Rob_Mitchell Posted August 7, 2012 Share Posted August 7, 2012 I am still not happy with the ammount of heat trapped under my bonnet. I have bought a DEI turbo blanket off jamie, got some DEI reflect a gold and also panel'd my underneath off with Kevler carbon sheeting. NOW has anyone fitted these? http://www.ebay.co.uk/itm/TEGIWA-BONNET-SPACERS-TOYOTA-SUPRA-TURBO-CELICA-G25-/170572935406?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item27b6f070ee Might held the heat disappear better if the back part of the bonnet is raised cheers Quote Link to comment Share on other sites More sharing options...
st3ven1 Posted August 7, 2012 Share Posted August 7, 2012 They don't actually work the way you hope they would. When stationary they will allow the air to escape out the back of the bonnet, but when you are moving the air deflects off the bonnet and onto the windscreen and actually causes air to swirl round and into the engine bay stopping the air from escaping. Sorry if this isn't the clearest explanation. Basically it doesn't work like you think it would and no car manufacturers would/have integrated this into their bonnet designs. Why would you want to look like a old RS Turbo anyway? Quote Link to comment Share on other sites More sharing options...
listy Posted August 7, 2012 Share Posted August 7, 2012 Do the old cut a vent job on the sides of the bonnet. Could look good with some gold mesh in there Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted August 7, 2012 Share Posted August 7, 2012 Would a vented bonnet not suit your car a bit better Rob? Without extra inlets at the front of the bonnet would you even get an drop in under bonnet temperature without raising the rear substantially? I run my own bonnet raise both front and rear, the original reasons being the stock airbox intake, which I still use with the 1JZ, is right at the front lip and also I thought the NA intake 'Y' pipe might benefit from a flow of cool air over it while the car was in motion. There is a genuine change of airflow with the bonnet in the position I run it in, I know this because I forgot to close the bonnet pins before a few hot laps @ Mondello and the bonnet never stirred from the first latch. Lucky me. Quote Link to comment Share on other sites More sharing options...
Rob_Mitchell Posted August 7, 2012 Author Share Posted August 7, 2012 Why would you want to look like a old RS Turbo anyway? I dont care what it looks like i want to reduce heat under the bonnet and it seems a cheap route to try. Would a vented bonnet not suit your car a bit better Rob?QUOTE] Yeah there is one carbon bonnet i like but at £700 its a fair ammount to fork out. Im very carful now after the doluck bonnet failure and losing out on nearly £1400 Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted August 7, 2012 Share Posted August 7, 2012 Dont do it, for three reasons.. 1. As already explained they dont really work. 2. They detract from the look of the car as it looks like it has a frontal impact. 3. Your bonnet will be raised away from the crash bonnet hooks so in the event of a front end smash (god forbid) your bonnet will turn into a guillotine. If you are still having heat issues then I would use a proper solution such as reflect a gold on the hot spots... Quote Link to comment Share on other sites More sharing options...
Parry_10 Posted August 7, 2012 Share Posted August 7, 2012 custom bonnet vents ftw works a treat and looks good as well Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted August 7, 2012 Share Posted August 7, 2012 custom bonnet vents ftw works a treat and looks good as well Agreed, the amount of heat that comes out of my vents is pretty surprising. When stationary you get wobble vision Quote Link to comment Share on other sites More sharing options...
Noz Posted August 7, 2012 Share Posted August 7, 2012 (edited) Due to the bollocks fitment on my wings I'm raisng my bonnet a tad to get it back in line. You could always get some custom spacers made up? Easy as pie if you know someone with a lathe. Edited August 7, 2012 by Noz (see edit history) Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted August 7, 2012 Share Posted August 7, 2012 Yeah there is one carbon bonnet i like but at £700 its a fair ammount to fork out. Im very carful now after the doluck bonnet failure and losing out on nearly £1400 I would go the cheaper route of a standard bonnet with a few wisely selected, carefully cut vents. I'd be surprised if you didn't have a few ideas for just such a project. Your bonnet will be raised away from the crash bonnet hooks so in the event of a front end smash (god forbid) your bonnet will turn into a guillotine. I lowered the crash hooks by the same amount the the bonnet was raised Rich so they are still effective, safety first! Quote Link to comment Share on other sites More sharing options...
wallis Posted August 7, 2012 Share Posted August 7, 2012 I feel u rob, had loads of issues with the heat from the turbo myself, sorted now but its taken a while!! Vented bonnet, ram air kit and loads of heat shielding! I ended up with a melted acceleration cable that became stuck on full boost, that almost killed me....lol Relocated that with a new cable fitted. Also all the heat matting behind my dash started to melt and drip onto my feet, wrecked a pair of good trainers ;-) As u know though rob a vented bonnet is a show cars nightmare, if I ever get caught out in the rain it takes ne hours to clean the engine bay :-( Quote Link to comment Share on other sites More sharing options...
