Diff cooler and inline filter
 

update, all finished, see post 30.



I'm making a diff cooler kit. Just curious if anyone knows the size of the threads on the diff itself where I need to install a NPT fitting or something with the other end having an AN line.

Also GTM uses an inline filter going to the pump...summit racing has a million of them. Anyone know the filter size I'll need or flow rate I'd need?

http://i39.photobucket.com/albums/e1...ps49f1bf35.jpg

http://i39.photobucket.com/albums/e1...ps98021986.jpg

edit 11/5/13


We'll if the 350z is the same I believe its a 18mm x 1.5 thread.

As for the filter I'm using a earl 140 micron.

So if anyone out there wants a rear diff cooler and doesn't want to pay $1300 or save $800-900!!!!!!! here's everything you'll need...at least the way I'm doing it.

Final build list

Another great idea synolimit :tup: Good having you around ;)

http://www.gixxer.com/forums/images/smilies/idea.gif Now that I think about it, I'll let mine burn up, giving me an excuse to do 3.90's & a Quailf :excited:

Wish I was making $900 a kit though selling these :(

Heck discount them at $750 :p

Don't tempt me.

This is a good idea. Might be worthwhile to run a switch to the cabin to flip it on when you intend beating on it.

How about a fan to go with this? :D

I am.

So I don't have to drill the diff cover I'm now buying and installing a -8 AN, 1/8 NPT, -8 AN Tee with it as close to the drain hole as possible. This will allow a temp sensor to screw in. When ever I see it get above say 240-260, ill flip the switch.

O yeah, working on a control panel now :stirthepot::stirthepot::stirthepot:

No need. I have no mufflers now. Where this will go is that hole big area where the big OEM muffler used to be. After I build a scoop for it, it will get so much wind down there it won't be funny.

Like a glove.

Still need to add the diff oil temp gauge and maybe a engine oil pressure gauge. What do you think? Oil pressure needed?

I don't think oil pressure is needed, and it's major function to me is that if a fitting comes undone and you lose your oil, you'll see the needle drop way earlier than noticing your oil is gone

Then needed it might be so you pull over ASAP and shut the car off no?

In that sense I guess yes, but I mean the car doesn't inherently have oil pressure problems. And while we might rev the crap out of a motor, we aren't usually towing 5000lbs that we need to watch the pressure to make sure it doesn't go to high, lol...

Yes, the 350Z diff covers are the same. I did not take a look at your fitting selection, but keep in mind. If someone is running a NISMO finned diff cover, they may need a different fitting to connect to the sump.

Also, diff cooler setups like this are easy for install, but can be a PAIN to purge and fill up later. You have to purge the system and then make sure you have the proper level in the diff. The only way you can do that is to run the pump with the line disconnected from the return and allow it to pour into a bucket while filling it up at the same time.

If you drilled into the diff case and put a seperate return port, you could then use the factory fill port as it was intended with less mess. I recommend going this route.

A few comments since I have done a few of these:
- MAKE SURE you put an isolator between the pump and the chassis. The vibration from the pump will be annoying unless you are going hardcore race car.

- Buy a pair of high quality electrical connectors and make the pump removable. Otherwise you will be cutting the harness up later if you have to service the pump.

- While you are attempting to cool the diff. Go ahead and buy some DEI Titanium Exhaust wrap and wrap the exhaust portion near the diff itself. The radiant heat from the exhaust is a contributing factor here.

Some really good pointers there ^^

Subd.. great info in this thread

synolimit,
Two more points that need to be made.

1) The Tilton Pump you have highlighted in that Summit Racing shopping cart is for "intermittent usage only". The pump is not designed to be used continuously.

Check out the Tilton 40-527 model. It is the SAME thing, but is slightly beefier and is rated to be run continuously. I would recommend that model since people often forget to shut things off and may accidentally run the pump longer than Tilton intends.

2) In your shopping cart, you have about 4~5 different fittings from different manufacturers. I saw Summit, Fragola, Russell and others. Most Hydraulic Line builders will warn you against doing that. Mixing manufacturers can cause some serious issues between tolerences and quality. I highly recommend sticking to 1 manufacturer if doable. Otherwise, do no more than 2 in a single build. Choose a good, high quality fitting manufactuer that will offer most of the fittings you need. I generally choose to use Aeroquip myself when doing personal projects.

