JPS SWB Subie

I don't know what coolant routing conversion they were trying to fix with that extra sandwich adapter on the t-stat housing, but it shouldn't be necessary if the layout is stock. What you do need to have is a bypass heater valve instead of a cutoff style valve to allow coolant to circulate when the heater is off. If you don't use a heater, you just need a hose between the heater out and in on the engine.

He claims the coolant is too cold returning from the heater and this is  causing the engine to run hot. I could see having problems getting the coolant up to temperature when you're talking sub-zero temps and dual radiator cores that a vanagon has and running the blower fans full blast. But cold coolant making the engine run hot doesn't make any sense to me, but again I don't know what sort of odd line routing they might have done to begin with that needed fixing. But if his odd "fixed" versions are any indication there probably was something wrong with it. Personally, I don't think you'd have the same problems in our cars.

Same location for mine Jerry.  Is the filler the cap of an expansion tank?  BTW, does the computer turn the fan on when the water reaches a certain temperature as mine does?  

YEP JPS DOES SWB

Hi Gerd,

Where is your flared coupe?

Justin, I hear you and while I don't specifically understand or know how Suby cooling systems are set up, they WILL overheat if they don't get a warm coolant return through the heater loop. David Stroud is right on the money with this one, don't doubt it one bit! It doesn't matter if they are transplanted into a Vanagon, a Speedster, a Spyder, or whatever.

JOHN STEEL says never remove the rad cap to the left of the engine on the subie motor--use the overflow tank to add antifreeze-the tank should be about 1/3 full--also my first day with the car was fine-the cooling fan only came on after I parked after driving 70-85 mph for about 40 minutes--the next morning the fan came on as soon as I started her up and ran the entire time that I drove--???

That shouldn't happen.

One of the idiosyncracies of Subi engines with remote radiators is that they REALLY don't like trapped air.  No matter how you plumb the coolant hoses, there will be an unintentional high spot that will tend to trap air.  There are well-published ways of "burping" your Subi cooling system, all of which entail removing the radiator cap to look for bubbles as the coolant temp rises and the t-stat opens.  It's not a job you have to do every day or every week, but it's one you should know how to do.  Sooner or later, you will need to replace a thermostat or a hose or change coolant.  Google Subaru burping, and you'll find tutorials and youtube videos.  John Steele's advice was meant to keep problems to a minimum by telling owners to use the expansion tank to add fluid, and not introduce air into the system by opening the rad cap.  Air can get trapped in the heater core also, so for air removal, it's best to have the heater on to keep coolant circulating through the entire system.  If you remove trapped air in your system, the fluid level in the expansion tank will drop, a sure indication of air removal.

Jim-- I understand about the trapped air-but that wouldn't cause my fan to be running-right?  Also it appears to me after being under the car today that the rad and fan were installed before the body was mounted-I don't see any way to remove them now if need be--

No, that'd be an electrical problem. The fan relay is likely temperature controlled (and from your initial description, sounds like it was) and shouldn't be running all the time. Could be a problem with a loose wire shorting out, terminals (on relay for example) touching their neighbor, the relay failed closed, whatever is controlling the relay (themostat, ecu) not working, etc. Start diagnosing at the relay and work your way out.

Jerry,

Justin is right about electrical problems.  Even if your t-stat was malfunctioning in the closed position, your fan shouldn't come on until the now-uncirculated water in the block comes up to temp.  I'm sure there's a way to drop the rad to get at the fan behind it.  A good auto electric shop or modern radiator shop should be able to diagnose whatever fault there is.  You may want to contact John Steele for his input also.  The fans on my SAS Subi engine were installed without relays, a condition that guarantees electrical problems. 

I have no electrical problems whatever with or without relays with my cooling system.  If the ECU is working correctly, the fan will turn on when the water temperature reaches a specific temperature.  If this is not the case, you are not working properly according to Subi specs.  I have seen this happening with a device connected to an engine monitor plugged into the OBD II port.    

The fan is not the problem.  If it comes on it is working as it should.  The problem is somewhere else-either the fan switch or something has gone haywire in the ECU.

