Very kind of you to say that John, however, I am sure there are several peeps on this board that would disagree with you!MaineBullitt said:Alan & I posted at the same time,beat me by milliseconds-he is one of the wiser people I referred to in my post.
:lol: Don't feel bad Alan-there are a few people on this board who I dont even rate high enough with to warrant a response to a question. I apparently was mistaken when I thought originally that this board was exempt from the snobbery & flaming that goes on elsewhere. It's still way better on this board than some of the others....John RP-51 Bullitt said:Very kind of you to say that John, however, I am sure there are several peeps on this board that would disagree with you!
Greg-that's tough one to diagnose without actually hearing the car. Have you called MPH yet to ask them? Did your car pop at all before the Mongoose kit? As far as the blowoff valve-when you let off the gas, especially after a more than gentle accelaration all that boost that the charger is making has to go somewhere-your throttle plates are closed, so the boost gets relieved through the blowoff valve. On my car I would lamely try to describe it as a low pitch growl until the motor is back down to about 1500 rpm or so. Hopefully some better educated forced induction guys will chime in here soon.....John Rbullitt00623 said:I have the bassani catted x pipe with the stock catback .Maybe back fire is the wrong word,it is more of a popping sound after i get off the gas.Yes it has been doing this right from the start.It seems to do it in the higher RPM range more though.How do you check to see if the bypass is working right.Do i need to get to the dyno and check this out.I checked all my clamps and found one had not been tightened at the bypass valve so i tightened it up.Could that be the reason why my car goes pop pop pop when i decelerate sometimes. THANKS GREG
You are 100% correct-my terminology has been wrong in this thread-the correct term is indeed Bypass Valve. That's what happens when a lifelong musclecar geek like me tries to get contemporary :lol: Thank you for correcting me-I'm never too old to want to learn.....John R :smile:stang4.6 said:I'm no expert, but here is my .02
The by-pass valve vents pressurized air to the intake tract before the blower. It does this to prevent pressurized air from bouncing off the closed throttle body blade and back to the impeller inside the supercharger. Pressurized air vererberating into the blower can cause damage to the impeller. It is not a blow-off valve, blow-off's are for turbos and vent excess exhaust gasses to the atmosphere to prevent the turbo from producing more than the desired boost. I really don't think an actual backfire (if that is what you are hearing) could be casued by a problem with the bypass valve.
Backfires are usually timing related problems, which in your case would mean a tune problem. It is also a problem that would likely be more evident at higher rpm where accurate ignition events are more critical.
Does your car have a custom dyno tune? If not, you may need to look into getting that done. If it does, I would suggest getting the car to your tuner, they should be able to monitor the car on a dyno and see if you have timing or ignition related problems that are causing the backfire.
Mine does too and always has since I added the Magnapacks.DOUBLE J said:If it's a popping sound under decelleration than it is normal. Mine has been doing this since day one of the blower install. I get dynoed before every shootout and not once has the tuners been concerned about this.