Finished 2nd out of 11 or 12 in the 135 mph average class - we averaged 135.010 mph (.225 seconds off target). Stopwatch only.

Got the car up to 161 mph for a bit (2:24 in youtube video). Water temps went to 243*F at the end of that long straight.

My gearing is poor for this event - shifted to 5th at 125 mph at 3800 rpm and left it. Never made it over 5,000 rpm.

Enjoy.



https://youtu.be/9dJD4RmxXGE

Awesomeness...

Thanks Tom

Now to figure out a solution to get the coolant temps down. Can't run a faster class if I'm cresting 240*F everytime I go over 160 mph. Talked with AFCO, got some ideas. The radiator I'm running is used in 700-800 hp dirt track cars with bad airflow.

Awesome Wade, that is a serious accomplishment. I have wondered about the effect of cooling at speed, my car has always struggled with it at speed even over 80-85 mph. Almost think its a trapped heat issue in the engine compartment. I know airflow is there in spades because when I first put my glass lift off hood on with no center rear hood pin, first pass down the quarter it turned into an umbrella at the rear. Lesson learned, but now where does all that air pressure go?

I seem to run cooler at higher speeds from 80-130.

I wonder if it has to do with the grill opening, shape, and obstructions?

I have a lower valance and get air from under the bumper between the valance too.

I've considered blocking off part of the grille opening for aero until I see a heat rise.

A friend brought up a point I haven't considered:

Why not just leave the electric fan on? I've got it programmed to not run at 30% TPS or greater. The temps would drop in the corners at BBORR - well that partially might be because the fan was coming on.

Obviously the fan solution isn't fixing the root of the problem, which is a lack of a pressure differential great enough to cause significant airflow.

Potential problems causing the lack of a pressure differential:
- 1" gap between hood and top radiator crossmember
- hood is not sealed to body at all
- hoodscoop
- holes in front radiator crossmember (behind the parking lights)
- AC condenser in front of the radiator (apparently needs to be 3/4"-1" away from radiator)
- Oil cooler in front of AC condenser (only behind the bumper - ran 240*F oil temps, btw)

Things I've done:
-lowered the lower radiator crossmember (and extended it to the sides with an airdam)
-Sealed the front airdam / splitter to the bumper
-sandwiched foam between radiator and radiator crossmember
-sealed a couple small holes in the radiator crossmember

BTW - I checked my temps from a recent TWS track day. Never got over 220*F. I also ran a session without the fan in the car - temps were nearly identical.

Post-race. tons of bugs. car was clean before the 118 mile round trip. Shows the air-dam and splitter. Which did a great job of keeping the front end down at high speed.


General location of the coolers:



Unlimited class cup car hit a buzzard at 160-180 or so. Finished the race looking out the passenger side of the windshield!

That's a lot of stuff in front of the radiator.

Need to seal top of radiator support to hood.

Maybe experiment with plugging air scoop.

Shim the back of the hood up so that there is a gap and see if that releases trapped air under the hood at high speed. If so you know you have an airflow "out" issue not an "in" issue going on.

I would think you want the seal between the core support and the hood to force the air to go through the radiator, not over. I would try that first.

I wouldn't be surprised if the scoop is the culprit, I have same one, but I absolutely MUST run my fans at freeway speeds. Air comes through radiator then what?

I also sealed my core support to hood with garage door seal. That was worth probably 10 degree drop. Wade that oil cooler is freaking hilarious dude!

at 160 mph a lack of seal between the hood and radiator support isn't an issue. Remember, what does in has to go out and if it can't get out, it can't get in either.

I told you it was huge! Hide it behind the bumper with no airflow and it STILL keeps it cool.

You just had to one up me on oil cooler girth didn't ya! LOL!

Awesome video and great car. I did one of the defunct nevda events years ago. Grerat fun and i hope to get my Challenger to one in the very near future.

Awesome! I also wonder about the ability for air to exit the engine compartment contributing to your problem. This is inspiring to watch..

Wade is there any way to have the front spoiler force some air right up into the front of the radiator? Wouldn't take much area to force a bunch of air through at high speed. That's what the C5 Vette uses, about 12 inches, but you shouldn't need that much...

In my opinion, some of you are looking at it the wrong way. Others are closer.

Too much air under the hood.

Instead of helping the air get out you need to limit how much is getting in.
You want a low pressure area in the engine compartment. Doing that will force the air through the cooling package.

Run your next high speed event with the hood scoop taped off. Your engine will draw hot under hood air but you will likely see the radiator temps drop. That's a cheap test that only costs a few strips of duct tape.

Any air coming in contact with the core support and cooling package needs to be handled. The air is stacking up and looking for somewhere to go. You can add paneling/baffles behind the grille to direct air into the cooling package. If so, make it narrower at the entrance than it is at the radiator. Air is more likely to be "trapped" and not spill out over the sides. This helps create a higher pressure area in front of the radiator.
A seal between the core support and hood would eliminate flow up there. I wouldn't hurt to add an under cover extending from the air dam to the back of the engine compartment.

Raising the back of the hood and doing other things to help air get out is essentially treating the symptoms, not the problem.

Air flow is often thought of as fluid movement. Use fluid. Put the car in high speed trim and block off the back side of the radiator. Grab your garden hose and spray the front of the car. The water will go where the air goes. Block off anything that allows the water to get to the engine compartment. Doing that will find your areas of concern. The scoop will be a big culprit. Check the air moving over the top of the bumper too.

Here's the view of your car from Gate 43 (about 15:16 in your video - 150 MPH)