Guide; FMIC Theory

[Dum-Dum]

An In Depth Look at FMICs (Front Mounted Intercoolers)

I am writing this guide to help people build themselves the best FMIC set up they can whatever their budget or requirements.

The most important question that will be asked is â??Why would I want a FMIC?â?

Well, Intercoolers are fitted to turbocharged and supercharged cars because when air is compressed it creates heat, this is worse on turbo cars because not only do you have heat from the compression but also heat soak from the exhaust that the turbo is bolted directly to. The intercooler cools this air back to a much more reasonable temperature.

Cold air is denser than warm air and so contains more oxygen, more oxygen means more power and more power is what we all want, right?

It is reckoned that for every 100*F drop in temp of the air entering engine your car will produce 10% more power. This is why your car feels faster on a freezing winters night compared to a scorching summers afternoon.

A lot of cars, vans and trucks come with intercoolers as standard. The 306 1.9TD has a Top Mounted Intercooler (TIMC) as standard but these are not very efficient because of their small size, poor standard air flow to them and the fact that theyâ??re mounted about 6 inches above the mega hot exhaust manifold and turbo meaning that a lot of people on the forums refer to them as inter warmers. It is not unknown for people on here to pack the TMICs with ice before going for a blast on a hot day and this is said to see good gains. 306 HDis do not have any sort of intercooling fitted as standard as Peugeot felt it was not necessary and with standard turbos and engines lasting well past 150,000 miles Iâ??d say they were probably right.

Most Peugeot 406 Diesels, weather HDi or XUD came fitted with intercoolers as standard. The coolers themselves are either not very efficient or just too small for a performance 306 application. The piping on the other hand is very useful for those that want to intercool their 306. For the XUD you want to get the whole inlet manifold, the manifold adaptor and all the piping. For the HDi you want to get the metal L shaped bend that bolts to them manifold and EGR pipe (2 x 13mm nuts and 2 x 5mm allen key bolts) and all the pipes.




So how do we make the system efficient?
What you need to bear in mind is that adding a FMIC system to your 306 WILL cause increased turbo lag. Weather or not youâ??ll notice this lag will partly depend on you but mainly on how your system is designed.

You have gotta remember to remember that the boost pressure, between the turbos exit and the inlet valves in the head, will be roughly equal across the entire length of the air piping. The more volume there is to this piping then the more time it will take for the turbo to fill it with air to the desired pressure.

With this in mind youâ??ll want the piping route as short as possible between the turbos exit and the inlet manifold youâ??ll also now be thinking that you need small diameter pipe and a small FMIC to keep the pressurised volume small and youâ??d be right.

BUT

Small pipes are a restriction and small FMICs do not cool as well as large ones.

This is where our dilemma comes in and this is why you need to think about all the parts your using and how theyâ??ll affect the air temperature and air flow. You need to think about what you want from your system. Are you the sort of driver that never goes past 3000rpm and only adding the FMIC to give a cleaner burn to your fuel and so better fuel economy? Are you FMICing the car as part of your route to a 250bhp track monster thatâ??ll eat GTi6s for breakfast or are you, like most people, looking for something roughly in the middle of these two scenarios.


Here I have a comparison of the same car with 2 different intercooler set ups. On the 165.1bhp run the car was using water/methanol injection. Its power without this was 161.4bhp and 276lb/ft.
Set up 1 is a Jaguar X-type diesel FMIC, it is quite small in size and comes with 2� outlets, the rest of the pipes are made of 2� stainless steel.
Set up 2 is a Massive (600mm x 300mm x 76mm) universal FMIC with 2.5� stainless steel piping
I donâ??t have a direct comparison of set up 1 vs set up 2 but you can see from the graphs (both the 3 actual graphs and my poor attempt at overlaying) that just swapping FMICs and pipes has gained 6.7bhp and 18lb/ft but the increase in lag on set up 2 means the power doesnâ??t come in till 100-200rpm later.












