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-   -   warm up time ? (https://www.rx7club.com/new-member-rx-7-technical-256/warm-up-time-1118288/)

GregoryRx7 09-01-17 12:58 AM

warm up time ?
 
hey guys just looking for some wisdom from some seasoned FD owners..i was wondering how long to warm up the car i usually do 5 mins before i start driving and another 5 mins of driving easy after that ? also i run the fans for about 5-10 mins after i park depending on how hard i ran her ? lil input would be appreciated in relation to the times

thanks always

Sgtblue 09-01-17 03:53 AM

IMO it's not a factor of time, it's temperature. Get it to operating temperature before boost. Depending on ambient, that can take more or less time. You should have a temperature gauge other than stock.
What do you mean "run the fans" after parking? Is that with the engine idling or just the fans? There was the old 'fan mod' which ran the fans for 10 minutes after shutting the engine off using a ground on the stock ECU...ostensibly to help with heatsoak. It doesn't hurt anything on an otherwise healthy car, but there was really no benefit to it.
Sitting and idling with the fans I'm not sure you'd see temps go lower than the stock fan thermoswitch, which is 108 C. (226 F.). Oil temps would tend to rise as well unless you just finished a hard boost run within the last minute or two before shut down.

Midsnow 09-01-17 05:39 AM

I agree with the above. No hoon'ing on it till the coolant is up to temp. Typically. Fire the car up. Let it idle for a few minutes just to start warming things up. Then drive (out of boost) with light throttle till the car is up to temp.

But I do have one thing to add on top of that.
Your oil temp and thus the pressure takes longer to warm up then your coolant does. So while cold your pressure may be higher the flow is much less and you will be adding wear to bearings on the turbos and the e-shaft until the oil is up to temp and flowing properly as well.

So safe bet is wait till engine temp is normal and then wait another 3 to 5 minutes before red-lining it. Unless you have a Oil temp gauge and can see it's at least above 170F.

Now I don't have experience on how long it takes for oil to warm up on a rotary yet, but my experience is with a Boxer motor in a BRZ with a 20G turbo. I find it takes about 3 to 5 minutes after engine is up to temp for my oil to get to 174F. I only have one oil cooler though. And that's when the ambient temp is around 74F or so. It will warm up faster in hotter weather and slower in colder weather, obviously.

Sgtblue 09-01-17 06:16 AM

Getting up to temp is probably a good idea in any engine, but maybe more so in a rotary due to th bi-metal sandwich construction. Intuitively I'd guess oil temps rise quicker in a rotary because of increased surface area of rotor faces vs pistons...but that's a guess. And I think film strength actually declines with temp. A reasonable viscosity range might be more important.

TomU 09-01-17 09:32 AM

Regarding running the fans after shut down, all that does is cool the water in the radiator.

After a track session, I will run the fans with the engine off then start the engine to circulate the cooler radiator water into the engine then shut it off before the engine starts warming up the water again. I do this a couple times (with the hood up). This is kind of a pain and would be a whole lot easier with an electric water pump that can circulate the water w/o running the engine.

After driving on the street, I just leave the hood up (don't go through all the rigmarole with restarting the engine). It's also good to let the engine run a little while if you've been in boost to cool down the turbos. I would not invest in a turbo timer though. Just let the engine idle (or drive it not in boost)

GregoryRx7 09-08-17 01:31 PM


Originally Posted by TomU (Post 12212653)
Regarding running the fans after shut down, all that does is cool the water in the radiator.

After a track session, I will run the fans with the engine off then start the engine to circulate the cooler radiator water into the engine then shut it off before the engine starts warming up the water again. I do this a couple times (with the hood up). This is kind of a pain and would be a whole lot easier with an electric water pump that can circulate the water w/o running the engine.

