By-pass valve

[Stang87]

I know this has came up many times but, the only place is ee people reccomend for a by-pass valve is tiny avenger. Does anyone else sell a bypass valve to use on the svo? thanks

[lonchair]

You can get bypass valves off any number of turbo cars and modify them to go on your SVO. What Tiny Avenger has is a kit that takes most of the guess work out of putting a bypass on an SVO. I think Tiny Avenger is out of buisness though. His website is down and his number is not in service.

The BOSCH brand of valves run about 50.00 each and are available from most parts stores. They were original equipment on SAABs and Porsches. I beleve that several super charger kits also use BOSCH valves. Here is a list of BOSCH bypass part numbers:

0280142102
0280142103
0280142104
0280142105
All of the above are used in SAABs 1986-2001 and rated for 15 psi and under.
0280142108 (used in some porsches)
0280142110 (higher boost version)

Other sources for valves are turbo aftermarket companies for SAABs, VWs, DSM cars, Porsches, Volvos, Subarus, ect. and many aftermarket ricer turbo companies.

[Stinger]

You can also run a blow off valve as long as it's a dual piston design engineered for metered air systems. The Bailey Evo and Forge units are two that come to mind.

Stinger

[Scott Evil]

Try clairparts.com

use this part number: 0280142110 (in VW/Audi parts catalogs it is 06A-145-710-N). $36 with clamps.

It seems like once a year I have to replace both bypass valves in my Audi. The 710Ns are pretty good, but will wear out depending on how hard it is used. Plumb the high pressure relief line from the I/C o motor to the side port and the plunger inside will last longer.

This link is for the same part used on an Audi TT:

http://www.clairparts.com/accessories4.asp?product_id=1790&PDID=189605

[Craig]

What is the use of a blow off valve?

[Stinger]

Originally posted by Craig
What is the use of a blow off valve?

It's the same "use" as a bypass valve only it vents the excess air to the atmosphere instead of recirculating the air into the vam hose. They are also a bit louder.

Stinger

[AT6svo]

Originally posted by Craig
What is the use of a blow off valve?

While Stinger did clarify the differences between the bypass and blow-off valves (BPV vs BOV), the use or purpose is to allow the (metered) compressed air to escape back into the intake tract (BPV) or out to the amosphere (BOV, big PSSSH shound). In either configuartion, the main benefit of this is that it keeps the turbo spooled up and hence will build boost quicker in the next up-shift, minimizing "turbo-lag". A side benefit is that it also reduces the probability of blowing off IC hoses/connections.

hth,

[turbizzy]

T/A BPV kit

I have a tiny avenger, Ford blue painted, BPV kit that i bought new a while ago, somewhere in my garage that i was thinking about listing on ebay. I really only used it for about few hundred miles until i swaped for a BOV. If anyone wants it... $75 shipped.

I did notice a big difference with it though, between quick shifting the boost is still there about 90% full. Then when you WOT it again on the next gear your already at 10-12psi-ish and you don't have to wait until boost builds again. For all the newbies to BPVs of BOV, these don't give you any HP gains however by eliminating boost lag between shifts it can make your ETs lower. I noticed about .1-.2 secs off at 18psi boost. Not to mention how much it really helps extend the life of your turbo. Depending on how hard you drive (boost in all gears all day like me), whenever you close the throttle on decel or to shift, the boost that is between the throttle blade and turbo surges back to the turbo and wears the bearing out faster. With the BPV when you close the throttle, the vaccum that is on the other side of the throttle blade helps pull the BPV open and releases the not needed boost.