Under bonnet temps

Discussion in 'Mechanical - Engine, Gearbox, Exhaust etc' started by Dave Smith, Apr 25, 2019.

  1. Hello, I have a R26 2008 reg running stock power, mid box chop and a KTR induction kit (after this evening) everything else standard.

    Ive noticed that even after a granny style driving that under the bonnet gets really hot. Now the engine itself seems to be happy operating at these temps and never had a spike on the gauge but im installing a KTR induction kit this evening and would be interested if there was any solutions people had explored to keep it cooler under there.

    Ive seen some lads that have vents installed and they arent particularly to my tastes but i did see a mk3 with a single vent on the bonnet over the intake that looked very well.

    What have people been doing for additional cooling?
     
  2. -Jamie-

    -Jamie- RSM Moderator

    When is it getting hot? Afyer a drive when stationary?


    Lot of these vents that people have fitted are in the completely wrong place tbh [emoji23]
     
  3. It just gets hot from general running. Any car id have before this would have cooled down a good bit before this one. For instance id come home after a 15-20 min journey mainly in traffic and park on the drive. By the time id change, eat and get set up to do some work on the car be about 30-40 mins. Engine still be piping hot. It doesnt affect the running as i said, just now i have the induction kit id like to lower the temps a bit.
     
  4. I've been looking at options on this subject too Dave. I think a turbo blanket/jacket would help. A vent above the turbo, Ive seen a few I like, along the lines of a Mitsubishi evo type or maybe late type fiesta st. If you are going to fit an induction kit it would be a good idea to run pipework/hosing all the way round to behind the headlight to avoid heat. But I'm no expert, just ideas I have been considering

    Geoff
     
  5. Before you start thinking about cutting your bonnet have you actually checked what your intake temperatures are?

    My R26 is running 297/306 with a Ktec induction kit and Forge intercooler and in normal driving my intake temperatures are only ~1-2c above ambient temperature. Even during sprinted driving it doesn't really go up. My coolant and oil temperatures (I've fitted an oil temperature sensor and gauge) also never exceed normal temperatures

    Bonnet vents in the incorrect position can have a negative effect. It seems most people fit them because they 'look good/because racecar' and presume they'll make a positive difference, yet no one seems to have any proof or data to back that up.
     
  6. Totally agree Dale. I think if they were necessary Renault would have used them. Everything on mine is at correct temperature's but when the car is sitting after even normal driving you can see the heat coming from the back of the bonnet. It's unnerving but nothing to worry about possibly?
     
  7. Surely the turbo blanket would make the turbo way too hot and you'll see the effect of that in oil temperature. Then you'll need an oil cooler to solve that problem and if that's the case you may as well dry sump the whole thing
     
  8. Turbo blankets seem to be all the rage at the moment, which I'm sure we will be told that actually the point you've just made is exactly why they are a bad idea.
     
  9. I think you’re worrying over nothing to be honest. The turbo and cat location on these is in a very airflow-restricted area, so that may contribute to there appearing to be a lot of heat given off from around it when stopped, but then Renault have designed it this way. I’d be concerned if your bonnet paint had started to melt above it, or other local components were being scorched, but I don’t think this is the case.

    Turbo blankets are more for the protection of things that are close by, on cars running more boost, and therefore generating more heat. Putting a blanket on will not make the turbo noticeably hotter, as the air around it isn’t contributing to much of the cooling of it (the engine coolant flowing through it is doing the work here). Under-bonnet temps will always be perceived to be worse at standstill, but remember that when moving that there is a good flow of fresh air moving the hot air out of the back.


    Sent from my iPhone using Tapatalk
     
  10. Oh is the turbo water cooled on the Mk2 and Mk3?
     
  11. Yes it is, or at least the core is
     
    Meg16_Beth likes this.
  12. have you tried removing the long rubber bonnet seal, that'll let hot air out when at standstill and shit load when moving
     

    Attached Files:


  • Share This Page