Raceghost

iTrader: (4)

Hi, I know there are many discussions on should or should not. However, no suggested tuning reference for any colder than OEM thermostats. Can someone suggest a tuning method, and what tables will need the change in temp to run right with a colder thermostat? I have a couple of tables that come to mind, but am looking for a tuner suggested tables.

Thanks in advance.

Edit 8/10/2018, 2 seasons after testing what is listed below. 2 seasons on the cooler thermostat and tune. Temps daily driving hovered at 79C / 174F. Road Race driving averaged 85C~90C or 185F~195F. Never once under extreme heat 100 F outside air temp race driving did water temps eclipse 200F or 93 C. I am sold that if you tune for colder thermostat THEY DO WORK.
Currently I just installed the Cosworth 160 F / 71 C thermostat. Retuning a little and will be running test associated. Look for more updates to come.

Original posts from 2016 below:
Edit: I decided to make another choice on T-Stat. I chose a 76 Degree C one.

Edit: Interesting write ups here.... http://www.tuneruniversity.com/blog/...-the-advantage
http://www.superstreetonline.com/how...increase-power
http://www.corvetteforum.com/forums/...ifferance.html Good Info even though it is a v-8 forum

Basically, after reading oodles of threads and forums on this topic, I have reached a conclusion. Colder Thermostats only open sooner. In a non modified motor, this can actually be unbeneficial. For a built race motor, looking for longevity, the entire cooling system as well as a lower thermostat can be beneficial. Virtually in any case, it is the temperature of the oil, that maximizes engine life. If you can maintain the motor's designed or suggested oil temp, then a colder thermostat is personal preference. Notation also, that just a colder thermostat is not all that is needed on a computer controlled motor, one must tune the cooling fans for a colder turn on temp as well.

I also read the FP OIL Thread on suggested oil to use on a built 4G63 with FP Red, and it suggest instead of the stock 10w30, we should be utilizing 20w50. My point is that if you built your motor, and it is no longer within any of the spec designations of the manufacturer except only with engine designation code 4G63, than you have to think outside the normal box, and make modifications based off of your specific needs.

Stock Thermostat for an EVO 8 is 82 Degrees C.
Aftermarket variants come in 80 Degrees C, 76 Degrees C, 71 Degrees C, 63 Degrees C, as well as one I saw for 60 Degrees C.
There are also some suggested High FLow Thermostats that increase the bore diameter almost 50% to the stock opening. Bigger bore on the plunger assembly, means you can move more coolant through the opening, cooling faster, even without stepping down a temperature in thermostat.

Also what came up, is the Radiator Cap. Stock is 108 kPa or ~15 lbs. After market is 127 kPa or ~18 lbs. Here is a suggested write up of the benefits/cons to using an aftermarket cap: http://www.tuneruniversity.com/blog/...-radiator-cap/

Read the other 3 links I posted, and all the info is there. I will of course post some findings of my own once I can test. Below are all the changes made to my ROM.

Edit: I am assuming, that all tables that rely on Coolant Temp will need adjusted as to the New Thermostat Level. Stock coolant tables have the highest heat output at 82 degrees Celsius. That is equivalent to 180 Degrees F on the stock thermostat. The next inline down is the 80 Degrees C which equivalent to 176 Degrees F, then 76 degrees thermostat which is equivalent to 170 Degrees F, then 71, which is equivalent to 160 degrees F. I am assuming that all tables will need to be scaled, and 76 degrees will be the hottest in any table that relies on Coolant Temp. Thing to note with my ROM/Maps and Tables that utilize the Coolant Temp, all of them, in the columns of 77/82 degrees C, are the same. So I am thinking that I am already tuned for colder temps in the coolant temp area's of tables. We'll see though. Hopefully some greats will pop in with suggested adjustments. If not, and so, I will probably do a write up in this thread on how to do it, if I can get it to work. Look for more to come, and thanks again.

EDIT: Ok, I have proceeded to go through the ROM 94170715 and Identified all 57 Tables that need Coolant Temp adjusting.

Current Scaling on 82 Degrees C Thermostat is listed below, with the difference or added temp between each additional temperature in red:
-32 +24
-8 +15
+7 +13
+20 +14
+34 +16
+50 +27
+77 +5
+82

New Scaling: 71 Degree C
-32 +24
-8 +15
+7 +13
+20 +14
+34 +15
+49 +16
+65 +6
+71

New Scaling: 76 Degree C
-32 +24
-8 +15
+7 +13
+20 +14
+34 +16
+50 +20
+70 +6
+76

EDIT: Ok, so far so good. 6 days with good results running the 76 Degree C Thermostat, and only changing temp values in the below listed tables. Heater still cranks good on the 0 Degree C Days we have had the last few days, along with snow. Car gets to about 79 Degrees C or 174 Degrees F, and stays there. It did go to about 82 Degrees C or 180 Degrees F under load, but has yet to climb higher than that. I think this is a go. Will update again in later weeks.

