Coolant Reroute Options
02-10-2021, 03:05 PM
#23
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@deezums @twopointwo Check our updated instructions for the note added about overcooling. https://supermiata.com/Supermiata_Qmax_Instructions.pdf
A link to these instructions is found on the main product page: https://supermiata.com/supermiata-qm...mx5-miata.aspx
A link to these instructions is found on the main product page: https://supermiata.com/supermiata-qm...mx5-miata.aspx
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02-10-2021, 03:22 PM
#25
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I'm sorry for what I started here.
My main question/worry was about the comparison between FM's offering, and Qmax.
"But the big difference is the turbocharger. We worked with the engineering department at Colorado Mesa University to map out all the cooling factors of the Miata engine, and discovered that a water-cooled turbocharger will increase the temperature of the coolant flowing through it by as much as the rest of the engine put together. To make things worse, this very hot coolant is mixed right back into the engine coolant, with no chance to cool down at all. Obviously, we decided to address this. We dropped the amount of flow into the turbo - they really only need the water cooling when the engine is off and they use thermal siphoning to get it - and plumbed it back into the water heading into the radiator so that it's cooled before going back into the engine."
The above is from the FM website. Reading it seems that the FM version would be better for a boosted vehicle.
My main question/worry was about the comparison between FM's offering, and Qmax.
"But the big difference is the turbocharger. We worked with the engineering department at Colorado Mesa University to map out all the cooling factors of the Miata engine, and discovered that a water-cooled turbocharger will increase the temperature of the coolant flowing through it by as much as the rest of the engine put together. To make things worse, this very hot coolant is mixed right back into the engine coolant, with no chance to cool down at all. Obviously, we decided to address this. We dropped the amount of flow into the turbo - they really only need the water cooling when the engine is off and they use thermal siphoning to get it - and plumbed it back into the water heading into the radiator so that it's cooled before going back into the engine."
The above is from the FM website. Reading it seems that the FM version would be better for a boosted vehicle.
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02-10-2021, 03:36 PM
#26
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No need to be sorry - this is a good discussion. Folks have questions, good to clarify what's up.
Regarding the overcooling thing, with the old m-tuned reroute without the bypass you'd see a real big cooling system pressure spike (measured with pressure sensors) until the thermostat opened, usually accompanied by a temperature spike. I experienced this on my personal turbo NB. To solve that problem, i drilled a small hole in the thermostat as recommended by M Tuned... creating a bypass. Solved the spike problem, but when it was cold out I had to block off part of the radiator to maintain sufficient coolant temp. It's a tradeoff. If you're not concerned about the spike, run a setup that doesn't have a bypass. For us, keeping cooling system pressures more even and optimizing the setup to work when driving the car hard is priority. Thanks for the feedback to those that are concerned about other customers as it sparked an improvement in our instructions.
I can't refute FM's study with hard data, but I do find it hard to believe that the turbo can put as much heat into the coolant as the rest of the engine put together. Either way, the QMax has been proven on turbocharged street and track cars time and time again and works great, including our own at well over 400whp, so it's largely a non-issue. If you have an FM turbo kit with FM lines and the FM reroute, maybe it's more plug and play - I haven't played with one to see, but maybe that makes more sense for your particular use case. But from what I see that choice makes sense only from an ease of use improvement, not from a cooling standpoint.
Regarding the overcooling thing, with the old m-tuned reroute without the bypass you'd see a real big cooling system pressure spike (measured with pressure sensors) until the thermostat opened, usually accompanied by a temperature spike. I experienced this on my personal turbo NB. To solve that problem, i drilled a small hole in the thermostat as recommended by M Tuned... creating a bypass. Solved the spike problem, but when it was cold out I had to block off part of the radiator to maintain sufficient coolant temp. It's a tradeoff. If you're not concerned about the spike, run a setup that doesn't have a bypass. For us, keeping cooling system pressures more even and optimizing the setup to work when driving the car hard is priority. Thanks for the feedback to those that are concerned about other customers as it sparked an improvement in our instructions.