Your Choices.
New Universal intercooler or used OEM one. There are some very good intercoolers on standard cars out there that you can find in scrap yards for very little money. A lot of turbocharged vans and 4x4s have good sized ones. Iâ??ve used one off an Iveco daily van and a Jaguar X-Type diesel. The X-Type one was nearly new and cost me just £12 off eBay. The other bonus of OEM ones is that they often come with hoses that point backwards and not out to the side saving you the cost of 2 90* silicone bends. New universal ones have bonuses in that they wont be full of oil and dust and that they will be all welded metal rather than having plastic end tanks just clipped on. They also tend to be more efficient and it is a lot easier to find a monster aftermarket intercooler than it is finding a monster OEM one thatâ??ll actually fit between the headlights.

2â? (51mm), 2.25â? (57mm), 2.5â? (63mm) or bigger piping. It is a heck of a lot easier to route smaller piping than larger stuff. You would be amazed at how easy it is to pipe up a 2â? system compared to a 2.5â? system. The bigger your pipes the more youâ??ll need to notch your chassis legs. Bigger piping is also substantially more expensive (go check the price difference between 2â? and 2.5â? stainless on an exhaust site). However if you want to run big power then you need to run big piping.

Single Pass or Twin Pass FMIC. A single pass FMIC tends to have a port at each side. The air goes in one side, passes through and goes out the other side. With a twin pass FMIC the air goes in one side, passes through the intercooler, is turned around inside the intercooler, passes back across the intercooler and goes back out a different port but on the same side it went in at. This sounds complicated but isnâ??t really if you think about it as 2 small intercoolers one above the other with a pipe connecting the 2 together at one side. Twin pass intercoolers are more expensive and harder to come by but can save a lot of hassle in fitting as there is more space around the radiator on the near side of the car and if your keeping your air con its almost impossible to fit a pipe round the off side. If you want a twin pass set up but without the cost you can use a silicone u-bend on one side of your single pass and then a long bit of straight pipe to run it back to the other side of the cooler like my current set up uses to avoid the air con system.

Pipe Material. The common ones are either ally pipe that you will get with some FMIC kits or Stainless steel pipe that is more commonly used in exhaust building. It is often easier to get stainless steel welded than ally and it can also be cheaper as well as being stronger if your likely to hit it on speed humps or road debris. As well as the stainless and ally you can also use the plastic intercooler pipes off other cars, If you can find ones the right size as cutting them tends to substantially weaken them, also if theyâ??re off a petrol car they may not like the 15-30psi that your about to try and stuff through them. That said they can be a great money saver on a low budget FMIC set up.

Fans. The standard fans on a 306 are quite large and need to be removed to make way for the FMIC. The commonly accepted thing to do is to fit some aftermarket slim line fans. The sizes and weather you run one or 2 fans is up to you (and is a whole massive choice in itself) but generally the sizes are 8â?, 10â?, 12â?, 14â? and 16â?. The most powerful set ups you can fit are either 2 x 12â? fans or a single 16â? fans. However, some people chose not to fit any fans at all. Well when was the last time you heard yours run? If youâ??re a HDi owner the chances are never because they donâ??t come on till 96*C and a healthy HDi will just not get that hot. But its nice to have a safety net say you get stuck in a traffic jam on a scorching day in the middle of the summer and you want to keep youâ??re A/C on.


Other work while itâ??s apart. So while your adding shiny bits to the car do you have some spare time or spare money to get some other bits done. Have you considered properly blanking the EGR system by having the port on the manifold welded over (picture below) and fitting a blanking plate to the exhaust manifold (available from eBay yet again). You may also want to use a sanding or grinding wheel in a drill to port out or gasket match certain metal pipes like the inlet manifold on an XUD or the L-Bend on the HDi (pictured below)




Budget. This is quite possibly the most important consideration in any FMIC set up. I wholeheartedly believe that it is possible to FMIC a 306 for under £100 if you run without fans or can find a second hand one. However you will find that most people spend around the £300 mark. If you want to pay someone to do it for you youâ??ll be looking at £600 to £1000.

