FMIC and now its too bloody hot under the bonnet

Oil and water temps are showing the car is way too toasty in this weather . Haven't plugged in charge temp sensor yet (am afraid to).

I think the following are my options...

1) Lag downpipe (H&S 3") - especially as its v. close to oil pipe
2) Remake air ducts from bumper to rad for better airflow
3) Cover up holes for induction pipes in undertray (similar reason to above)
4) Bigger water/oil rad?
5) Insulate manifold/turbo somehow (I believe lagging manifold shortens life somewhat?)
6) Erm...
7) ... thats all I can think of

Doesn't seem too promising... anyone got any better ideas?

Cheers,
Mark

what sort of temp are ypu running?
sometimes an intercooler can disrupt the airflow to the rad

More than I used to

Even on mway its a couple of degrees higher and tarting around at constant 40ish its 80+ and 90+ within a minute of idling. And the heatsoak into the induction pathway is shocking (think I need to lag those pipes as well)

Drive round with the heating on full

Lose the undertray?

Has anybody ever had any problems caused by having no undertray?

My car has never had one and runs nice and cool all the time, fans only ever come on in traffic jams. Also, my air filter is low down on the end of a SIP getting fresh cold air which probably helps.

I put a new rad on my car after I had fitted the FMIC as my water temps had risen noticably.

Never noticed a difference after fitting a FMIC, maybe your rad needs replacing or the thermostat is dodgy?

Are you using really thick oil?

Mine runs a bit hotter with 10W50 in than it does with 10W40.

Would do that but the leccy windows have packed up

Not quite sure if the undertray helps or hinders cooling - certainly helps aerodynamics tho. Have tried it both ways and haven't noticed a difference at medium speeds. However, having one stops me worrying about getting stones in the timing belt etc.

Re. oil - am using bog standard 10/40 atm.

Maybe new rad or bigger alu rads is the way to go (except when they crack).

Mark

New OE rad or bigger 'un?

Mark

New OE, helped temps a lot - and I still run an undertray

You can't fit a bigger rad - there is no space. If the standard rad is more that 3 years old I would replace it anyway.

I have a pro alloy rad - which are expensive (and not a whole lot better on the road IMO, though they dont wear out in theory), and I still have high temps when standing as I have a whacking great FMIC which restricts the air flow to the rad. when moving this is not an issue though.

Are you sure that your fans are kicking in properly? There should be a low speed, and a high speed fan - if either is knackered then your temps will rocket. Leave the car at idle and listen for both. Low speed will kick in first and then the higher speed when the temps are up near 100.

near the top of the rad there is a plastic housing for a rheostat which governs the switches (green tube about 2 cms long). The connections on this corrode and it can fall out (I found mine traped in the heatshield).

If you have aircon the putting it on will assist keeping the temps down.

You can also rig up a switch to override the high speed fan, a few minutes on over-ride will bring the temps back down. I wrote a guide for this which is in the how to section - though you have to have an aircon car for it to work....takes about 15 mins to do when you know the right wire to splice into.

Thanks for the info Mike - might have to do that (its lost a lit of wiggles anyhow)

Thanks for the info on the pro-alloy Simon - looks like I won't be getting one of these then!

Defo not the fans - had the resistor on these blow once before when driving (then) new gf back home, good thing I could use her AA membership - btw IIRC there's a relay which can trigger them on the non-aircon cars at least. Also the FMIC shouldn't really affect idle temps much with either fans on/off unless there's significant heat-soak in the IC...

So I'm thinking back to better insulation on downpipe/manifold/turbo (anyone tried this?) then sorting out the airflow. Thanks for the replies ppl, will post back if I find anything interesting.

not quite true re heatsoak. What happens is when you are sitting in traffic the heat cannot easily escape out the front as it would normally do as there is a huge intercooler in the way.
The radiators become massively less efficient with age as Suba says. I think on the original FMIC guide I wrote that it was important to replace the radiator if it wasn't in tip-top condition and also recommended putting water wetter or a more advanced coolant in. Most people mix coolants (or coolant brands if you like) which is not actually great for cooling as they often are not compatible with each other and the net result is less efficient.
Also if your thermostat is in poor nick it won't help and could actually cause the problem

In terms of better insulation you could wrap the downpipe but the OE downpipe was already designed to provide some protection which is why it is double-walled. If you wrap the manifold it will inevitably accelerate its demise as what you are doing is basically making a layer of uneven heat distribution. You can fit a pusher fan between the intercooler and rad - this works well and could get it to kick in earlier with a thermostatic switch. My fans kick in some way below 90.