I can't refute FM's study with hard data, but I do find it hard to believe that the turbo can put as much heat into the coolant as the rest of the engine put together. Either way, the QMax has been proven on turbocharged street and track cars time and time again and works great, including our own at well over 400whp, so it's largely a non-issue. If you have an FM turbo kit with FM lines and the FM reroute, maybe it's more plug and play - I haven't played with one to see, but maybe that makes more sense for your particular use case. But from what I see that choice makes sense only from an ease of use improvement, not from a cooling standpoint.
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02-10-2021, 03:45 PM
#27
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Thanks for the answer! It definitely clears some things up. Here in Ottawa in the fall it definitely approaches and goes under 50f or 10c. But in the summer months it'll be 95f... So I need the system optimized for street/track duty at both of those temps.
Autocross isn't a worry as much since by the time the car gets too hot, it'll rest in the paddock awaiting the next run for a solid bit.
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02-10-2021, 03:47 PM
#28
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Yup. Note that the FM will have the same style bypass, so you'll still have the same overcooling at low ambienttemps. a piece of cloroplast works great and easily folds and tucks behind the driver seat. It's what I had to do in winters in Utah and Oregon to maintain coolant temps with my M tuned reroute.
Whatever you choose to do, good luck with the project
Whatever you choose to do, good luck with the project
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02-10-2021, 04:21 PM
#29
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I'm sorry for what I started here.
My main question/worry was about the comparison between FM's offering, and Qmax.
"But the big difference is the turbocharger. We worked with the engineering department at Colorado Mesa University to map out all the cooling factors of the Miata engine, and discovered that a water-cooled turbocharger will increase the temperature of the coolant flowing through it by as much as the rest of the engine put together. To make things worse, this very hot coolant is mixed right back into the engine coolant, with no chance to cool down at all. Obviously, we decided to address this. We dropped the amount of flow into the turbo - they really only need the water cooling when the engine is off and they use thermal siphoning to get it - and plumbed it back into the water heading into the radiator so that it's cooled before going back into the engine."
The above is from the FM website. Reading it seems that the FM version would be better for a boosted vehicle.
My main question/worry was about the comparison between FM's offering, and Qmax.
"But the big difference is the turbocharger. We worked with the engineering department at Colorado Mesa University to map out all the cooling factors of the Miata engine, and discovered that a water-cooled turbocharger will increase the temperature of the coolant flowing through it by as much as the rest of the engine put together. To make things worse, this very hot coolant is mixed right back into the engine coolant, with no chance to cool down at all. Obviously, we decided to address this. We dropped the amount of flow into the turbo - they really only need the water cooling when the engine is off and they use thermal siphoning to get it - and plumbed it back into the water heading into the radiator so that it's cooled before going back into the engine."
The above is from the FM website. Reading it seems that the FM version would be better for a boosted vehicle.
BUT; the flow through a CHRA is so much less that the flow through the engine. Heat flow is water flow times temp difference. Don't confuse temp rise with heat transfer.
DNM
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02-10-2021, 10:15 PM
#31
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02-10-2021, 10:18 PM
#32
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Something we didn't encounter on the several cars we tested it on, but there's quite a bit of variance in OEM EGR pipes. That note is now on the product page so nobody is surprised by it. I expect FMs is similar in that some cars will bolt right in and some won't.
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02-10-2021, 11:28 PM
#33
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"But the big difference is the turbocharger. We worked with the engineering department at Colorado Mesa University to map out all the cooling factors of the Miata engine, and discovered that a water-cooled turbocharger will increase the temperature of the coolant flowing through it by as much as the rest of the engine put together. To make things worse, this very hot coolant is mixed right back into the engine coolant, with no chance to cool down at all. Obviously, we decided to address this. We dropped the amount of flow into the turbo - they really only need the water cooling when the engine is off and they use thermal siphoning to get it - and plumbed it back into the water heading into the radiator so that it's cooled before going back into the engine."
No way a turbo CHRA sheds the same BTU output of the engine. DNMakison has this on lock.
What really bothers me about the above is the last sentence. A CHRA has VAST temp swings depending on the EGT and amount of flow occurring. They need major coolant flow anytime boost is being created. Reducing total flow through the CHRA seems like a very bad choice to me.
