Cost effective ways to reduce under bonnet temps

davekmoore · Postby **davekmoore** » Thu Sep 04, 2014 12:38 am

With all the extra cooling the motor's running cool enough now, even after 30 consecutive laps.

But under-bonnet temps get high enough in traffic and after a track session that there's 70 degrees at the intake, causing unreliable or no idle and, no doubt, loss of power.

Any thoughts on getting these temps down?

Further bonnet venting?

Wrapping parts of the hot side?

Postby **Okibi** » Thu Sep 04, 2014 1:55 am

Dave do you have a few under bonnet shots, might help give some ideas.

Typical things would be, airbox, cermaic coat turbo manifold, heat shield turbo and manifold, bonnet vents and perhaps even reflective wrap on the pipework.

gslender · Postby **gslender** » Thu Sep 04, 2014 7:01 am

Assume A2AIC is just heat soaked. If so, and AIT is mounted into heat soaked IC the. There is t much you can do. More details might help more.

Magpie · Postby **Magpie** » Thu Sep 04, 2014 7:47 am

Here is a good article http://www.autospeed.com.au/cms/article.html?&A=2159

Just adding vents/scoops could make the issue worse. I have noticed a small engine bay temp drop since I covered the hole in the firewall where the mania intake was. The hole is in a high pressure zone and therefore allows more air into the engine bay, increasing its pressure and reducing the pressure drop over the radiator.. Simple.

davekmoore · Postby **davekmoore** » Thu Sep 04, 2014 8:26 am

Ducting is about to go in the foglight holes to feed the brakes and the air filter.

There won't be any further vents added at the front of the car as the fact that there's no overheating of the motor after 30 laps shows there's already more than enough air intake to keep the motor cool despite the presence of air con and a grille to hide the large intercooler.

There's already a hole in the bonnet for a rearward facing vent above the radiator so I've no qualms about further attacks on it (maybe just a mesh above the turbo?).

I'll add some pics tonight.

Magpie · Postby **Magpie** » Thu Sep 04, 2014 8:36 am

Nice. As said by others it sounds like heat soak, hence coatings and wraps may help reduce them.

Brake ducts will do wonders for cooling your brakes.

Threads always go better with pictures.

gslender · Postby **gslender** » Thu Sep 04, 2014 10:09 am

Oh, if idle is poor due to AIT temp problems the the tune is poor. Any decent ECU can tune around that problem.

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sailaholic · Postby **sailaholic** » Thu Sep 04, 2014 12:15 pm

That was my thought also G, but I wasn't sure enough to say it.

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davekmoore · Postby **davekmoore** » Thu Sep 04, 2014 5:01 pm

Yes, this was my final conversation with my (ex) tuner, even though he now works for free. The killer was that for extra under bonnet cooling he also suggested bonnet lifts, as used on all his V8 projects!

Recommendations for a Haltech and MX5 tuner nearest to Mornington Vic who properly understands both?

emily_mx5 · Postby **emily_mx5** » Thu Sep 04, 2014 5:10 pm

Hood risers? Club Roadster spec haha.
There is a great thread on miata turbo about how bad they are.

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kazama · Postby **kazama** » Thu Sep 04, 2014 5:30 pm

bonnet spacers increase under bonnet temps & can cause the bonner to spear through the glass in a frontal collision

davekmoore · Postby **davekmoore** » Thu Sep 04, 2014 6:29 pm

I know, that's why I'm looking for another Haltech tuner.

gslender · Postby **gslender** » Thu Sep 04, 2014 7:29 pm

davekmoore wrote:Yes, this was my final conversation with my (ex) tuner, even though he now works for free. The killer was that for extra under bonnet cooling he also suggested bonnet lifts, as used on all his V8 projects!

Recommendations for a Haltech and MX5 tuner nearest to Mornington Vic who properly understands both?

You shouldn't need to understand the MX5 to tune with an ECU. The tuner can't be that good with Haltech if he can't manage a stable idle (or the ECU is poor).

I'd contact Haltech and explain to them that you're unhappy that the ECU isn't able to accommodate a fuel/spark tune that maintains a stable idle even with various intake temps - anything from 0 deg through to 60 deg would be normal air temps, and so it should idle fine through that range without any "need to cool the air". I'd be surprised if they say "sorry, we can't recommend anyone in VIC who knows how to tune a 4cyl turbo motor".... !!

G

Magpie · Postby **Magpie** » Thu Sep 04, 2014 8:16 pm

for gslender's comments.

Also hood lifts are bad!

greenMachine · Postby **greenMachine** » Thu Sep 04, 2014 8:24 pm

I'm glad to hear about the 'ex' status of the tuner.

Talk to the guy I mentioned in my PM about who he might suggest (though he might be limited in what he can say, for the obvious reason), and be prepared to travel to get the good tuner(s). As you know, my initial tunes were done by someone a 300km drive away in Sydney. In fact Daniel did the last tune at Deckspeed too, after he installed the PS1000 in the racecar. Getting a good tuner is THE best investment, in both performance and longevity, so don't skimp.

And yes, don't even think about raising the rear of the bonnet. If it is breathing hot air, shift the intake to somewhere where it can breathe cool air ...

:mrgreen: