Matrix front end work

[Weather Spotter]

Well Now that I have a boat tail on my matrix it is time to focus on the two remaining areas for aero improvements.

Underside and front

I have a few questions for you all about the front end:

1, should I try to have the air flow under, over or around the car?

2, how bad is my current front end?

3, how much gain can I get from changing it?

[piers.singer]

Ideally, the air should go over or around the car. If it goes underneath then it gets all caught up in exhaust pipes and suspension gubbins (unless you already have a belly pan, however over and around are still better). Upper grille block looks fine although you may wish to plug or tape any gaps between it and the bodywork. A lower grille block would be a boon also. Seeing as you live in Michigan you could probably gett away with a full one and not worry about over-heating. As for gains, I'm going to dodge the question and say YMMV

[Weather Spotter]

I do have a lower grill block, it is a stealth one and is remote controlled from switches in the car all winter it stayed closed, but now I have to open one half of the bottom 3/4 of the way to and from work. On days over 75 I have to open the whole bottom.

I figured that the top and sides were better but which is more better? If I were to make a nose cone should it deflect most of the air up or around or split it evenly?

Should it have the same angle as the back ~ 15 degrees?

[camopaint0707]

What did you use all over it?

[Weather Spotter]

What are you asking about?

[3-Wheeler]

Originally Posted by Weather Spotter

Well Now that I have a boat tail on my matrix it is time to focus on the two remaining areas for aero improvements.

Underside and front

I have a few questions for you all about the front end:

1, should I try to have the air flow under, over or around the car?...

My bet would be to allow the air to also go underneath the car. This would also imply smoothing panels to allow the air the minimum obstruction to the wind to achieve this.

All the high performance super-mileage racers use this same technique.

Keep us posted.

Jim.

[Weather Spotter]

You hit a sore spot, I know I need to smooth out the bottom of the car but I have found good mount points. And I do not want to drill into the fame if I can avoid it.

[3-Wheeler]

Originally Posted by Weather Spotter

You hit a sore spot, I know I need to smooth out the bottom of the car but I have found good mount points. And I do not want to drill into the fame if I can avoid it.

Hi Spotter,

Well it might not be a sore spot any longer... Why?

I had the same concern when putting underbody panels on the Insight, and there are numerous locations where a wood block was glued to the subframe with thickened epoxy.

1) Choose a good spot for a wood block application
2) Completely seal the wood block with epoxy
3) Sand both the frame location and surface of the wood block that are to be bonded together
4) Mix up epoxy
5) Thicken epoxy with flour (consistent with peanut butter)
- do not use microballs as these are not structural; the bond will be too weak
6) Apply paste to joint and hold in position until hard
7) You now have a nice spot to mount the body panel

Jim.

[Weather Spotter]

So you epoxy the block, let that harden then do a second batch to hold it to the car?

[3-Wheeler]

Originally Posted by Weather Spotter

So you epoxy the block, let that harden then do a second batch to hold it to the car?

Hi Spotter,

Yes, that's right.

Coat the wood block with pure epoxy and let it soak in. It may need several coats depending on the wood used. I use pine with good success.

After the coating is finished, sand the surface of the wood block with 60 grit to rough up the epoxy, and the frame too.

Make sure the joint is nice and tight before mixing epoxy. You want good adhesion over a large area.

Then mix up the epoxy paste and apply.

As for the block location, pick a spot that will not collect water. No standing water on any of the blocks. Taper the edges of the blocks to encourage good water drainage. It's usually the details that makes a great project, so sweat the small stuff and your results will be very satisfactory.

Where the fastener goes into the block, make sure that this surface is facing towards the ground. Again, prevent water intrusion into the drilled faster hole.

The panels will get lots of water, so their construction will be a whole other matter. Just make sure the blocks dry quickly after getting wet.

Jim.