Radiator Block

[tsh]

Has anyone looked into this with the CRZ? The theory being that with a more efficient engine, at low ambient temps, the car spends much longer before reaching optimum operating temperature. Blocking airflow through part of the radiator helps with keeping the engine warm enough, so long as there is no risk of needing to run the fan too much to keep from overheating.

With ambient temps below 10C at the moment, I notice it takes about 10 minutes for the coolant to reach 80C (stabilises at 82-84). I'll start experimenting (and keeping an eye on the OBD data)

[SS2CRZ]

Reminds me of the huge pieces of cardboard the bus drivers had on the buses when I was a kid. You know, it gets HELLA cold outside in the "winter" in Florida.

[kmanatt]

On this topic, I believe that aerodynamic efficiency could be improved by not letting so much flow go into the radiator. (I know almost nothing about this topic) I have heard that if we force the flow to go around instead on through where it ends up increasing the pressure under car, we get less drag? So maybe a block would help us in more ways. I think we should have a temperature guage to know when to remove the block.

Anybody know if I am blowing smoke out my diffuser?

K

[robert 2011]

Why block your radiator. this is not a v8

[tsh]

Because the first 5 minutes of a trip seems to cost more, and for a sheet of card that can be changed.
Temperature logs with stock radiator...

and a run to the supermarket after. Temperature levels off at about 70C.

[Whocares05050]

What is all this "C" temperature stuff. I only know "F"

[Jordan]

I blocked the radiator in my del Sol with good results. Was getting 39-40 MPG lower speed highway trips, afterwards 41ish consistently and also year round. I think the key to the improvement I saw on that car was because the nose is very rounded, and the grill block set flush with it. On a brand new CRZ that is going to look really tacky. For now I wouldn't even attempt it, but if they come up with some aftermarket grille kits that set differently I might be willing to give it a try.

There are factory cars that have grilles that open and close at various speeds and operating modes. Probably a little out of the league of most DIYers though.

[tsh]

I just used some card slotted between the radiator and the nose, not visible from outside. I took it out once the ambient temperature reached about 20C (on a hot day) since that seemed to be about the point when the coolant got up to 94 (which I think is when the fan comes on). There was a small mpg drop (1-2, too small to measure accurately), and I am thinking that a half-block might be worthwhile.

[Jordan]

Originally Posted by tsh

I just used some card slotted between the radiator and the nose, not visible from outside. I took it out once the ambient temperature reached about 20C (on a hot day) since that seemed to be about the point when the coolant got up to 94 (which I think is when the fan comes on). There was a small mpg drop (1-2, too small to measure accurately), and I am thinking that a half-block might be worthwhile.

I think I saw a Pontiac Vibe on ecomodder, or CleanMPG before that had the stock grille covered from behind like what you are talking about.

I would just say to start conservative. This thing already has a belly pan so air flow is already restrictive to begin with. I know I will be looking into a block heater in the near future, at least before it gets cold and I don't want to go in the garage. Temperatures around here are, how you would say mid 30sC so blocking the grille for now is out of the question, and to be honest with you if I lived somewhere where it would be a more permanent addition I would go the route you are talking about.

[gomarlins3]

This 'trick' use to work great on my Insight. I may try it next winter.