Okay... everything that you've heard.. forget it.

Here's the issues.

The reason that your engine is cutting out at higher throttles is because IT IS STILL NEW. That RB S7 will take min. 1/4 gallon before it really starts to break in. If you get lucky you will get one that takes almost a gallon. That means it will last a loong time.

I wouldn't run that pipe with that engine. You have a killer engine, don't cheap out. Get a JP2 for it. Or an OS 2050. They cost but they are worth it.

Get O'Donnell 30% fuel and O'Donnell 99 glow plugs.

Throw that motor saver air filter away. Get a real filter. Mugen makes a great one. XRay's is good as well.

Everyone @ my track runs almost exclusivly RB engines.... There's been 4 S5's broken in this week... every single one of them does the cutting out at high speeds. I don't know how you broke it in but try to get your temp in the 220 - 240 range and don't run the car to fast. Drive it around sort of slow with little bursts of full throttle. 1 - 2 seconds for now. do that for a little bit and you'll see it start to work better.

Heck if you still can't get it to work right ship it to me with money to ship it back plus fuel and I'll break it in for you.