I would prefer to have additional cooling of the CHRA after the engine is shut off but this a MINOR thing and although "thermal siphoning" does work it works slowly. If it was really important we would all use auxiliary coolant pumps (real common on late model cars) to help cool our turbos and I've not seen anyone do this.
No need to be sorry - this is a good discussion. Folks have questions, good to clarify what's up.
Regarding the overcooling thing, with the old m-tuned reroute without the bypass you'd see a real big cooling system pressure spike (measured with pressure sensors) until the thermostat opened, usually accompanied by a temperature spike. I experienced this on my personal turbo NB. To solve that problem, i drilled a small hole in the thermostat as recommended by M Tuned... creating a bypass. Solved the spike problem, but when it was cold out I had to block off part of the radiator to maintain sufficient coolant temp. It's a tradeoff. If you're not concerned about the spike, run a setup that doesn't have a bypass. For us, keeping cooling system pressures more even and optimizing the setup to work when driving the car hard is priority. Thanks for the feedback to those that are concerned about other customers as it sparked an improvement in our instructions.
I can't refute FM's study with hard data, but I do find it hard to believe that the turbo can put as much heat into the coolant as the rest of the engine put together. Either way, the QMax has been proven on turbocharged street and track cars time and time again and works great, including our own at well over 400whp, so it's largely a non-issue. If you have an FM turbo kit with FM lines and the FM reroute, maybe it's more plug and play - I haven't played with one to see, but maybe that makes more sense for your particular use case. But from what I see that choice makes sense only from an ease of use improvement, not from a cooling standpoint.
Regarding the overcooling thing, with the old m-tuned reroute without the bypass you'd see a real big cooling system pressure spike (measured with pressure sensors) until the thermostat opened, usually accompanied by a temperature spike. I experienced this on my personal turbo NB. To solve that problem, i drilled a small hole in the thermostat as recommended by M Tuned... creating a bypass. Solved the spike problem, but when it was cold out I had to block off part of the radiator to maintain sufficient coolant temp. It's a tradeoff. If you're not concerned about the spike, run a setup that doesn't have a bypass. For us, keeping cooling system pressures more even and optimizing the setup to work when driving the car hard is priority. Thanks for the feedback to those that are concerned about other customers as it sparked an improvement in our instructions.
I can't refute FM's study with hard data, but I do find it hard to believe that the turbo can put as much heat into the coolant as the rest of the engine put together. Either way, the QMax has been proven on turbocharged street and track cars time and time again and works great, including our own at well over 400whp, so it's largely a non-issue. If you have an FM turbo kit with FM lines and the FM reroute, maybe it's more plug and play - I haven't played with one to see, but maybe that makes more sense for your particular use case. But from what I see that choice makes sense only from an ease of use improvement, not from a cooling standpoint.
In fact TurboFan just sold another Qmax set up with that post. This is the way I'll be going...
Read literally: The differential temp of the water going though the CHRA is roughly the same as that for the engine coolant inlet and outlet.
BUT; the flow through a CHRA is so much less that the flow through the engine. Heat flow is water flow times temp difference. Don't confuse temp rise with heat transfer.
DNM
BUT; the flow through a CHRA is so much less that the flow through the engine. Heat flow is water flow times temp difference. Don't confuse temp rise with heat transfer.
DNM
And finally the single best tip on install I've heard of, Thanks Joe!
OP- this is a good thread, best "differences" thread I've seen yet regarding reroutes.
Threads like this one make MiataTurbo the only forum for me.
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02-11-2021, 08:44 AM
#35
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Good Point
But I figure Mitsubishi put the water ports on for a reason. The same one that Subaru had when they plumbed to those ports. I don't have any comparison, but I know that I don't take any care on shut-down procedures. And I use good oil. I suppose that OEM has to figure in the longer oil change intervals, and possible lower grade oils that are more prone to coking.
DNM
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02-11-2021, 10:51 AM
#36
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^^ This is true. ^^
But I figure Mitsubishi put the water ports on for a reason. The same one that Subaru had when they plumbed to those ports. I don't have any comparison, but I know that I don't take any care on shut-down procedures. And I use good oil. I suppose that OEM has to figure in the longer oil change intervals, and possible lower grade oils that are more prone to coking.
