577HondaPrelude

I'm in the possess of putting together and testing a trans cooler for my prelude race car. ….and why would I want to do that you ask??

1) I logged trans temp last year and it gets to 300 F!!
2) We add aggressive LSD's to the trans. (more heat)
3) We up our rev limit to 8500+ RPM, (more heat).
4) We up our power by 20-50%, thus more force on the gears (more heat).
5) The front air damns we use all but eliminate any cool air going to the trans case (more heat).
6) Adding an oil filter to the system will keep the oil nice and clean!
7) Every racer I know who is using a H22a has had at least 1 trans go Ka-Boom in the past 2 years! Maybe a cooler / filter setup is just what we need.


For the pump I went with a 12v gear spur pump (2.0 GPM up to 20 PSI) from RB-racing. I went with this type of pump over the diaphragm type because they tend to be more reliable and last longer especially when moving hot oil. At 2.0 GPM that fills the transmission with new oil every 15sec. The oil pump removes oil via the transmission drain hole (fitting used = M14x1.5 to AN-6), it then sends the oil to a Mfactory remote oil filter mount. After passing through the oil filter the oil gets sent over to a thermostat were if it’s cold it then goes directly back to the trans or if it’s hot it goes to an oil cooler (B&M Supercooler 4.5x11x1.5inch) then back to the trans. The return port on the trans goes into the fill hole. The fill hole is M19x1.5 and I could not find anyone who makes a M19x1.5 to AN-6 fitting so I had to do a little custom work by tapping a hole into the fill plug (1/8 NPT). I also made a simple bracket to mount the pump and oil filter to the fire wall. After spending a small fortune on AN fittings I hooked it all up.
The system added about 2 qrts for a total of 4 grts of transmission oil. I ran it at summit point a few weekends back and the oil would take about 3 laps to get up to temp and then stayed right at 210 F. Thus it seems to be working great!


The oil ump


Drain port.


Pump, oil filter, and T-stat mounted to fire wall were the evap system used to live.


The trans cooler. The larger line is a AN-12 line for the engine oil cooler / filter.


P.S.
After finishing this project I found out that my sponsor Mfactory is actually developing a system just like this and I’m sure it will be a lot cheaper than buying all the fittings/components separately like I did (Doh!), and you probably don’t have to make any custom brackets or tap holes yourself.

STN_Pat

what kind of motor oil temp were you seeing when it was 300F in the trans. ?

nice set-up !

Lo-Buck EF

interesting....

577HondaPrelude

I used Amsoil 85-90 gear oil, and also tryed Schaffers #293 gear oil (85-90w). I used honda MTF but it looked burnt after 1 day.

b18cKoupe

I don't road race or anything but good job. Good problem solving, a little innovation goes a long way. Make sure to update how it holds up over time.

vbspec

Looks cool. You have PM Walter

GI8U2racing

Well thank god B-series motors make no torque, which I *believe* is what matters for clutches/transmissions getting hot/worn, or else we may have to do this too. It may be interesting to get a temp gauge in there just to see though...

RED_90TEG

..... there trannys are made with the thought that the engines make no torq. so in reality the torq of a b series is alot for the tranny...

spAdam

iTrader: (1)

Cool stuff. I've always wondered if this was an issue with our cars, but it just seemed the conversation has never come up.

to you for steppin up.

sander

Looks cool, is there any published information what an ideal transmission oil temp should be? Or are you just satasfied because its less than 300 degrees?

And, 1/8 npt seems a little small for an "in" hose, had you thought about drilling a larger hole and welding a fitting on to the fill plug?

Regardless, cool set up, Id be curious to see what your filter looks like after a race weekend or two. (cut open)

sander

Andrie Hartanto

Hi Walt,

you can easily eliminate thermostat. We just run a switch for the pump and a warning light on our dash. If the temp gets to 210 we flick the switch and it maintain the temp at around 210 to 220 for the duration of the race.

On my transmission, I also use the scavenge on the drain plug, but use the return line onto the reverse light switch. It uses 18x1.5mm. I also uses diaphragm pump, but uses mocal pump.

I do use a lot bigger cooler. I uses the size you use before, but for some reason it won't maintain temp and keep increasing, albeit at slower rate.

6spdKEG

Is there such thing as a tranny with too much fluid in it?
Possibly a slight power loss with an overfill on the tranny or do you think the reduced temps out-weigh this?


Andrie,
Does the scavenge device you use help with cavitation of the pump or?

STN_Pat

Sorry, what I mean is what was the motor oil temperature at the moment of a 300F from the transmission oil.

Was the motor oil hotter or cooler than the transmission one ?

577HondaPrelude

210F is the temp at which most gear and motor oils are rated for viscosity and other parameters. Most OEM differential & transmission coolers (on other cars) also keep the gear oil at or close to 210F so it's a safe assumption that 210 should be a good temp to keep a Honda manual transmission's gear oil at.

I thought about doing this also, but I figured I would just let a T-stat do it for me, and also with the pump on the system will always be filtering the gear oil.

There is still only 2qts in the transmission case at any 1 time, I did not increase this one bit. The extra 2qts is just what's in the tubing / cooler / filter. ...and yes I would think that you don't want to over fill the transmission over the normal OEM full level.

Ah. OK. The oil temp and H2O temps are both held at about 220 by a big ars radiator and engine oil cooler. Thus the transmission was creating it's own heat to get up to 300F.

STN_Pat

Thanks for the answer. That's scary in some way !

-RedneckDave-

Friction causes heat. Not scary, but should be respected none the less.

Very well done on the whole setup.

redzcstandardhatch

cool setup. i've been thinking of ways to do this!

Ekasey

90-105 deg C

Black R

This may be a silly question, but...

Wouldn't you want the filter before the pump; in case of some catastrophic event whereupon shrapnel could get sucked up in there?

577HondaPrelude

You can't see it in that picture but there is an in-line prefilter before the pump to keep the bigger stuff from entering the pump. This pump does a much better job of pushing oil than pulling oil so there is a limmit to how much resistance you can put on the input side, thus the oil filter needs to go on the output side.

slammed_93_hatch

i hope you're running some more clamps on those hoses... We've seen that hose fail.. and it sucks when it does!!!

DR

Walt, any word on the MFactory trans cooler kit?

Back2JDM

iTrader: (1)

That's a clean kit, I got some questions because I wan't to do the same thing on my CTR tranny.

I got the Mishumoto tranns cooler core...

Why is it that you have to run an external pump?
I is because the trans is a sealed system, so if you don't run a pump you wont get the Trans fluid to run through the system.

Also you ran the send and return line through the drain and filler plugs on the tranny?
Did you have to tap the holes or did you just get fittings that screwed directly into the thread on the stock ports?

Why didin't you use steel braided for the return and filler lines?

Thanx Man....

Lo-Buck EF

There has to be a pump externally because there isn't a 'pump' internally.

That line he is using (aeroquip) is plenty for that application and is less abrasive. Braided lines cut through other stuff if it rubs on it. plus it keeps the cost down.

MR.johnson

this is very neat. nice job.