I personally have tried 160* and noticed a decrease in performance.

I went back to stock 195* and have been there since. Would it be wise to try 180*? I dont want the computer to stay in the wrong mode while cruising or at WOT.

------------------
92 Formula
305 TPI 5speed
1LE package
Mods: SLP headers,SLP catback,SLP air foil,ported plenum,K&N, Crane AFPR (47psi),MSD6AL, Holley 9mm Annihilator wires, Bosch O2sensor, 3:73s,JET fan switch, Macewen white face gauges, Intellitronix Digital Gauges

 

unless you have a aftermarket computer chip that low of a thermostat is'nt going to help a whole lot

 

I have a 89 305TPI with a thermomaster chip and a 160 stat and fan switch. Alot more power, runs great, and its great in the summer. Go with a chip and a 170* stat from TPIS or 180 if you're worried and geta warmer switch.

------------------
1989 Iroc-Z. 305TPI 5spd, G92 (230hp/300ft/lbs). 91-92Z28 groundeffects. Corvette Admiral Blue Metallic paint. Thermomaster chip, 160*stat & fan switch, Bosch +4 plugs, MAF screens removed, custom ram air, Flowmaster cat back, K&N, adj. fuel pres. reg.
72,000 miles. SWEET!!

 

Not trying to gain any performance. Just trying to extend the life of engine.

 

do they make 185*s?

------------------
92 Formula
305 TPI 5speed
1LE package
Custom cold air intake w/K&N, SLP airfoil, ported plenum, Crane AFPR (47psi),MSD6AL, Holley 9mm Annihilator wires, Ac Delco cap,rotor and plugs, Bosch O2sensor, Slp 1 5/8 headers and catback (all stainless steel!), 3:73s,JET 195* fan switch, Macewen white face gauges, Intellitronix Digital Gauges

 

I'd go w/ the 170* chip...engines actually make more power at higher temp, but the extra heat increases the fuel temp which offsets the power gain. don't waste your money w/ tpis, I've got the acdelco part number here somewhere and you can get it from the dealer for $5.



------------------
87 IROC-Z, 5.7, auto, 3.27, leather, !cat, Holley fpr, K&N'S, SLP 1-3/4" Jet-Hot coated headers, SLP .218/.224 .495/.502 cam, Comp 1.5 roller tip rockers, $uperPITAram, Edelbrock lower intake, Holley 52mm tb, Dynomax\Flowmaster catback. Coming Soon(?)- Fasttrack/Accell DFI

1989 Pontiac 20th Anniversary Turbo Trans Am - 161,000 miles, !cat, 9" K&N

 

I have a 160 and i am switching to a 180. It is better for the engine to run a little warmer for the computer to work right. 160 is to cold unless you only drive it when it is only 85 -90 or hotter.

------------------
1987 Camaro Iroc-Z Z-28 with a TPI 5.7
-Ram Air,K&N Filterchargers, Gutted Mass
Airflow Sensor, Throttle Body Airfoil,
Edelbrock TES Headers and Y pipe, Gutted
Cat, 3 inch exhaust, Flowmaster
-Hypertech Thermomaster Chip, 160 deg Stat,
Adjustable Fuel Pressure Regulator
set at 50 psi, MSD Cap, MSD 8.5mm wires,
Accel Coil, MSD 6AL Ignition Box, Accel
Plugs
-Richmond 3.73 Gears, B&M Transpak,
B&M Rachet Shifter, Energy Suspension
Products
-Fiberglass Cowl Induction Hood,
Purple Neon License Plate Frame,
16X8 Rims with BFG 245 50's,
Pioneer Deck, 2 JL 12's in a Q-Logic
Box with a 300 Watt amp

What you can put between your ears,
no one can take away.

 

hehe i bet i win this one!

I have a 0-degree thermostat!

meaning: i took mine out.

that and i have my fan wired to always be on. my car has always run hot. but not anymore! wahh hah ha!

 

When you put a lower temp 'stat on a TPI car, what is it actually doing, computer-wise? Is 160 deg. below the min. temp for the computer to go into closed loop? Does this richen the mixture?

 

160* will enrich your fuel mixture I think, and does something with trouble goin into closed loop. But this is only if you don't have a chip to compensate for this change.

------------------
1989 Iroc-Z. 305TPI 5spd, G92 (230hp/300ft/lbs). 91-92Z28 groundeffects. Corvette Admiral Blue Metallic paint. Thermomaster chip, 160*stat & fan switch, Bosch +4 plugs, MAF screens removed, custom ram air, Flowmaster cat back, K&N, adj. fuel pres. reg.
72,000 miles. SWEET!!

 

I wish I would have read this thread earlier because there's LOTS of misinformation here.

First, read my tech article on GM cooling fans on this website. Now, to set the facts straight.

Closed loop is attained when exhaust temperature reaches 600 deg F and coolant temperature reaches 104 deg F. This is not a misprint. I attain closed loop within three minutes of starting my engine. Therefore, it is irrelevant what temperature t-stat you use. You will always be in closed loop way before the t-stat temp setting.

