So I rebuilt my 3.0 into a much higher hp 3.2, I think its pushing 280hp. Problem now is just spirited street driving it runs at 210f with it be 80f outside; I'm sure on the track it will run 230+. I am running an engine cooler and the factory GT style Setrab oil cooler. If I want to run more track how large of an oil cooler do I need? What have you guys done in the past?

Also I am only running a GT lower valance, not a GT bumper, the hole seems large enough, could the GT bumper make that big a difference?

I deleted the stock engine cooler and run a 20 row setrab cooler in the front with a fan pack. I was concerned about stop and go traffic so I feel the electric fan should help. It’s set to come on at 190. I also made sure the air exit was pretty generous. I have not ducted the cooler yet but right now I’m still sorting the car and have not put it through it paces in hot weather.

Thanks. Is the fan pack on the cooler or on the floor? What size motor? When I had a stockish 3.0 it ran much cooler closer to 180-190 all the time except track was 230-240f. I also think my new larger headers are making more heat below the motor which is exasperating the problem.

A built 3.2. Euro compression, 964 cams, custom chip, etc. running Ben's SS heat exchangers. Fan pack is on the cooler. Air exits the bottom of trunk from the stock holes in the cover plate - pried up covers that are held in place with seam sealer.

You need more air in , no fans to obstruct flow , sealed ducting , and ample unrestricted exit for warm air.....people ask this all the time , with the money and fabrication to get to this point it nuts to stop at the most critical system for long term track survival....if that doesn't give you the temps you need , then a bigger cooler....same install...15 grand and up for a good motor ...spend the 2 grand to cool the oil ...sheese !

Thanks, I will try that first. It's not a matter of spending money, I am more asking what size oil cooler I should have. But it sounds like making my airflow more ideal may be enough.

Interesting, I never thought fans could actually hurt you on the track. Makes sense.

Also to add to that- what is the ideal and acceptable oil temps for track? So far in my readings I gathered you want to stay under ~230f.

I think 190...most like 220 ...some story about boiling off water from humidity....I think on a track car with appropiate changes that is akin to muffler bearing...My concern is keeping the heat expansion shifting too a minimum...I did the 12 hours with a 3 liter ..never above 190...but mild air temperatures...the higher temps come from the water cooled world in my opinion...

I don't remember the exact make and model of the cooler i'm running, McMark would know.
No cooler on the engine and no fans.

This keeps my 3.6L cool, runs at 180 all day on the street and gets up to 215 on the track.


PS: The shroud is removable for easy access to the trunk. I can still store plenty of stuff in there actually.
Just ignore the crappy louvers in the hood for now, eventually those will be made to look nice.

I'm going to open a can of worms on this response to Andys photos of his hood vent . I am tired of dodging the intermittent rain here while trying to work on my sail boat , So what the heck , I may learn something . Several months ago , there was a thread that was discussing how to exit the warm air from your front mount cooler....Tons of ideas where mentioned but the first absolutely thing you would never do is duct it under the car....I think that may be completely false...an assumption like the need to adjust back pressure in tuning , or some such baloney....914 's generate lift...watch the rear in in a high speed turn....warm air creates lift in two ways , less density and higher velocity . Both would normally be desirable under a car ( lower pressure ) both would be undesirable over the car...again Lower pressure....ground effect devices that harness the air for a designed purpose are exempt from the above , if they exist

I'll give you some real world experience to your theoretical engineering since i used to vent the hot air under the car for several years before i went with the shroud and hood vent.

I can tell you in no uncertain terms that the car handles *much* better now at high speeds of 100+ mph.

There's no if, but or maybe about it. Before, my car was scary at those speeds with the rear end being completely lose and all over the place.

Now the car is firmly settled and the rear end is a lot more stable all the way up to my speed limit of about 135mph.

I'm sure there'll be plenty of theoretical this and that about how that is caused by some or such not related to the venting, but all i changed was the routing of the hot air.
Nothing else has changed on the car.

I moved from the Setrab to a Fluidyne DB30417....gives almost 50% more actual cooling surface area & is built like bulletproof....

Science is never valid for a true believer ....

I work in scientific research, you have not brought forward anything even remotely science related.

Great thanks! Did you have the 12 row setrab designed to fit the stock gt oil cooler shroud? How much of a difference did it make? I like how it's aluminum.

