makes.
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If you want to fill out the 4 link calculator I can help with that. If you want to do the location part of shock page as well, with the airbags as the coilovers, I can get more accurate results. I can also provide driveshaft data as well if you fill out that page.

Suspensions using panhard bars are more likely to have oversteer / understeer behavior as you raise the suspension.
 
Treefrog said:
If you want to fill out the 4 link calculator I can help with that. If you want to do the location part of shock page as well, with the airbags as the coilovers, I can get more accurate results. I can also provide driveshaft data as well if you fill out that page.

Suspensions using panhard bars are more likely to have oversteer / understeer behavior as you raise the suspension.
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I must be senile. Cant find the link calculator. I’ve actually used it before. In a search, I get “adjustable link calculater” which is a thread about it, but not it.
 
WaterH said:
I must be senile. Cant find the link calculator. I’ve actually used it before. In a search, I get “adjustable link calculater” which is a thread about it, but not it.
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irate4x4.com

4 Link Calculator

The long used 4 Link Calculator. Though it may have changed a bit. Features in the newest version include: Analysis of 4 link, and limited analysis of 3 link with panhard, 4 link with panhard Front, rear, and vehicle analysis Imperial and...
irate4x4.com irate4x4.com
 
Ok, broken record time.

Two weeks ago, both relays on the AC fans fry. Cut one open. The selinoid snaps fine, but the contacts don’t conduct. Black dust all over everything. I had two spare relays that I swapped in. Since I know it wasn’t “fly back” and I know the polarity is correct, I could only figure it was bad ground. (I had ground trouble on the radiator fans and added another ground wire) so I add a ground wire to the AC fan frame. I ordered two more relays because I’m fixin to go on a 2000 mile round trip in a couple days.

Today my wife and I make an hour long trip and the AC fans quit. Son of a B, this is really getting old. This time the relays are not at fault. The 50 amp mega fuse blew. I noticed the wire from the fuse to the relays was kind of melted. This is aircraft wire that is Teflon coated. If it is melted, it got hot. Installed a new fuse and turned on the fans. The wire is very warm. Not too hot to hold, but definitely warm and that’s only after 30 seconds of run time. This is not a small wire. It’s about 8 or 10 gage. You sure would think it could handle 44 amps of fans. I guess I’m going to run 6 gage wire.

Anybody got another idea?
 
Bebop said:
You don't know what gauge wire you used ?
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It’s aircraft wire and says on the side, but difficult to see right now. The wire part measures .200” . The factory wire on the fan measures .160” with the rubber coating. Inside I imagine it’s about .120”.

Question, can the wire getting hot blow the fuse? Normally, I think of the fuse blowing to prevent the wire getting hot.

Along time ago I measured these fans amp draw at 22 amps each. Is it likely they draw more with age? They still move lots of air. I have two fans that I bought used and two that I bought new. I don’t know which are in the AC.
 
Any bad connections (power and ground) or corrosion will raise resistance, which raises heat. Like Treefrog said, throw an amp clamp on there & see what you're actually drawing amp-wise. Then, size your wire & fuses or breakers to match. If you had a shitload of spark bites on relatively new relay contacts, your relays might be stuttering - that'll eat into the million-cycle design with a quickness.

EDIT: and Bebop did the thinking for you - just wire that mu'fugger right, already :flipoff2:
 
ExWrench said:
Any bad connections (power and ground) or corrosion will raise resistance, which raises heat. Like Treefrog said, throw an amp clamp on there & see what you're actually drawing amp-wise. Then, size your wire & fuses or breakers to match. If you had a shitload of spark bites on relatively new relay contacts, your relays might be stuttering - that'll eat into the million-cycle design with a quickness.

EDIT: and Bebop did the thinking for you - just wire that mu'fugger right, already :flipoff2:
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I think my amp clamp busted. I need to get another. As far as wire size, it appears I have one 4 gage that’s getting hot. Two 10 gage is not going to cut it. I’m going to get some light battery cable.
 
WaterH said:
I think my amp clamp busted. I need to get another. As far as wire size, it appears I have one 4 gage that’s getting hot. Two 10 gage is not going to cut it. I’m going to get some light battery cable.
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There is obviously something wrong with the part and/or the install.

There is no way a 4 gauge wire isn't cutting it.

