Would a hood scoop help my problem?

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Cudafever

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Here's my problem, i have big swing in et when my engine has cooled (still up to temp but my water pump and electric fans are not on) when it has cooled enough to turn of the pump and fan.(run off of thermo switches) My car will run a full tenth faster. 8.27(1/8 mile) Hot lap it and it runs a 8.35.

With my old motor, i have a full throttle kill switch that killed the alt charge while i was going down the track. i believe it helped, but.............

Those that have installed a hood scoop, do you think it's the hot air being ingested from under the hood or do you think the alt is robbing that much power when it's trying to keep up with two electric fans running???
 
If you have a scoop you need to seal it to draw outside air. IMO an open air cleaner pulling hot engine compartment air is the worst setup you can run.
I run a 160 thermostat and temp bulb switch to control the elect fan solenoid in auto mode/street driving. I also have a maual overide switch to turn the fan on.
I try to stage the car at the same temp and have the fan manually on. After burnout I turn the manual overide off and let the temp bulb switch takeover the fan. At 100+ mph the fans should not even turn on.
I turn the manual switch back on after the run and repeat.
My car runs the same ET or quicker when I hotlap. I have a good cooling system and run a tight converter for a street/strip car.
 
mderoy340 said:
If you have a scoop you need to seal it to draw outside air. IMO an open air cleaner pulling hot engine compartment air is the worst setup you can run.
I run a 160 thermostat and temp bulb switch to control the elect fan solenoid in auto mode/street driving. I also have a maual overide switch to turn the fan on.
I try to stage the car at the same temp and have the fan manually on. After burnout I turn the manual overide off and let the temp bulb switch takeover the fan. At 100+ mph the fans should not even turn on.
I turn the manual switch back on after the run and repeat.
My car runs the same ET or quicker when I hotlap. I have a good cooling system and run a tight converter for a street/strip car.
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No hood scoop as of yet, but yes would seal it up.
My water pump turns on at 160 and cooling fans turn on at 180.
Wouldn't be two hard to re rig up my full throttle switch to kill my fans instead of my alt like i had it before.

Just can't decide if i should mess with killing the fans at full throttle, or just sealing the carb from the radiator/header heat?
 
If you want some cheap fast do both cold air intake and alt/fan shutoff.
Just a switch to kill alternator field when you run would do it, because the draw of the fans isn't the problem.
The alt trying to keep up with that draw is.

Kill the alt field and cold air intake would probably get you a fair amount faster than your lowest time to date.
 
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TrailBeast said:
If you want some cheap fast do both cold air intake and alt/fan shutoff.
Just a switch to kill alternator field when you run would do it, because the draw of the fans isn't the problem.
The alt trying to keep up with that draw is.

Kill the alt field and cold air intake would probably get you a fair amount faster than your lowest time to date.
Click to expand...
With my old motor i had the voltage regulator isolated from the ground and had one of them hood alarm buttons set up on the throttle. at full throttle ground losted, no alt charge. I killed a tenth of a second. but i also removed factory fan and installed electric water pump at the same time. The reason i didn't us the alt kill on my new motor was because the fans pull on the battery enough that i had to bring a generator and a battery charger to keep the battery charged enough to start the car, if i went several rounds.(I have a better battery now as well)
With over 12.5:1 compression with my new motor, i didn't want to worry if i had enough time to get it charged back up before the next round.
The other thing that worried me by killing the alt charge was whether i was pulling the voltage down to low with the cooling fans to affect the spark of my ignition. so i didn't hook it up with this eng.
 
I just went on Wallace racing calculators to see how much HP it would take for a .10 difference. (1/8 mile )
Basically, between the hot air and alt draw is, 17 HP loss(.10 sec loss). So just for giggles i went back and keep everything the same except changed air temp from 70 degrees to 90 degrees and there was a .07 swing slower. That tells me that there is more power lost from the Hot air then there is the alt draws.....
 