Subbed. I recently measured and documented the GTM kit on Mike's car in order to copy it on the cheap.

Pretty much what gtm said to do about the fluid. I'm going this route since I don't want to remove the diff cover to drill. Less work=less headache.

Thanks about the isolator. The pumps going into the cabin so not sure if it will matter since I'll be hearing it a few feet behind my head anyways.

I'm going to install just the sensor first to monitor diff temps. I have some wrap so maybe ill wrap later to see if there's a temp drop to confirm that. I have straight pipes though so no a big muffler retaining heat near the diff, but I get the pipes themselves carry heat. Things to experiment with.

I want to run it intermittently while watching the gauge. Being in the trunk I won't forget to shut it off haha. I saw the continuos one but its $25 more. However tilton says its 2 pounds lighter. Not sure how a beefier pump is lighter, but if it really is then $25 is worth it to go lighter and better pump.

As for the fittings, I guess that's a risk I take. Its bull **** whats these ******* things cost and I'm not paying more for a Russell when the earl is cheaper but then earl has another fitting that's more than the Russell. If they leak I'll see it, smell it, replace it after bitching to summit and getting something for free for my headache.

Good thinking. You'll save about $900! Do you know what filter they're using? The Russell I have says for fuel, but whats it matter when its a SS mesh. Its a 40 micron. Earl has one that says for oil but its 140 micron. That's way to big to stop this ultra ultra fine powder. I do plan on buying a 1x1" neodymium magnet and sticking it to the underside of the diff at the drain location since I'm losing the OEM magnet. This should help with the shavings. If I ever do diff bushings, then ill pop the cover and clean out what the outside magnet catches.

Modified the list. I could use less hose, added the gauge and how it will hooked inline and found cheaper parts for some but added better parts for others like the oil filter. Still decided on the pump.

Most everything is from summit because I had a $20 off and their fittings are cheap. The 3 LFA's are from Home Depot because brass NPT is really cheap. And the thread sealer was from autozone. Only thing now is some aluminium 0.05" plate and a diy write up in the diy section.

A little heads up on your filter. Make sure that it can flow 75w-90 cold. Fuel will flow through a 40mic filter awhole easier then 75w-90 will. Do alittle reseach on it. ;) At work, we use 10W all the way to 320. Pressures from 10lbs to 5,000lbs. Every system has filters in it. Pick the wrong filter, you got problems.

Well that's why I changed the filter. It's 140 micron made for diff, engine etc. unlike the 40 micron fuel I had. still not happy about the 140 but installing a neodymium magnet on the bottom of the diff should help combat the shavings to protect the pump.

Just took my longest trip since the diff cooler gauge install. Drove about 45min (80mph) 35 highway and 10-15 min side streets. It was a cold 50 degrees out and the whole time on the highway the diff never stopped rising in temp. It got to 194* before I pulled off. I'm going to have to take a longer trip to see if it goes higher. Interesting to see at such a low temp outside the diff gets so hot. I can't imagine a hot summer day on a race track. No wonder people don't like the OEM vlsd! If you could keep the diff temp at a constant lower temp I bet it performs well-er haha.

http://i39.photobucket.com/albums/e1...ps19044622.jpg

Huh no shi* Good job keep us posted:tup:

No prob. Now I just need to finish it. It will be cool to video say 190* temp, turn the pump on, and watch the temps plummet as the fluid travels through the cooler.

So if anyone was wondering what I'm gonna do about the magnetic drain plug removal, here it is.