Oh wait... you don't now what gauge wire you're using. It went from 10 to 8 to 4 AWG in the span of 3 messages.
 
Bebop said:
There is obviously something wrong with the part and/or the install.

There is no way a 4 gauge wire isn't cutting it.

Oh wait... you don't now what gauge wire you're using. It went from 10 to 8 to 4 AWG in the span of 3 messages.
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I wonder if something has gone wrong suddenly. I can’t believe it has been that hot all this time. Maybe a wire has rubbed through somewhere?

I have tons of 16 and 12 gage aircraft wire. I knew it was thicker than them. I guessed 10 or 8. I just goggled wire gage and it said .200” was 4 gage. That’s how I came up with 4 gage. No conspiracy here.
 
If you don't have an ammeter, you could at least test voltage drop across each component and wire run in the system - that would tell you if you have high resistance somewhere. Wish I was closer, this stuff is peanut butter sammich simple to me. FYI Bebop is an actual wiring guy - feed him good information (not guesses) and he can give you wiring gospel.
 
ExWrench said:
If you don't have an ammeter, you could at least test voltage drop across each component and wire run in the system - that would tell you if you have high resistance somewhere. Wish I was closer, this stuff is peanut butter sammich simple to me. FYI Bebop is an actual wiring guy - feed him good information (not guesses) and he can give you wiring gospel.
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So I just came from two different hardwRe stores and HF. None of them have a clamp meter that measures DC amps. I can’t remember if the one I busted did that. (It was for freezer work) I know I measure the amps on the fans way back when, but I guess I had an amp meter gage. I probably still have it and will look for it.

When I did measure the 22 amps, it was in open air. How much would you expect the amps to go up in front of a condensor?

MattS said:
Is this new wire or old? Old shit that is all corroded will get hot AF.
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Was new about two years ago. Don’t see any corrosion. The truck is in a garage most of the time.
 
Bebop said:
Marginal. Maybe 10 to 20%
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That’s kind of what I thought. Right now I’m going to add a 12 gage wire (or two) redundant to the big wire and see if that cools the big wire. I want to order a bigger aircraft wire, but I won’t have it for my trip.
 
So I googled DC clamp meter and HF has one that measures DC amps. I clicked “check stock” at my store and they say it’s there. When I was there, none of them did DC.
 
WaterH said:
That’s kind of what I thought. Right now I’m going to add a 12 gage wire (or two) redundant to the big wire and see if that cools the big wire.
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FUCK NO

Assuming the resistance of a piece of wire is negligible, it will split the amperage in half in both circuits and will overload your smaller wire.

Run one wire per fan and if you MUST use multiple wires for the same circuit, use identical wires.
 
Measure in "in rush" current of each fan when switched from off > on. It is common for a fan to draw 30 amps at startup and drop to 22 amp continuous. Now add the fact that these are AC fans that may cycle on/off just like the compressor clutch.
Each on cycle adds more amps, over time this translates into heat = melted wire / blown fuse.

Absolutly resolve any inadequate wiring.
 
RustyC said:
Measure in "in rush" current of each fan when switched from off > on. It is common for a fan to draw 30 amps at startup and drop to 22 amp continuous.
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The last HP spal fan I measured had an inrush of 95amp for a steady state of 17amp.

It's wild how much draw there is during the start up phase.

Another reason why the brushless ones are so good.
 
Bebop said:
FUCK NO

Assuming the resistance of a piece of wire is negligible, it will split the amperage in half in both circuits and will overload your smaller wire.

Run one wire per fan and if you MUST use multiple wires for the same circuit, use identical wires.
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It’s done with a 10 gage wire. I turned the fans on and neither one gets hot. Hard to say if they even get warm because it’s 90+ in my shop.

RustyC said:
Measure in "in rush" current of each fan when switched from off > on. It is common for a fan to draw 30 amps at startup and drop to 22 amp continuous. Now add the fact that these are AC fans that may cycle on/off just like the compressor clutch.
Each on cycle adds more amps, over time this translates into heat = melted wire / blown fuse.

Absolutly resolve any inadequate wiring.
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Fans are DC.
So this is my amp meter.

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Can’t say it’s great, but it appears to work. I measured both fans separately. Both of them peg the meter during startup. After that, one goes to 21 amps and the other about 19.

