Vented bonnet

The RPS version would seem to offer some advantages - the deflector being a big plus if it does work leaving the spare wheel in place - but also in terms of appearances, subjectively speaking. I prefer not seeing the vents showing, which they do more in the TF200 and from memory more so again on the CJJ bonnet. Others may prefer seeing them, but having them in the vertical plane with only the sculptural shape suggesting they are there is to me nicely discreet. Another small plus is they have gone out of their way to slightly raise the rear bonnet edge to hide the wipers at rest. The rest of the bodykit is a different story, but as I mentioned, it is only the bonnet that interests me.

It'll suit you car definitely!. Nice colours.

cant see the point of having a vented bonnet on a standard car unless you keep beers under there and you need to keep them cool......







unless of course this was under the bonnet :wave:

English beer is always kept in the boot so the engine can keep it warm. Rob Bell's TF200 article explains why a vent is useful.

On a less serious note, RPS sent over details of their deflector. All it requires is a pair of cut-outs at the back of the bonnet slam plate and then their 'deflector' moulding fills the gap between slam-plate and bonnet vents. Nice and simple.

They also did an experiment with the top bumper vents blanked and open, and found cooling significantly better open. They use a baffle (in their front bumper moulding) to separate the air from top and bottom vents, and when the top vent air is forced directly onto the rad it does help cooling, which perhaps suggests the MIRA experiments by Peter Stevens in designing the TF were not wasted, and that a baffle fitted to the standard bumper could also work.

I had a closer look at the CJJ under-bonnet arrangement, included by mgtfbluestreak in his selection of picture, in relation to that offered by RPS (keep getting those iniitals wrong). I won't put their picture here as it will be their copyright, but it really is an ingenious solution. Instead of the big area created by CJJ with sheet metal and repositioning of various components that were in the way, they send the simplest possible template to cut out one section on one side of the back of the slam panel, and turn it over to cut out the same shape on the other side.

There are no changes to metalwork and the spare wheel stays where it is, adding the benefit of its weight to the downforce on the front wheels.

It looks to me, although this is nerdy speculation, that their vents are directly above the rear of the twin radiator fans, potentially re-using the work of the fans for the purpose of pushing the air that is behind the rad directly up into their 'deflector' moulding, which fits tightly and directly to the two vertical vents in their bonnet.

The other plus is that, unlike the Polish car in bluestreak's pics, and also to some degree CJJ's vent - the RPS one is located almost exactly where the TF200 one was located. The supreme importance of that it is the first third of the bonnet that has low pressure, and as you move up the bonnet that gives way to a zone of high pressure.

If the vent is not wholly in the low-pressure area it negates the whole purpose of providing downforce where it is most needed. The Polish one looks to be nearly all in the high-pressure area and the CJJ one seems to straddle the border, but the RPS is almost exactly where the TF200 research at MIRA showed it needs to be and thus should be as effective as possible.

Track tests of the RPS one had the stewards suspicious - how could that particular TF not apply the brakes for another 20' later than the rest of the field? That sounds like the downforce is with them.

A final super-nerdy thought is that the mesh the TF200 used, which looks like standard TF front-bumper mesh and frame is both octagonal (a theme there?) and very 'clear', that is to say not much wire and a lot of air, which is what you want when you are trying to push air out. The octagonal type is available, I found, at up to 85% 'clear' (the non-Scientology version) - which means only 15% wire and 85% air - the way to go!

I'm in line for the plain bonnet (not the one that goes with their bodykit) and the 'deflector' panel - I just need some help with a good painter, who can match my aged LEF, not too expensive and not more than a couple of hours from London - any recommendations?

I'm in line for the plain bonnet (not the one that goes with their bodykit) and the 'deflector' panel - I just need some help with a good painter, who can match my aged LEF, not too expensive and not more than a couple of hours from London - any recommendations?

I used a guy in Cheadle Staffs who did an excellent job with my LEF TF, 2 hours is about just manageable depending which end of London, but I would think practically its not viable.
Anyone in the Staffs area, I cannot recommend this guy enough, Cheadle body shop and his no. is 07854 969585. He does take great care and also goes over and above the call of duty by fine detailing anything on the car that needs doing, even if you have not asked for it. For example when he treated my wheel arch rust spots, he lined the arches with anti stone chip, waxoyled the inner arches and inside the sills, fixed a loose side indicator and re-aligned my front bumper so it was a much better fit. He should have some LEF left in stock too.

Sundance