TurboXS RFL Blow off valve
After reading and researching this blow off valve for nearly weeks prior to purchase, I was very skeptical yet excited to do a review for the valve. I hope this will answer all the questions that any have about the TurboXS RFL.
If you are familiar with the RFL, you know it is a piston-type blow off valve, and does NOT use a diaphragm. The way it is designed is to have direct metal on metal (piston + housing) to attempt a seal.
I received it in the mail, finally. The first thing I noticed is that this thing is a LOT bigger than I thought it was. I unscrewed the top and pulled out the spring and piston. The piston was not greased well, and was nearly dry. I picked up some White Lithium Grease and put a light coat on the piston before putting in back inside the housing. I then decided to insert all the provided (6) shims with the spring because I am running 20 psi, and have read that others have needed more at that boost level. I used a vacuum pump on the nipple of the unit and sure enough, it was leaking and pulling air through the horn. It was not opening, just leaking past the piston. I removed the piston yet again and applied more grease to it. This time it held a little better so I decided to install it on the car.
Install was very straight-forward. I had purchased the 1G install kit for it since I have an SSAC FMIC. I reused the gasket for the 1G BOV and installed the flange piece. Note that this piece will allow you to mount the RFL directly onto it pointing straight up. This did not work for me as it was nearly contacting my hood so I had to use the 90* adapter it came with. You just put the adapter on, tighten the three little supplied bolts into the groove on the flange, and then install the RFL in the same way.
First thing I did was boost leak test it. At about 10 PSI, it began to leak from the horn area, not from the valve opening but past the piston. At 20 PSI the leak was very significant and would stop if I put a rubber ball into the horn. I came this far so I decided to to a road test with it.
After warming the car up I tried to blow off at 5 psi, and got flutter instead. At 10 PSI the valve opened and the sound was quite loud, although I could hear the faint sound of compressor surge prior the valve opening. At 20 PSI the sound of compressor surge was gone, and the blow off sound was very loud. A side note, I was running rich due to the boost leaks this thing created.
To wrap up my review, I will state that this valve disappointed me. It is very poorly designed. The spring is fairly weak even compared to a stock 2G BOV. The lack of diaphragm made it nearly completely prone to leaks despite filling clearances with grease. The sound wasn't as loud as I thought it was going to be, and I tried less washers and more washers on a few different runs. It is going to mess up your tune and make you run richer in boost since you have a boost leak.
Please note also, I am using a MAF-T on blow-thru. For those who are on the stock MAF or a MAF that requires recirculating, this is probably the worst choice in blow off valves you could buy. The only people who could possibly use this valve without issues are people running speed density, and they would still suffer from slightly slower spool time. My advice is to stay away from this valve and save your money.
Cursed Auto 97 GSX