I just upgraded to a 16g from a 14b with blown seals. Now, every time I hit full boost and keep it there, the car falls on its face as if I had slammed on the breaks. I was slightly concerned about my welding on the BOV flange. Could it be a leak that's causing this? The car is fine while building boost, it only ***** up under full boost. Could it be that I'm maxing out my stock fuel pump? Spool time is also a lot more with the new turbo as opposed to the old one. I thought the 16Gs and 14bs were so similar that fuel consumption/spool time wouldn't be effected this much. Any help or insight would be appreciated.

 

did you have a wideband on it, or are you just winging it? Did you even change anything with this tune?

And a leak at the bov would be pretty evident as your boost gage would fall flat on it's face with the car. aside from the fact that leaks are usually continuous not just at full boost, so spool time would blow.

 

16g's and 14b's want very different things from your engine. You didnt retune it did you?

Make sure the compressor housing has its o-ring. If yours is a ching chong meow version, it might have been forgotten. Find your boost leak and get it retuned.

 

So you think it is a boost leak?



Also, yeah, I didn't get the car retuned. I figured the turbos were similar enough to where I could drive it around until I got the chance to retune it. I just wanted to test it a few times to make sure everything was working the way it should be before I drove 3+ hours to get it retuned.

 

How about telling us what kind of car and setup, before asking for help...

 

Also check your plug gap.

 

Car's a 2000 Ford Focus non-SVT. 42 lb/hr injectors, stock fuel pump (might needed upgraded, not sure), 2.5" charge piping, 2.5" exhaust. Plug gap is .028 where it should be.

 

What is full boost?

I'd upgrade the wire to the pump, it's probably got 50-100 whp caught up in the stock wiring's failure.

 

Full boost is around 10 psi.

 

when it was tuned was boost cut set? if so then you could be hitting it