It could be as simple as this: water in the fan relay. John is not known for making cars that don't live in sunny California. Not faulting, just stating a fact. If you washed the car or drove it in any rain, it is VERY possible water is in the relay and causing your problem, if there is a relay. Looks like three of them on the right side of the engine bay. Maybe one is the fan? This happened to me on a BOSCH relay mounted to my oil cooler/fan. The solution was to drill a small hole in the relay at it's lowest point to let it out. I got water in it when I washed the engine!

well she hasn't seen any water yet-so ill check the relay wiring and yes the rad and fan drop out straight down after removing 12 bolts, 2 hoses  and a couple of wires--

Justin: here's how cool water can make a Sube run too hot:

The thermostat is on the bottom of the engine, guarding it from the newly radiated cooler coolant that comes back after its trip through the radiator. Why they did this i don't know, but they did. So to make the thermostat open when needed, Suby engineers routed the heater core return line to a spot just above the thermostat. That's water that was just inside the engine, and it's supposed to give the thermostat more of a "true reading" of the temp inside the engine. (Because the cool coolant is just on the other side of that thermostat, the Suber geniuses used a low temp stat--172 degrees). So when the engine is ina Subaru, the heater core coolant is always circulating through the heater core. This doesn't matter much because it doesn't lose much heat in the short (3 feet?0 trip in and out of that heater core. Presumably the arrangement also allows Subies to have faster/better winter heat for anyone riding inside the car. BUT!

When you put the Sube engine in a Speedster (or a VW-based TD replica, or a Bug), all that well-balanced Japanese engineering goes away in favor of, well, PO engineering, let's say.

The coolant lines are suddenly subject to being really, reaallyy long.

(And the air bubbles come--but hold that thought a minute).

The longer lines, if run to a heater core inside the VW-based transplant, may allow for the coolant that works the thermostat to come back too cool.

The thermostat is thus tricked into thinking everything inside the engine is hunky-dory, when in fact, it is not.

And one of the reasons this engine is not running super cool is, paradoxically, because of the extra coolant in those long lines to the radiator up front. 

And the fact that those lines run a mountain range on the way. If there is any air in them, that air bubble finds its way back to the engine--particularly in the heads or in the spaces where the heads and the case meet. Air means no coolant-touching-real-hot-aluminum-parts.

The extra heat from those hot parts tends to expand the bubble. You get a serious hot spot, and eventually that gets you a blown head gasket.

Stroud had a typical experience with this--and he was pretty diligent about "burping" the air out.

It doesn't take much at all. 

I am not sure if this Subie  radiator issue is better or worse than clogged idle jet 

Jerry, does your car have a water temperature gauge?

The only time I ever hear my fan turn on my Subie is after I turn the car off and the key is in the accessory position.  Must never get hot enough to kick on when driving. 

different engine, but same thing, my radiator is exposed a weeeeee bit and never comes on when I'm driving it. Only when I've been beating on it and I come to a stop and turn the car off. 

Thanks, Ed. So is the solution to have a constant bypass loop to the thermostat housing no matter what? Or is there a solution where the thermostat is moved to a more conventional location?

I recall on Rabbit/Scirocco motors the thermostat is on the inlet to the water pump, bottom of the engine, kind of a similar arrangement.

Ed, I agree if you have an air bubble in the system that it can cause overheating issues. It's also applicable to both the radiator and heater circuits. But an air bubble is a separate issue from the claim of the coolant being too cold and overheating the engine. The heater circuit coolant will keep circulating through the engine regardless of thermostat position.

Let me put it another way. Put a foot long hose between the heater outlet and inlet on the engine so you are guaranteed the bypass system is operating the thermostat correctly and we can ignore the whole heater business. Let's say our front radiator is very efficient and the returning coolant is 150 degrees. Would you claim this would make the engine overheat? Is there a difference between radiator coolant flowing into the engine at 150 degrees and heater coolant flowing into the engine at 150 degrees?

The only thing I can think of that might cause overheating is that the heater circuit inlet on the water pump is smaller than the radiator inlet and the flow rate wouldn't be enough to get the coolant all the way through the engine before it gets too hot. I would accept an answer like that, but I haven't seen any claims to that effect, hence my skepticism that the only problem is cold coolant from the heater.

Ron--I do have a temp gauge-Its been raining so much I have not had the chance to see what it reads when the fan comes on--only have 100+ miles on the car so far--

Justin, you're getting closer. The rad will easily overpower the heater circ coolant. Consider the volume of a half inch tube fighting that of a one and on half inch tube. And, it's not 150 against 150 either. Today in rain, ambient 75 deg, no stat installed (yes, correct), at 70 mph the coolant temp coming OUT of the engine was 110 deg. Imagine if you were operating when ambient was much lower? 

For Danny Pip, I experimented with a BMW inline stat on the outgoing side of things two weeks ago, but couldn't get the bypass hooked up right intimer to travel.

