Technical Hot air inlet

[Teaman]

hey

I've read that most people just bin the hot air pipe coming from the exhaust manifold, and the thing it connects to, with the diaphragm and stuff.. But I can't find any info on what it is this system does exactly, and how the components work together.. Surely there must be a reason why Fiat put this on the inlet?

Does anyone know what it does and how it works? And what are the consequences of not having it?

 

[jaygrint]

Hi mate. Yes it's there for a reason. What it does, as long as all the vacuum/thermocouplings are working as they show, is on cold start up it directs warm/hot air from the top of the exhaust manifold into the air intake pipe. This helps with cold running and helps stop flat spots from cold.
Once the engine warms up a couple thermocouplings then stop the vacuum pipes working which closes the flap in the air intake pipe so it blanks off the air coming off the exhaust manifold and then draws in cold air only through the intake pipe.

Like I say that as long as the couplings and vacuum flaps are working correctly.

When I bought my first Cinq Sporting it had all of this original stuff remove and only had a pancake filter over the spi unit. It ran crap when cold. I then converted it all back to the standard air filter box and pipework with the hot air intake and it totally changed how it ran when cold, it's so much smoother and it has made no difference when hot which means all is well.

Hope that helps.

 

[Teaman]

ah that makes sense.. maybe I should run it in the winther months then..
I guess the ecu have no problem adapting back and forth?
is it also relevant on cold start up in the summertime?

 

[jaygrint]

Doesn't affect ECU.
It still works in Summertime but depends on how cold it gets, it will also cut the hot air off quicker when air temps are warmer.

Best thing to do is to experiment with it all standard and then with whatever your looking to replace it with. You may find that you don't notice any difference with it all fitted. Likewise you may also find that when you replace it with whatever mod/induction kit your thinking of fitting the new kit doesn't improve performance either.
Alot of people mistake the better sound a induction kit gives as an improvement in performance too. Not convinced with induction kits unless combining them with other mods i.e larger throttle bodies etc.

Individual preference really.
I'm happy with both of mine which are bog standard. But that's just me. Trial and error have a play about but don't do anything that you can't simply put back to normal if required.
?

 

[Teaman]

Thanks for the help
I would've fitted a fancy cold air intake, and get the engine bay looking good but, function comes first I guess you could make a custom job with alu pipe and samco hoses with the hot air intake build in, the stock setup just doesn't look cool, but then again better to accept it being alittle rough on warm up..

 

[jaygrint]

Have a play about. I'm not suggesting you don't mod it.
You might not notice any difference as yours may not be working correctly anyway.
Alot of people aren't bothered about the flat spot issues when cold with it all removed. And to be honest even with it fitted and working as it should there's no guarantee you wont have flat spot from cold issues. Very common fault.
I do agree the standard air box and pipes look terrible but then again when I'm driving I can't see it and if I've got my bonnet open I've problem got some other fault that's pi$$ing me off at the time.
???

 

[dac69er]

i just have an induction kit and no warm air feed thing. i have also removed the carbon canister and purge solenoid piping.
the first couple of minutes it doesnt run perfect i guess, but its perfectly driveable and you wouldnt really notice.

 

[David C]

When I got my 899 Cinq in 2005 the hot/cold flap mechanism in the filter housing was broken & flapping about. So I took it out, removed the hot piping and blocked the hot inlet.

No problems at all even from a very frozen cold start in the depths of winter.

 

[zedorio]

When I got my 899 Cinq in 2005 the hot/cold flap mechanism in the filter housing was broken & flapping about. So I took it out, removed the hot piping and blocked the hot inlet.

No problems at all even from a very frozen cold start in the depths of winter.

What's that hot air entry?