Higher outside temp = slower acceleration?

[RedRobin]

You're talking ambient temps here, so intake temps. Intercoolers won't do squat against that, you need a decent cold air intake. If you're thinking of the type of system that uses a cone filter somewhere in the wing or behind the bumper vents, make sure you get a 'sock' for the filter or you risk sucking in water. Hydraulic lock is very messy!

....I don't know enough to challenge that, but others have often said that an aftermarket intercooler helps. It's why Forge sell more Twintercoolers in hotter climates IIRC.

Of course, open fog grilles are the best solution 

[topher]

More efficient intercoolers certainly help in warmer climates (well, they help in general really), where the air passing over the fins of the core is cooling the charge temps i.e after it's already gone through the turbo, but in this instance we're dealing with intake temps where the only thing the air is passing through is an air filter and the air-mass meter before it hits the turbo.
Obviously the very best solution would be to use both but when you compare just how hot charge temps are compared to intake anyway, this little problem of feeling slower on warm days can be solved by getting the denser air into the system in the first place... because once its in there it's going to hit 40 degrees anyway.

[E30M3]

What kind of Sock for the CAI ? ? a normal smelly one ? 

seriosuly what kind of sock, can you buy it from the manufacturer of the air intake ?

[topher]

Usually yeah, i know K&N do one, in various colours!

[E30M3]

does the sock affect performance somewhat ? ?

does Forge do one for there CAI, or is it just a K&N stuck onto their pipeS ?

thanks for the help.

[RedRobin]

More efficient intercoolers certainly help in warmer climates (well, they help in general really), where the air passing over the fins of the core is cooling the charge temps i.e after it's already gone through the turbo, but in this instance we're dealing with intake temps where the only thing the air is passing through is an air filter and the air-mass meter before it hits the turbo.
Obviously the very best solution would be to use both but when you compare just how hot charge temps are compared to intake anyway, this little problem of feeling slower on warm days can be solved by getting the denser air into the system in the first place... because once its in there it's going to hit 40 degrees anyway.

.... Thanks for the useful explanation

[You are appreciated even if some of us sometimes rant at you!]

[topher]

here's an example of one http://www.force-metric.com/proddetail.asp?prod=5017r

they're specifically for dry filters (if you're using an oiled filter, shame on you!)

i'm sure the manufacturers will claim they don't affect performance, but they must do slighty.. not something i'd be too concerned about with a forced induction engine though.. it won't be a restriction to worry about.

[E30M3]

thank you Topher, was wondering why Forge state their CAi should not be used in the rain !

I'll enquire with Forge whether they make one for their system .

[RedRobin]

....

Some of the Mk4 R32 guys I know have used a different anti-hydro system which is installed in the pipe run.

[topher]

Yep there are ways to catch it in the pipe run too, but in my personal opinion it makes more sense to leave the vortex of air well alone to do its thing once it's moving. Probably less of a concern with N/A engines though.