So what is the prediction here. The wires will get hot after more time? (I had them on for about three minutes) Will the fuse blow? I put another 50 amp in it. Will it fry relays? Will it work for my 2000 mile trip? I will be doing some upgrades when I get back.
 
AC being Air Conditioning.

I would not trust that ampmeter for inrush current. It may not react fast enough. A digital clamp on is much better.
 
RustyC said:
AC being Air Conditioning.

I would not trust that ampmeter for inrush current. It may not react fast enough. A digital clamp on is much better.
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Well it pegs anyways, so no info for inrush. The inrush is not what I’m worried about. There isn’t much inrush in my system because I turn them on until I shut them off. (They don’t cycle with the compressor) I have a delay timer on the second fan, so the inrush is not at the same time. If the inrush blows a 50 amp fuse, I’ll put a 60 in there. (The 50 has worked for 12,000 miles)

Im just courious why that big wire gets hot with approximately 42 amps continuous. I don’t believe there is any wire rubbing the frame because that would make it hot even when the fans aren’t triggered.
 
So before my long trip, I wanted to see if I could lower my EGT numbers. As it stands, I’m at about 1000 cruising at 60 mph. That’s not great, but when I hit a hill, it’s easy to hit 1200 or more if I want to hold 60. I’m talking about Florida hills, which really aren’t hills. My trip is to the Arrondack mts. In NY. (Yes I know it’s spelled wrong)

I allready have a water/air intercooler on the truck, but it is plumbed in to the radiator. Since that water is around 150 on the cold side, it’s probably not cooling much. Some guys run a complete separate system to a little radiator. I really don’t like the idea of that because I would need an expansion tank, pressure cap and overflow tank, in addition to the cooler and fan.

I came up with the idea of pumping the engine coolent from the cold side of the rad to a new little cooler and then on to the intercooler. That way, the 150 degree water can be cooled some more right before the intercooler.

I bought this cooler / fan setup from Summit. It looks not bad for quality, but I don’t really think Derale is a good brand. I had to buy new larger fittings to plumb into my existing system.

DB22F987-5FDB-407F-AF6F-AD3630BF48AE.jpeg


I needed a shroud to run air to it. I had a duct from the front that dumped air in front of my radiator. I didn’t think it made much difference, so I decided to run it to this cooler. First thing to do was bend a flange. You can buy these ready made for up to 3” duct. Of course, my duct is 4 1/2”. Ive made these in the past with my bed roller. It works, but it seems there must be a better way.

This is after one minute.

B0FF3EF8-CD68-4296-8896-0CF07D30E077.jpeg


This is after five minutes of hard work.

4E0740CE-EF3F-42C0-89FD-4C7AAB55567F.jpeg


This is after half an hour and I’m ready for a drink.

6BA7A484-203C-4ABC-82DE-423D973AB9C2.jpeg


I fabed this up pretty quick.

01BDDF4E-38E9-4C0E-BEB1-B99C6E66CD68.jpeg


AECE8920-D43C-4105-868E-96B1E766FEAD.jpeg


Then it was on to a mount. A couple hours of shitty welding and I have this.

10E68A54-7A78-479D-A62E-C3398BE1EDC2.jpeg


It kind of looks like this. (except they weld better than me)

C463D200-DF70-4840-9B49-1229AA5B3C4C.jpeg


Anyways, all together I have this.

03D2BD8B-E51A-40B1-BDEA-B05EB3F2CF82.jpeg


I bolted it to the T-case cross member and plugged the duct on. Amazingly enough, it was perfect in length. Just got it done the night before I left.

Today I drove about 300 miles. On flat ground, at 60 mph, it runs about 40 degrees colder EGT. (1020 to 980) That sure didn’t seem to be worth all the work. But I did notice that I could hit a decent sized hill and hold 60mph at 1200 EGT. That was definitely an improvement. The bigger difference was it seem like I had more power at a lower boost. For example, normally I’m running 17 psi to go 60 on flat ground. Now it will do it at 15 psi. I would say it is 2 psi less across the board. Of course, I don’t care about the boost. I just want the EGTs to go down.

In other news, both relays on the AC fans fried. The fuse is good, the wires are good. The AC worked good all day and failed as we were locating a hotel. Tonite in the hotel parking lot, I wired one fan direct. Those fans are so powerful, I believe it will be fine. I have two 100 amp relays with me, but they are going to have to wait till I get to my friends house.
 
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