I see on a few VW forums that a popular choice of IC for vehicles that have had a 20vT engine conversion is to use the FMIC from a Merc Sprinter. I think the sizes are as follows:

Core size: H 226mm - W 715mm - D 35mm

Inlet: OD 65mm

Outlet: OD 65mm

Overall size: H 280mm - W 955mm

So the question is this. Merc Sprinter ICs can be had relatively cheaply but how would the performance differ between the above and a full on Forge jobbie for example? Is it simply a poor mans alternative?

I'd be interested to know anyones thoughts.

BTW it's good for boost pressures upto 2bar apparently.

Is it simply a poor mans alternative?

I am that man;) and I'm always up for a DIY alternative, It sounds to be worth a try.

Are van FMICs readily available? I'd guess written-off vans often have smashed front ends(?)

I assume that it's just a case of extending the hosing from the existing IC to the front and mounting the new IC behind the lower bumper?

It's chosen because it's cheap and small enough to fit a mk2 golf.

It's not gonna be a massive improvement over stock on the Octavia and is used on cheap conversions because the SMIC won't fit.

also depends on the inlet/outlet desgin

if its a single pass fmic then you will either need a return pipe over the top or buy a TT inlet manifold.

Good stuff. Keep it coming

A 2nd hand Sprinter FMIC can be had for £70'ish....

70 quid's not bad. Would it be worth leaving the OEM IC in place too or just replacing it with the FMIC?

I'd think the SMIC would be removed - you'd probably end up with too great a pressure drop across both ICs for little benefit.

I've done a quick search and it would appear that the sprinter FMIC is a single pass unit therefore the inlet / outlet connections are on opposite ends so again PD may be a problem due to the more tortuous route of boost pipework.

Saying that though surely there would be reasonable improvements over the stock SMIC? After all the fact that the Sprinter one is front mounted must be a benefit (it's in a direct cold air stream and won't be as succeptable to heat soak like the SMIC) plus the sprinter unit is a fair size bigger therefore more heat transfer area over the SMIC which is the size of a postage stamp in comparison.

Maybe I'm talking ****** but it would be an interesting experiement to cobble one together and compare inlet temps with the stock unit or even with an aftermarket FMIC for that matter.

the core for my intercooler was about75quid new..

custom piping etc took the total cost upto about 350....