After driving on the street, I just leave the hood up (don't go through all the rigmarole with restarting the engine). It's also good to let the engine run a little while if you've been in boost to cool down the turbos. I would not invest in a turbo timer though. Just let the engine idle (or drive it not in boost)


Thanks ill let the car run after i park for a 5 mins then run the fans for another 5 mins ...thanks guys for the help and info just trying to make my rotary last

Bart_94RX7 10-04-17 04:39 PM

cool down period
 
I've had installed a rocker switch on the center console.
It activates all 4 relays that control the engine fan speed.
Note:
1st relay turned on causes low fan speed
next 2 relays turned on cause medium fan speed
4th relay turned on causes high fan speed.
(otherwise, only way to turn all 4 relays on is to turn A/C on...
surprisingly a high engine temp only results in 3 relays being activated)

THUS, a couple minutes before I expect to shut off the engine I throw the switch
and I watch the engine temp gauge on the a-pillar slowly go down.
Thus, the water temp is usually down to about 195 when I shut off the engine.

Aaron Cake 10-10-17 07:38 AM

There's nothing complicated that needs to be done. Start car, put on seatbelt, and just don't beat on it until the engine is up to temperature. No need to waste time and fuel letting it "warm up". Same with shutdown. Unless you have been beating on the car moments before, just park, turn off and walk away.


Originally Posted by TomU (Post 12212653)
Regarding running the fans after shut down, all that does is cool the water in the radiator.

Coolant still flows due to convection.

Sgtblue 10-10-17 10:36 AM


Originally Posted by Aaron Cake (Post 12222495)
There's nothing complicated that needs to be done. Start car, put on seatbelt, and just don't beat on it until the engine is up to temperature. No need to waste time and fuel letting it "warm up". Same with shutdown. Unless you have been beating on the car moments before, just park, turn off and walk away.

Unless you’re forced induction/turbo’d. Then I’d stay out of boost until it’s warmed up...fully. Not complicated, but needs to be done.

Originally Posted by Aaron Cake (Post 12222495)
...Coolant still flows due to convection.

VERY slowly but I doubt it would keep up with heat soak, especially with water cooled turbos, even with fans going. The old fan mod was pretty useless imo.

acestro 10-11-17 08:10 PM

I do the few minutes then rev low until my temp gauge hits normal then I’ll boost.

Sgtblue 10-12-17 03:45 AM

^Good practice. But what's normal? Your profile lists an FD. If you're relying on the stock temp gauge, know that it isn't linear. That means that anywhere from maybe 160 F. to about 230 F. it sits just below half-way mark. And once it begins to rise at all above that mark you've pretty much already over-heated. I always recommend to new owners that they install a decent aftermarket temp gauge if they don't already have one.

PeloNZ 10-13-17 03:27 AM

I've got a digital temp gauge on my stock FD. It has multi stage warnings and peak recall for the extra paranoid.
I can't sit idling in my garage due to fumes. My start up procedure is pretty liveable. Open the door, check it's in neutral, start the engine. Then sort out my wallet, phone, jacket, get in, sort music, put on seat belt. That takes a minute or two. The temp will have moved from ambient to about 35c by then. I just drive out of the garage, and cruise. The temp gets to 50c quickly, which is where I've got my first stage low temp warning (flashing bright blue) set to stop. This corresponds to the stock temp needle getting to one quarter. After less than 5 minutes of off boost, under 3k rpm driving, the temp will be at 75c which is good. Give it a few more minutes to warm up the oil and boost away! Heavy traffic temps peak at 95c and at track days I've never seen over 105c.
For cool down, just take it easy for the last 5 minutes of your trip. If you've been thrashing it, the best thing to do is open the bonnet and keep the motor idling for a few minutes. Don't leave it down as the heat has nowhere to escape. You can turn on AC to switch the fans to high mode, it does make a difference.

Below is an example of how the oem temp gauge works.
https://cimg4.ibsrv.net/gimg/www.rx7...29ed79603f.jpgstock temp gauge readings

spd11 10-16-17 07:41 PM

Are most rotary headaches caused by not warming up properly? I've only just heard this notion recently, but it keeps popping up everywhere.

Sytfu_fd3s 10-17-17 03:40 PM

I myself am new to rotaries but I do not warm up my car. I just get in and drive. But I like to keep the rooms below 3k and stay out of boost until it warms up


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