eViLRotor

iTrader: (2)

This is a follow up post to Snrub's cooling for the track post.

I'd like to know what youTII and FD guys get for coolant and oil temps during road racing/lapping days.

I have an 87 TII, with a large KKK turbo, Griffin Rad, FMIC, running 14psi. Running 70/30 H20/EG mix.
Ambient temp was around 28C.

My water temps where 225F (105C) at the engine block (just below the oil filter) and 235F at the filler neck.

The first reading in from my EMS, the second from an Autometer gauge.

I don't see temperatures anywhere near that during street driving, and i'm certain my cooling system is in good shape.

Are those kinds of temperatures normal for road racing, or am I in danger here?

Thanks.

Silkworm

Nevermind

80-CU.IN.T

That is hot. I would like to see pics of your installation -
Radiator, intercooler, oil coolers. ducting ect. before offering any advice.

Carl Byck

195-200 max, both oil, and water, cooling mods are extensive. A second TII oil cooler, Huge Griffin, AST, Hood cantilevered up 1.5" in the back(all insulation removed) All accessories removed from front of car, radiator panel, Large hole cut in bumper, and bumper support Oval, about 2.5" high, and 24" long centered where moulding should be. 88TII TO4S ETC

racedriver

water pump will cavitate above 6500 rpm, you may nee pulleys, or a bigger rad

SleepR1

105 C to 112 C is normal for my FD, hotlapping @ 90% @ Putnam Park (www.putnampark.com) for 20 minutes in ambient temps of 87 to 88 F. I have a GReddy Type 24 V-spec FMIC with Koyo rad. Water mix is 85% distilled, 15% antifreeze, with 1 bottle of Redline Water Wetter. Koyo rad core is sealed off with ducting foam to force air through the core. I think a vented hood would help me. FWIW, my KDR motor has silicone o-ring seals, enlarged oiling and cooling passages, plus eccentric shaft mod. It was built to take the heat I have an R1, so I have dual oil coolers. Oil is Mobil 1 15W50. Problem is--Power FC retards ignition @ 110 C, and thus the power is way down despite the boost reading 0.70 to 0.75 kg/cm^2 (10 to 11 psi), and air intake temps reading 45 to 47 C. From a performance standpoint, I need better cooling, cuz the boost and AITs are definitely right for power production; the motor can't shed the heat fast enough to maintain the zip at the 10-11 psi boost levels...at least during warm days. Cool autumn days are a different matter (60 to 65 F ambient temps) Hee Hee I'm looking forward to my Sept/Oct DEs @ Mid Ohio and Road America (moo haa haa haa )

eViLRotor

iTrader: (2)

Pics can be found here. Don't know how helpful they will be...
http://www.teamfc3s.org/forum/member...view&car_id=52

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So it seems that hight temps like that are normal for an FD, but too high for an FC?

I have not tried water wetter yet. Maybe I will add some.
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Carl Byck: from what you are saying, it sounds like your car is specifically built for road racing. My car is mainly a street car, and I go lapping a few times a year, so I'm guessing I can't expect super low temperatures like yours on a mainly street-driven car.

On the street, my temperatures are usually 87-91C max.

I was under the impression, that even though my coolant temps at the track where high, as long as the coolant is doing its job and the heat is transfered from the housings I would be ok?

Thanks for the input so far

tims

high water and oil temps will wear the engine prematurely and may lead to a break down. I said this earlier the stock turbo II and 3rd gen cooling system when in perfect condition is barely adequate for street driving and is not good enough for track duty. so if you modify the car for more power, which equals more heat, and take it to the track you are going to have problems. to protect your investment in your car upgrade the cooling system just as you upgraded the engine performance. it does not matter if it is mainly a street car you can never have "to much cooling". this is what thermostats are for, to control the temp in the engine. my own turbo II engine which ran 10psi of boost at all times never runs over 210*F water or oil in 120*F days.

eViLRotor

iTrader: (2)

Thanks.
I agree with you.

I'm already running a large Griffin Rad, and the biggest E-fan I could put on it.

I'll have to start looking into ducting as much air as possible to the radiator...

SleepR1

Water temps are funny thing. I have not overheated @ the track, but the water temps are high. Ask the guys running Evans waterless coolant. Their water temps are much higher, but I have not read of any heat-related failures...yet.

SleepR1

Duh-aauhm! That's a serious T2! Big old single turbo! Serious mods...I'd say you have your bases covered. Ducting the rad might help a bit...at the very least it will let you stay out for longer sessions...although 105 C (221 F) ain't that hot for track lapping in warm weather...

redrotorR1

I've been told by some rotary engine builders that you can get up to 120C without serious damage to the engine. BUT, it's highly recommended that anytime you see anything above 115C, that you slow down and take a couple laps off-boost and pit. And repeated abuse like that will definitely result in shorter engine life.

