So i finnaly have it cleaned up and stop leaking. Now I want to get it to perform better. other than cold air intake, exhaust, spark plugs and wires; what can i do to increase throttle response? wider throttle body maybe?

 

Bigger TB on a stock motor will decrease throttle response and shift your powerband up into the higher RPMs. It is all about the amount of air compared to the velocity of air.

Think of it as a garden hose with X amount of water. A smaller garden hose will be able to shoot the water out faster, however, will only be able to shoot so much. A huge garden hose with the same amount of water will have the water dripping out, but can support much more water, if it was there.

Anyways, you want more performance? Go boost. That is the only way to get a decent amount of power out of a D series. Many have documented all motor builds and come up with no more than ~170 hp. A small turbo kit will put you past that easily. The 170hp builds usually involved machining and replacing most everything within the motor, which can get expensive, quick. A small bare bones turbo kit will run roughly $2k or so.

I am in the process of building a higher compression z6 motor to install my supercharger on. So far, I am at ~$2k, and that is not including the supercharger/ecu/tuning/all the other things I have already purchased and installed onto the car. The motor, once complete (boosted and higher CR) will end up costing about $3.5k. I expect to be at around 225whp/200wtq.