Pictures from weekend @ Willow Springs, too hot - questions... Options

[siverson]

I spent the weekend at the NASA event at Willow Springs. It was pretty fun, and a very fast track - 125 on front stretch, about 105 or so on the back stretch. Turn 8/9 right at about 90/100 mph. Yowzers. I had never driven on that fast of corners before.

It think it was about 105 degrees out too, and my car started to get too hot in the afternoon sessions. I actually had to stop the 20 minute run sessions early. I was quite surprised by this, as I had previously been concerned that the car is running too cool on the freeways. Hmmm...

I'm running a 3.6 with a front mounted Mocal cooler that's 20x6x2 or so. Another 914 there had a 4.0 (from a 3.6) with the factory C2 cooler under the rear trunk AND a front mounted cooler that was 16x6x2 or so.

I think my DME programming might still be a little off (too lean) contributing to the heat. I'll have to check it out.

Does anyone have any real world experience with the GT engine lids? Do they really make a cooling difference? Anything else to consider besides fuel/timing and engine lid before I start cutting away for a second cooler somewhere?

-Steve

[siverson]

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[siverson]

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[siverson]

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[siverson]

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[Howard]

Steve, nice car, nice pictures. You are my hero..I only run the 'Streets' and sure don't do it July through Sept. How high is your temp?

My 2.0 4 has GT lid and small rear mounted oil cooler, and yes, it's hard to get oil to 200 in even spirited street driving. Track only get to 220. Apparently was a concern to PO also, as a JAZ condensor tank was installed. It seems to do a good job of trapping condensation.

The GT lid 'may' help cool intake temps, but I'll bet it does nothing oil temp. How about mounting a fan on the oil cooler? You could switch activate when needed. Here's my engine lid and kind of fan I mentioned.

[andys]

I was there spectating on Sunday. A friend didn't show at The Streets, so I went over to the big track. Looked over the teeners (in the pic's), but no owners/drivers in sight. Just as well I suppose, as it was too hot to work on anything anyway. Amongst the exotics (ok, roadrace oriented types) were the stockcars which brought back fond memories from a past series I was involved in, in the late '80's/early '90's (The Toyota Sportman Stockcar Series). Anyway, these guys were running 1:25's/1:26's with stock (spec motor) ZZ4 crate 350's with 390 four barrels. Pretty inexpensive way to go fast, and they are fun to drive! BTDT.

Andy

[Martin Baker]

Looks like a Damn Bus sitting next to that SWEET GT Look Car.

[SLITS]

The GT lid 'may' help cool intake temps, but I'll bet it does nothing oil temp.  How about mounting a fan on the oil cooler?  You could switch activate when needed.  Here's my engine lid and kind of fan I mentioned.

Yeh Howard, paste one of those to yer ass for WCC2005 and try to stay cool (IMG:style_emoticons/default/slap.gif)

[brant]

I don't know that a front mounted cooler would be better benefitted with a fan...

sure in stop and go it would help...
but on the track- at speed- I think more air is going to be forced through a cooler than any fan can pull...

in fact the fan could partially block air flow...

I ran 3 different exit set ups on my front cooler. Using the same exact oil cooler I was able to drop 20degrees by changing the air exit to increase flow...

you might want to consider that..
is there anyway to reduce exit restriction on your set up?

brant

[drew365]

My car had an under rear trunk cooler and fan and it was pretty much useless on the track. Before I move the oil cooler up front I put a GT engine lid on. It helped but not a lot. I would make sure your air/fuel mixture is right and try a GT lid if you want but I wouldn't bother with an under trunk cooler. You didn't say, how high were the temps getting?
Also is the intake for your cooler sealed to the cooler so that no air is escaping to the sides?

[siverson]

> how high were the temps getting?

245 and then I went in. 245 isn't crazy high, but prior to this weekend I hadn't seen higher than 210. On the freeway just cruising along it'll drop to 190-200 (right where the thermostat opens). -Really- surprised me how much harder the engine/oil cooler was working on the track.

> re: fan

Yeah, I'm not sure if a fan would help or hurt. I know temps do climb when just idling in traffic (up to 210 or so), but they go right back down once some air flow starts moving through the cooler again. A fan would help in this situation, but on the track you're always going at least 40 or so...

> re: intake sealing

the exhaust is pretty well sealed, but the input isn't. There is some room for air to "leak out". Another guy at the track suggested this. I'll look into it.

> re: Looks like a Damn Bus sitting next to that SWEET GT Look Car.

Ha! I know. I didn't really notice it at the time but that picture really emphasizes things, huh?

> re: exit air flow

I'm venting via a shroud through the trunk floor. Right now the exhaust area is about the same size as the intake area. It would be pretty easy and non detrimental to open this open more, so I think I will just for the sake of it (and it'll save another .5 pound or so!)

Hey - BTW, just for fun I put my car on the tech scales they had setup and it came in at 2184#. Lower than I would have thought for my porky 3.6 car...

