Stephanie, my issue with your coolant reroute was primarily the temp sensor location. If the temp sensor should be in the head, not post-thermostat.

I think you guys could look at what I did on mine and make a "kit" which puts the heater bung pre-thermostat, and still use the 99 clt sensor location. We could make the heater and sensor work, which would keep everyone happy.



btw, I thought I saw you last night, but apparently there's a blonde around waco in a light blue miata with an intercooler hanging out the front. You girls should get together.

 

FWIW I have the BEGI reroute and originally used it as intended, teed into the upper radiator hose. I had the same problems with slow warm up times and temperature readings. Plus now that I have an oversized radiator I do not really need it.

So I moved the tee to the lower radiator hose. I agree that it is like stock again with one exception; the return line is no longer a metallic pipe in close proximity to the exhaust. This may save a little bit of heat being dumped into the cooling system from the exhaust manifold.

I also put my coolant sensor for my dash gauge in an unused, plugged hole on the back of the head. The dash gauge now agrees closely with the stock sensor based on the fan turn-on temperature.

 

There are two reroutes being discussed here.

One is the reroute included with the turbo kits, the other is a true reroute.

 

Well you can figure it out based on my description. But to be explicit, in my case I am talking about the 'turbo kit' reroute, that uses the stock thermostat location, and just relocates the return line from the heater core.

 

That's kinda the problem. As much as I seriously hate poo-pooing on Bell, their "street" re-route kit does not seem well thought out to me. In addition to not addressing the problem of coolant being bled off the front of the engine through the stock thermostat, it also ensures that the coolant coming out of the back of the head runs through the radiator all the time, thus causing warmup problems.

Their "racer" kit actually seems much more well suited to street applications, IMO. Assuming one opts to block the front thermostat entirely and run on the rear thermostat only, then it should produce both quick warmup and provide better cooling than any other kit I've seen- the downside of course being that the heater won't work until the thermostat opens.

The Qmax kit (is it still available?) and the forthcoming M-tuned kit both seem to be a good compromise position. They take the heater feed before the thermostat (so your heater will work better) however to avoid the problem of slow warmup, they return the heater into the stock mixing manifold. They're better than stock in terms of cooling performance, as the thermostat itself is taking water from the back of the head, rather than the front, however the ratios of cooled coolant to uncooled coolant being pumped back into the block are going to be similar to stock, as the fact that the heater return goes to the mixing manifold. You'll never have 100% of the coolant passing through the radiator.

My belief is that a "most optimal" system would be designed like the M-tuned kit, where the front outlet is blocked off and the heater feed is taken pre-thermostat, however the heater return passes through a second gating thermostat which directs its flow to the mixing manifold (lower rad hose) when cool, and to the upper radiator hose when warm. In this scenario, nearly 100% of the coolant would pass through the radiator when the engine is hot enough to activate both thermostats, nearly none of the coolant would pass through the radiator when the engine is cold, and coolant would flow through the heater core at all times- regardless of whether the thermostats are open or closed.

 

Quoted for truth.

On a side note: comparing a freeze plug in the front and outlet in the rear only versus two outlets (front+rear) and mixing them in the upper rad hose. What are the pro's and con's of each and what is preferred? I have the latter right now.

 

I chose to make sure all water went from front to rear, so the front is plugged. Its crazy how fast the temp drops when the t-stat opens according to the logs.

 

With two thermostats, there is the potential for coolant to still exit the head at the front, when that thermostat opens. When this occurs, the total volume of coolant flowing through the engine will decrease, and the efficiency of the system will be reduced. One of the principle benefits of doing a reroute is that by blocking the front outlet, you force nearly 100% of the water coming out of the pump to flow through the entire engine all the time. This problem can be reduced (though not entirely eliminated) by running a higher temperature thermostat in the front than in the back.

