EFI guys

[jbrown]

What are you doing with your blow off valve. Are you venting back to the intercooler or to atmosphere? Also are you using the stock bosch plastic one or is there a better choice.
I was told the bosch is a little small...
Thanks John

[philip j]

John, I have done both, vented back to filtered intake air, and now, vented to atmosphere. No difference in performance, not even a change in sound I run the stock 965 black plastic valve, which works just fine. Philip

[dos531]

If your system is running speed density then there is no reason to recirculate it.

[turbobrat930]

I think I have the "Q" series of BOV's from TiAL. It is right above my turbo outlet, and just before the inlet of the I/C. It vents to the atmosphere.

[jbrown]

Originally Posted by dos531

If your system is running speed density then there is no reason to recirculate it.

I was told that I can vent to atmosphere. Right now I have it recirculating. If there is no difference I would like to leave it. If it makes a difference or is recommended to vent to atmosphere .
Thanks John

[Tippy]

Psssssshhhhhhhh

[dos531]

Originally Posted by jbrown

I was told that I can vent to atmosphere. Right now I have it recirculating. If there is no difference I would like to leave it. If it makes a difference or is recommended to vent to atmosphere .
Thanks John

I cant imagine it would hurt anything to recirculate it, but its just extra plumbing.

[jbrown]

Originally Posted by dos531

I cant imagine it would hurt anything to recirculate it, but its just extra plumbing.

Is your car EFI? If so I was curious if you are using the meth injection and where you have it plumbed in.
I have meth injection and the jet is in the out pipe of the intercooler. I am bringing it to the dyno Monday and I was wondering if it would interfere with the temp sensor, which is only about 8" away from the meth jet. I would like to keep the system in. It cools the charged air and worked great with the CIS system.

[jbrown]

I should have read the bottom of your reply. It shows BL WUR, so you are still CIS.

[dos531]

Originally Posted by jbrown

I should have read the bottom of your reply. It shows BL WUR, so you are still CIS.

Yep still cis for a short time longer. Currently still assembling my EFI hardware. I have been researching the same question to determine where I will be installing my IAT sensor in relation to the methanol jet. I have not found a definitive answer to whether it should be installed before or after the meth jet. I'm leaning towards installing it after the jet, but out of the direct spray of the methanol. That way its reading should take into account the cooling effect of the methanol. If I remember correctly your iat was installed in the Cold start valve location? If so, that is what I am planning to do as well, but with a spacer to insulate the sensor from heat soak as well as hopefully keep it from being sprayed directly with liquid.

Hopefully someone with more knowledge can chime in regarding the iat/meth jet orientation.

[Tippy]

If the nozzle is far enough upstream to not freeze the IAT, I think it would be fine. Meaning, I wouldn't have the IAT directly sprayed or it'll think the actual air temp is extremely cold and go pig rich.

[xbmwguy]

Dump to atmosphere. And plumb it as close to the tv ass possible, so when the tb blade slams shut you still maintain some in all plumbing.

[krasuskyp]

FRANK! (always plumbing "it" close to the "tv ass", you are!)

8-)

[pkracer21j]

BOV's aren't necessary. But we typically vent to atmosphere when they're used.

[Tippy]

BOV's aren't necessary. But we typically vent to atmosphere when they're used.

Really?!?! I prefer not to crash my wheels back in forth in the CHRA!

[jbrown]

I already have it set up to vent back into intercooler. If there are any performance gains or the car runs better dump to atmosphere then I will chance it but if there is no difference except for sound I prefer to keep it the way it is. Thanks John

[dos531]

Originally Posted by jbrown

I already have it set up to vent back into intercooler. If there are any performance gains or the car runs better dump to atmosphere then I will chance it but if there is no difference except for sound I prefer to keep it the way it is. Thanks John

It actually vents FROM the intercooler and is recirculated into the intake before the turbo. The 964 bypass valve does look like kind of backwards like that though. On mine it is just a bov mounted on a flange on the back of the intercooler.

[xbmwguy]

Pete is correct. Most modern turbos are made with anti surge ports

[Tippy]

Yeah, modern turbos, but most here are in the K27 camp.

[xbmwguy]

Sorry to hear about their bad luck