DNM
But I figure Mitsubishi put the water ports on for a reason. The same one that Subaru had when they plumbed to those ports. I don't have any comparison, but I know that I don't take any care on shut-down procedures. And I use good oil. I suppose that OEM has to figure in the longer oil change intervals, and possible lower grade oils that are more prone to coking.
DNM
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02-11-2021, 01:33 PM
#37
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The fact that you worked for BEGI taints everything you post online and makes me want to put you on global ignore.
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02-11-2021, 05:14 PM
#38
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I worked for Corky Bell when he had Cartech Engineering and Japanese GTs. BEGI was 20 years in the future at this point.
Miata's were 7 years in the future as well.
Back then Cartech was the only turbo shop that had a clue. Everyone else was lost, I don't think any of his competition survived.
I couldn't stand Stephanie when she was 7 years old, she just got worse as she aged.
Corky was a poor "business man" but an excellent engineer.
I was an 18 year old newbie and didn't know anything then.
I cannot understand why my far distant past should create such a dislike in someone I don't have any history or interactions with.
I have no animosity towards you and I cannot fathom why the reverse apparently exists...
I'm guessing your hatred of BEGI is overwhelming.
In regards to this thread Corky's "re-route" and MANY of his Miata mods are the "bottom of the barrel" and should not have been produced.
Complete trash! his fueling mod is one of the worst things I've ever seen.
The single most common Miata turbo manifold is a Corky design and although it doesn't have the flow paths it needs will continue to be sold for years.
It might be the most copied aftermarket manifold in history...
I would purchase a Q-max reroute before using a free BEGI re-route. Corky's design is flawed.
I'm buying a Kraken set up and I've never even spoken to Corky about what he might have stashed away. Kraken's stuff is far better IMO.
4 years ago I tried to purchase BEGI's MSM upgrades for a customer. Stephanie was just too much.
I could not work with her. BEGI is gone now as well. This is a good thing.
Ended up buying a "big enchilada" from FM with the Hydra. This set up and the teething problems I encountered with it soured me to anything FM related.
Only "good" thing with the FM set up was their support. They finally got it right but...
Both my customer and I now wish we'd gone MKTurbo and a MS3. It would have been less expensive and made more power.
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02-11-2021, 08:26 PM
#40
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It's the oil...
CHRAs will run between 400 and 900 degrees F without cooling depending on load.
Anything over 250 degrees degrades oil, Synthetics can handle a bit more but nowhere near what a CHRA runs
So every single time an oil molecule gets run through the turbo it gets overheated and damaged a tiny little bit.
If you reduce the feed (restrictor) the oil molecule spends more time in the CHRA on each pass.
The coolant passages are needed to protect the oil.
I'm guessing they reduce the thermal load on the oil 75%...
An aluminum CHRA cannot be used without cooling flow. The heat will mess with the alloy.
When I started working with turbos 37 years ago getting 50K out of a turbo was rare. They would always die from being "coked" up on the exhaust side of the CHRA, they almost never actually broke.
Take apart, soak CHRA in carb dip overnight, new bearings-seals and a re-balance fixed them up fine.
The modern ball bearing CHRA with water cooling has an almost indefinite lifespan. 300-400K miles are extremely common on turbo diesels, replacing the turbocharger is a very rare job.
I've seen 10+ blown up EcoBoost V6 Ford trucks in the last 4 years, the turbos are never the problem, everything else hooked to the turbos is trash...
Having an uncooled CHRA is fine but you will need to do oil changes more often and use the best oil you can purchase.
Intentionally reducing this coolant flow as the bit from FM reads is NOT an option IMO.
When you see a change in the automotive world that ALL of the OEMs add it has already passed the "is this added expense worth it against our bottom line" test.
Cooling the CHRA is one of these changes...
DFI is another: everyone adopted, everyone has problems with dirty intake valves (because of NO catch cans), Mercedes and Ford have already added port injectors to solve this issue, all the others will follow...
Soon all the gasoline powered new cars will have two injectors per cylinder, one direct and one port. Tuning will become more complicated but will yield better results.
EO2K, I'm glad to get our issue straightened out. I really like this forum and would prefer to be helpful without stepping on other's toes
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