For the £100 set up youâ??ll be looking to get an OEM cooler like the ones in reference images for £30 or less. Youâ??ll then need to visit a lot of scrap yards and think very hard about the intercooler pipes your picking up, 90* hose bends are the difficult ones to get and usually a scrap yard will want £5-£10 a hose, a tip is to leave the joiner on the end of the hose and hope they price it as one item. Try visiting your local custom exhaust place and seeing if they have any off cuts of stainless pipe they will give you, maybe in exchange for a few beer tokens. While your rummaging through scrap bins try and get some metal strip for mounting the FMIC but donâ??t worry, you can mount them with cable ties if theyâ??re light weight. When you remove the standard fans unbolt the fans from the plastic frame work and this will give you some nuts and bolts.








Some hints.
- Try and avoid changing pipe sizes up and down all the way through. Pick the size your gonna use and stick with it as far as possible.
- The most efficient way to mount the FMIC is with the outlets at the bottom because as we all know warm air rises so this extra bit of efficiency means youâ??ll only get the coolest air out your cooler.
- If you have air con and it doesnâ??t work or you donâ??t want it then get rid of it. Itâ??ll make it a lot easier to keep your pipe routing short.
- Gradual bends and increases in size are the best for air flow so on the HDi swap the 406 HDi plastic pipe from the turbo that has big jumps in size and some very tight bends for the one off some Citroen C5s that has a gradual increase in size.
- When mounting your FMIC try to have it leaning forward from the top by 1-28 off vertical as this is said to improve air flow.
- When considering a whacking great FMIC think about how your going to feed it with air, remember that if it doesnâ??t have direct air flow then it wont be doing a lot of cooling and the â??mouthâ?? on standard 306 front bumpers is quite small. You might be better off saving your money and just getting one thatâ??s a little larger than the â??mouthâ?? in the bumper.





How to stop boost blowing pipes off.
First and most importantly is use good quality hose clamps. If you try and make do with cheap jubilee clips youâ??ll end up buying better ones soon after so theyâ??re a false economy. Get on eBay and buy a big bag of â??Mikalor styleâ?? clamps that will not break. They will crush your boost pipes before you snap them.
Second is making sure that your silicone hose has something to grip onto, not just shiny smooth pipes. If your using thin ally pipes then youâ??ll want to make a pipe beader like the one shown below or if youâ??ve got the skills get a bead of weld put around the outside. If your using stainless steel exhaust pipe then the easiest thing to do is to run a couple of rings around the end with an angle grinder as shown below.









My Current set up
I have fitted a lot of 306s with FMICs now and think that I have just about built myself the perfect set up for just above average power. It uses a medium cooler, 57mm (2.25�) piping and optimised parts. It has been proved on a dyno to be making very good power.






Parts List
Medium FMIC Kit with 57mm piping â?? eBay £149.99
2 x 12â? slim line fans â?? eBay £36.99
4 x Smaller hose clamps for turbo â?? eBay £5.99
40mm 90* Silicone bend for turbo â?? eBay £8.32
57mm 45* Silicone bend for inlet â?? eBay £13.97
57mm 180* Silicone bend for FMIC return â?? eBay £13.97
3 x 57mm 90* Silicone bends â?? eBay £41.91
Exhaust Manifold EGR plate â?? eBay £4.50
Welding EGR blank £40
Welding 2 Pipes together £30
Peugeot New Inlet L-Bent £70.13
Peugeot New Gasket for above £0.40
Peugeot New C5 turbo Pipe £35.52
TOTAL £451.69


I wonâ??t include the pipe beader in my FMIC costings as itâ??s a tool I will use many times in the future.
Vice Grips to make Pipe Beader £27
Welding / Fabrication for Pipe Beader £50
TOTAL £77






Reference images.
All these images are my own but hopefully will let you all see what can be done and what it will cost

Jaguar X-Type 2.0 Diesel, cost me £12





Iveco Daily FMIC, cost about £40




Monster Universal FMIC, cost £110 new. Was so large that when fitted it touched both headlights. Core Size of 600mm x 300mm x 76mm





Medium Universal FMIC, Cost £150 with a universal piping kit.

[Pugmarshall]

A great guide/explanation Dum-Dum

In theory HDi's don't run intercoolers because they're common rail so they are more efficient/produce less heat, just incase anyone wanted to know?

