Chopping the Civic

[Cd]

HOLY HELL that looks awesome !

[some_other_dave]

Wow, looks super nice from this angle!

But I don't think you'll get anywhere near the weight reduction you're talking about without changing a bunch of metal and glass to lighter materials. Still, dropping the CG won't hurt the handling one tiny bit, and shaving some weight off the ends will be good for polar moment--so it will change directions more easily.

If you can do it, go for it!

-soD

[Hasbro]

Originally Posted by vtec-e

Hasbro, if you've got the skills then you've got to do this! It looks awesome and for that alone, it's worth doing. More mpg is just the icing on the cake.
On a practical note, how do you propose getting around the crashworthiness issue, since there will be heavy cutting of the structure?
ollie

Lol, I don't have the skills but that has never stopped me before. If it works out to be feasible I can do it.
I don't see a problem with crashworthiness re. the chop as interior bars could make it safe/rigid. There seems to be plenty of room for bumpers further in the chassis. The overall length would be shortened by 7 3/4-8 1/4".

Originally Posted by MetroMPG

That looks cool.
One thing to keep in mind if you lay the windshield angle back is you'll have less pressure for flow through ventilation (typically relies on high pressure at the base of the windshield).

A body piece of about 3" between the bonnet and windshield would be needed to tie the two together, which would be just right for working that problem out.

Originally Posted by some_other_dave

Wow, looks super nice from this angle!
But I don't think you'll get anywhere near the weight reduction you're talking about without changing a bunch of metal and glass to lighter materials. Still, dropping the CG won't hurt the handling one tiny bit, and shaving some weight off the ends will be good for polar moment--so it will change directions more easily.
If you can do it, go for it!
-soD

I have pages of weight reduction notes and believe I am being conservative. Oh, gotcha, the 500 lbs. I mentioned above relates to all my reductions. Not counting the sun roof (32 lbs) I think this project might remove 50 lbs give or take. I have removed about 275-300 so far.
Thanks for everyone's input, really helps. Very encouraging.

[kane66]

Great look.... Not only would you get some great FE but you could take it to shows to promote eco-modding

..... hate to sit in the back seat though

[trikkonceptz]

Now let me shed some reality on the project.

We start off behind the eight ball because it is a unibody car. Laying down the A-pillars, means you have to cut them in order to get to the angle you want. By doing so you drastically reduce the strength of the vehicle as A-pillars, B-pillars are the major areas for both crumple zones and rigidity for impact.

Once you get past the windshield, the roof will have to be segmented to make up for the shortened length & the B-pillars have to be cut to meet the new lowered height. Once you do this the doors no longer close so those have to be modified, along with the glass. Here you can go with lexan, but cut glass means non tempered which is dangerous.

Reconstructing the rear will challenge anyone because the hatch becomes useless, therefore new metal has to be shaped to cover the area while retaining the strength of the original components. New glass will need to be made for the hatch area, heavy bracing will have to go around the b-pillars and in support of the rear of the car. Kinda like a roll cage. Believe it or not reshaping the bumper will be easy, however reshaping the wheel wells, not so much.

If you manage to get past all the metal work and your car doesn't leak, then its time to tackle the interior and reconstruction of all the plastic pieces inside the car that do not fit. From this point on it becomes the expense of all custom fabricated parts.

This is not a DIY project by any means unless you are willing to throw away the car. Work like this is a challenge for the most experienced hotrod shop and should never be taken lightly. Often times it is done strictly to show cars and for very practical reasons. No one can guarantee their safetly over time or in accidents. Once you cut and weld metal you weaken it.

I am planning a similar mod for my xB, for show reasons, and it is something that we have been planning for 2 years. We may be ready to make first cuts in the coming months.

If your goal is 50mpg that is not the best way to get there, I am almost there with a relatively stock Vibe and it is no where near as aero as your civic.

Its an incredible project, but often done by those who have nothing to lose and the skill to DIY it. If you were building a $50K show car, I'd be the first to help you plan, but to save gas .. no way.

[Hasbro]

Originally Posted by kane66

Great look.... Not only would you get some great FE but you could take it to shows to promote eco-modding

..... hate to sit in the back seat though

What back seat. Although because of the chop I think a small on the floor custom seat would be pretty cool.

Originally Posted by trikkonceptz

Now let me shed some reality on the project.

We start off behind the eight ball because it is a unibody car. Laying down the A-pillars, means you have to cut them in order to get to the angle you want. By doing so you drastically reduce the strength of the vehicle as A-pillars, B-pillars are the major areas for both crumple zones and rigidity for impact.

Once you get past the windshield, the roof will have to be segmented to make up for the shortened length & the B-pillars have to be cut to meet the new lowered height. Once you do this the doors no longer close so those have to be modified, along with the glass. Here you can go with lexan, but cut glass means non tempered which is dangerous.

Reconstructing the rear will challenge anyone because the hatch becomes useless, therefore new metal has to be shaped to cover the area while retaining the strength of the original components. New glass will need to be made for the hatch area, heavy bracing will have to go around the b-pillars and in support of the rear of the car. Kinda like a roll cage. Believe it or not reshaping the bumper will be easy, however reshaping the wheel wells, not so much.

If you manage to get past all the metal work and your car doesn't leak, then its time to tackle the interior and reconstruction of all the plastic pieces inside the car that do not fit. From this point on it becomes the expense of all custom fabricated parts.

This is not a DIY project by any means unless you are willing to throw away the car. Work like this is a challenge for the most experienced hotrod shop and should never be taken lightly. Often times it is done strictly to show cars and for very practical reasons. No one can guarantee their safetly over time or in accidents. Once you cut and weld metal you weaken it.

I am planning a similar mod for my xB, for show reasons, and it is something that we have been planning for 2 years. We may be ready to make first cuts in the coming months.

If your goal is 50mpg that is not the best way to get there, I am almost there with a relatively stock Vibe and it is no where near as aero as your civic.

Its an incredible project, but often done by those who have nothing to lose and the skill to DIY it. If you were building a $50K show car, I'd be the first to help you plan, but to save gas .. no way.

Appreciate your pointing out the difficulties. I've ordered a book on chopping and have posted this idea on some other forums for constructive feedback. I understand chopping is a fairly complicated process but so far don't see anything that will dissuade me. The structural integrity will be stronger with the use of a roll bar-like structure that would be welded to the unibody instead of a separate roll bar structure. Wheel wells won't be changed. Rear three windows to be Perspex. Interior is gutted. I think the hardest part is the fitting of the sides, especially the door windows. The hatch I think would be lift off and the existing rain gutters used for drainage and structural. I would work with a shop on some of the finer work. My welding is somewhat limited. The project isn't actually for fe, that would be a side benefit. I just can't leave anything stock!
I had a track Mini that I wanted to chop. The proper way was to also shorten the entire body all around by several inches along with lowering the roof! Pretty daunting.

[Hasbro]

Ecomodder.com version (original car in pic is about 1 1/2" too low).



I would like to change the final and 5th gears -especially after reading MetroMPG's tranny change- which would change 5th rpm from 3000 @60 mph to 2242 @ 60 mph! 34% lower for 5th and about 20% for the other gears.

The K20a3 motor is fairly torquey for a Honda lump and can be tweaked quite a bit. It's amazing how versatile the K series is because almost all the parts from all the motors/trannies can be swapped around.