Edit:
Just found this in another post... https://www.evolutionm.net/forums/ec...l#post10831962
Can anyone comment on this, if it is true or not? This is definitely a need to know answer.

Edit:
Working on possible TRIM's issue currently, will report back. (refer to above edit)

Edit:
Napa part #'s: After a quick search, it seems THM 6 is the correct part number for 170F, 106 shows 180F.
Thanks to Ace33joe Cross referenced part #'s: Stant 14177 / Gates 33557 / Motor rad 320-170

Edit:
Here is a list of ALL Tables within the ROM that need adjustment. Really your just changing the Temp in the left columns of these tables and leaving for the most part, the right columns alone. Some but not all, do need a little adjustment in the right columns.
Also definitely to note, the Thermo Fan Tables listed, require moderate adjustment. I will post screen shots of stock vs modded below the list of tables. I could probably tune the fans to a colder turn on point, but we will start with what I have.

MAF Water Temp Compensation
Closed-Loop Post Start Inhibit Delay #1
Closed-Loop Post Start Inhibit Delay #2
Closed Loop Short Term Fuel Trim Max
Closed Loop Short Term Fuel Trim Min
Fuel Cut Decel Fuel Resume RPM v Temp
Warmup Enrichment Base Closed Loop Coolant Gain
Warmup Enrichment Base Open Loop Coolant Gain
Startup Enrichment Base Coolant Temp Coeff.1
Startup Enrichment Base Coolant Temp Coeff.2
Startup Enrichment Decay Timer.2L
Startup Enrichment Decay Timer.2
Startup Enrichment Decay Timer.1L
Startup Enrichment Decay Timer.1
Startup (Normal/Main) Adder IPW
Startup (Normal/ALT) Adder IPW
Startup (Hi-Temp) Adder IPW
Cranking IPW 2 Before Engine Fires
Cranking Primer Enrichment
Cranking IPW Delay After Ignition Key ON
Accel Enrichment Base Coolant ENrichment Gain
Accel Enrichment Decay Factor v Coolant Temp
Throttle Enrichment Coolant Compensation
Throttle Enrichment Open Loop Coolant Correction Timer
Throttle Enrichment Closed Loop Coolant Correction Timer
Throttle Enrichment Collant Correction Timer (Closed Loop)
Async Accel vs Coolant Temp Adder (ALT)
Decel F/C End Base Coolant Enrichment Gain
Decel F/C End Coolant Temp Limit
Lean Spool Min Coolant Temp
Spark Coolant Temp Trim
Warmup Spark Retard Control
Target Idle RPM AC OFF M/T (N)
Target Idle RPM In-Gear M/T (G)
Target ISCV Position AC OFF (MT/N)
Target ISCV Position AC1 ON (MT/N)
Target ISCV Position AC OFF In-Gear (MT/G)
Target ISCV Position Cranking
Startup IDLE-UP Position Adder
Startup IDLE-UP Position Decay (per step)
Idle Error Feedback Subtractor Learning Limit
ISCV Demand CTS Adder AC.2 Mode (Heating) N
ISCV Demand CTS Adder AC.2 Mode (Heating) D
ISCV Demand Adder Post WOT.1 59B6
ISCV Demand Adder Post WOT.1A 59C4
ISCV Demand Adder Post WOT.2 59D2
ISCV Demand Adder Post WOT.2A 59E0
Fuel Pump Hi-Speed Mode Water Temp Switches
Thermo Fan Duty 20-50-80 kph AC OFF
Thermo Fan Duty 20-50-80 kph AC ON
Thermo Fan Duty 0-20 KPH
EGR Duty Coolant Temp Interpolation
o2 Sensor Heater Control Coolant Temp Limits 2
Sync Load Accel Compensation vs Coolant Temp Table #1
AirCon Coolant Temp Cut-off Control
SAS Min Temp to Trigger

Raceghost

iTrader: (4)

Bump.

Raceghost

iTrader: (4)

Little closed minded don't you think?

You have 31 posts on this forum, that has been around for 16 years, of which I have been on here since then. Running colder is not simply a fail. You can tune around colder Thermostats. THere are several post of people utilizing it, with no issues, as well as several post of users saying it caused them issues.

