Measuring air flow changes through the radiator after adding splitter and air dam

[496BBC]

Well I've got the motor back together and the carb is just about dialed in so its time to bring this one back to the top.

I was having trouble getting reliable readings from my data logger so I had to do some digging. I found the sensor wire connected to the ground instead of the hot wire. Today was my first trip with it connected to the logging software and looks promising. I'll have to dampen the input but I think the software has that capability so it shouldn't be hard to do.

I'll have to put a switch in the temp sensor line so I can shut the fans down while driving. I was able to make a 10 mile run without the fans coming on but once I stopped and they came on they don't shut off. Its 92* with 60% humidity today so its hot. I think with the right fan switch the fans would shut off, my off switch may be a little low with the T-Stat I'm running to shut the fans off on a 90* plus day.

The first run shows that the fans just start turning at around 45 mph and at 50 right at 1 volt, at 60 its at 2.3 volts and at 70 its at 3.5 volts.

I'm going to make a few more runs in the next few days to get a good base line.

My plan is to install a splitter like BJ to see if this makes a measurable increase in air flow over the radiator.

I wish I would've done this before I modified my frontal area to see what the flow was in stock condition.

Neal

 

[phantomjock]

Neal, that's all good news. It will be interesting to see the results before/after the splitter. I was a bit slow in getting some oics together - but have them now. Hopefully they'll clarify a bit of my ramblings.

First, is the airflow and drag picture:



Then, a simple graphic showing the "go-zinta/go-zouta:"




Not a C3, but you get the idea for the hood vent:




Must be a good idea - Looks like Greenwood used it too!




An AIRBOX helps keep the flow Through the Radiator and Out the hood:


Here's a nice shot showing the forward Laydown Radiator:


Thats the approach I'm planning, enough typing - I have some work to do!

Cheers - Jim

 

[496BBC]

thanks for the pics of the different arrangements. I've thought about making the hood shorter and have the forward edge at the top of the core support. That way I can lean the radiator forward and not have to worry about the hood hitting it when opened

I've opened the vents (heat extractor at the front) on the L88 hood back when I was having cooling issues. I may block them and see if the air flow changes in the future.

I need to spend some time sealing the front area with weather stripping to make sure all the air is passing through the radiator. I lost the top piece of weather stripping on the core support while driving a while back and could see a voltage drop on the meter when measuring voltage from the fan motor.

It will be interesting to see how big of a difference sealing the front will make on flow.

Right now I can look through the hood scoop and see daylight between the core support weather strip and the hood so I know I'm letting air around the radiator.

Neal

 

[496BBC]

A few shots of the data I've got logged so far.

The gold line is the fan voltage and the black line is the motor rpm's, I'm runing 4:11 gears so just double the rpm for the mph. Its not perfect but its close. The mph are a little lower than the doubled rpm, 2500 is around 48 mph.

Starts producing voltage at about 40 mph, 3.5 volts at about 60 mph

[/IMG]

Just under 60 mph 3 volts, right at 100 mph is 5 volts. this is the max my data logger will show/

[/IMG]

cruising at 3000 rpm (60 mph) right at 3 volts, increase to 3500 rpm (70 mph) volts jump to 3.9 volts.

[/IMG]

I punctured a tire sidewall (not sure how I did that) so it may be a little while before I can do some more testing.

I'll post back when I get some more data.

I don't have a screen snag program so I took pics with my camera and posted, that's why they are not very clear. You have to have the logging program to be able to view the file in its original format.

Neal