Split bonnets / split hood conversions

"Split personality"

Split hood

Bonnet styling

Most bonnets are rather conventional and boring. However with a little imagination and the use of some everyday car parts you can create something unique.

The most dramatic bonnet styling modification has to be the split bonnet. Rather than opening on a hinge at the top or bottom the bonnet will open from the middle to each side.

First off remove the bonnet from the car and see where the supports are (you will need to remove the sound deadening at this stage too). You must aim to keep the bonnet rigidity and may need to weld an additional support to aid strength. 

Custom split opening bonnets are the ultimate style statement and are fairly easy to do. 

You can either do a straight cut down the middle, an off center cut on a diagonal or you can cut triangles or other shapes along the edge. The simplest and most impressive has to be the off center diagonal cut. Expect to paint the bonnet when refitting it as you will be cutting metal and will need to protect the cut against corrosion.

Plan your cut carefully and mark it out with some heavy duty masking tape. Take an angle grinder or jig saw (an angle grinder will give a nice straight edge but will make it harder to cut shapes) and proceed to make the cut in the bonnet.

You will need to decide which part is the leading edge and weld an overlapping seam on the other half for this to rest on. Next we need to balance the weight using a rear parcel shelf stay / spring mechanism.

The idea of the stay is to give a smooth opening action and reduces the amount of spring strength required. Hinges must be fitted to the outside edges of the bonnet and then you should connect them to the car ensuring they open without fouling up and leave a nice even join where the 2 halves meet. The photograph below shows the seam welded along the join.

After adjusting the hinges and fixing the 2 halves in place you are now ready to fit the opening mechanism. Depending on the weight of the bonnet you should install an appropriate set of springs and counter balance pistons.

Next step is to focus attention on the release mechanism. Thankfully most standard release mechanisms are sprung loaded and allow the bonnet to pop free of the catch leaving your sprung loaded split doors to flip up under their own steam.

To get more information, tips, suggestions and advice on all aspects of car styling please join our very friendly and helpful community. We have a number of interesting projects on the go in our forum.

Please Check out my YouTube channel, we're regularly adding new content...

PLEASE HELP: I NEED YOUR DONATIONS TO COVER THE COSTS OF RUNNING THIS SITE AND KEEP IT RUNNING. I do not charge you to access this website and it saves most TorqueCars readers $100's each year - but we are NON PROFIT and not even covering our costs. To keep us running PLEASE Donate here

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.

Feedback - What do You Think?

Please use our forums if you wish to ask a tuning question, and please note we do not sell parts or services, we are just an online magazine.

Help us improve, leave a suggestion or tip

Your Constructive comments on this article, I really want to improve this article with your help and suggestions.


Please watch this video and subscribe to my YouTube channel.



Member Benefits

Join our forum today and benefit from over 300,000 posts on tuning styling and friendly car banter.

You will also have full access to the modifed car gallery, project car updates and exclusive member only areas.

(All car owners of all ages and from all countries are welcome).


BMW 335i - 2021 COTY

We gave the BMW 335i our coveted car of the year award, read more about this awesome car and see why 335i Tuning Guide

Tips for N54 Tuning

Tips for N55 Tuning
Tips for B58 Tuning

Popular articles

Diesel tuning
Remapping the ECU
Double Clutch
Induction Kits
Customize a car
Chip Tuning
Modded Car insurance
Track day insurance cover
Remapping Diesels
Work out your MPG
Unblock a DPF
Stage 1 Tuning


Engine Knock

How to avoid engine knock and pinging
Read more...

Suspension Settings

Suspension setup and suspension settings and fine tuning.
Read more...

Suicide Doors

Suicide doors
Read more...

Engine Covers

Engine covers – carbon fibre, plastic and painted
Read more...

Paint Protection

Ways to protect the paint on your car.
Read more...

Best Car

The best cars and ultimate must drives
Read more...

MPG Calculator

MPG calculator UK miles per Gallon – calculate MPG
Read more...