I asked for tables that would need to be adjusted. Not a one line Pass or Fail. Can you keep your opinion out of this one, and post up suggested adjustments whether you think it will work or not?

Thanks

Abacus

iTrader: (9)

I'm sorry but I don't have the fueling tables for the stock ecu but I did run a lower t stat.

My car used to run about 190-194* just driving around with the factory T stat. I track the car and I wanted to reduce cylinder head temps for more safety(knock threshold, oil temps etc.) so I installed a Ralliart 168* T stat. The car would run about 178*-180* in the summer time in Fl and about 170* at night. I was on SD hackery at the time and the fuel trims would move a bit from hot to cold . I was finally done messing with the stock ecu all the time, and for other reasons moved to a standalone. For me, it was a huge difference and the car ran much better everywhere.

I've run sebring at 450whp on E85 and only saw 185* after 30 min sessions on the Ralliart t stat and stock radiator. Between the Ecu with smoother timing,E85 and the lower T stat it seemed to run cool even though it was 80-85* and being tracked.

This looks like it
http://www.rhdjapan.com/ralliart-spo...ct9a-ct9w.html

RazorLab

iTrader: (8)

Don't even bother replying to that joker. If you look at his recent posts he is just going around being an *** to up his post count. He is probably some teen in a basement somewhere.

Raceghost

iTrader: (4)

He/She posted in my other thread on Low Load, and said my calcs were off, but will not give single educated calculation to use or example to explain what he suggests. This is why I stated my rebuttal in my second post. Thank you for the support.

Raceghost

iTrader: (4)

Bump. Edited original post.

Raceghost

iTrader: (4)

Bump. Edited original post.

Klaiceps

iTrader: (18)

Just curious but did you have to adjust anything else on your standalone when you were running the Ralliart T-stat? I was under the impression that no tables would need to be adjusted when switching to a t-stat. I guess I need to read up...

Raceghost

iTrader: (4)

Bump. Will a MOD, SuperMOD, Admin, please change the name of this thread? Will you please change the name to: "Tuning for Colder Thermostats", please. The new title is better suited for all Colder Temperature Thermostats, which is what this thread truly encompasses.

Thanks in advance.

Raceghost

iTrader: (4)

Bump. Will a MOD, SuperMOD, Admin, please change the name of this thread? Will you please change the name to: "Tuning for Colder Thermostats", please. The new title is better suited for all Colder Temperature Thermostats, which is what this thread truly encompasses.

Thanks in advance.

ace33joe

iTrader: (2)

I tuned an 04 STi that has lower thermostat, and what you did is similar as what I did - changing temperature scale, but don't have experience with low thermo'd EVO yet.

BTW, which 76 C temp thermo did you get? I looked for one a while ago, and that time I could only found 71 C for EVO 8, and as far as I know EVO 7 & 9 uses the same thermostat and EVO 8 uses something different.

I would be interested in trying 76 C which wouldn't hurt both normal highway use and track days.

Raceghost

iTrader: (4)

Seems to be working fine so far. I only had to rescale the two warmest temps in the temp scaling values.

So if you looked at any part store mainstream, the ones listed are for a base lancer even though they say they are for the evo. The thermostat itself is to tall, and the boar opening is 2/3rds to small.

The one I found is not for an EVO by straight part swap. It is for the v6 variety of a toyota. It measures out correct on size, shaft/boar opening, spring size, etc. The only difference is, all the EVO ones have a rubber shaft seal, vs the one I got is metal. I do believe the 7 and 9's use the same thermostat, but don't quote me on that. I will call my buddy at Napa again, and find the part number on the thermostat we crossed with.

There is also this link I got, but have not verified if they are still available. So mine looks identical, only metal vs the big rubber stopper in the center.
http://www.rhdjapan.com/ralliart-spo...ct9a-ct9w.html

ace33joe

iTrader: (2)

Thanks.

Yes, I ordered a thermostat from rockauto and found it does not fit.

Thermostat is pretty universal part, as long as it has the same dimension, it should work ok, will look forward to the compatible part number.

It would be even better if high flow version is available.

Raceghost

iTrader: (4)

It is, and the one I got is the ticket. Same boar on the plunger as ours. They do not make a bigger plunger, that I could find. I'm thinking because of the outer diameter of the thermostat body that the rubber seal goeas around to seal the thermostat in the housing, and what is left for boar on the plunger. Think there might not be enough material there to make it any larger in diameter. Not sure though.