OK, my car is a 94 touring with a downpipe and K&N filter. I opened up the stock airbox today and when I was test driving it. I hit boost cut at top of 3rd gear. The car seems a lot faster, but that boost cut makes me nervous to get on it. Is it something I should worry about? The car only has a downpipe on beside the intake, but the temperature was like 30 degrees. Would that make it hit boost cut? My A/F ratio was right around 13-13.5 when I tested it.

Bottom Line

Drilling out the airbox made a big difference in performance.
I hit boost cut with only a drilled air box and downpipe.
Should I be worried about the boost cut or was it just the cold weather? (30-40 degrees)
Should I look at getting a PFC or Boost Controller?

Thanks

LJ

 

You will need a boost controller sooner or later so might as well get one now and see if it helps. I basically have the same mods as you and never hit boost or fuel cut. Of course this is Texas and I wouldn't drive my car even if it was 30 degrees.

 

Can someone please define boost cut to me?

TIA!

 

Are you sure you didn't hit the rev limiter? That's real easy to do in 3rd if you're at WOT watching the boost gauge and not the tach.

I don't know of any 'boost cut' feature in the stock FD. The stock ECU has no idea how much extra boost you're making with the mods you've done.

 

Im posative it wasnt the rev limiter. I dont have a boost gauge, I was looking at the tach. The stock ECU can tell how much boost with the MAP sensor. The stock ECU cits boost at diff pressure depending upon RPMs, there is a chart somewhere on the forum. Any one with any ideas?

 

You can install what is essentially a pair of holley carb jets, one in the pre-spool and one in the wastegate vent lines. This limits the amount of boost that can be produced and also prevents spiking for under 10 dollars. This is also what Pettit reccomends to do when you install even just a downpipe. If you give them a call they can probably help with what sizes you need for your application.

Hope this helps,

Andrew Wojteczko

 

I was wondering about the fuel cut on the FD. Ive never heard of FDs needing a fuel cut defenser??? I have a stock K&N air filter, dp and cb but I really don't think I've ever hit fuel cut. I have had the boost gauge spike at 13-14 psi.
Am i missing something?

 

I think you might be missing an ECU upgrade.

 

your 13-13.5 mixture is startign to get lean i woudl either get an ecu or lower teh boost. DO NOT lean out the motor or u will be looking at your apex seals shortly