Ford Mustang Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
705 Posts
Discussion Starter #1
95 Mustang GT w cobra front bumper
331ci na making 432 crank hp
I use it for road courses in southeast

i have a huge 22" L x 5.5 W x 2" setrab on it now.

I would like to get a smaller one and move it away from in front of the raditor.

I think it has been limiting oil pressure engine make 50psi 3000rpm at and at 7200rpm drops to 47psi.

read about series 1 ,6 and 9 setrabs

thinking about setrab 50-925-7612
anyone have experience with these?
 

·
Registered
Joined
·
125 Posts
I don't have experience with that cooler, but was planning on the 50-625-7612 or 50-634-7612 this spring. I selected these based on the pressure differential data Setrab provides.
These have less pressure drop than the 925/934 series.

In general, the narrower and taller cooler will have less pressure drop than the wide and short units.

Attached is a quick comparison I was using for my selection.

I also have a 95 GT with a 331 making similar power.
 

Attachments

·
Premium Member
Joined
·
3,147 Posts
It is a myth that more rpm requires more oil pressure to stop the bearings from rubbing on the journal. At high rpm, the hydrodynamic forces are what primarily keep the bearing from touching the journal. At low engine rpm, enough oil pressure is required to keep the bearing and journal apart based on the area and combustion forces. Anything greater than that only creates wasted heat. Your oil pressures look fine.
 

·
Registered
Joined
·
1,034 Posts
Be careful assuming the pressure drop is coming from the oil cooler. I run 2 oil coolers in series with a std melling pump at 60psi and no pressure drop both on a 331 and 347.

However, on separate occasions throughout the years I have confirmed 5psi pressure drop using regular aftermarket oil filter vs. K&N, 5psi from an oil pump with the relief spring cap pressed in only 90% of the way, and another 5psi from 10W-40 vs. 15W-50 oil weight. I have also found 5psi from from tired, but undamaged bearings at high rpm (oil slings out of the slightly wider bearing clearance at high rpm and the pump can't keep up with the volume, so pressure sags a little)

One way to be sure the cooler is or isn't the restriction is buy a smaller cooler, then plumb it in parallel with the first one. Put a shutoff valve in front of both coolers. Run it on the track all 3 ways and check your temps and pressures.

FD
 

·
Registered
Joined
·
705 Posts
Discussion Starter #5
Thanks for the info really appreciate it. I just installed new rod and mains bearings after 7years of road course duty which brought my pressure back up to where they are now.
My oil temps on track are around 255-270 thats why wondered if smaller cooler could run same temps. im not sure what the target oil temps should be.
 

·
Registered
Joined
·
1,034 Posts
Those temps are just about perfect. Under 280 under all conditions is my rule of thumb. If you're at 270 on a 95-100 degree day, then you could go a little smaller, but if that's on a 85-90 degree day, I would leave it alone.

You can still try getting your pressure up using another method too (oil weight/filter). If you can get your oil pan out easy, I am pretty sure you can make sure your pressure relief spring cap is bottomed out with a punch with everything in the car. Also, the sandwich adapter should have a check ball relief valve. You can investigate that situation and see if you can lower the setpoint which will lower the oil cooler flow/deltaP at the expense of slightly increasing temp (similar to smaller cooler).
 
1 - 6 of 6 Posts
Top