| Author | Message | ||
| BILL CHIUSANO (My355)
Junior Member Username: My355 Post Number: 118 Registered: 3-2003 |
-------------------------------------------------------------------------------- quote: manual override switch -------------------------------------------------------------------------------- QUOTED... If I remember correctly, Ferrari was nervous about this switch feeding back into the ECU. We installed diodes to protect it, and Ferrari supplied a schematic. FYI. Gotcha my mechanic is from Ferrari factory 25 yrs.in Italy and working here testing etc. I'll assume he's communicating w/ them on this "But I'll run it by him anyway"  Thanks | ||
| DamonB (Prova7)
Junior Member Username: Prova7 Post Number: 59 Registered: 7-2002 |
I daily drive and compete with a '93 RX-7; a car known for being prone to overheat conditions and the best advice here is certainly the water/coolant ratio. I run 80% distilled water to 20% coolant and it makes a world of difference in the hot Texas summers. I believe it was already mentioned that you need to keep some antifreeze in the system for its anti-corrosive properties as well as to lube the bearings in the water pump. This also means I change coolant twice a year as for winter I need more antifreeze to protect the car. Not a big deal and cheaper than most oil changes. I know many people who use Water Wetter and have heard some unproven issues about it. My point of view is to stay away from it if I don't need it. | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 645 Registered: 11-2002 |
If I remember correctly, Ferrari was nervous about this switch feeding back into the ECU. We installed diodes to protect it, and Ferrari supplied a schematic. FYI. | ||
| BILL CHIUSANO (My355)
Junior Member Username: My355 Post Number: 108 Registered: 3-2003 |
ok heres the gig.dual cooling fans are being fabricated and installed w/ temp set as well as manual override switch.replace all the coolant and see how it does.plus it will stay on via timer switch after shut down .that was the conclusion that my mechanic and i came to. i'll letya know how it goes. TIA the proud owner of the AZ plate MY355 | ||
| Dave Helms (Davehelms)
New member Username: Davehelms Post Number: 32 Registered: 5-2003 |
Rob, John Amette warned me about this, as he was able to track down enough data from those that failed. He found that a great majority of those that failed were running water wetter. When the Challange ran at PPIR (back in the 355 era), they were trying to have them run the SCCA track profile (keeping the cars off the banks). John, and the Chief Steward, Jim Barbor, were faced with 100+ deg. ambiant temps, and engines near melt down. The warning was already out on water wetter, so they had no choise but to run the banking simply to save the cars. I have no first hand experiance with this failure, but when John tells me something, there is usually a great deal of fact to it. | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 600 Registered: 11-2002 |
First, "no pressure?? What you feel right now is, depending on weather and altitude, 14.7 lbs per square inch air pressure caused by our lovely atmosphere. So, I think your confusion is the difference between 'absolute' pressure measurement and gauge pressure measurement (like a tire gauge) assuming standard atmospheric pressure is 'zero' and anything above atmospheric is positive, anything below is 'negative pressure' or 'vacuum', all terms which confuse the h#ll out of people trying to talk about the same thing but using different standards of measure. As for the boiling point vs. pressure data, I just read it out of the steam tables from Fundamentals of Engineering Thermodynamics by Moran & Shapiro, 1985. | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 275 Registered: 4-2003 |
Rob, is the 212 degree boiling point correct at 14.7 lbs PSI?? I thought it was 212 degrees at sea level with NO PRESSURE. You quoted: It boils at 212 degrees at 14.7 lb/in 2. Standard radiator caps "Pop" at 15 lbs PSI. If I remember correctly: 1 lb increase in cooling system pressure raises the boiling point by 3 degrees. Now you have 212 degrees + 45 (3degrees x 15 lbs)= 267 degress at sea level. That is why you see some american made smog dogs running at 250 dgrees + without boiling over. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2330 Registered: 9-2001 |
Rob is correct. For the best cooling you want a mix of 25% coolant and 75% distilled water. I always add RedLine WaterWetter as well. Even my Boxer stays cool in Atlanta traffic ! | ||
| Frank K Lipinski (Kaz)
Member Username: Kaz Post Number: 307 Registered: 11-2002 |
Dave � Great point, I forgot to mention the bleeding�. Rob � you statistical knowledge just amazes me! I humbly bow down�  | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 598 Registered: 11-2002 |
Interesting. I had not heard this. My thoughts were poor choice of material in a racing environment. I remember everyone in the paddock dropping fuel tanks and replacing impellers with EMD'd ones FOH had machined for them to solve the issue. | ||
| TomD (Tifosi)
Advanced Member Username: Tifosi Post Number: 3725 Registered: 9-2001 |
yeah, we used to do that in chemistry class, also the reason its hard to get a hard boiled egg in Denver | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 597 Registered: 11-2002 |
Anti-freeze, not anti-boil.. Ethylene glycol has less specific heat capacity than water. A manufacturer does not mix the coolant according to the prevailing weather where you live, they don't know where the car's home is, where you'll drive, so everyone gets a 50/50 mix, and off you go. Though the system's designed for 50/50 mix operating in the AZ desert, one can improve on the cooling capacity by reducing the amount of anti-freeze if one wants or needs to. Maybe you have an older car, maybe you tow a 18,000 lb race car trailer with a dually. With Ferrari's, maybe you race it. What helps with increasing the boiling point is the radiator cap. Increasing the system pressure, raises the temperature at which water boils. It boils at 212oF at 14.7 lb/in2. Raise the system pressure with a 0.9 bar radiator cap, and the boiling point goes to 248oF. BTW, you can boil water at room temperature if you reduce the container's pressure to 0.3 lb/in2. Easy to demonstrate, and fun at parties! | ||
