Hello there,

Has anybody mounted a FMIC and SMIC together on a 1.8T engine? If so, did you encounter any pressure drop? I would like an objective feedback.

Thank you.

why dont you mount one on the roof too for good measure?

joking aside, i very much doubt it.....why bother, an FMIC or uprated SMICs are more than up to the job.

Why try to create lag and boost/presure drop by fitting lots of extra pipework thats not needed.

Edited 26 August, 201015 yr by sweedish

There is a member on here with a K04 I think that has a SMIC and an FMIC twintercooler... I'm trying to remember their name... hopefully they'll spot this post

EDIT: Found him - it's jmf

http://briskoda.net/forums/topic/140282-engine-temperature/page__view__findpost__p__1756233

Edited 26 August, 201015 yr by chicken_eyebrow

I've not carried out a twin IC mod, however I can confirm that such a set up would result in a greater pressure drop.

And the resulting combined AIT's wont be as low as you might expect either.

This is due to the fact that the thermol efficiency of the second stage IC will be significantly decreased compared to the first stage IC.

The reason for this is that IC's work most efficient when the difference between charge air temperature and road draft ambient air temperature is at its greatest.

So for example, if you had two identical IC's, which on there own were capable of operating @ 70% max thermol efficiency and you piped them into a turbo system in series, you would not get 70% + 70% max thermol efficincy from the two IC's.

At a guess I'd expect more like 70% + 15% max thermol efficiency.

HTH

Bill.

Bill clearly knows his stuff....kudos!

Yes, i have one, but unfortunately I bought the car this way, so I couldn't tell you the difference from before the mod. I can however tell you that the intake air temp is about the same or a bit lower than some friend with just FMICs, BUT they have some generic FMICs, not brand name ones (one for example is from an Iveco Daily truck lol).

Another thing is that, compared to a 1.8T with just FMIC, when booting it from 2000rpm, he just jumps ahead, because at 2000rpm i have quite a lag and spool up time. When booting it from 2500rpm or 3000rpm it's a bit the other way around. BUT, I don't know if this is necessarily a intercooler issue or a K04 issue (haven't driven a factory k04 car yet, so can't say). Ah, and booting it from 1500rpm does nothing, it's just dead

Anyway, I would guess that the added pipework would at least induce some more lag and if I had to fit an intercooler myself right now I'd just go for a FMIC and inverted intake manifold.

as said, proof from the owner himself.......LAG!

what fmic do you have jmf? take it its a standard smic too?

My first thought was that the extra volume, and changes in cross-section, would take longer to pressurise, and reduce total volume flow relative to a single intercooler having the same volume as the 2 units connected in series. Competition single turbo dual intercooler systems connect the coolers in parallel. Jmf's post #6 seems to indicate that this is born out in practice. That's before considering the thermodynamics of an air-air cooler, which are correctly discussed in vrs180's #4.

Q=UAdT

And it's been a looooong time since I've trotted that one out!

I forget the number of pressure heads dropped by having the extra sudden expansion from having the second cooler in series, however...

Begs the question why on the Audi BAM engines did they have two SMICs in series if the second one is only going to provide an extra 15% cooling. They might as well have had one big SMIC instead :S

Definately not Vorpsrung Durch Technik

Edited 27 August, 201015 yr by chicken_eyebrow

Begs the question why on the Audi BAM engines did they have two SMICs in series if the second one is only going to provide an extra 15% cooling. They might as well have had one big SMIC instead :S

Definately not Vorpsrung Durch Technik

One possible reason that Audi engineers choose to fit two smic's might be give BAM engined vehicles an improved degree of boost repeatability ie: increased resistance to heat soak.

Two stage (in series) automotive intercooling can work very well and produce very low AIT's.....but in order to achieve this the following (or similar) would be required.

1st stage: A high efficiency air to air intercooler.

2nd stage: An expanding liquid or Peltier electronic heat exchanger.

If I was trying to reduce AIT's to a minimum and was in the market for a two stage IC system (and money was no object).....then it would be the Peltier system I would go for.

HTH

Bill.

Thank you, guys! Very useful information. Very useful.

Smic is standard, fmic is noname. Winning formula lol!

Begs the question why on the Audi BAM engines did they have two SMICs in series if the second one is only going to provide an extra 15% cooling. They might as well have had one big SMIC instead :S

Definately not Vorpsrung Durch Technik

Holy thread resurrection Batman!

I'm guessing slightly here, but there likely wouldn't be space for a bigger SMIC, an FMIC would be part masked by the bumper and crash bar, and also an FMIC will compromise the cooling for the air con and engine water radiator.