RPX500 bonnet for TF?

Hello all.

I am considering getting that bonnet for my TF. It could help the radiator in Madrid’s summertime hot temperatures, specially with the AC on.

But being fiber I worry about cracking and long-term disadjustment.

I haven’t been able to find anything in the Forum, can somebody give me some insight on this??

Thank you,
Pedro

I think the RPX bonnets look good but do not know anyone who has this type of bonnet. I believe you have to cut out part of the metalwork above the radiator to allow the hot air to escape upwards through the RPX bonnet vents. This allows the radiator to work more effectively

RPS do make good quality parts. I have their front and rear bumpers for my MGB,

A vented bonnet was going to be part of the next MGTF upgrade before MG Rover went under. During testing they discovered that only about the lower third of the radiator contributes to actual cooling. Part of the problem is that it is a tortuous route for the air to exit under the car, combine that the poor bumper design that also allows too much under car and you have a problem in hot climates. They also discovered that air exits the top slots in the top part of the bumper.
From photos of the cars undergoing testing in the Australian desert, the full package was the bonnet vent, filling those top vents on the bumper, scoops to collect more air for cooling the engine bay, a larger hot air outlet on the boot lid and finally a Gurney flap on the boot lip. The combination of all these mods not only gave better cooling, reduced both front and rear end lift to zero, removed wander at speed and reduced the aerodynamic drag by ten per cent. A big chunk of that simply from having the bonnet vents.

I have to say I look forward to MGB281’s contributions, they are informative & enjoyable even for the old lags. Referencing the Gurney flap put me right back to the days when Dan Gurney & I think it was the Eagle team added an upstand on the rear of the car. No one really noticed never mind questioned if it was contributing to the performance, but once the other teams cottoned on everyone had them & still do.
M

It just shows our age, I grew up in a time when the motoring magazines were full of technical information about cars. I always read “The Motor”, it was always carrying articles written by engineers rather than journalists. I have always been more interested in the engineering rather than the gloss of marketing. When I bought our TF it was a cheap one £600, I knew at that price I could rebuild all the suspension, subframes and brakes to new or better spec and still have a cheap car. My knowledge has come from vociferous reading of articles, you soon learn who are the ones with knowledge. Rob Bell (a MGF racer) has written a good deal about tyres, brakes and aerodynamics, Rob’s; http://mgf.ultimatemg.com/ is one of the very best sites for “engineering “ type of info.
Roger Parker’s book “Everyday modifications for your MGF and MGTF” carries a lot of info and photos on the bonnet vent modifications. The problem is that having been written a good while ago things move on.
At the moment I have a MGB to get onto the road but after that I have a rolling MGTF body shell and have an engine and gearbox to go in it, but it’s not a MG engine and gearbox, I want an ultimate for me MGTF.

Checkout Clive's modifications for his Vented bonnet

Each new issue of Motor magazine was eagerly awaiting by the family. After the squabbling between the three interested parties, my mother would be ensured of a period of quite whilst the winner absorbed the new edition, usually my brother, whilst dad got on in his workshop & I’d read last months.
The dog eared & we’ll thumbed copies we’re bundled into years & committed to the loft.
After my parents died & the family home resolved, Motor magazines had their final run out to the recycling centre, no doubt to be pulped.
There wouldn’t be a single issue that didn’t have several articles of interest, after all they were diaries for the advances in the motorcar in all forms especially motorsport.
And yes the technically writing was of a high standard, with advertisements being as interesting as the text, although some devices were of very debatable value.
Motor Sport with the green border & banner headline was my favourite.
M

Thanks so much everybody for the answers and pearls of wisdom.
I’ll get that bonnet, then

Let us know how you get on, now that RPS are gone there is no other choice.
The linked thread was interesting reading but more about the development rather than the installation mods. If you can get an emergency spare then you can probably get a decent size opening, otherwise rely on a can of tyre sealant/inflater

I will let you know, although it will take some time. I have to drive my Defender to UK in November and will take the chance to bring the bonnet then