Have you chhecked that the FMIC actually allows the air through to the radiator? Not so stupid as that sounds, my first FMIC was more effective as a radiator blind

I have had the same setup for over a year but recently I have seen the rise in water temp on my car especially in traffic. All my parts are near enough new so I am putting it down to the high ambient.

Cheers John - new radiator is on list now. Flushing coolant and putting in water wetter isn't a bad idea either!

But thats not going to stop heatsoak in induction system - wrapping downpipe (its H&S so also is damn near oil pipe) maybe jacket for turbo and something better than the manifold heatshield and insulating the pipes can't hurt.

I do like the sound of more/uprated fans tho...

Reasonably chunky evo8 one... so its blocking quite a lot... about 2x more than the heat exchanger for the charge cooler that was there before. Thing is I also removed the 'ducting' that Fiat put there to direct flow to the radiator... so there might be a lot of air going through the engine bay barely touching the sides!

With all of that air flow entering the engine bay from the front, where does it leave?

Like always it just flows from high pressure areas to low

Back of envelope figures and you'd need (very!) roughly a cubic meter of air per second through the radiator to keep it kewl just tootling around - this must primarily flow from the middle of the bumper through to the underside (i.e. thru the slots/spaces in the undertray).

Manufacturers spend a lot of time and money making sure this stuff works then we dick around with it in blessed ignorance of the effects

Nah.....Italians make a car in this order:

1. Let's make it pretty.
2. Let's make it go fast.
3. Lets stuff a load of wires in to make the electrics work as best we can. This is boring, so we wont spend much time on it.

I'm sure that airflow to the rad featured somewhere in those plans....

Trevor - how would you go about testing that?

Where is that though?

Does the air exit at the back of the engine bay and go over the car, or underneath, or at the side?

Maybe if the flow of air is so bad it's because it cant get out, rather than in?

Like I mentioned "this must primarily flow from the middle of the bumper through to the underside" - these are the available high low pressure zones.



Sure - its the pressure differential that matters (air can't get out and you have a pressure buildup inside the engine bay)... along with any resistance and making sure the air goes where you want it to along the way

the best interoolers are designed with the fins at an angle so that they are in direct contact with as much air as possible as it passes through. That has the effect of reducing the amount of air going to the radiator as Trevor says. When I first tested using an Evo-style FMIC I started by using a cardboard mock up that basically was the same size (to check it fitted) and blocked half of the rad as I sssumed that would be the impact of the intercooler on the airflow.

If you want to buy a shield for the turbo the best ones are the blanket style ones - horsepower in a box sell them as do Owen Devs in the UK. Downpipe can be also wrapped and both should give you a modest improvement in power as the extra heat improves the exhaust gas speed. Only downside is that turbine housings do warp and the GT28xx series turbos are not immune from this.

I have used the turbo blanket and heat wrapped the manifold, turbo and downpipe but I still have high temps in this summer traffic. There is a 2 inch gap between the rad and intercooler and I don’t get cooling problems in the winter.

Here is the link to the cheapest kit in the UK that I used:
http://www.jdmperformance.co.uk/item_detail.php?prodID=449007023

Here are a few pics:
http://img233.imageshack.us/my.php?image=dsc00631pr5.jpg
http://img233.imageshack.us/my.php?image=dsc00632rq1.jpg
http://img181.imageshack.us/my.php?image=dsc00635al6.jpg

I am now gonna try some water wetter since I got it for £6 but I think it isn’t gonna do jack. The point is summer is here so I wouldn’t worry too much if you have the same problem in the winter then you have a problem. My PC and cable box are also over heating too

Well the push fan I have fits in that 2" gap (won't work on aircon cars though) - I think it is about 50 quid for a 14" pusher fan

I already have an uprated fan but it just stays on a bit longer in this hot weather that’s all.

In the past few weeks, you would have been lucky to have seen ambient temperatures above 20 degrees C! How do people in Dubai / UAE cope with ambient temperatures above 40 degrees?