Secondly, it does no good to use a lower temp t-stat UNLESS you are able to turn the fan(s) on earlier. It is NOT necessary to replace your stock prom to do this. My article describes it in detail. I call it my "Total Fan Control" system.

I have found that a 170 t-stat is the best year round. You do not have to purchase it from TPIS. At one time, I thought they were the exclusive source for this t-stat. My article has a GM part number for this t-stat and is about half TPIS's price.

It is not a good idea to run without a t-stat. The t-stat actually helps to restrict coolant flow, allowing it sufficient time within the radiator to cool. Without this restriction (t-stat), the coolant flows much too fast through the system, thereby not allowing enough time for it to cool to the radiator's ability.

If you have any more questions, please direct them to me via e-mail.

------------------
Willie

Supercharged 1987 305 IROC-Z, Daily-Driver, Emissions-Legal.
12.57 @ 111 mph.
12.04 @ 114 mph (50-hp nitrous).
http://members.optushome.com/au/downunder1/rides/willie/willie.html

1987 "20th Anniversary Commemorative Edition" Z28 Convertible -- Super Chevy Show Class Winner, 1998.

[This message has been edited by Willie (edited December 12, 2000).]

 

I run a 170 degree stat too. Got it at Pep Boys, but it's not identified as being for a Vette.

The OD is slightly larger than the Vette stat but with the help of my little Mikita high speed grinder, reducing the OD was easy.

I've tried 160 and 180 before. The 160 made the engine run too cold and the 180 kept it at 200; the 170 is perfect, maintaining around 180 degrees.

Hope this helps.

Jake

------------------
1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

Jake, do you have the stock prom? mine is stock is it a problem?

 

i have a 170* stat and a hypertech fan switch and the car never goes past 180* even in the hottest summer day.

 

Engines (as discussed here) make best power at about 200. use a 195dF thermostat and a GN rad fan switch (turns fans on at 210ish).
Running colder just always forces the engine to be closer to a choke mode so it is richer, with more timing.
Rich with excessice timing always feels better.
IF you use the GN fan switch to turn on the fans, then use a 220 ohm resistor to tell the ecm your at 160 when running 190 if you really like that feeling, though depending on your application it might help but generally no.
Pistons are designed for best sealing at a particular operating temp., cooler reduces the head bolt preload, is MUCH slower to percolate moisture out of the oil. But, to name a few items.

 

Moroso sells restrictors, if you don't want to run a thermo. It's just a metal disc with a hole in the center; you could even make it yourself.

I personally have my thermostats (160 summer and 195 winter) drilled "north and south" with a small bit; that way I don't get any of those damned air pockets between the engine coolant & the bottom of the 'stat. The car runs a bit cooler with those holes.


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

What exactly does drilling holes do? Do the air pockets that form make the car have cooling problems?

------------------
91 Formula
305 TPI 5speed
1LE/G92/WS6
Custom cold air intake w/K&N, SLP airfoil, ported plenum, TB coolant bypass,Crane AFPR (47psi),94 octane,Crane Extruded Alum. 1.6 full roller rockers, Timing set from 4*BTDC to 10*BTDC,MSD6AL, Holley 9mm Annihilator Laser shot 50 wires, Ac Delco cap,rotor and plugs, Bosch O2sensor, SLP 1 5/8 headers,SLP catback,3:73s,JET 195* fan switch, Macewen white face gauges, Intellitronix Digital Gauges

Stock throttle body, runners,intake manifold,cam, and heads.

 

First, it's basically 1/2 of a racing idea.
Second, it does prevent air from being trapped from running in real low temp areas where the thermostat doesn't open much cause the heater is enough to about cool the engine.

If you plug the cooling bypass system then you have to punch a few holes in it. The thermostat is basicly open or closed, the bypass, helps to average the temp from open to closed.

Does make filling the system easier.

 

running a 160 thermostat get you about 6% more fuel and a couple degrees more advance.

In back to back testing (changing thermostats at the strip) using optimised tunes, I saw absolutely no difference in ETs or Trap speeds. If you run a cold thermostat and go faster then its cause the higher temp calibration is wrong.

Running cold means the pistons are at the wrong clearances, the head bolts aren't being stressed right, and the oil is slower to percolate moisture out of it. I don't see any advantages there.

The cold thermostat stuff started in Flat Head Ford days. Just been repeated so many times folks think it's fact.

 

The optimum system would include blocking off the water pump bypass and drilling holes in the t-stat body. This allows a small amount of coolant to continuously flow throughout the system, preventing the formation of hot pockets of coolant. Hot pockets can cause certain sensors to give false readings. I do this on all my Camaros.

Willie

 

No, I'm running a TPIS Stage V PROM.

I'm not sure of what you mean by "is it a problem?" Can you clarify it for me?

Jake


[This message has been edited by JakeJr (edited December 26, 2000).]