| Dave Helms (Davehelms)
New member Username: Davehelms Post Number: 25 Registered: 5-2003 |
Careful with the water wetter, it has a tendency to make the plastic impellor brittle. The challange guys found that out early in the series! Make sure that both fans are comming on, one a second or 2 before the other. Try bleeding the cooling system at the top of the thermostat housing, a very small air bubble there can make quite a differance. Grounds, and dirty connections to the temp sender used to give us fits when the cars were new. The factory packed the connections with dielectric grease. Wash that out with contact cleaner and apply Stabilant 22 to the connections. The only time you should see 3/4 gauge is on the race track after 6 or 7 hard laps, other wise there is a problem somewhere. | ||
| Frank K Lipinski (Kaz)
Member Username: Kaz Post Number: 305 Registered: 11-2002 |
Bill - 190 (or it may be 195) is center and it should stick and hold there. In fact, the fans will go on and the temp will drop about a notch below, then the fans go off. It will climb back up to 190, fans on...etc etc. I lived in PHX for a few years and know what it's like. I'm in MIA now. A few days ago it was about 90 and I was stuck in South Beach..it took 45 minutes to move one block...the fans stayed on and she never went past the center mark. If the fans are not kicking on or are intermittent usually it�s the thermo switch on top of the LH fan. Easy DIY fix or about a buck and a half to have it done. Also � separate from the thermo switch - the RH fan should go on when the AC is switch on�check that also. I had a small prob of my temp going up, even though the fans were on. Turned out, and I kid you not, somehow I sucked a plastic bag through the vents. Went all the way in, even through the grills in the door jams� | ||
| BILL CHIUSANO (My355)
Junior Member Username: My355 Post Number: 105 Registered: 3-2003 |
If I remember "center " is 190%.Right?? whell it is normally ranging from 1 dash and a half below center to 1 dash and a half above that (in the extremes) Yes you definatly here fans coming on around 190% and I'll double check this myself this evening. MYNSX/MY355 | ||
| Fred (I Luv 4REs) (Iluv4res)
Member Username: Iluv4res Post Number: 395 Registered: 8-2002 |
Rob, I'm curious..... If you have the vast majority of your coolant as water, as opposed to 50/50% coolant/antifreeze, doesn't it boil quicker? My experinces w/ coolants are that if there's too much water, it boils, flows into the overflow tank then out onto the ground. Once the car cools, the coolant level is below where it should be. I thought the antifreeze/coolant was mixed to avoid boilover situations (as well as freezing). ?????????? | ||
| Frank K Lipinski (Kaz)
Member Username: Kaz Post Number: 302 Registered: 11-2002 |
Agree with Rob..BTW Bill does have a C grill according to his post. Re: Heating...yeah AZ is hot, but the car should not overheat even in traffic. At about 190 the fans should kick in and keep her right there. If your talking about overall engine bay ambient temps...well yeah they do run on the warm side. Sometimes while at a light I can see the heat vapors in my rear view mirror.. don't know about mounting fans..would have to be pretty large fans and more work on the elec system load... IMHO if the car does not overheat, it's not a real problem. What I do after some hard driving on a hot day is pop the hood when I shut her down for the day to let her cool of better...seems to keep rubber hoses / wires / etc from premature cracking and looking fresh.. but that's just me | ||
| Rob Schermerhorn (Rexrcr)
Member Username: Rexrcr Post Number: 594 Registered: 11-2002 |
You want to maximize R.O.I.? You live in AZ? Drain you cooling system as much as possible. That will leave a bit of anti-freeze behind in the system. Go to the store and buy three gallons of DISTILLED water, $0.99/gal. NOT mineral water! Refill the system. Now you've just increase your cooling systems heat exchanging capacity 20% in two hours work. Water Wetter does help, not mandatory IMO, though I run it in race cars. 100% water is best for heat transfer, but you need some anti-corrosion properties of anti-freeze for aluminum and lubricity for the water pump. Challenge grill does help, but the ROI for lower engine compartment temperatures is much higher. Do make certain both cooling fans are working. Don't remove your catalysts. | ||
| Manu (Manu)
Member Username: Manu Post Number: 728 Registered: 2-2002 |
Are you running cats??? If you're are then bin them for test pipes.... should get rid of quite a bit of temperature in the engine bay. Challenge grill works too! | ||
| BILL CHIUSANO (My355)
Junior Member Username: My355 Post Number: 101 Registered: 3-2003 |
I was recently caught in standstill traffic "no overheating" BUT I'd like to see the engine bay be able to stay further away from the red area. I remembered from my drag car a theremostatically controlled dual fan unit "kinda generic" but it did assist through years of 8 second runs. I was asking around and someone mentioned "Water Wetter" red coolant.I have seen this product but unaware if this could be a partial answer to the engine cabin exessive heat along w/ an additional exhaust fan that possibly was thermostat controlled or even a stealth mounted manual switch to make active possibly pushing some heat out through the challenge grill. Any suggestions from experience. PS... It gets pretty hot 115% in AZ "NOW" is the time for action the real heat is coming soon. thanks in advance. |