Honda Insight (potential mods for reduced drag?)

[donoman]

I know this car is one of the most aerodynamic out there, but what else have you guys done to improve the aerodynamics?

Here's what I'm thinking:
1) Grille block
2) Front lip / splitter
3) Remove passenger mirror

If any of you have done this already please let me know. That way I don't waste my time if it's useless.

I think the car could definitely benefit from a front lip...

[Daox]

I think the best mod you can do for an insight is a warm air intake to extend your lean burn capabilities. After that I'd block the grill.

[aerohead]

I'm unclear with your mention of "splitter",can you help me out there? Personally,I'd leave the mirrors alone.The Insight has a frightening blindspot at the rear,and I think you need all the outward vision you can get.Safety first! With respect to the grille block,since you have a very expensive electronics package aboard that car,you must be much more careful than those of us burning only dinosaurs for motion.If you do the block,start small,monitor temps religiously,and work your way up incrementally to more blockage.The Insight is certainly a compromise between an extreme-performance vehicle and a limited mass-production, profit producer,however,I do believe HONDA has invested a lot of wind-tunnel time on the body of the car.The upshot is that the fore-body is very clean,the frontal area hits about where your head is,and then the body begins it's teardrop-taper for the duration of the body length,yielding the Cd0.25,which is great! The downside is,that there's very little to be gained by modifying the front of the car.If you'll look back in recent history,you'll find that,for virtually all car companies,setting out to break records,they went to the back of the car to do it.Whether the Chrysler Airflow"boattail",GM Oldsmobile Aerotech "Longtail",GM Sunraycer"Pumpkin-seed",GM Saturn Impact/EV-1/EV-2,boattailed LSR,Mercedes C-111, Volkswagon' 145-mpg Diesel,Porsche 917 long-tail,Cadilac"le Monster",etc.,they all turn to the wake of the car for added performance,and I'm afraid your facing the same challenge if you want to see measurable performance increases.Should you follow basjoos lead,you should end up in 90-mpg territory,while out on the open road.Not shabby by todays standards.Put the whole rig up on railroad tracks and your looking at 105-mpg.

[Cd]

Actually, I'm not too impressed with the .25 drag coefficient that the Insight has.
After looking at the the Lexus LS430, the ( rounded ) brick like Audi A2, Opel G90, as well as several others, I have to wonder why the .Cd on the Insight is so high.
The body seems so well designed for a low .Cd yet it only just matches the non streamlined looking Lexus.

If I had an Insight, the first thing that I would do is block that huge grill opening, put wheel 'whisker' style spoilers on and improve the smoothness of the underside. I would then add a deck lid extention as well as one on the underside ( a diffuser )
The mirrors and the antenna would be removed and replaced with cameras.
I would then lower it as much as I could get away with.

I see the Insight as a diamond in the rough for aero mods.

[Red]

I'm in the same boat is .Cd. Joel's Mazda5 had a CoD of 0.29 and thats a big honking minivan like vehicle. The Insights CoD should be much much lower. Heres a pic of the front end of an Insight. The hood is unlatched.



The stock cooling system uses a half length radiator for the engine, and a full length evaporator for the AC. The batteries are air cooled internally using the cabin air. I haven't really driven mine around, but the cooling system only takes a gallon of coolant for an overhaul, so I am figuring the engines cooling demands are very low. My gut feeling is that its low enough that even a half radiator is overkill. My plans are making a grille block on the top most radiator opening, then depending how well that is working, block off the bottom. The bottom opening is fitted with a grille to deflect air upwards into the engine bay. The front plate bracket I really want to get rid of, but I'd need to find a good way to relocate the plate.

I don't have any pictures of the underbelly, but there appears to be full length panels running underneath covering about 75%. Waiting to get my Dad's Camry fixed up before I can put Rommie on the ramps and get a good look.

[Cd]

Originally Posted by Red

The front plate bracket I really want to get rid of, but I'd need to find a good way to relocate the plate.
.

Why not incorporate it into a grill block ?

( Never mind the bottom left hand corner of the image. I was showing how that I can remove the temporary block in a few seconds and have it folded for underseat storage. The plate actually holds the temporary block in place.)

[donoman]

Insight owners have very commonly run 1/2 radiator blocks in <80 degree weather. For me, that's almost year round. My fear is that I previously tried a radiator block in one of my CRX's and overheated the car, requiring a new radiator. D'oh. However, I would only be blocking off the bottom grille and not the nose intake so maybe it wouldn't be so bad. I will try something with cardboard tomorrow. Wish I owned a Scan Gauge...

The idea about the front "splitter" or airdam is that it effectively lowers my car without needing a suspension change. I can't find aftermarket suspension parts and truthfully I think it's too bumpy already, so a front airdam sounds like a great solution. The car sits and rides very high already. A guy on this forum did this before. I would want mine to look a little cooler in the end but you get the point. One cool thing about the Insight is that there is already an "undertray" to the engine area so attaching a splitter should be cake.

[MetroMPG]

If I had an Insight:

- Rear wiper delete. (If I'm not mistaken, the CRX had a Cd .01 difference with the wiper on vs. off.)

- The passenger mirror delete will help a little as well, with more attentiveness and a large convex replacement on the inside to regain most of the lost functionality.

- partial grille block

- investigate additional under-car panelling

More involved/radical:

- Phil's right in that the biggest gains are to be had at the back of the car. But extending and continuing the taper of the existing body lines is no small task.

- Front wheel skirts, a la Aerocivic.

[MetroMPG]

Just remembered: I believe I've seen an Insight with both side mirrors replaced by backup cameras.

[fabrio.]

donoman, have you some picture about underboy of your car?