Cooling recommendations?

[Venom525RWHP]

I see a lot of you guys are running much lower boost when at the track...why? As long as you keep an eye on your vitals like water and oil temp, and oil pressure, you should be fine. I'm running a Steggy ported blower, TB, and plenum along with a 2.76 upper and 4# lower. I have all the supporting mods to go with it as well, and tuned with A/F at 11.8 and only 20 degrees timing. I run really hard at the track usually for 30 minute sessions. My car has never gone into limp mode, and my vital temps are just fine. And I'm running 18 pounds of boost.

All cars are not the same I quess, I have an interchangeble pulley setup with 5 dia's available and tried everything on the track, 10 psi is my car's limit so far...
This year I want to try a little more boost - 12, maybe 14psi - with my new full size HE setup and larger bumper opening.

 

[TroyV]

Only time my car hits limp mode is when its 100f+ outside and I forget to turn the heat on. My car doesn't limp, it just pukes antifreeze.

Interesting. I'm puking that stuff as well. It happens very little though..

Maybe I just drive too slow.. I roughly turn 1:59's at Tremblant, 1:54's at SP Shenendoah, 1:19's at NHIS, and 1:06's at Lime Rock. This is pretty much only good enough for mid pack in the class I run in, which isn't great, but I don't think it is slow as a sunday cruise either.

 

[racebronco2]

When you car goes into limp mode depends on how hard you push your car, engine and cooling mods, and weather. When i was almost stock without a pulley it would go into limp mode in weather above 80 degrees. I am now running a 2.93 and stock lower and with the addition of the hood mod i have not experienced any cooling problems but the weather has not been any warmer then 70 degrees.

 

[TroyV]

Hmm.. Maybe the hood mod really delivers. That was one of the first things I did with the car. I'll check and see if my buddy did that... It might at least offer a partial explanation.

 

[nightstalker865]

What is this hood mod people are talking about? I have my blanket removed and the vent flaps cut off. Is there anything other than that?

 

[TroyV]

That's it... though you can also remove the gasket between the hood and cowl during events for increased airflow.

 

[nightstalker865]

That's it... though you can also remove the gasket between the hood and cowl during events for increased airflow.

I know alot of the vettes do this. Is it that big of a help on our cars? Any downside to doing it?

 

[TroyV]

Before I did it, folks had told me that the hood paint could discolor.. I have not noticed any change in the finish on the hood. I have a few buddies with white and yellow cars and none of them had noticed a change either. Besides that I can't really see a downside..

 

[Cadex]

Venom525RWHP-

I open track quite a bit and heat is always a battle. Noticed in your avatar, the Cobra R type front splitter I'm considering. Did you notice any heat improvement?

 

[racebronco2]

That's it... though you can also remove the gasket between the hood and cowl during events for increased airflow.

I have done some testing with this mod and it does increase air flow but the air is going into the engine compartment. I mounted a camera on the cowl with 3" pieces of string taped to the hood about 6 inches apart and getting up to 80 mph all the string ended up between the hood and cowl. I believe since our hood are raised up about 1 1/2 in the rear it creates a low pressure area at the rear edge of the hood and a high pressure area at the base of the windshield forcing air into the engine compartment.

 

[TroyV]

Interesting test..

So.. I think what you might be saying is that due to this..there could be forward flow over the engine, or perhaps downward flow between the firewall and engine. Could either of those be so bad? If it is forward flow, then I would think the hood ports would draw that flow out... If it is downward flow, the air flowing under the car would draw it out....or some combination thereof..

I'm speculating of course.

 

['03 Sonic Blue]

I have done some testing with this mod and it does increase air flow but the air is going into the engine compartment. I mounted a camera on the cowl with 3" pieces of string taped to the hood about 6 inches apart and getting up to 80 mph all the string ended up between the hood and cowl. I believe since our hood are raised up about 1 1/2 in the rear it creates a low pressure area at the rear edge of the hood and a high pressure area at the base of the windshield forcing air into the engine compartment.

100% agreed. I've measured the pressure differential between the areas above the cowl and just inside the hood at speed. The cowl is a high pressure area. (that's the concept that cowl induction is based on).

Speed--------Pressure differential (pressure lower under rear of hood)
60 mph-------0.25 inches of water
80 mph-------0.50 inches of water
100 mph------0.75 inches of water

If you remove the gasket, you will push air underneath the hood from the rear and increase the underhood pressure. This is counterproductive if the goal is to get more air through the radiator.

YMMV (but I doubt it)

--Mike

 

['03 Sonic Blue]

Another place to look is underneath the radiator. My Fluidyne radiator has about a 1/2 inch gap between it and the lower support. So air that manages to make it through the AC condenser has a chance to escape under the radiator without going through it. I've plugged the gap with closed cell foam. (AKA 1/2" pipe insulation).

