Like the title says I'm looking for the best spark plugs for my 98 Audi a4 1.8t Quattro, it's chipped, will be getting a new performance turbo soon, and a racing clutch. So needless today I want performance plugs, while still maintaining fuel economy and durability. I looked at the Ngk Iridium but they don't sell them for my car, any ideas? (I'm open to all brands and types except copper)

Couple of the ones I'm looking at:
Bosch Iridium
Autolite XP Iridium
Autolite Double Plat.

I'm open to all suggestions but if you say ngk please explain why, they are twice as expensive and seem the same

Plenty of info on the forums on this topic. NGK is an OE supplier for Audi/VW 1.8T engines and they are very inexpensive. $8.00 a set, usually available at any local parts store. Use NGK BKR6E or BKR7E. Cooper or platinum, your 1.8T will need plugs every 20K miles. Platinum shows no benefits with a K03/K04 application, so stick with the NGKs. Audi B5 A4 Quattro 1.8T > Engine > Ignition > Spark Plugs > ES#8924 Spark Plugs - Set Of Four (#BKR7E) - BKR7EKT-4CYL

Do you have a full Scorpion exhaust, or just the muffler?

Q: What about Spark Plugs? What should I get?

as stated above just use ngk bkr6e or bkr7e. fancy **** is not needed and there wont be any real gains. on your 98, if you want ignition upgrades, id go icm delete and fsi coils.

Ok I'll pick up a set of ngk's, and it is a full stainless steel scorpion exhaust

If you're stock BKR6E are recommended. Chipped go for BKR7E. Also, these copper plugs typically should be replaced every 5-8,000 miles. But for $2 each and maybe 15mins of your time, that's no big deal!

I found a set of four ngk bkr7e (4644) on eBay for the same price as ecs but with free shipping, are the 4644s the ones I need?

Doesn't matter, as long as they are BKR7E. That part number only designates the packaging (i.e. 4 in a set).

K cool thanks