Tom Sheils has a verifiable cure with his adapter for all weather conditions. Believe it.

U GUYS R TOO TECHNICAL FOR VINCE AND I

HERE IS A PIC OF US THE LAST TIME WE WORKED ON OUR CARS

Thanks, Clint, but I just don't know whether you're correct or not.  One of the many problems I encountered with the car is that only one of the two fans would engage, no matter how high the engine temp.  I had both an experienced radiator guy and an auto electrician try to help me get the car running normally.  Neither one could follow the wiring completely, as most of it was bundled near the longitudinal beam that runs down the right side of the car.  Not only bundeled, but butt spliced and competely open to road debri, water, etc.  I have since placed a piece of aluminum sheet metal to shield the wires.

I know that, after adding two new relays, the fans now work as intended.  Unfortunately, that's only part of the problem, as the car still overheats.  Non-functioning temp gauge, bad t-stat, intercooler mounted directly behind the pull through rad fan, restricted down pipe (since the builder took a ball peen hammer to the piece that wouldn't fit, and effectively made a 1.25" pipe out of a 1.5"), a fan that wouldn't come on when the engine was shut off, and the list for overheat conditions goes on and on . . .

I paid to have a tuner dyno the car before I picked it up.  The dyno came in at 213 HP.  The engine is stock rated at 260 HP.  It's interesting that SAS still advertises on its site that my car has 315 HP, a mere 100 HP error.  At least the tuner knew enough to detune the ECU, due to excess heat, so that detonation wouldn't guarantee a meltdown.  Boost is only 4 lbs, as additional boost would cause detonation.   That seems consistent with the builder's approach to the build.  Rather than figure out why the engine is overheating, and fix it, let's just detune the engine and forget it.

After I get it all straightened out, I'll do a comprehensive review that others may find interesting.  Some things on the car are excellent, some are unbelievably bad.  BTW, I think your reference to "dune buggy wiring" is misplaced.  There are several sites that manufacture complete Subaru (or any make and model) wiring harnesses, all made to user specs, ECU, etc.  The beauty of these harnesses is that there are none of the butt splice joints that SAS uses.  Cost is about $600-$700 for a complete set.  That's what the vanagon/Subi installers use, as well as almost every hot rod builder in the US. 

Following the builder's instructions, I had to expose and inspect the wiring under the dash on my trip home, as the builder thought he knew how to fix a starting problem I was having.  I shuddered when I saw the unorganized jumble of spaghetti under the dash.  The original speedo and tach were still attached in the mess of wiring, splices, etc. 

Quality control issues still abound, which is inexcusable in a shop that only has 2 people working on a car.

U CAN TELL BY THE PIC WE WERE JUST KIDS

I haven't been on this site in months and Jim's car is still in repairs. It is simply bad business and bad reputation to make a customer wait 2 years for a replica car with faulty mechanics. 

2 years?  Wow, you have been out of touch, Dan.  My car took 5.5 years to build, and that's about average for the last 3 cars.  SAS currently builds 1 car/year, as mine was the only car built in 2013.  The two guys who build the cars look to be in their early 60's.  There are currently 18 buyers on the list, who have all paid deposits.  The top guy in the queue joined in 2007.  At the current build rate, the builders will be in their graves before those in the current queue get their cars.  I've been hearing for over 4 years that new employees are going to be hired, but nothing yet. 

JIM ABOUT 4 YEARS BACK SOMEONE TOOK POSSESION OF HIS SAS CAR

WAS BEAUTIFUL AND HE LIVED IN SANTA BARBARA

HIS CAR DROPPED OUT SHORTLY DUE TO OVERHEATING AND WE HAVE NEVER SEEN HIM AGAIN

wow, 5.5 years!  That reeks of a Ponzi car scheme. At least they should build a car in under 4 years and test drive it for 1 year to fix all the bugs before giving it to the customer.

Seriously, 5.5 years is a long wait for any car. I am glad you finally received your car but it sucks to keep repairing and finding new problems.

Jim, I'm all for putting technology in these cars and pushing the envelope toward the future. I admire what you are attempting to get and hope you get it. You may remember the conversation(thread?) we had about ABS, traction control, torque vectoring etc. in an SAS versus a stock Suby 4wd. It is a lot to ask to magically transfer this stuff to a completely different platform and expect it to work. It appears you have plenty of conventional bugs to get rid of before you get to the real techy hurdles. Best of luck and wishes.