Sir Andy, thanks for sharing your install detail also.

Andy now you are being silly , air flow over and above a car is the primary interest in the science of fluid dynamics as it relates to race cars....directing warm air below a car is a common practice from F1 on down . to increase velocity to help both down force and reduce drag....a damn sight more than a vague claim that insignificant addition to the total airflow over your car made it go from not handling well at a 100 ....( that already shows a less than optimal setup ) to being an entirely different can at 135 . realize that the air stalls in front on your oil cooler to about 25 miles an hour at those speeds , it helps visualize just how small the volume of additional air is to the overall flow at 135. The under car volume is much less and even then its hard to quantify an improvement...thats why it basically doesnt matter with you car , sans other aero improvements....I know you blow all the above off , people have an emotional need to be right...but others that are using this site to improve there cars might have at least pause for thought .

I'm amazed how you can diagnose this from wherever you are without having ever driven my car.
Neither before nor after the change to the air-flow on my cooler setup.

Thanks for telling me what my car does or doesn't do, i had no idea!




I see you are no exception ...

You are welcome......apparently......touche

Mine was a 19 row 6 inch high by 12 inch wide with 2 inch core. Earls number 81900ERL. Peter Dawe said to get a bigger one when he did my 2.7 "refresh". You can research the core sizes on line at the manufacturers websites to get the comparisons. Fluidyne looked the best to me.

Here’s mine. I will build a shroud for it if it can’t keep up.
Even though I don’t have a cooler on the engine, the cooler shroud is blocked off so I should have a bit more air cooling down the cylinders.

Thanks guys. I appreciate the oil cooler info. I heat wrapped my oil line that was next to my header, and sealed up my front oil cooler shroud better. I am down to 195f at 80f outside, with spirited driving. I'm going to do an HPDE in December and I will see how quickly it wants to get to 230f.

I am thinking of heat wrapping my headers and getting a GT bumper as my next steps. Although a GT front bumper is more than an oil cooler...

I'm using the Roger Sheridan designed front spoiler--it's distributed by Eckler's now as part number 65-229865-1....costs about $250. You may not like the look, but it sure does help stabilize the car.....I've had it over 150 at Daytona...here's a poor photo...Click to view attachment

I like that spoiler! My cars so damn low I'd probably tear it off...

That looks like the Mazda cooler I had in 222. Never any issues with oil cooling after installed. I'll confirm that the air in and out setup is crucial.

Here's a picture during fab time:

Click to view attachment

I have some experience and opinions to share on this. My racecar has about 260 hp and uses an older B&B cooler that is about 26" x 6" x 3" and have the cooler on the engine removed and replaced with a filter. I run 190 degrees on track. You'll want something similar sized at your horsepower level if you want to stay in the 200 degree range and plan to track your car. The one in Andy's picture looks like the Fluidyne one, which I've heard good things about and is a good size, and a pretty good value at something like $400.

You'll hear a lot of opinions about how to duct air to/from the cooler. Venting out the hood is a common way and I've heard works well. I saw comments in this thread about the low density air, and that's true. Racecar designers don't like to vent out the top of the car because it puts hot, low density air to the rear wing which isn't good for downforce. We mortals would probably be hard pressed to notice the difference. I vented mine into the front fender wells and have found that works well.

To the point about downforce from directing the air out the hood, it can't hurt but you won't get much that way. Air through radiators, oil coolers, etc. slows massively as it passes through - to like a third of vehicle speed. So if you're doing 100 mph, air is only going like 30 mph through the cooler and the ducting. You won't get a lot of downforce from that, though I guess it can't hurt.

Important points:
1. Make sure you seal the ducting leading to your cooler well. If there are gaps, the air will escape and never hit your cooler. Design the ducting to be close fitting and use foam tape (the stuff you get at Home Depot to seal doors and windows). I was sloppy sealing the edges when I first built my ducting, and later got a 20 degree oil temp drop just from taping and sealing small gaps less than half an inch.
2. Give the air a place to go without restrictions after the cooler. Hood, under the car, wheel wells, etc. Air won't go through your cooler if it can't get out. If you do your ducting well, you shouldn't need fans unless you spend time in stop and go traffic in the summer.

Scott

Thanks Scott, those sound like all great valid points