Weight +'s:

- 3.6, 915 transmission, front mounted cooler

- GT reinforcement kit

- Brad Meyeur longitudinal kit (~50 lbs? I dunno, it's heavy though!)

- about 10 ft of tubing reinforcement (front and rear)

- 1/2 tank of gas


Weight -'s:
- two seats, but otherwise no interior (no backpad, door panels, no carpet, no knee pad, no sound deadening of any kind) (all windows were in)

- front and rear carbon fiber lids

- no under coating

- no top, no spare, no tools (all left track side)

That was ready to go weight, just without the driver. I was guessing it would have been closer to 2300#+s... ? Anyways, just hijacking my own thread. Thanks for the input on the oil temp problem...

Hey, is the guy that was with Scott's Porsche here? Thanks for letting my borrow some of your tools!

-Steve

[campbellcj]

Steve - glad to hear you had a fun day. I'm really starting to jones as I've only done a few track events all year so far.

What kind of ducting setup does your cooler have? I am kind of surprised that a cooler that large would not be adequate even in summer Willow conditions, if the airflow and engine tune etc. were all correct. I have a similar sized cooler up front of my car and have never gotten it over 200-ish even in 20+ minute sessions under the most brutal conditions; granted mine is a 2.2S spec vs. a 3.6...

Also I'm wondering if there is sufficient flow to and from the cooler? I think most guys recommend AN-16 lines for 3.6 applications that see track use. (IMG:style_emoticons/default/confused24.gif)

I wouldn't freak out over 245° oil temps but it would be a good idea to run synthetic oil, and keep an eye on the gauge in case it ever goes beyond 250...

[siverson]

> What kind of ducting setup does your cooler have?

Pretty simple. Here's a picture. It's sealed pretty well all the way around (on the exhaust/trunk side), but inlet isn't forced in (can bleed around the edges).

> I think most guys recommend AN-16 lines for 3.6 applications that see track use.

Not sure about that. I thought -16 would be overkill, but now in retrospect I wish I had done that just so I wouldn' t have to consider it.

> but it would be a good idea to run synthetic oil

I am running Mobil 1 10/30. Maybe something heavier would work better... ?

I am actually beginning to suspect it has more to do with DME programming than anything. I'll find out this weekend, it's dyno day for PCA San Diego. One crucial peice of information I left out is that the engine start to occasionally ping when hot, and I think that just makes the problem worse...

> and keep an eye on the gauge in case it ever goes beyond 250...

That's the problem! Where I am supposed to look down on the big track at Willow Springs?!?! As soon as I had a chance to look at the gauge and it was getting too high, I knew I had to pull off then because it would be another 1.5 minutes until I had a chance to look again (ok, ok, 2.5 minutes later (IMG:style_emoticons/default/smile.gif) )!

-Steve

[siverson]

Cooler while being installed:

[siverson]

Cooler shroud:

[Jack Olsen]

It's not easy to keep a 3.6 cool. The cars they were designed for were able to generate really good airflow through the cooler. It's hard to tell from the pictures: did you cut outlets for the cooler airflow down below the shroud? On a 3.6-swapped 911, air is sometimes vented back up, through the hood, or to the sides and into the wheelwells.

You can also add an engine-mounted cooler from a 3.2, assuming you've eliminated the power steering pump.you

Oh, and a fan helps. I don't know why (considering the speeds you can get up to at Willow), but it does.

Dash-16 lines are the safe choice for track applications. Some guys swear your engine will cook with just dash-12. I run dash-12, into two fender-mounted coolers, in my 911. On days as hot as this weekend at Willow, I need to pull both headlights so the buckets can function as addiitonal air scoops. It's not an issue in street driving at all.

I wish I had gone with dash-16.

Another cooling problem comes from the heat sink effect after you shut the car off. The 3.6 liter cars would have the heater blower keep running air through the heat exchangers after the motor was turned off. When you swap a 3.6 into another tub, you generally lose this automatic function. The exhaust cooks the heads, and you see more leaks.

But enough about cooling. That much motor in that light a car has got to be awesome at a track like Willow. What kind of times were you running?

[1973914]

Saw a 3.6 track-only car that had 2 coolers that size back to back in the front with a splitter/flow-restrictor to make sure the oil moved through slow enough to get proper cooling. His temps were high prior to going to that setup, but now he is golden.

[SLITS]

"That's the problem! Where I am supposed to look down on the big track at Willow Springs?!?! As soon as I had a chance to look at the gauge and it was getting too high, I knew I had to pull off then because it would be another 1.5 minutes until I had a chance to look again (ok, ok, 2.5 minutes later )!"

The only safe place is on the front straight between 9 & 1.

[drew365]

Welcome to the board Jack Olsen, co-winner of the Open Track Challenge '04! (IMG:style_emoticons/default/pray.gif) (IMG:style_emoticons/default/smilie_pokal.gif)