I love my Spyder and am not thinking of selling it or anything like that. But I keep thinking about a coupe, in addition to the Spyder, mid-engine and turbo-Subaru, oh what fun! Heat, A/C, and A$$-kicking performance, 5 X 130 Fuchs, great brakes, IRS, great handling, 5 speed. Sounds like auto heaven....and a very nice stable of toys, for this guy anyway.

For Jim Kelley,

I don't want to get into a argument on "words" but you said:

“BTW, I think your reference to "dune buggy wiring" is misplaced.  There are several sites that manufacture complete Subaru (or any make and model) wiring harnesses, all made to user specs, ECU, etc.” 

If you look at the picture of the engine in the post you will see a Stinger box, it is the ECU provided by companies like Outfront Motorsports 

http://www.outfrontmotorsports.com/ems_computers.htm

As you can see on their site these units are for "Off-road Applications" aka Dune Buggies.

You also mention HP... the reading by a tuner is Wheel HP vs. Brake HP.  Normally you see a loss of 20% to 25% between WHP and BHP.

BTW, my SAS Turbo puts out 300+ BHP and I have never had any overheating or other issues like you have had, I have over 20K miles on my car.

Hope this helps.

Hi Clint,

I didn't express myself as well as I could have regarding the wiring.  The distinction I tried to make was that the "original Subaru wiring" you referred to has been modified by SAS to accommodate the different replica platform and delete the circuitry no longer used.  Additions are also made to accommodate different gauges, lights, etc.

I feel that SAS would be money, time, and quality ahead by having a professional after market wiring company make the appropriate harnesses.  This would eliminate the current butt splices that SAS routinely uses.  I'm not saying that other manufacturers don't use dune buggy harnesses, but there are dozens of wiring companies that produce harnesses specifically to customer specs.  Since SAS states that it takes them 2 weeks to modify the harness, it would seem more efficient and fiscally smart to have them made. 

BTW, I'm glad your car is running great.  Some day in the future, mine will be too.   

Hi Danny,

Yes, when I get the car sorted, it will be sweet.  I do remember the thread about old school, a/c vs. H2O, mod cons vs. close to the bone, etc.  My needs have changed over the years, and so have those of my child bride.  Since we've been married for 46 years, her opinion holds some weight.  A closed cab, heat and air/con may help to persuade her to right seat with me, but my coupe is a poor stepchild when compared to our grandkids, so I don't expect much company from her on any long range trips.

SAS has raised the bar on technology, but it's not without its drawbacks.  Still, this is not my first rodeo, so I will either fix what's wrong or find the right guy to fix it.  Glad to hear you're still pressing hard on the pedal.  One of these years, I'll show up at Carlisle and try to show up you young rascals.

Jim, I completely agree about the harness. The original gauges are stuffed up under the dash? Seriously? Ed is having his harness done by Tom Shiels in Toronto, he does the Vanagon conversion thing. He does an awesome job, as they are tested and guaranteed to work!

Sounds like Clint got a better wiring job than you, Jim. That sucks. John Eastman's car threw a code on the way to Carlisle last year, crappy butt connectors on the speed sensor wiring(I cleared the code, which came right back). I'm thinking it's a matter of time for Clint.

The Stinger ECU is aftermarket but is a good standalone ECU and a lot less complicated than stripping the Suby harness. Nothing runs as good as a factory ECU, but it is harder as time moves on to keep the factory units "happy". You still need a good map in the Stinger, and it appears they have gotten better with time as well.

I'm glad I wired my car, the crank-fire ignition has been flawless since 2008. Of course I still have carbs to deal with occasionally, but I spend way more time on others than I do my own!

FYI, the Vanagon/Subaru guys had a problem with cooling because the engine is now in back and it is a long way to the front. Just like in a Speedster. The stock Suby has the radiator VERY close and right in front of the engine. My friend Pete did some prototype work on a remote thermostat housing that is now used often in the Vanaru world.

its been 9 days since my JPS arrived and I have been busy working on it-which is good -keeps me away from the TV-- these are the things I have done and she is ready for Carlisle--installed all the mahogany pieces, interior lights, 2  12v ports, shot rubberized undercoat in all 4 wheel wells to give the fiberglass some cushion against anything thrown up by the tires(just in case), rebalanced the rear wheels due to shake at hwy speeds, fitted the wardlow bra,sized and installed the dead pedal, located antifreeze leaks and installed a small catch can on the overflow tube, still need to sort the cooling fan issue and get the correct speedo from John-

Jim, is your intercooler mounted behind your rad, or did I read that wrong?