This a neodymium N40 magnet. Not even the strongest kind you can buy. But for $9.99 shipped on eBay for two of them in 1x1x0.25" it was worth it. This thing still has me laughing for how freaking strong they are!! One can hold just over 30 lbs and together over 73 pounds. Just playing with them is dangerous for it feels like I can lose a finger! I only installed one on the diff so far and this thing won't be coming off! Its freaking stuck on there. I figure with so much pulling force it will magnetize the inside of the diff and it will catch anything on the inside right where it's placed. I put it on some 0.20" AR500 (AR15 proof haha) steel and as you can see anything on the other side is stuck. I might be placing both on there for more power but we'll see. When I hook up the pump I'll stick my finger in the drain hole and feel around for shavings and decide then.

http://i39.photobucket.com/albums/e1...ps2baa151c.jpg

http://i39.photobucket.com/albums/e1...ps322dec7a.jpg

http://i39.photobucket.com/albums/e1...ps21fe0288.jpg

Just took my first long drive, about 80 miles or so. At 54 degrees out and 75 mph I got the diff temp up to 206 degrees. That seems where it finally tops out under normal driving. Again I can only imagine summer heat and racing and what's happening to diff components with no coolers.

All done. Will post pics tomorrow after my cooler scoop is done getting painted.

So it was 34* out tonight. Not as warm as 54* like the post above, but just driving again on the highway at 75 I was able to get the diff fluid up to 184*. I then hit the diff pump for the first time. Within 30 seconds it dropped to 160*. But it took another 9 minutes and 30 seconds to finish and reach its final temp of 144*. I was hoping for a cooler temp but I guess ill take it.

The reason why I was hoping for more was I know people have said their diff temp can reach 300* on the track. With only a 40* drop from this test means on the track the diff fluid might still reach 260*. I was hoping to go no more than 240* so the diff fluid wouldn't start to sheer off and hopefully the OEM VLSD could still do its job by keeping its temp within a good operating temp. I guess only time will tell now what happens. 4 months of winter to go!

At higher fluid:air temp differentials, heat transfer is greater and you will get rid of heat faster (assuming the cooler area and air flow is enough to get rid of the extra heat). Ie, you may be in better shape than you think.

That'd be good.

Pics...

Pump and lines

http://i39.photobucket.com/albums/e1...ps93c1ffe6.jpg

http://i39.photobucket.com/albums/e1...ps8706a266.jpg

Cooler with no scoop yet

http://i39.photobucket.com/albums/e1...psc4f51eeb.jpg

Notched out arm incase diff flexes to much.

http://i39.photobucket.com/albums/e1...ps331bb1ff.jpg

Fill hole

http://i39.photobucket.com/albums/e1...psa3e133de.jpg

Scoop/cage getting painted. Extremely strong so wind can't move it at high speed.

http://i39.photobucket.com/albums/e1...ps969133ba.jpg

Instead of having to look at the gauge to know when to turn the pump on, you should look into getting a temp control switch. Cuts power on when it's at xxx degrees and shut off at xxx degrees. Might take some guess work and cut down on one less distraction on the track.

The pumps good for an hour. Events are probably no more than 30min. I'll probably just run it from beginning to end. A switch isn't bad but having it kick on daily idk.

Just wanted to update this since it's been warm out now. My normal driving diff temps in the summer have been around 210*. I kicked the pump on for a few seconds yesterday and it dropped to 192* but I hit traffic and tuned it off. I can't wait to see real track temps. It's going to be insanely hot.

I was on highway last Saturday night for about an hour average 130mph and got my whole rear bumper covered with LSD oil, now I'm thinking about doing the same thing. I am going to use a 16 row cooler and maybe another 10 row cooler in series since I have them laying around already. How did you come up with this motor? Do you think a higher flow rate motor would help the temperature better?

You can have too much flow. The fluid doesn't spend enough time in the radiator. May not be a problem for you but something to be aware of. Lots of info on heat exchanger design, heat exchanger calculations, and heat exchanger equations on the Web.

That's what I was wondering. I'll need to find out the appropriate flow rate motor.

I am impressed with the thoughtfulness and record keeping on this DIY -- great job!

I may have missed this, but what is the target temp range for optimal performance?

On this matter, I have to confess, I am utterly ignorant, so I could only imagine this in regard to what I know of engine oil, but diff oil undoubtedly has very different characteristics...

If you have a clear target, maybe a thermostat could be incorporated? No need to over cool, which may or may not be happening when switched on.

Either way, nicely done and thanks for sharing! :tup: