Preparing turbo m20 for a hot texas track day - Z3M Radiator?

[saturnv7890]

So I'm toying with the idea of taking my car to the track once I dyno tune it and get new brake pads.

Right now I'm just sort of thinking about loud here, but I like to come up with a good plan before I go out and do it.


One worry I have is the cooling system. So far on the street the only time my temp gauge has crawling above halfway is when sitting at the lonnng stoplights in Houston. So I think my cooling system is in fairly good order.

I'm worried when it's 110* outside, and I'm on my boost for the longer times seen on the track, that my engine might start to get uncomfortably warm? The sessions are about 20 minutes long.

Is it worth it to spring for the 3 row Z3M radiator here? I was thinking about going with an ebay aluminum one (can anyone comment on fitment?)

http://www.ebay.com/itm/3-ROW-FULL-ALUMINUM-RACING-RADIATOR-98-02-BMW-Z3-M-COUPE-ROADSTER-E36-3-2L-L6-/190792148395?pt=Motors_Car_Truck_Parts_Accessories&hash=item2c6c1925ab&vxp=mtr#ht_3880wt_1100

Additionally, what other systems should I take a look at before abusing my car out there? Suspension is tight, brakes will be new soon, engine tuned, timing belt very recent, good tires, what else?



TLDR;
-ebay Z3m rad worth it for turbo on track?
-ebay Z3m rad fit e30?
-what else do I need for track?



Thanks!

[lcoleman]

I ran the Dragon a lot with my setup (pretty hard, which is stressful in a way similar to track driving), and my biggest issues were with head lift even with good studs. Even when pumping out "coolant" that smelled more like bad gas after a run, the engine never technically overheated. More cooling capacity can't hurt, but I would also direct some focus to charge cooling and, more than anything else.....a GREAT tune. A "good" tune won't cut it.

Good luck, and post your results! I would love to examine a setup that could do a 20 min stint at 10/10ths. There don't seem to be many.

[saturnv7890]

Thanks for the info! I'm running ARP studs, and will definitely get a dyno tune before hitting the track, so hopefully head lift won't be a huge problem?

And being my first track day I'll probably do an instructor day, I hear it isn't until the last run that you really start to push the car

[Kershaw]

i bought a chinese aluminum radiator off ebay. the expansion tube to the reservoir was a bit funky, had to bend it. but other than that, it's great. no leaks and it fit fine.

[Dj Buttchug]

you might want to invest in a turbo blanket and some manifold wrap as well for the long term. Also, you didnt mention if you are running the stock fan clutch or an electric fan. E fan would probably work better for hot days/ auto x.

[unevolved]

You can never have enough cooling capacity for summer track days in Texas. I worked at TWS in college (not sure if you're wanting to go to TWS, MSR, HHR, or what) and I saw quite a few turbo cars puke their guts out halfway through their first session. The thermal stress on your car is unbelievable compared to street driving. Pretty much any time I inspected a "tuner" car that was very turbo'd and hadn't been on track before, it wouldn't be able to handle it.

[jlevie]

The engine temperature climbing when idling or in stop and go traffic is more a sign of insufficient air flow from the fan. If using the stock fan/clutch, replace the clutch and make sure the shroud is in place. If you have deleted the engine fan, use a 16" 2300cfm electric fan in it's place. It needs to be turned on by an 82-83C thermos switch.

Delete the A/C condenser and aux fan and install a good sized oil cooler (at least 6x14") in place of the condenser. Then move the spring in the oil cooler thermostat to the other side of the element to cause full time flow through the cooler. A large full time oil cooler has a big affect on engine cooling.

[Dj Buttchug]

imo you need a high cfm 16 inch fan switched manually so you can move air constantly.

[Emre]

I used to run a turbo track car (see sig), so I've been down this road. A few quick ideas to consider:

• Upgraded oil cooler - buy a larger B&M oil cooler from Summit Racing for $50. Mount it up high in front of your rad.
  
• Spray cooler - This is an old trick in the rally community. Spray a thin mist of water, washer fluid, peroxide, etc. directly onto the radiator/intercooler. It greatly increases the rate of heat transfer. Lots of low-budget options. There was an article in GRM a few years back where the windshield washer tank/pump was redirected to the intercooler using cheap garden spraying equipment from Home Depot. Look at how they mist vegetables at your local supermarket to see what I'm talking about.
  
• Tuning - Some guys tune their engines to run a little rich at WOT. They say the extra fuel acts as a charge cooler and keeps cylinder temps down. You'll need to get rid of the cat, obviously.
  
• Engine oil - Make sure to run a heavyweight oil that's known to hold up to high heat and resist coking. Look at what the air-cooled, turbo Porsche guys run. The classic choice is Brad Penn PG-1 (the new version of the old Kendall GT-1 used in the '70s).

[KEVORM]

imo you need a high cfm 16 inch fan switched manually so you can move air constantly.

The fan isnt doing much when the car is moving at track speeds. No fan (that'll fit in a car) is moving that much air that fast. Behind a pace car or on your cool down lap however, the fan can be a life saver.
The nice thing about having the auto-on temp switch is that in the heat of the moment, if you forget to flip the fan on, it's got you covered. There is a ton to think about in a race car, especially the first handful of times out, temp switch on the fan and you have one less thing to forget.

[Dj Buttchug]

The fan isnt doing much when the car is moving at track speeds. No fan (that'll fit in a car) is moving that much air that fast. Behind a pace car or on your cool down lap however, the fan can be a life saver.
The nice thing about having the auto-on temp switch is that in the heat of the moment, if you forget to flip the fan on, it's got you covered. There is a ton to think about in a race car, especially the first handful of times out, temp switch on the fan and you have one less thing to forget.

true. fans run by temp relays annoy me tho. As soon as you are back waiting in line ect it takes a while for the temp to rise up and turn on the fan. then the fan will randomly turn off and on, regulating temperature. I just like the idea of having total control over the fan. If i want it on i turn it on. If Im moving and about to do a run I can flip it off.

I dont really know about driving a racecar, But i never forget my fan.

[matthugie]

true. fans run by temp relays annoy me tho. As soon as you are back waiting in line ect it takes a while for the temp to rise up and turn on the fan. then the fan will randomly turn off and on, regulating temperature. I just like the idea of having total control over the fan. If i want it on i turn it on. If Im moving and about to do a run I can flip it off.

I dont really know about driving a racecar, But i never forget my fan.

I have my fan wired to my a/c switch since it was pulled from the car. I agree it doesn't matter much at speed, but for cool down after laps or between runs in autox it's great. I pretty much just leave it on when I'm street driving just so I don't have to worry about it.

[Northern]

I'd like to see how that ebay rad compares to the z3m mishimoto.

Its so goddamn cheap! I'll take 3!

[saturnv7890]

Well thanks for all the good info guys!

So it looks like I might pick up the radiator before the track day, extra cooling can't hurt.

As for fans, I have a stock clutch fan and an electric pusher fan. It does come on and help, but the thermo switch for these cars is such a high temperature that it doesn't come on until about halfway I believe.

As for an oil cooler, right now I don't have an oil cooler, so if I were to upgrade, it would probably cost me a lot more than $50 because of the lines required. Is it worth the cost? And is there anything cheaper than -AN that will still work effectively?

[blunttech]

oil cooler is worth the money .. It dropped my oil temps 20 degrees on the track in my NA s52 car which equates to lower coolant temps