TommyC 33 Report post Posted November 15, 2017 Having watched many videos on Forced Induction for the GT86/BRZ, many (specifically the big power builds) complain of under bonnet temperatures causing significant issues (especially when the heat has 'soaked in'). I'm curious that there aren't many fixes for this talked about. Bonnet Hinge Spacers have at times been a common mod in certain circles (even for those just wanting a 'Motorsport' look). I'd have thought these to have been one of the first things attempted?! Another thought is to put some effort into making the front wing 'vents' actually work. I know this would mean cutting holes in the wing panels behind the 'trim' pieces etc but if thought through and designed well, could they extract a decent amount of heat/induce enough additional airflow at speed to make a suitable difference? (I know a bit about fluid/airflow from work, but these are just my idle thoughts) Share this post Link to post Share on other sites
Kodename47 446 Report post Posted November 16, 2017 http://www.ft86speedfactory.com/velox-slanted-hood-louver-vents-kit-2013-ft86.html http://www.86worx.com/beatrush-underpanel.html The back end of the bonnet is at incorrect pressure for getting air out. Side vent would work, but a lot of effort and very few actually are vented. What specifically are you trying to resolve? Oil/Coolant/just the fact it feels warm? Also setup will play a big factor, exposed manifolds, turbo etc. 1 TommyC reacted to this Share this post Link to post Share on other sites
Church 209 Report post Posted November 16, 2017 IIRC front wing vents do work a bit (if modded to functional ones, by installing mesh and cutting out fenders a bit), but very slightly, as at that place there is not big pressure difference. One is much better off installing hood vents for that reason, as there is more of pressure difference / more effective air evacuation, thus better air evacuation for lower underbonnet temps & a bit downforce. But imho it should be enough to add oil cooler to heavily tracked or high power FI builds. 1 TommyC reacted to this Share this post Link to post Share on other sites
Mark-in-Stoke 488 Report post Posted November 16, 2017 A few more options https://www.oldhallperformance.com/heatshield-products/thermal-barriers 1 Lowe reacted to this Share this post Link to post Share on other sites
TommyC 33 Report post Posted November 16, 2017 8 hours ago, knightryder said: http://www.ft86speedfactory.com/velox-slanted-hood-louver-vents-kit-2013-ft86.html http://www.86worx.com/beatrush-underpanel.html The back end of the bonnet is at incorrect pressure for getting air out. Side vent would work, but a lot of effort and very few actually are vented. What specifically are you trying to resolve? Oil/Coolant/just the fact it feels warm? Also setup will play a big factor, exposed manifolds, turbo etc. Just trying to explore a solution to a problem. I've not exactly experienced it but I'm just trying to understand/discuss solutions to an apparently common problem. I would like to go FI in the future but this depends on a number of things and is likely to be years away, if it happens at all. I understand what you say about the pressure at the back of the bonnet, but if there was enough of a pressure drop/draw, at speed, at the vents then flow would still be achieved?! Also I generally prefer function over form (but not exclusively). It's always slightly bothered me that the side vents are purely cosmetic... Share this post Link to post Share on other sites
Deacon 1357 Report post Posted November 16, 2017 15 minutes ago, TommyC said: Just trying to explore a solution to a problem. I've not exactly experienced it but I'm just trying to understand/discuss solutions to an apparently common problem. I would like to go FI in the future but this depends on a number of things and is likely to be years away, if it happens at all. I understand what you say about the pressure at the back of the bonnet, but if there was enough of a pressure drop/draw, at speed, at the vents then flow would still be achieved?! Also I generally prefer function over form (but not exclusively). It's always slightly bothered me that the side vents are purely cosmetic... If you're not going to be fi for quite some time I wouldn't worry about it as it's not really necessary for na. If you intend to track a lot an oil cooler of some type would be a good idea as the engine temperatures really climb on track and lead to quite a drop in oil pressure. 1 TommyC reacted to this Share this post Link to post Share on other sites
Church 209 Report post Posted November 16, 2017 Forced induction intercooler usually comes in front of main rad just behind front grill anyway, doesn't it? And even if not FI, stock air intake is cold air intake, whose inlet/snorkel is before engine compartment, above crashbeam. Vents may help lowering underbonnet temps, but how much they matter for moving car? How much actually gets heatsoaken with air passing at big flow speeds through plastic tubes? Imho not enough to care much about it. Main cooling also has more capabilities and is not limiting factor. There is thermostat in coolant loop and electronic regulation to electric fan, if needed to be it can stay longer spinning and get more out of existing cooling system/capabilities. But oil temps often get on the high side on our cars. Often even if iddling in traffic standstill or if tracked in hot summer day. So for extra engine reliability/longetivity it's oil rad that i'd add to more heavily used car (track and/or FI). If i'd think of adding vents .. they would come after oil rad, after oil catchcan, after stronger engine internals. And vents in fender after hood's vents. BTW, my own choice would be leaving all those mods for later if not abandoning them at all .. but rather spend that money on actually tracking car and/or maybe some slight suspension/tires/brakes upgrade. You'll spend less, spend on actually having fun, and you'll gradually upgrade main part of them all - yourself as a driver. 1 TommyC reacted to this Share this post Link to post Share on other sites
Bfranklyn86 52 Report post Posted November 16, 2017 As an FI owner, I only ever had a minor issue with oil temps on a very hot day on track. Then I bought an oil cooler and it was fine. Ive never had a problem with charge air temps (I.e power loss) or coolant temps even on hot days. I think it’s quite dependant on the FI kit too - traditionally (looking at FT86) it has been the turbo guys who have struggled. I also remember Cosworth’s Matt saying his one heat management mod would be the Beatrush undertray. Share this post Link to post Share on other sites
