chief455

iTrader: (21)

Same combo as last year but new AFR heads with less compression (8.6:1)

only 20 miles so far, but it hovers under the 210 mark at 2500-2800 rpm cruising, seen it drop to 170 for a mile, then back to 200, sit at a light or slow a few city blocks it goes to 220 - what to do?

has a restrictor plate in the t-stat, last year it ran a little lower (~5-10 degrees)
just tight tolerences?
how can I get the thing to run 190 or lower? What should I look for in the tune?
bigger radiator? fans are about all they can be due to space.
It is crowded under the hood, but...

D1SC supercharged so I'd like ambient heat at miniumum

Blackbirdws6

iTrader: (7)

Are you running the factory rad/fan system? I'm running the stock components on my TA with a 160 deg t stat. Temps don't get even close to 210 and normally hover in the 180 range. Make sure both fans are working also. The spacers provided by procharger pushed my drivers side fan into the radiator effectively seizing it.

Check for air in the system as well.

chief455

iTrader: (21)

All good questions.
I think previous owner put a 160 stat in - or maybe none? in hot Nevada then, cooler Ct. now.
Stock cooling/fans. Both fans do work. I clearenced the driver side during install Will bleed out air - but did that afer start up already.

Can I try turning the fans on/off with Tunercats?

96capricemgr

iTrader: (1)

Do you have an electric waterpump?
With your cruise rpm you are above the rpm at which a stock pump exceeds electric capacity.

Tunercat is used to adjust fan on and off temps but once moving forward at any decent speed vehicle motion usually provides airflow so fan generally will not affect cruise temp. Actually the facory programming has a speed where they turn off and freewheel so they don't restrict airflow.

chief455

iTrader: (21)

stock water pump.
Looking at my ECM constants, fans are set on at 167 degres F (oil temp)
fan high/low speed threshold = 45mph
enable high A/C pressure = 35mph/ disable = 36mph?

are you saying above 2600rpm cruise an electric pump would provide higher capacity than stock?

Blackbirdws6

iTrader: (7)

He is saying that the mechanical pump will flow more than an electric at that RPM.

What type of coolant are you running? I'm running mostly distilled and will swap back to a mix as it gets colder. It def brought down the temps considerably. I would first make sure you have all the air out. It can be a bit finicky but just make sure.

96capricemgr

iTrader: (1)

set the fan temps by water temp, only the Vette had an oil temp sender.

chief455

iTrader: (21)

check out my settings in Tunercat:

96capricemgr

iTrader: (1)

Some malware screwed up my tunercat on my desktop so I can't look right now and find it exactly but look in the regular tables I think some versions of tunercat have it in a table instead of a constant for the coolant fan temp settings.

speed_demon24

iTrader: (6)

Do you still have the air dam on?

chief455

iTrader: (21)

yes, in good shape too. I bought it from Nevada, came with water only running just under 200 and heating to 220/240 through traffic nd after hard 1/4 mile pulls.
I'd like to lower the motors ambient temp for break in and to allow for the superchargers heat.

Can anyone post up where in Tunercat the fan on/off is?

The pic posted above is based on oil temp/constants table.
I found another low/high rpm - temp based setting with only 2 entries.
I can post a pic later from home.

Datalogging, it ran ~200 degrees until I pulled it to 5000 rpm through the gears and cruised ~2600rpm - went to 215 degrees.
It runs boggish at the higher temps - and I really don't want to fry the new motor once boost cranks up the heat.
Anyone with Tunercat show me their fan tables?

Mystery Bird

iTrader: (7)

Can't remember off the top of my head but it's something like fan enable vs. coolant temp vs mph or something like that. The newer versions of TC have this in the regular tables instead of the constants.

69gto96z

iTrader: (13)

Why a restrictor plate on the t-stat?

chief455

iTrader: (21)

Fan enable coolant temp vs speed?
if so, these temps are a little high (190/196 low speed- 190/198 high speed) and it does stay ~ 200 low speed, rises a bit at higher speeds, and in traffic.
Should I set all 4 blocks to 75 c (167 f)?

draggin97s10

iTrader: (2)

i would.

Mystery Bird

iTrader: (7)

No not all 4, then your low and high speed would run together. Shoot for 15-20 degrees above your t-stat rating for low then another 10-15 above that for high. This is my preference unless fans run too much then I'll adjust from there. You will find varying thoughts on this and some like to run thiers hotter or cooler.

chief455

iTrader: (21)

Thanks Dave
At least I know that is the correct block for fan settings.
I will stagger the low/high speed settings as you mention, but have both fans the same. (75/75 low, 80/80 high) I want to run cool to allow heat from boost.
Curious - how do the fans know to shut off during high speed freeway driving?
Only if the temp falls below these settings?

shbox

I would not. Your fans would never shut off.

If you are using a restrictor instead of a thermostat, your coolant is not being routed efficiently. Not all of your heated coolant is making it to the radiator and not all the cooled coolant is making it to the engine. They are mixing in the pump. You need an LT1 thermostat for it to work like it should. It is not like a simple SBC system.

The fan enable/disable MPH constants tell the fans what to do at certain speeds while the a/c is on. Temperature tables will always override any other fan functions (except when the SES comes on).

chief455

iTrader: (21)

Thanks shbox
I bought the car this way and have changed about everything!
I am installing an LT-1 160 stat. I've had them in a few other cars and like the temp range.
I notice my current car/tune does get warmer as soon as I turn the AC on and cools down when I shut it off. Sounds like those settings need to be tweaked as well.

96capricemgr

iTrader: (1)

Really good catch shbox.

Maybe we should post a link to cheif455's last post in the "what is my engine worth" thread. Buying a built car is very often a lesson in how to fix someone else's mistakes.