I don't know if the stock radiator has the same gap.

--Mike

 

[01cobravortech]

The first cooling mod i did was the head cooling mod. In under 70 degree i had no problem with limp mode. I did go into limp mode in over 70 degrees and thought i blew up my engine the first time( i did run with the heater on to help with the coolig and it helped). I did the radiator and h/e, this did extend the amount of time in warmer weather but it still would go into limp mode. I did the remote thermostat and water inlet and still had cooling issues in 100 degree weather. I would limit myself to about 10 minutes on the track or i would just slow down to get the temp down. I was running the 3.10 pulley most of the time.
I am running a 2.90 and have all the cooling mods and i usually push it harder then most people. If you do a search you will find that i did the vent/hood mod and i run 20 degrees cooler then most of the cobra's. This mod is the only one that actually lowered the engine temps while on the track. From octomber to now the hottest my car has ran at the track is 205 but usually in runs 195 degrees. hope this helps you out.

Does doing the hood vent mod allow rain to enter through the vents?

And does the motor get out of limp mode by itself when the temps go back to normal or does this require a reflash or disconnecting the battery?

 

['03 Sonic Blue]

Does doing the hood vent mod allow rain to enter through the vents?

I took the inner liner out of mine and remove the plastic inserts at the track. So yes, the rain definitely comes in. The openings are above the space between the degas bottle and the PS reservoir on the driver's side and above the radiator hose on the passenger side. The only harm done is that the insulation blanket around the battery gets soaked. But then, the only time mine gets wet is at the track and at the car wash. Otherwise it's in the garage when it rains.

And does the motor get out of limp mode by itself when the temps go back to normal or does this require a reflash or disconnecting the battery?

It resets itself when the temp drops to around 235. It only takes about 30 seconds, but seems like an eternity when you're on the track and have cars coming up on you like you're standing still.

--Mike

 

[Venom525RWHP]

Venom525RWHP-

I open track quite a bit and heat is always a battle. Noticed in your avatar, the Cobra R type front splitter I'm considering. Did you notice any heat improvement?

Yes, the splitter and ducting dropped my temps by 15- 20deg's!! On a hot day she was running around 220 with a high of 230.
This is what I am working on for this year...

hopefully it will drop my temps another 10deg's.

 

[Jimmysidecarr]

Yes, the splitter and ducting dropped my temps by 15- 20deg's!! On a hot day she was running around 220 with a high of 230.
This is what I am working on for this year...

hopefully it will drop my temps another 10deg's.

WOW!!!
That is a nice piece!!!

That is the opening we really need!!!(properly ducted also of course):rockon:

 

[Jimmysidecarr]

I'm bumping this old thread back up because I'm looking for updates on what is working from you guys.
There are some great ideas in here and I need to start incorporating some or all of them.

Currently with temps in the low 80s I was getting about 5 VERY HARD laps in and would then have to go easy on some straights to cool back down.
20 minutes At TWS would be about 9 laps total, running about 2.08s

I'd like to be able to stay in it the whole time, but I'm also not rolling in dough.

So the low buck ducting stuff is looking pretty attractive right now.

How about it guys? Pics? Updates? Success stories?

Some of the links to pics are corrupted and red Xs have begun to invade.

Thanks!:beer:

 

[brkntrxn]

I put an LFP radiator on my car over winter and swapped to an 03 hood (this is on my ProCharger 99) and the car temps were fine at VIR. However, that was in 50-60 degree weather. Now that the engine is toast, I won't get the chance to test it out when the heat of summer hits.

 

[David Hester]

Interesting test..

So.. I think what you might be saying is that due to this..there could be forward flow over the engine, or perhaps downward flow between the firewall and engine. Could either of those be so bad? If it is forward flow, then I would think the hood ports would draw that flow out... If it is downward flow, the air flowing under the car would draw it out....or some combination thereof..

I'm speculating of course.
Do not remove the gasket from hood unless you plan to run the car parked. Hot air rises, but air in motion sucks high pressure to low pressure.
You want air to go through the radiator. This is the cooley thing it does.
It counts on low pressure behind the radiator, otherwise air won't flow through. (that's what the fan does.)
Remove the seal and the high pressure in front of the window forces air into the low pressure area under the hood. Follow me here. If you have air coming in from the back of the engine, less air flows through the front. BAD BAD BAD

Sealing ALL the area from grill to radiator helps direct air- don't really need the back of headlights cooled.
Another thing that helps is an air dam below the radiator, ala old Fox body.
This creates even more low pressure BEHIND the air dam which sucks even more air through the radiator- if it is ducted and sealed.

NASCAR has all the holes in the back of their hoods sealed to the carburetor not the engine bay.