Rob_Mitchell Posted August 7, 2012 Author Share Posted August 7, 2012 Dont do it, for three reasons.. 1. As already explained they dont really work. 2. They detract from the look of the car as it looks like it has a frontal impact. 3. Your bonnet will be raised away from the crash bonnet hooks so in the event of a front end smash (god forbid) your bonnet will turn into a guillotine. If you are still having heat issues then I would use a proper solution such as reflect a gold on the hot spots... ouch didnt think about that yeah the reflect a gold arrived today, i only need to use it on two areas which concern me, the panels i made have made a huge difference so i think the gold will do the job. custom bonnet vents ftw works a treat and looks good as well No offence but it looks cheap and nasty but thats only my view as i never had liked it. Quote Link to comment Share on other sites More sharing options...
Rob_Mitchell Posted August 7, 2012 Author Share Posted August 7, 2012 I feel u rob, had loads of issues with the heat from the turbo myself, sorted now but its taken a while!! Vented bonnet, ram air kit and loads of heat shielding! I ended up with a melted acceleration cable that became stuck on full boost, that almost killed me....lol Relocated that with a new cable fitted. Also all the heat matting behind my dash started to melt and drip onto my feet, wrecked a pair of good trainers ;-) As u know though rob a vented bonnet is a show cars nightmare, if I ever get caught out in the rain it takes ne hours to clean the engine bay :-( The heat aint that bad lol, i have noticed 3 tiny blisters appear in the bonnet and are soft to touch after a long drive, this has reduced since i fitted the carbon plate but i still need to think of more things plus its fun as i get to use 'reflect a gold' yummy shiney stuff! Quote Link to comment Share on other sites More sharing options...
Parry_10 Posted August 7, 2012 Share Posted August 7, 2012 (edited) No offence but it looks cheap and nasty but thats only my view as i never had liked it. How can you say that when your on about raising your bonnet, now thats cheap and nasty LOL Edited August 7, 2012 by Parry_10 (see edit history) Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted August 7, 2012 Share Posted August 7, 2012 How can you say that when your on about raising your bonnet, now thats cheap and nasty LOL Hey! There are plenty of things cheap and nasty about my Supra but the altitude at which my bonnet sits is not one of them. Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 7, 2012 Share Posted August 7, 2012 The scuttle area is a high pressure region, so it'll push air in rather than vent it out. You need to create a low pressure region instead, so a vent hole on the bonnet pointing towards the windscreen. That'll suck air through the engine bay. Quote Link to comment Share on other sites More sharing options...
safcdixon Posted August 7, 2012 Share Posted August 7, 2012 Bonnet spacers worked imo on my old escort rst but more when sitting still rather than moving and it doesnt look great tbh even on that, have you thought about a removeable cold air feed?, so would cool the turbo side of the bay but could be removed when at shows etc Quote Link to comment Share on other sites More sharing options...
mellonman Posted August 7, 2012 Share Posted August 7, 2012 Rob i have just come up with a genius way of getting nice cold air into the bay just where you want it, But you wont like it one bit as its a hack but you could do a good job of it if you took your time with the correct tools, what i have done is cut away the plate where the stock airbox sat behind the headlight i cut it down 3 sides then bent it down to act as a scoop from where the original side mount intercooler was,i also removed the rear bonnet rubber to let the extra air out more easily.i have also now made a heat sheild also to keep that enginebay heat away from the filter. it works very well indeed as the other day i touched my filter and it was hot to touch which i thought was not good at all so then done my mods after a 45min drive the filter is cold to touch.im very sure people could expand on this idea like even getting a massive hole cutter and put some ducting in there Quote Link to comment Share on other sites More sharing options...
bigbloodyturbo Posted August 7, 2012 Share Posted August 7, 2012 I've noticed this problem aswell and to be honest I think there is only so much you can do with shielding as eventually it will heat soak and you'll be back where you started. When i get round to it I'm going to try some testing with manometers to see where the most viable low pressure area is but the most obvious place I can see now is the front wings, hence why m3's and such like have them there. Quote Link to comment Share on other sites More sharing options...
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