[Moonstone2.0]

great guide! will refer to it next year

[jo3]

great guide for this its helping me quite a lot, but due to the fact the peugeot garage in my area... (for anyone in portsmouth area knows perrys) the parts bloke is the most useless c*** ever. if its not on hes screen it doesnt have it you could be holding it in front of hes eyes and he will tell you no.

anyway lol do you have part numbers for:

Peugeot New Inlet L-Bent £70.13
Peugeot New Gasket for above £0.40
Peugeot New C5 turbo Pipe £35.52

just to make it a bit easyer i tryed looking on the service box but cant seem to get on it, if not i will hunt around on a c5 and see if i find one.

[Dum-Dum]

great guide for this its helping me quite a lot, but due to the fact the peugeot garage in my area... (for anyone in portsmouth area knows perrys) the parts bloke is the most useless c*** ever. if its not on hes screen it doesnt have it you could be holding it in front of hes eyes and he will tell you no.

anyway lol do you have part numbers for:

Peugeot New Inlet L-Bent £70.13
Peugeot New Gasket for above £0.40
Peugeot New C5 turbo Pipe £35.52

just to make it a bit easyer i tryed looking on the service box but cant seem to get on it, if not i will hunt around on a c5 and see if i find one.

If thyer not in one of my other guides then no but ill dig them out of service box if you pm me.

Oh if your coming up to ace cafe ill sell you 2 of the gaskets for 50p

[maguire1992]

Does the turbo pipe of a 406 do the same job as one of a c5??

[vlj]

Does the turbo pipe of a 406 do the same job as one of a c5??

Yes, just a mildly different design

[maguire1992]

Oh ok thanks

[JJtheHITMAN]

If i get a complete intercooler setup off a 406 would that fit straight on mine?

[silverzx]

If i get a complete intercooler setup off a 406 would that fit straight on mine?

It's not worth the hassle. They're designed for an engine running 110 bhp..

[Rippthrough]

To be honest, when it comes to the pipework, you're better with the bigger intercooler and smaller pipework, I'd bet 95% of the people on here don't need anything more than 2" intake pipework.

[silverzx]

2" worked fine on my HDi, 2.5" was a ball ache on my XUD. 2.25" is what I've settled with as its the same size as the Xantia inlet.

[JJtheHITMAN]

Would the pipework suffice? I was contemplating getting the whole setup and modifying it to take a reasonable sized frontmount?

[Skinner]

So what do you actually need intercooler universal pipes 406 L piece and c5 bottom pipe and in simple terms where does the L piece bolt to and where does the bottom pipe go to I know it makes me sound daft asking this just want to know

[Dum-Dum]

It largely depends on what intercooler you use and how you want to run the pipes but the l bend bolts to the inlet manifold and the lower pipe attaches to the turbo via a silicone joiner.

[padge]

chris, how did you make that pipe beader?

---

http://www.youtube.com/watch?v=JVDUM2ZxoW0

[DeeTurbo]

Out of interest do you know if on a stage 2 you get better MPG on long motorway run compared to a stage 1?

[mcglynn]

in theory it should be, as you have more torque. In reality it will probably use the same amount of fuel

[SupaStar88]

any other pics of this mate? I've one to install :/ lol

[Kcbhoy111846]

An In Depth Look at FMICs (Front Mounted Intercoolers)

I am writing this guide to help people build themselves the best FMIC set up they can whatever their budget or requirements.



Most Peugeot 406 Diesels, weather HDi or XUD came fitted with intercoolers as standard. The coolers themselves are either not very efficient or just too small for a performance 306 application. The piping on the other hand is very useful for those that want to intercool their 306. For the XUD you want to get the whole inlet manifold, the manifold adaptor and all the piping.

sorry for stupid questions but im currently doing a bit of reserch on a fmic but every time see a vid or guide everyone says you need diffrent things and not alot of info for xud . for xud is it a 406 inlet manifold and manifold adaptor . what else is needed for xud exept the obvious fmic, piping , and fans any help is muchly appreciated . great guide btw

[Paul_13]

406 inlet you don't need a manifold adapter. The manifold adapter is needed when you have the 306 inlet with TMIC