 Hot weather driving, Which is better for the car? |
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| MoveQik |
 Jun 27 2005, 01:39 PM
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#1
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What size wheels can I fit?  Group: Members Posts: 4,654 Joined: 5-April 05 From: Scottsdale, AZ Member No.: 3,881 Region Association: Southwest Region   |
Is there a rule of thumb as to the most efficient way to drive during the summer in order to keep things as cool as possible back in the engine bay?
For example, is it better to keep the RMPs slightly higher to keep the fan pushing more air or is better to keep RPMs lower to keep the engine from generating more heat. If you can follow that logic. (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif) |
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Replies(1 - 11)
| TravisNeff |
Jun 27 2005, 01:47 PM
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#2
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914 Guru Group: Members Posts: 5,082 Joined: 20-March 03 From: Mesa, AZ Member No.: 447 Region Association: Southwest Region 
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You need to drive with the engine off and have someone push you.
It's nice to hop into the car first thing in the morning and before you even start it, it is halfway to being fully warmed up (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif) |
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| MoveQik |
Jun 27 2005, 01:49 PM
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#3
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What size wheels can I fit? Group: Members Posts: 4,654 Joined: 5-April 05 From: Scottsdale, AZ Member No.: 3,881 Region Association: Southwest Region |
Yeah, I've noticed it never gets too hot rolling down the driveway.
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| TravisNeff |
Jun 27 2005, 01:55 PM
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#4
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914 Guru Group: Members Posts: 5,082 Joined: 20-March 03 From: Mesa, AZ Member No.: 447 Region Association: Southwest Region
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I'll soon have the kids in shape enough to push me at full sprint and even make the engine noises for me. A couple of moutain dew's and I can go for 20 miles. Cheaper than gas!
I think that if you lug the engine down you will create more heat, as well if you are revving the piss out of the engine. 2800 to 3500!?!? I really dunno. |
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| jasons |
Jun 27 2005, 02:08 PM
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#5
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Jackstand Extraordinaire Group: Members Posts: 2,011 Joined: 19-August 04 From: Scottsdale, AZ Member No.: 2,573 Region Association: None |
I am of the opinion you should keep the R's up so the fan spins and keeps air circulating.
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| redshift |
Jun 27 2005, 02:10 PM
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#6
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Bless the Hell out of you! Group: Members Posts: 10,926 Joined: 29-June 03 Member No.: 869 |
Stop and go? NEVER going to be happy...
Idle is rough, but long periods of idle, after holding 3000 in second don't seem much better. M |
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| Rand |
Jun 28 2005, 04:30 PM
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#7
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Cross Member Group: Members Posts: 7,413 Joined: 8-February 05 From: OR Member No.: 3,573 Region Association: None |
RPMs affect different things. Move more air, cool the heads... but also create more friction that heats the oil more. Yada yada.
The way to KNOW is to have good accurate gauges for oil and head temp. If something starts pushing red then you can address it. |
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| airsix |
Jun 28 2005, 04:39 PM
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#8
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I have bees in my epiglotis Group: Members Posts: 2,196 Joined: 7-February 03 From: Kennewick Man (E. WA State) Member No.: 266 |
My understanding is the typeIV fan cavitates at higher RPM's and actually moves LESS air when you spin it fast. Higher road speeds = higher head temps. The only way to know for sure what's going on is to use oil and head temp gauges. Hopefully the wise ones (John Larson and Jake Raby) will join this thread.
-Ben M. ps- didn't mean to imply that others here aren't wise. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) |
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| BMartin914 |
Jun 28 2005, 04:50 PM
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#9
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||| Group: Members Posts: 1,408 Joined: 30-May 04 From: Oregon Member No.: 2,128 Region Association: Pacific Northwest |
The faster I spin that engine, the cooler the heads are. Exactly the opposite for the oil. Double-edged sword.
Never saw head temps above 300* at this past weekend's track event. Oil temps however approached 260* (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif) |
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| nebreitling |
Jun 28 2005, 04:53 PM
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#10
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Member Emeritus Group: Members Posts: 3,314 Joined: 26-March 03 From: San Francisco Member No.: 478 |
i believe that i recall someone *wise* once saying that maximum effeciency of the fan is at 4600 rpm. but cruise at 4600 rpm and you'll be cooking your oil on most engines (w/ out an extra oil cooler).
certainly, never cruise at less than 3000 rpm. 3200-3600 seems to be a nice balance to me. in any case, i would rather change the oil a little more often and run cooler head temps. |
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| MoveQik |
Jun 28 2005, 05:07 PM
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#11
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What size wheels can I fit? Group: Members Posts: 4,654 Joined: 5-April 05 From: Scottsdale, AZ Member No.: 3,881 Region Association: Southwest Region |
Thanks for the info. Sounds like good gaugees are in order. Any recommendations?
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| LukeD |
Jun 28 2005, 05:45 PM
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#12
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Member Group: Members Posts: 254 Joined: 14-November 04 From: Atascadero, CA Member No.: 3,117 Region Association: None |
I have a VDO Cht in the console and a calibrated, Numerical oil temp VD0 were the e-bralie light used to be. try Palo Alto Speedo do a Google for the website. After having them and Seeing how they react to different situations I wouldn't feel comfortable driving without them.
Luke |
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