Zulu's Build Thread (Honda CR-Z)

[cRiPpLe_rOoStEr]

I have only seen a CRZ at distance, but when it comes to tuning I'd take a look at Hondata before trying anything.

[CigaR007]

Hey guys. I have been lurking on ecomodder for the past few weeks and decided to revive the CR-Z thread.

I have been working on the main grille block of the CR-Z. I will be posting pictures of the progress over the weekend.

I am happy to be back.


Cheers !

[California98Civic]

Welcome back, hey!

[mpg_numbers_guy]

Welcome back!

[JulianEdgar]

I like your stepper motor control of the grille opening - very good.

Just a point re the flow (etc) into and out of the engine bay - lots of development on directly measuring these pressures has occurred since you were last here, so basically guesswork is no longer needed.

[CigaR007]

This is my vision for the CR-Z. The front of the car is pretty straightforward, aero-wise. The rear is just a concept. I have no idea if it would help.




Here is the progress :

Preparing the grille fascia with aluminium foil



Insulation foam applied on grille opening



Foam is then carved to desired shape



First layer of fibreglass is applied. This was my first attempt at using fibreglass. I used a polyester resin and it was a mistake. The expanding foam deformed in some spots and the surface became very uneven. Polyester resin is a no go with expanding foam. Switched to epoxy resin for the other layers. Another no go would be applying the fibreglass vertically...I paid the price for not wanting to remove the bumper. Lots of lessons to learn from !



The cost for these mistakes ? Lots of body filler and elbow grease to level the surface...Another mistake in this photo, I somehow miscalculated the epoxy and hardener ratio (5:1). This layer of epoxy was not as hard as it should have been. It looked nice though



Lower grille opening was cut out. Some body filler and sanding. Two layers of fibreglass mat with the correct epoxy-hardener ratio this time. The result was pretty good. Slowly learning...



Onto trimming the unnecessary fibreglass mat. This turned out to be another lesson. Try to keep fibreglass mat to the smallest size possible, without compromising the structural rigidity. Trimming was a tedious process.



Grille block from different angles :








View of the front end of the CR-Z without the bumper. Seems to be pretty optimized in terms of ducting and controlling the incoming cooling airflow.




Cheers !

[JulianEdgar]

Originally Posted by CigaR007

This is my vision for the CR-Z. The front of the car is pretty straightforward, aero-wise. The rear is just a concept. I have no idea if it would help.

Make the rear bits out of cardboard and do some testing first.

Lots of work with the grille blocker.

However, putting some black-painted foam rubber strategically in here..



...would have achieved much the same aero outcome in about 5 minutes!

[CigaR007]

Originally Posted by JulianEdgar

Lots of work with the grille blocker.

However, putting some black-painted foam rubber strategically in here..

...would have achieved much the same aero outcome in about 5 minutes!

Agreed, but where is the fun in that ? hehe

I tend to overdo things, but I end up learning many things along the way.

Here's the grille block evolution on my other vehicle, as an example :

https://ecomodder.com/blog/cigar007s...ock-evolution/

[California98Civic]

The block is coming along nicely. Do you remember Metro's Gen1 Insight with the boattail? There were a couple others too. Botsapper? 3wheeler? I forget who. Anyway, their testing showed MPG results. You could build a shorter version and test it. What I liked about MetroMPG's was he worked around the OEM taillights. Bring the edges of the rear box cavity closer to the sides of the car...

Build it with carboard and painter's tape at first and set up ways to measure aero effects, fine tuning in light of the results.

Great pictures!

[aerohead]

I've not seen anything in the literature which addresses a partial cross-section box cavity. The sides would be isolated, leaving only top and bottom with access to the active flow. Pressure spikes would be likely. Vorticity.