I have seen 117C before after coming off course and it's definitely not confidence inspiring. However, this was during a June time trial where ambient temp was ~95F and on HOT concrete. My radiator is not ducted and neither are my oil coolers. I think I need to accomplish some form of that in addition to a vented hood, before I venture out to another time trial. I imagine that your TII needs similar fixes. And there is another option ... albeit a not so fun one ... crank down the boost.

SleepR1

Yup. I usually run 0.80 to 0.85 kg/cm^2 (11.4 psi to 12 psi) in the fall months. Summer--I turn the boost down to 0.70 to 0.75 kg/cm^2 (10 to 11 psi). Even then I see temps in the 112 C at the end of the session...

eViLRotor

iTrader: (2)

Thanks for the compliment. I'd still trade it in a second for an FD like yours

I'll definitely work on improving my airflow to the rad, but at least I'm not as worried as I thought I should be...

SleepR1

Yeah, just watch your temp gauge, and take it easy when you see the water temps climbing too fast. Have fun! It's a blast to track an Rx7. They were designed for road course work, as you know!

80-CU.IN.T

It looks like your radiator has a large enough surface area to dissipate the heat that is generated but you are not getting enough air to it. I would do some creative cutting to your front bumper. The air needs to be ducked to the radiator and through it. From the pics I saw there a lot of space for the air to go over and around your radiator. - Between to cross brace and hood - through spaces on the sides for intercooler plumbing. Hard to tell from the pics.

I am using a Griffin 27" X 16" with 2 rows of 1-1/4" tubes. Here are some pics of what I did. Hope they help. 3rd Gen but principal is the same. Old pics I have modified it since these were taken. I even made plugs so I can replace the ducts for my intercooler and oil coolers. I am using a Apex'i front bumper because it is cheap, easy to replace and has larger front intercooler and oil cooler openings.



https://www.rx7club.com/forum/attach...postid=1245825

SleepR1

Nice set up...single turbo FDs run much cooler too...

MrZUMZUM

I just ran my FD for about 5 hours this past weekend at Sebring and ran it pretty hard.............Completely stock setup cooling wise except for the AST.............

It was about 95 degrees out, and I ran 207-212 all day.............errrr...........until I smelled coolant going into turn 10 and saw my digital gauge read...........227....243....257...........needles s to say I jerked the car off the track, turned the key off and raised the hood to a steam bath..............the overflow tank had given way and so had my radiator cap...........

Praise Baby Jesus that nothing in the engine was harmed.............I towed it in, cooled it down to 100 F, then refilled it with coolant, check the oil for foam, etc...........all was OK...........after a new radiator cap I think I'm back in good shape..........

Anyway, I'm glad to see that my 207 to 212 is OK.........

David

SleepR1

Close call!

redrotorR1

Yikes! I had a similar experience. At the end of the morning session, I pulled off and was letting the car cool off. I popped the hood and was spraying everything down when I noticed coolant starting to pool up underneath my feet!!!!! I run to the driver side and see the temp needle at about 3/4 ... and if you know anything about those dummy gauges, 3/4 means it's too late! I grabbed every piece of water and ice from my cooler and sprayed down everything I could get near. Turned the car off and spent the next half hour essentially giving my engine a bath.

Checked everything and guess what the culprit was ..... the fan fuse had blown. Lucky that I didn't need the defog fuse so I flopped them and was back and running .... on a probably 90% DI coolant mixture then.

If it makes you feel better, I haven't noticed any problems since the near-catastrophic failure. So far so good.

PaulyDee

Just to let some people know, running a rotary at or above temps of 220, is not doing the engine any favors. The constant high heating and cooling of the engine causes a degenerative condition. That cast iron and aluminum (engnine housings) expand and contract at different rates. Over the long term, housings will warp and cause water jacket seals to leak. That equates to engine replacement sometime in your future.

Fritz Flynn

iTrader: (263)

My temps are always above 220 and thats with large rad, oil cooler, and duct work. If your temps are not above 220 on a summer day at the track your not driving hard enough

I guess I'll be getting a new engine soon but probably because of low compression from flogging it 100 times a year for 30 minutes.

Basically if you can't run with the big dogs then follow them slowly

80-CU.IN.T

Thanks - I just wish I wasn't so broke so I could beat it on the track. Oh well - just have to bite my lip and wait a bit longer.

SleepR1

Fritz, you, sir are a BIG DOG! Hope to drive VIR with you soon....I'll want to ride with you to get the "line" down

SleepR1

Duh-auhm...who isn't broke in this hobby LOL