Tuesday, 19 March 2013

Bonnet stays, fog and reverse lights

Bonnet stay, fog and reverse lights

Front bonnet stay

I purchased a CBS bonnet stay 300 - 530mm on the grounds that one of the build pictures featured on on the Sylva demo car had it fitted. After investigating this arrangement I decided that the suggested method of mounting (one of the build pics)  was far too complicated. Instead I opted to place the brackets adjacent to the petrol tank. It was surprisingly easy to mount it here for something I have been avoiding for months. I subsequently found a hazard in that a gust of wind can collapse the bonnet by triggering the latch on successive gusts. I have modified the stay to include a fail safe latch part to the latch.

Rear bonnet stay

I have used a horse box towing tether to stop the rear tub touching the ground. I have two lengths of stay a short and a long say. The short one needs no adjustment to the exhaust and allows access to check the oil and water. The longer stay needs the exhaust tail rotated but gives mush better access to the engine bay.

Fog and reverse lights

The mounting of the rear fog and reverse light mountings as the suggested location is remarkably close to my exhaust hot bits. I decided to make up some ss heat deflectors that hide some of the exhaust plumbing. I then attached the LED light units to the deflectors.


Decided to try out the exhaust for the first time fully welded up. Some shots of the car in my workshop. It was snowing outside:http://youtu.be/2A36uziawaM


* CBS Bonnet & Boot Lid Stay Large Ref. Code: BNSTY 300mm- 530mm
* Contents list: http://sylvabuild.blogspot.co.uk/2012/01/sylva-j15-is-kit-car-designed-by-jeremy.html

Exhaust finally welded up

Bonnet stay anchor

Bonnet stay attachment

Bonnet stay retracted and unattached

Rear bonnet stay


  1. These CBS bonnet stays, no doubt along with other supplier's similar products, vibrate like hell when the engine is running and I believe create quite a row. I had some noise checks done recently for sprinting and it was quieter at 5,500 revs than at 4,500. I am not certain the stay was the culprit but I am considering changing to gas struts.

  2. I am getting significant vibration from the engine. I suspect the engine supports are just too stiff. It is particularly noticable when I hold on to the roll over bar and rev the engine. There are some quite uncomfortable resonances in that rail. You don't notice it quite so much when driving it because the noise is at the back of the car. Perhaps it will be better when I finally weld up the exhaust now that I have stopped modifying/developing it (only tack welded on).

  3. From experience these types of cars always vibrate like mad anyway. Its just the noise I am concerned about. Goodwood, for instance, is super strict on noise and having booked a test day there for 2 April at £250 I don't want to be sent packing!

  4. Just downloaded an app to my smart phone that mesures noise:
    Sound Meter (ver 1.4.9) Developed by Smart Tools co androidboy1@gmail.com

    1. Have just downloaded something similar to my iphone. It will be interesting to see how it works. I bought a meter from Maplin's a few years ago but it was useless.