Assuming a blocked front outlet (there is no advantage to not blocking it), the two kits (Bell Racer vs. everyone else) differ primarily in how they treat the water going into and coming out of the heater core. In the Bell system, the heater receives water only when the rear thermostat is open, and it returns this water to the radiator inlet. This has the disadvantage of reducing heater effectiveness, but the advantage of forcing 100% of the water through the radiator when the thermostat is open.

In the other systems, the heater core is fed pre-thermostat, and is thus effective even when the engine is only partially warmed up. The downside is that to prevent over-cooling and slow warmup, the water coming out of the heater is routed back into the pump without passing through the radiator. Thus, even when the thermostat is open, some coolant does not pass through the radiator. It is still a great improvement over the stock configuration, though the theoretical maximum cooling capacity is less than the Bell system.

Does anybody know of an inexpensive 3-way solenoid valve with reasonably-sized ports (say, 1/4 NPT or larger) that will handle water at >100°C? I've got an idea for the reroute to end all reroutes, but it hinges on that part.

 

How is your heater plumbed, both feed and return?

 

This is how mine is set up. Speaks for itself basically.

 

I have exactly that. OEM stat in front, BEGI (lower temp) in rear.

No sorry, but you want to switch the heater return between (a) waterpump mixing when cold and (b) upper rad hose when hot? That sounds brilliant.

 

Basically, it just jumps the thermostat. Its a major bitch to get to. I had to make it out of random rubber hoses. I want BEGi to make a metal pipe for me. I also had to slightly "clearance" the firewall, and now the coil packs don't fit either.

I had to use the 1.8; t-stat cap to clear the 99 clt sensor location.

then I had this spacer made to get the heater port pre-t-stat.

the return is short, and a bitch to get to (there's a barb for the water from the heater core which is a standard begi piece):

hose routing:


The clt sensor is in the back of the head, the heater feed is also pre-thermostat, the return is downstream in the upper radiator hose, and I get 100% cold water to the water pump. I specifically wanted that last part because of Texas heat and track days with a huge intercooler. I don't know of anyone with a reroute liek mine, not using a mixing manifold of any sort. Will that be a problem? Any chance the water could be too cold and cause damage? I've heard of some Exige issues with water being too cold when the t-stat opens.
I think Corky could look at mine and see the reason why I didn't use the one they sent me, and make a reroute which is cheap, simple, and would work on athe 1.6, 1.8, nb 1.8, and even swap cars like mine. I think my reroute addresses every possible exception.

 

Is there any reason not to remove the heater core lines all together and just plug the ports and then just run the rad inlet to the rear of the motor?
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Hmm yea, if that is possible, you can create a tap like this:

in the heater return line during track sessions. Or a shutter solenoid instead of a solenoid valve.

 

Why would I need that?

Does coolant need to flow before the t-stat opens up?
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yes, water must flow or something bad happens to the water pump.

 

Sorry, let me rephrase. Yes you can remove the heater core and all lines together, but then you have no heater

I was just thinking: instead of removing it, you could also add a shutter valve (tap, screw, cork, solenoid, whatever) to it. So then you can selectively enable the heater circuit (street) or disable it (track) to ensure all water goes through the rad for max cooling.

 

Would a few holes drilled into the edges of the t-stat be enough flow before the t-stat open and not cause any damage?


Well I live in South FL and I have never used the heater before so Im just looking to simplify things.

What im hoping to do is route the water out of the back of the head, block off the front and eliminate all the heater core stuff.
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I think most people loop the heater lines together (remove the core and connect inlet to outlet). So there is still a circuit.

Others will have to chime in and tell you what to do and what not.

 

I must be mis-interpreting your design somehow.

It sounds somewhat like the blocked Bell Racer system, except that your heater feed is pre-thermostat so you will have much slower warmup. In fact, it sounds to me like the thermostat is kinda pointless in your install- whether it's open or closed, you're still passing 100% of the coolant through the radiator all the time. What am I missing here?


Yes. Specifically, you want water circulating throughout the engine so that as it warms up, it does so evenly. If there is no circulation, then you will have lots of variation throughout the engine- hot spots and cold spots.