[Bmw doubles]

Originally Posted by 535_BiTurbo

So I was running my buddies Cobb Pro-tuned 2015 Subaru WRX on E30 (30% E85/93 mix) a few weeks ago, and we ran from a roll and were dead even from 40 to 100. My mouth was like "" because my car (2012 550i JB stage 1) hadn't giving me any issues other than an occasional Drivetrain Malfunction.

I figured it would be an easy win for me again a car weighing almost 1000 lbs less and making about 270-290 rwhp. I also noticed that his top end was stronger than mine and I had to short shift at 5900 rpms just to keep up. I realized something was wrong with my top end, the pull wasn't there and it felt like the car was running out of steam up top.

I just replaced my plugs (BMW originals) about 12,000 miles ago and didn't think to check to gap. So today I pulled the plugs to clean them and check the gap. I found about 5 plugs gapped between .040 - .041 and 3 plugs gapped between .035 - .037. I gapped all of them down to .029 and WOW, what a HUGE difference! I'm ready to re-run my buddy again with my night and day difference on the top end.

Always check the gap when you purchase plugs.

I'm gapped to .22 MPG is destroyed though and yeah we have a much stronger top-end then a 4 banger