I'm again going to recommend reading Greg Bannish (GM OEM calibration engineer and performance tuner/teacher) book Engine Management Advanced Tuning, and any other books you can get your hands on.

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04 Indy SS build #972
XP, TOG's, Lightning injectors, 2.8 pulley, 105 CC springs, Wizaired, 3.29 gears, tripleedgeperformance ported blower, machined LIM, 180* tstat, RS12YC@.053, FP rewire, Alt rewire, stage 1 V boost, PRJ wires, Stage 2 IC

Stock 99 GTP is 68* before allowing open loop. I should have posted where that quote came from. I can't see it in a 3.8 bin but IIRC the knock sensor don't operate until a given temp, which I thought was real close, if not too close the 160* range.

I believe you are very worng on the cyclinder wash running a 160* tstat, and unless you are loaded with money, I wouldn't promise anyone that running a 160 won't cause cyclinder wash. The only place I've seen anyone saying that a 160* on a daily driver car is a good idea is on Internet forums, where people are guessing. In the book I mentioned above, it was stated that most OEM systems are calibrated to 200* for best emissions and combustion. However dropping 20* allows for cooler CCtemps and will let you run a few more degrees of timing thus making more HP. It was also stated that intentially running too cold ETC was reserved for drag racing engines where emmissions and cylinder wash from raw fuel isn't a concern.

Go over to HPTuners ( I know you are a member there, because I've see your questions) and see what the consensus is. fwiw I assume you know Greg is a member there as well.

fwiw, I really don't care whether someone runs a 195 or 180 tstat as it won't harm their engine. I really hate to see some one, who is tight on cash, doing soemthing as from everything I've seen could potential and unknowingly damage their engine.

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04 Indy SS build #972
XP, TOG's, Lightning injectors, 2.8 pulley, 105 CC springs, Wizaired, 3.29 gears, tripleedgeperformance ported blower, machined LIM, 180* tstat, RS12YC@.053, FP rewire, Alt rewire, stage 1 V boost, PRJ wires, Stage 2 IC

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GreenBastardPerformance
2000 GTP Coupe (the green bastard)
XP, Pacesetters, LS1 TB & MAF,MSD System, P&P LIM, P&P GenV w/ 3.2, 3.0, 2.8, Devil'sOwn Injected 100% Methanol,PowerTuned, TripleEdge Trans w/3.29's
12.97 @ 106mph

Well i based my opinions on the fact that i have gathered from my own tests. I have had a 160 in the car since the time that i owned it. No cylinder wash down at all. I would have to agree that it is probably not the ideal tempeture that the engine should be at. But I also know it is almost 100* outside and in city driving (thats all i do) my ect is always between 170-180. Here is a quote from eddie from hpt who also owns a gtp with a combo much like mine.....

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1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~Coated Pacesetters~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's

Quote from eddie over at hpt....experienced tuner.....



LOL - I ran a 160* stat for about 1 year. The ECT for closed loop on a stock 2000 GTP is about 10*C, and a stock 98 GTP is about 24.5*C. These are the only 2 files I have here at work, but I can promise you that it will not stay in closed loop OR wash down the cylinders. I had no problems with fuel trims, O2 sensors, or washed out cylinders.

That being said, you will get a little more carbon buildup with a cooler thermostat. This is one of the reasons (along with the cooler temps of winter) that I went back to the 180* I run now.

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1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~Coated Pacesetters~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's

Im not in any way saying that a 160 is the idel t-stat to have. Matter of fact I wish i had gotten the 180...and since then have almost gone and put the 195 stock one back in.

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1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~Coated Pacesetters~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's

how easy is it to switch from stock to a 180* or from a 180* back to stock?

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http://www.cardomain.com/ride/3055051

2 bolts (water neck) a hose clamp (for the radiator hose) and about 7 minutes of your time. 10mm socket also I belive.

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1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~Coated Pacesetters~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's