TDX61 Turbo
Water/Meth
AEM Smart Coils
14-20psi, 400-500whp dynos

When changing out the sparkplugs I noticed the previous owner had (2) BUR7EQ and (2) 6725-115's

Doing some reading I felt that having (4) 6725-105 was a safe bet. Overkill? So I installed them and it seems to have better response, acceleration and idle? Or is it me?

 

anyone hahah

 

Run the coldest plug you can without fouling them. We've run 11.5s on daily drivers with no issues but the engine has to be well sealed and the tune up has to be solid. Typically, for what you're doing, 10.5s should be sufficiently cold for the power you'll be making.

 

so looking at the previous setup (2) BUR7EQ and (2) 6725-115's. What would the reason be behind it?

 

Previous owner fouled the two 6725-115's in the LEADING position, and put a set of BUR7EQ to call it a day?

Even at 400rwhp, I would run 4 BUR9EQ at a minimum, no idea why somebody would run BUR7EQ at those power levels.