the links are good, Ive found autospeed to be a good source.

 

precision core- http://www.nolimitmotorsport.com/prod/AS1021

i dont think they make a kit to fit the b5 a4's so you'll have to get piping seperate

 

this is the difference between ebay and quality cores

 

The godspeed is a very low dense core where the garrett/precision (they both use garrett cores) are very high dense cores. The precison 350hp core will work for you. Its about $300 and will keep the temps a few deg above abient as were the godspeed core will keep it probably closer to 20-30* higher, depending on size.

 

I didn't know the 3.5 inch would fit, I guess its only 6 inches high and doesnt interfere with the bumper support?

 

it shouldnt. But if you want to get a 3" core, you can get the garrett 400hp core from atp but its more.

 

on a stock a4 bumper it would require some trimming

 

thank you,

I'll probly get this http://forums.motivemag.com/zerothread?id=3551132so don't have to think about custom piping, hacking the bumper should be enough pain. Plus the moulded hoses look very cool-OEM like.

 

That would be the best one to go with. Its a garrett core and should fit well

 

i have the exact same core as the one that 034 is selling. it is leaps and bounds above the AWE core as far as reducing and pretty much eliminating heat soak. i am very happy with it. it fits nicely under my stock B6 bumper(although my rebar installed. so you'll have to trim that up if you keep it on your car).