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Thread: Intake and Boost Temperature

  1. #1

    Default Intake and Boost Temperature

    Hi there,

    Has anyone with diagnostic tools done much monitoring of temperatures they could share? Looking at the change once installing of an upgraded TMIC or FMIC on boost temp and intake temp? WI or MI? Would be good to see real world data and see the actual efficiency gains.

    I have a FMIC but dont have a baseline from stock temps to compare to!

    I reckon Matt will have some good input on this one? Any info or discussion on this would be great.

    Cheers
    Sam
    Last edited by damsicko; 28-01-2009 at 11:04 AM. Reason: spelling

  2. #2
    Join Date
    Dec 2008
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    Sydney
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    49
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    1,834

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    Picking on me again Sam....
    OK heres my observations after fitting my FMIC, I usually have the Dashhawk showing IAT & BAT temps,

    Lets start with the stock top mount, aside from the fairly large pressure drop (4psi) across the core (Ill address this issue in a moment), this intercooler works very well....as long as you are moving with clean air ahead of you.

    I have seen differences of only about +10 degrees even when getting up the car, however as soon as you stop for extended periods, thats when it all falls to bits, the core heats up very quickly, and you can see BATs around 90ºC sitting in traffic on a hot day, the hot air forces the car to retard timing and this causes a very flat feeling on acceleration, there is nothing worse than booting it expecting the usual surge of power and getting a very flat feeling engine ( it feels like your taking off in second gear), especially if your trying to get into the faster lane with a truck bearing down on you.

    Now the pressure drop issue, the stock core loses 4psi in transferring the air from the turbo outlet to the inlet manifold, this is done to "hold" the air in the IC tank for a longer period allowing greater heat transfer to occur, the downside is that to produce 15.7 psi at the manifold, the turbo needs to produce 19.7 psi at the compressor wheel, the more you compress air the hotter it gets, the harder the turbo works to produce this air, and it is also very near the ceiling of the turbos efficiency (~21psi), also the boost spikes with the top mount (I have seen this reach ~22 psi at the manifold) is just blowing insanely hot air through an already hot intercooler.

    The stock core also takes a long time to cool down, I have seen elevated boost temps for some time after driving in clean air, the whole time your BATs are high the car will be pulling timing to compensate.

    Now for the cp-e FMIC comparison, now everyone knows I am a cp-e fan, but any aftermarket IC will give improvements over the stock.....even TXS (there...I said it)

    After fitting the cp-e kit, the first thing I noticed was the car just felt a lot smoother, there was definitely a little more lag there (not much, but enough to notice).
    Anyone who tells you there is absolutely no extra lag with an FMIC is full of sh!t, you are taking a very short path of air from the stock setup and replumbing it half way around the engine bay and back again, you are also filling a larger core volume with air, so lag is going to happen, even an upgraded TMIC will have a little more lag, this would probably be minimal as its just the larger core capacity that the turbo is filling.
    The upside to the lag is the top end of the rev range is opened up a lot more, the car isnt choking at high revs like it did before, it also feels a lot stronger the more time it is on boost, you can feel the power lasting a lot longer on a long boost run, rather than falling off as the intercoolers efficiency drops.
    There are also no where near the boost spikes as with the TMIC setup, my boost gauge has a peak hold feature, and I really dont think Ive seen this peak at over 18 psi, incidentally the cp-e FMIC boasts a mere 2psi pressure drop, so the turbo isnt struggling to meet its 15.7 target, the first time I opened the car up in 5th gear the boost gauge was fluctuating between 15.7 and 16.2 psi, you could tell the wastegate was controlling the boost, rather than the car struggling to hit its quota.

    Getting back to the point of temps & efficiency, the FMIC cools down so much quicker than the TMIC, it shocked me the first time I tested it, I was on the freeway and cruising along in 6th gear, as I approached a hill I accelerated (as you do), as the car came on boost I was watching the Dashhawk, the IATs were around the mid 20’s the BATs were in the low-mid 40s, as the boost rose the BATs were dropping in 2ºc increments on the dashhawk, and settled in the high 20’s, the stock top mount had never been that fast to react, or drop that close to the IATs before.
    What a lot of people also dont realise is that an FMIC will still heat up quite a bit when sitting around in traffic, an intercooler only really work when there is boost travelling through it, so sitting around at idle the IC is outside the lower end of its efficiency range as well, it just doesnt have the heat of an engine / turbo / exhaust adding to it.

    Another point to consider is the common mistake of "How much power will brand x intercooler give me", dont be fooled by people advertising ridiculous power gains just from an intercooler kit.
    An aftermarket intercooler will hold the available power better and longer than the stock item, the car will not retard timing and will benefit from the cooler, denser charge, and will allow you to run more boost if you tune for it (as you arent hitting the efficiency ceiling of the turbo).
    But the turbo will still only produce 15.7 psi, and the engine will only ingest so much air, the intercooler will just work more efficiently at cooling that air, so dont expect your $1500-$2000 FMIC kit to produce bulk horsepower.
    I have also noticed lower fuel consumption since fitting the FMIC, doing a fair bit of traffic driving I think the TMIC was suffering, and the ECU was compensating with timing, and richer fuel (to cool the combustion chambers).

    The next item Sam mentioned was water/meth injection, I have a kit at home, but havent installed it yet, but others using these systems are seeing BATs at, or below their IATs, these results are even reported from people using TMICs.
    It is a very popular mod in the US, you can tune for it and get some very impressive results (methanol increases the octane, or knock resistance of fuel, so you can advance your timing, lots) although if your pump or nozzle die in the middle of a run you can kiss your rods, block, pistons (all the expensive bits) etc goodbye.

    There is a lot of discussion regarding water/meth on the MazdaSpeed Forums for those interested in doing a bit more reading on the topic.

    I think that about covers it.

  3. #3
    Join Date
    Nov 2008
    Location
    NSW
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    Thanks for the input Matt, great write up.

  4. #4

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    Thanks Matt - really useful. Would love to see once youve installed the meth kit.

    Cheers
    Sam

  5. #5
    Join Date
    Nov 2008
    Location
    Narellan, NSW
    Age
    36
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    624

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    Very thorough write-up there Matt! Hope to have a FMIC on mine within the next couple of months (after a CDFP upgrade & tune)

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