ChevyKen

iTrader: (1)

Hello all,

I'm thinking of changing my termostat to a cooler one in my 86 IROC w/the 305TPI.
The main reason is that she is running warmer than I'd like on warm days. If it is sitting still running on a 80°F day, the temp will be between 220 and 260 - while at approx. 220-230 while driving.

What would you guys suggest (what t-stat)?
Do I need to do other changes i.e. PROM etc ?
What is the approx. cost of the parts neccesary for this upgrade ?

Thanks for any and all inputs,


Ken

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Bright red 86 Iroc-Z Choo Choo Customs Convertible
A few free mods
ChevyKen's Cars (ALL new!!)

Administrator @ ChevyWorld.net (Now in a BRAND NEW Design)

leirch

I'd probly go with some sort of a fan switch and a 180 stat, with those you should be able to leave the prom alone. Now if you went with a 160 stat your asking for trouble(didn't mean to open another can of worms from all of the 160stat Believers) and would probly need a prom change. I have a new radiator, dual fans and a 180 stat, i drive around and sitting still i NEVER get past 220. Driving down the road i am ALWAYS at 180-185 degrees.

Brendan

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1987 IROC-Z L98,SuperRam,EB 6085's,LPE 219/219 Roller, Crane 1.6RR, EB TPI Base, 58mm TB, ADS 24#, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, MSD 6AL, MSD Blaster 3, Aluminum DS, 94 Disk Rear, Adjustable Valve, Precision 3.73 Gears, Sub-Frame Connectors, Hotchkis Lower Control Arms, KYB Shocks/Struts, Suspension Techniques Lowering Springs, Polyurethan Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm,

To see the ROC, Check out the webpage Here

rondubbs

i have a 170* stat and hypertech 176* fan switch,, my car is never hotter than 200* in stop and go city traffic,, its 170 on the highway..

Lounge Lizard 6

Go with the fan switch. If that isn't enough, then I suggest a high perf water pump. I put in a Stewart Stage I and it knocked an easy 20 degrees off of just a fan switch and Tstat.

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Mike

'90 IROC-Z , 5-speed, ZZ4, G1 Trick Flows
Moderator SEThirdgen

ChevyKen

iTrader: (1)

Thanks guys!
So, the way to go is either a 170° or 185° stat and a 170° fan switch..?

Where would I find these parts, would AutoZone/NAPA have it, or does it need to be ordered from a place like Summit..?

Thanks again!


Ken

custman87T/A

remember the fans should be switched to go off approx. 5 deg. higher than the thermostat is rated for. If you use a 180deg thermo you want your fans to come on at approx. 200 and OFF at 185.

chret

Everything I have heard/read, is that you don't need to go below 180. I got mine at pep boys for 9.95. Performance resouces said that hypertech is wrong and that you can achieve just as much performance with out having to go to 160. 160 is way too low. your thermostat would stay open all the time. and without modifying your chip, the computer would stay in open loop mode all the time resulting in crap performance. (or is it closed loop mode) anyway. Yes you would benefit from a cooler engine but go about it using other methods that a 160 stat. Also, run some sort of cleaner through your cooling system before you change the stat and flush the sytem when you finally change it. Made a huge difference for me.

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'92 Camaro Z28 5.7L LT1(B4C) 25th Anniversary Edition Holley Air Foil, MSD Coil and Ignition, Dual K&N Air Filters with modified intake, TCI StreetFighter 700R4, TCI Saturday Night Special Torque Converter, TPIS Aluminum Drive Shaft, Performance Resources Computer Chip, No Cats, True dual exhaust with dual Flowmasters,

camarojoe

Chret is on the money. 160 is defineitely too low for the stock computer or even most aftermarket chips. I have a PR chip and recently rebuilt my engine, adding new heads intake and cam. I decided to go with a 160 degree stat, because I was sick of having my car temp go up to 230 degrees in city traffic. At first I thought the stat change was good, the car never got past 170, but then I started to notice a bigger than expected decrease in fuel mileage. The car also ran like ****. About a week ago I spun a rod bearing, so I had to tear the engine out and completely disasemble it. I noticed that my brand new heads and intake were coated from carbon, this was with only 800 miles. The car was running waaay too rich and it was because of the 160 stat. Anyway, to answer your q, go with a 180 stat and fabricate your own manual fan switch. Peace.

MouseCamaro305

yeah, check out the free mods section (l think thats what its called) for making your own manual fan switch. it'll save you some bucks and so far there have been no one to reccomend the 160 degree stat and l hope it stays that way. with a 160 stat you dont have a good chance to pass emissions, your motor will never internally heat up, and like someone above said its gonna run like absolute crap! people think just because the motors cooler it's gonna run better, and run faster, thats not true, its only true if the intake charge is cooler, and that can be acheived by a throttle body coolant bypass.

bjankuski

I run a 160 degree stat with a stock chip and hypertech 176 on 166 off fan switch. The car runs great, get over 20 miles per gallon, and runs 13.80's in the quarter with my current mods. The car does operate in closed loop and I have no drivability problems. The engine also has 103,000 miles on it and is still running strong. I have no complaints with the 160 stat and fan switch.

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1988 Formula 5L/5sp 3.45 gears, SLP cold air kit, MAS gutted, TPIS air foil, TPIS AFPR, MAC headers, Mac under drive pulleys, MAC cat back, Relocated MAT.
Best ET street tires 13.85
Best 60 FT street tires 1.930
Best MPH street tires 99.29

F22Raptor

Well, I took my A/C out not too long ago and the car will not go over 190-200 with a 180* stat, not matter how much you run the car. One of the fans relay will die after running a while leaving just one fan running, but it still won't overheat. The condenser really restricts the airflow to the radiator.
Rick

yellowiroc

Could someone please explain to me in detail how to hook up a fan switch. Right now I'm running a 160 thermo and after reading above, I'm debating on switching back to a 170 or 180. I'd also like to do the bypass, so if anyone has done it on a car just like mine... I would really appreciate instructions.
Thanks in advance

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86 IROC 305 TPI LB9 700R4 W/ Shift kit, K & N, Flowmaster gutted cat 95 Z tips, airfoil, 160 thermo, removed emissions, Summit cam kit 442 lift springs and lifters, ADS super chip, Summit timing chain, modified MAFS, tranny cooler, polished rims, Good Year yellow letter nascar 235/55 tires, polished runners and plenum, 145 Speedo, remote start, keyless entry, alarm, yellow neons underneath.