In the book "WE WERE THE RAMCHARGERS" Tom Hoover wrote that the Max Wedge & 65 Hemi hood scoops did little for air to the engine,,BUT made a big difference with under hood tempetures and engine cooling. I ran the 65 Hemi scoop on my Belvedere. Compared to my flat hood at least a 20* temp drop Idling around the pits and return road.Even more on the road.Forgot to add that the alternator cut out switch showed little to none advantage during a pass.Just a thought..

LVMS_APR05.JPG
 
Of course I run no hood at all at first because of the dual quad tunnel ram. And now I think about a fiberglass hood or something but I've grown used to being able to see my motor in between passes and visualize anything being wrong.
 
I've never had an alternator kill switch, but I do run my fan and pump together all the time. I'd be more concerned about the underhood temps with its effect on the fuel system than the charging system. Do you have your fans on relays? A couple fans kicking on isn't going to drain that much from the system if they're wired on relays.
 
Do not run your electric fan during a run. If you have to run it you have cooling issues. The only time I run my electric fan is after I make a pass and in the pits cooling down. I never turn my fan on while street driving either. It never gets over 180*.
 
D-50394 said:
Do not run your electric fan during a run. If you have to run it you have cooling issues. The only time I run my electric fan is after I make a pass and in the pits cooling down. I never turn my fan on while street driving either. It never gets over 180*.
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You must have an incredible cooling system.
 
Yes there wired with relays.

My old eng, it took some time to cool down. this eng, i pull in the pits, with fan running, hook up charger, electric fans turn off within minutes. Water pump turns off within 15 minutes.(Note: this is in 75 degree weather.) and this engs has more compression too!

I think what would be best is to kill the fans AND the alt with my full throttle switch. the only thing that worries me is a voltage spike when they both are instantly turned back on. The fan take more power/amps to start the fan then to run it. I need some kind of delay relay that will turn on the fan.....I'm going to have to think about that some more......

When i built this eng i didn't put my LD 340 manifold on because it required one of them bugeye air filters to clear the hood. If i cut a hole in my hood i can use my 14" open air filter that i have on it now.

Thanks for all the thought and opinions so far!!!
 
j par said:
Of course I run no hood at all at first because of the dual quad tunnel ram. And now I think about a fiberglass hood or something but I've grown used to being able to see my motor in between passes and visualize anything being wrong.
Click to expand...
Them quads are kind a snooty, they don't care if you put a hood on or not. there still going to stick there nose in the fresh air either way! :poke::D
 
Hows the mph on these back to back runs? Are you losing the ET in the 60', or progressively down the track? Wire the fans so they're on during both runs and you're theory on that should be answered. What kind of fuel system do you have?
 
gumper said:
Hows the mph on these back to back runs? Are you losing the ET in the 60', or progressively down the track? Wire the fans so they're on during both runs and you're theory on that should be answered. What kind of fuel system do you have?
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.9 or basicly 1 mile per hour, .007 slower 60'
I don't run a thermostat, the water pump sensor controls the water flow. if i flipped both switches, aka constant, it would be way too cold by the time i got up to stage. I won't stage with less than 160 degrees(when water pump turns on.

I'm running a Walbro GL392 inline electric fuel pump with 4 port regulator(with return) set at 8 psi.
 
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As a side, what thermostat switches are you using? I put one in my car for this year, and it only worked 5 times and that was that. Had to go back to my fan wired to a manual switch.
 
Amazon.com: Derale 16759 Adjustable Fan Controller: Automotive
and this for the water pump
I cant find the other one but the only difference is one has a push in probe for the cooling fans and the other one has thread to screw into you intake to run water pump.
Been in for a year and half. no problems yet.
Edit:
Here is the wire
http://www.jegs.com/InstallationInstructions/200/259/259-16759.pdf
I tied the yellow wire directly to the battery because i wanted the fans and pump to run with the key off
 
I run a 22x18in Summit brand aluminum radiator and a ProForm electric water pump.
 
And loving it ! :lol:
I was giving my nephew a driving lesson (I know scary) and we stopped at a friends and he said "want this?"
20160613_161837-1.jpg
I said ok......
Cudafever said:
Them quads are kind a snooty, they don't care if you put a hood on or not. there still going to stick there nose in the fresh air either way! :poke::D
Click to expand...
 
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