Open loop, closed loop - Page 2

MetroMPG · 02-09-2006, 03:17 PM

my WAI didn't do anything either (though it also didn't hurt, so it's still on the car).

but blocking my car's grille made a small (2-3%) but instantly observable improvement (aero effect), plus it helps build/retain engine/transaxle heat. (FYI there's a page on my site about the test.)

however, my car's grille openings appear to cover a much larger area than the del sol, so the benefit may not be as great for you.

krousdb · 02-09-2006, 03:50 PM

Quote:

Originally Posted by MetroMPG

dan, are you not running a grille block? that would fix the problem pronto, plus contribute to improved aerodynamics.

OK, grille block is installed. Two layers of cardboard covered in duct tape and even painted milano red. Held on by wire ties. I also installed my 200W magnetic heater to the oil pan. Probably wont help the coolant temp much but at least the oil will be warm. Next will be a recirculating ebh.

rh77 · 02-09-2006, 06:54 PM

Quote:

Originally Posted by krousdb

Now more bad news. At this point I start my long 6 mile down hill coast with the engine off 80% of the time. By the time I get to the bottom of the hill, the temp gauge is back down to a few notches above C. And more bad news. At this point I have a 6 mile uphill climb, possibly steep enough to be considered high load again with a 1.1 to 1.3 multiplier. About halfway up I am back to full temp. In the last seven miles I have another long downhill followed by a steep uphill, another potential for a multiplier. On the way home from work, due to the reverse route, the engine gets warmed up fairly quickly under low load conditions and stays warm for the remainder of the trip.

I had the exact same problem -- turns out the thermostat was sticking open, so the radiator was doing it's job with the coolant cycling through. The rad-block might help a little, but replacing the 'stat would probably do the trick, and negate the need for a block (even though I run a cheesy piece of cardboard over mine -- you have to look close to see it. ;-)

Definitely go with a hotter 'stat -- I assume 170 is stock, and 192 is available (which is what I went to). It made a world of difference.

RH77

SVOboy · 02-09-2006, 06:59 PM

I think our puny 100hp d15s use 175 stock with 195 available.

You need to boost that b18 of yours, 300 whp on a stock block...

rh77 · 02-09-2006, 07:15 PM

Quote:

Originally Posted by SVOboy

I think our puny 100hp d15s use 175 stock with 195 available.

You need to boost that b18 of yours, 300 whp on a stock block...

Wait a minute, what site is this? ;-)

RH77

krousdb · 02-10-2006, 06:21 AM

Quote:

Originally Posted by MetroMPG

dan, are you not running a grille block? that would fix the problem pronto, plus contribute to improved aerodynamics.

The grille block made a huge difference on the way to work today. The coolant got up to temp faster and stayed there the whole trip.

This mod is a keeper. I had the stuff lying around, so it was free.

rh77 · 02-10-2006, 06:38 AM

Quote:

Originally Posted by krousdb

The grille block made a huge difference on the way to work today. The coolant got up to temp faster and stayed there the whole trip.

This mod is a keeper. I had the stuff lying around, so it was free.

What did you use as a grille block? It looks like we have similar bumper designs, and I'm looking to improve aerodynamics. Also, glad to hear that it worked out for you to keep the temps up. Our cooling systems are just really efficient.

RH77

MetroMPG · 02-10-2006, 07:35 AM

a couple of thoughts on grille blocking. some people equate it with radiator blocking, but they have different effects.

- rad-blocking is the easiest approach: usually involves placing a piece of cardboard in front (usually in contact) with the radiator. this works for keeping temperature up, but it also makes the cooling fan less effective when/if it comes on, as it can't draw air thru the block. also, this approach does little to improve aerodynamics because air still enters the engine compartment (though maybe less, since the pressure likely rises somewhat in front of the blocked radiator).

- the best route is to block/reduce air from entering the engine compartment in the first place. better aero effects, but trickier to do if you're concerned about aesthetics. also, doesn't hinder the cooling fan's ability to pull air through the radiator should it need to (ie if there's too much blocking for the ambient temp).

- i've been informed by someone who knows about aerodynamics that it matters little whether you block grille openings from behind (more difficult, less conspicuous) or outside (easier, more conspicuous)

krousdb · 02-10-2006, 08:12 AM

Quote:

Originally Posted by rh77

Quote:

Originally Posted by krousdb

The grille block made a huge difference on the way to work today. The coolant got up to temp faster and stayed there the whole trip.

This mod is a keeper. I had the stuff lying around, so it was free.

What did you use as a grille block? It looks like we have similar bumper designs, and I'm looking to improve aerodynamics. Also, glad to hear that it worked out for you to keep the temps up. Our cooling systems are just really efficient.

RH77

What is noce about the del Dol is that there is only one grille opening and it is recessed. I just cut 2 pieces of cardboard into 34" x 6" rectangles, arrenged them sid by side to double the thickness and covered them in duct tape for waterproofing purposes. I spray painted it red to match the car and used wire ties to connect it in front of the grille. Since it is recessed, you really don't know that it is cardboard unless you look closely.