Helmet loop

One of the many issues concerning fitting GRP seats in a J15 is the roll-over bar helmet clearance. I took advice about hill climb/sprinting the J15 and the verdict from a track-side scrutiniser was that the helmet clearance to the roll-over bar was insufficient. Apparently for MSA road going class this is a grey area but the advice was "don't do it".

The other issue is the supports for the roll bar have not been installed by me as the rear tub has to be cut. I think the one bar to the rear chassis leg would have less impact on the rear tub.

I recently obtained a special seamless tube from Jeremy bent in a loop to create a helmet loop. I made templates out of plastic ducting left over from the Virgin Broadband install.

I have now welded the loop in place  I got a piece of 37mm high tensile seamless tubing 2mm wall thickness from Blakes Metal Merchants which made up the rear stay.

The rear chassis leg support bracket strength has been enhanced by an extra support to link it to the lower chassis leg.

Creating templates

Welded loop

Chassis leg attachment point

Some chassis paint

Rear stay fitted

Contents
http://sylvabuild.blogspot.co.uk/2012/01/sylva-j15-is-kit-car-designed-by-jeremy.html 

Re-visit Dynamometer

There was a problem with the last power plot I did last year as the throttle body butterfly was not opening fully. This visit back to Sitech Racing was to validate the update to the throttle body linkage. Here is the plot from my visit in August 2013: http://sylvabuild.blogspot.co.uk/2013/08/ecu-re-mapping.html

The standard engine produces 125bhp at the flywheel so no increase in power was observed in August. Since then I have fixed the butterfly versus pedal position.

You can clearly see the maximum power has increased by 43bhp to 155bhp @ 6700rpm a most agreeable result for the cost of a sift in pivot point in the throttle linkage.

Contents
http://sylvabuild.blogspot.co.uk/2012/01/sylva-j15-is-kit-car-designed-by-jeremy.html