to vent or not to?

[LRP]

should fingers crossed get my car back this week with v-mount fitted !the way it guides the air flow should i run a vented bonnet? i hav alot of polished bits under the bonnet does anybody do a  bonnet with a removable rain tray? and i dont want carbon!?:driving

[rx7veilside]

u will need a vented bonnet for the v mount to work otherwise the hot air will struggle to exit the car..just put one from rotary art on my car and have to say gary is superb to deal with .he spent ages helping me fit mine as i swapped over at his place and helped fit the bonnet pins and everything

[LRP]

ill giv them a try only thing i dont want bonnet pins?!

[nikp]

You\'ll have to have bonnet pins if you have a GRP bonnet - Gary had a few customers who chose not to fit pins, and they lost their bonnets at speed from the air getting underneath and lifting them.

Gary is very helpful - i went to his place to test fit his bonnet to my car to see if it fitted. Got a couple of cups of tea, spent a bit of time fitting the bonnet, chatted, etc. Great! Very nice bloke.

[B9 KLF]

I run a knightsport v-mount and you dont HAVE to have a vented bonnet since it works fine on a run. The vented bonnet is good in town though, since it allows the heat to get away quicker if your stuck in traffic.
With a vented bonnet and an induction kit there is a lot more noise.


Keith

[iaint]

There are a few fairly subtle vented bonnets around that aren\'t as in your face as, for example, the scoot one.  It\'ll help a lot in town but a decent one will come into it\'s own at speed as it\'ll actively draw air from under the bonnet.

As for pins: a must have in my opinion.  It\'s not so much the flex that\'s a problem (depending on speed) but the strength of the main catch.  It\'s a piece of metal stuch into the fibreglass and with the forces on it at speed and vibrations they do fail (not just on rexes).

I\'ve got flush fitting locking pins that don\'t stand out as much as the \'race car\' style ones and they, imo, look much nicer.

Another thing to take into account is the quality of the bonnet you have fitted.  Mine\'s pretty solid and doesn\'t flex at all (i\'ve had it up to a verified 156mph).  I\'ve been in cars where they do flex a lot at legal speeds and bow a few inches at 120+.  Make sure the bonnet is adequately braced from underneath and isn\'t just a simple sheet of fibreglass!

Iain

[Shyne]

This is not V-Mount specific, but a general weekend warrior trick for removing heat from the engine bay with a stock bonnet, no cutting and not too much effort.

The idea is to use riser blocks (washers on some budgets! lol) on the stock bonnet hinges to raise the rear of the bonnet to allow an increase in flow through the enginebay rather than a collection in it.

I no longer have the stock bonnet so I can\'t look into the possibilities as I think they are stubbed not bolted like most aftermarket versions.

On the Pug we used to race, we used little rubbed knobs, that you put behind house doors to stop them banging on walls, these give you the 20mm to an inch that will allow heat ventilation.

[probedb]

I\'ve got flush fitting locking pins that don\'t stand out as much as the \'race car\' style ones and they, imo, look much nicer.

I\'ve seen these as well, they do look much nicer. I\'ve seen them on a rex that had a carbon fibre boot lid.

[McCARTHY]

air always trys to equilize itself with this in mind a vented bonnett helps creates a lower air pressure behind the intercooler so then when the high pressure air thats hiting the front of the intercooler is sucked through the fins a little quicker thus keeping it a little cooler.

this happens wether you have a vented bonnett or not but having a vented bonnett would just speed up the process a little. I have no idea if it would any significant difference but no cooling is bad cooling