Boost spike on auto SR20 S14 / BOV - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Spins · 11-11-2003, 06:07 PM

I have a 95 240 with a 95sr auto swap. My car is stock except for a walbro fuel pump, cone filter and a 3inch dp/exhaust. My car boosts 8 psi until it shifts into the next gear. It then boost spikes to 10 psi. When it engages the next gear the wastegate dumps and the boost falls to around 6psi and the turbo starts to respool. I'm running a s14 recir.valve which leaks at idle. I think this is hurting my spool up.
So I tested my friends Bailey's BOV which vents to atmosphere from his turbo miata. This bov doesn't leak at idle. The turbo miata guys have the same problem as the sr20's seem to have at idle using a vta bov with the stock ecu.
My car ran good with the baileys bov.Idled great. It boosted 9psi instead of 8psi but still spiked as it shifted and fell back to 7psi but seemed to spool quicker. The only problem is after the bov vents when I let off the gas I could hear what sounded like compresser stall. So I believe the bov spring is set to a hard setting and will not vent enough. This bov is not adjustable.
Anyone know what I can do to stop the boost spike/waste gate from dumping so much? The SR is new to me and being an Auto seems to make it harder to find info.
And before anyone asks why I got a auto Sr. I have a leg/knee injury from a bike crash. I also have a 90 Miata running 12psi on a Flyin Miata turbo setup and it's a stick. I can't handle driving a stick everyday in the city. It's too painful.

11-11-2003, 06:07 PM	#1
Spins Join Date: Jul 2003 Location: Davie Posts: 14 Trader Rating: (0) Feedback Score: 0 reviews	Boost spike on auto SR20 S14 / BOV I have a 95 240 with a 95sr auto swap. My car is stock except for a walbro fuel pump, cone filter and a 3inch dp/exhaust. My car boosts 8 psi until it shifts into the next gear. It then boost spikes to 10 psi. When it engages the next gear the wastegate dumps and the boost falls to around 6psi and the turbo starts to respool. I'm running a s14 recir.valve which leaks at idle. I think this is hurting my spool up. So I tested my friends Bailey's BOV which vents to atmosphere from his turbo miata. This bov doesn't leak at idle. The turbo miata guys have the same problem as the sr20's seem to have at idle using a vta bov with the stock ecu. My car ran good with the baileys bov.Idled great. It boosted 9psi instead of 8psi but still spiked as it shifted and fell back to 7psi but seemed to spool quicker. The only problem is after the bov vents when I let off the gas I could hear what sounded like compresser stall. So I believe the bov spring is set to a hard setting and will not vent enough. This bov is not adjustable. Anyone know what I can do to stop the boost spike/waste gate from dumping so much? The SR is new to me and being an Auto seems to make it harder to find info. And before anyone asks why I got a auto Sr. I have a leg/knee injury from a bike crash. I also have a 90 Miata running 12psi on a Flyin Miata turbo setup and it's a stick. I can't handle driving a stick everyday in the city. It's too painful.