: Finally re-circulated my bypass valve
charlie2020 10-10-2002, 02:02 PM And all I have to say is the mother f&^$#! kicks ass even more know, feels like I gained feaken 15-20 horsepower along with:
1) Perfect drivability
2) No lag inbetween shifts (barely if at all noticeable)
3) Better gas milage
4) Able to drive a part throttle without bucking
5) Car dosen't automatically want to boost at very slight throttle
6) It just feel right
7) A/R ratios during closed loop now fluctuate like there suppost to i.e. .100mv - .900mv and steady open loop A/R ratio readings.
8) Now when I tune with the SAFC I can see a change with just 1% increase or decrease on my digital A/F ratio guage.
9) No more backfires.
Extra
10)Stock clutch still holding up.
ITR_KILLR 10-10-2002, 02:11 PM glad you're running good:D
javierb14 10-10-2002, 02:20 PM 5) Car dosen't automatically want to boost at very slight throttle
this is good?
charlie2020 10-10-2002, 04:30 PM Originally posted by javierb14
this is good?
Yes, because know I have control over part throttle, whereas before no matter what come 3,700-4,000rpm the car would start to boost. Don't get me wrong though believe me the car boost when I want it like a mother.
See before recirculating bypass valve the turbo was having to work harder because the bypass was open to atmosphere thus letting presious (sp) air escape while trying to maintain speed.
With a bypass valve during cruising (part throttle) it bypasses potential boost psi back to the compressor side to keep you from boosting until positive pressure is seen in the ITM then the bypass valve shuts and then you have boost.
The problem with a bypass valve open to atmosphere is alot but I'll try to describe one scenario when you are cruising part throttle the bypass valve is open thus letting usable air escape the cylinder thus resulting in the turbo having to work harder to feel that loss and as a result the turbo goes into boost and you have very little control over it but to let off the throttle because with an open to atmosphere bypass valve there is no in between (part throttle) it either boosts or doesn't boost if you try to maintain steady state driveing you start bucking and stumbling.......again because the bypass valve is open during these situations (part throttle and idle).
It would be a whole different story with a aftermarket BOV though.
You must remember for those that don't know there is a difference between (CBV) compressor bypass valve and (BOV) blow off valve.
Good Links
http://johnmonnin.netfirms.com/BOV.html
http://www.machvw.com/ilovthatpsso.html
http://www.newdimensions.com/products/page_11.html
http://216.239.53.100/search?q=cache:uzfKjn541bUC:turbobricks.saliv8.com/cbv_bov.html+my+blow+off+valve+stay+open+at+idle&hl=en&ie=UTF-8
http://216.239.51.100/search?q=cache:ZzAsh7pFDz4C:www.geocities.com/kennethjlem/Pages/Spec7.html+BOV+open+pressure&hl=en&ie=UTF-8
Read between the lines and remember in one of these links they are selling BOVs so of course they may talk down on CBV bypass valves. But I can assure you that there is nothing wrong with CBVs in fact there probably better for your engine anyways. Although I don't see anything wrong with BOV neither just remeber that some or more restrictive than other thats how they make there sound.
The BOV is supposed to be recirculated too, right?
charlie2020 10-10-2002, 04:44 PM Originally posted by pdr
The BOV is supposed to be recirculated too, right?
No, a BOV vents to atmosphere or it can be recirculated but then your just wasting your money
Yes, a Compressor Bypass Valve CBV needs to be recirculated.
All most all factory turbo cars come with CBVs.
All SR20DETs come with CBVs.
Hope your clear on this now.;)
sonnypippo 10-11-2002, 10:53 AM Originally posted by charlie2020
No, a BOV vents to atmosphere or it can be recirculated but then your just wasting your money can you elaborate on this statement?
spicez 10-11-2002, 12:41 PM why pay the big price for an Aftermarket BOV to make a nice psshhhhht sound, when in the end you recirculate it.
Instead get any kind of OEM Bybass valve, you can probable find a really cheap on at a local scrap yard from any car that uses turbo/maf.
charlie2020 10-11-2002, 12:45 PM Originally posted by sonnypippo
can you elaborate on this statement?
I said (no) that a BOV does not need to be recirculated because it has a more aggresive spring that keeps it from opening during idle and cruise although if you like and the BOV allows for an attachment of a recirculation hose you can do that also but I figured most people that buy a aftermarket BOV do it for the sound and if you recirculate it you defeat the purpose and should have just saved you money.
sonnypippo 10-11-2002, 12:46 PM Originally posted by spicez
why pay the big price for an Aftermarket BOV to make a nice psshhhhht sound, when in the end you recirculate it.
Instead get any kind of OEM Bybass valve, you can probable find a really cheap on at a local scrap yard from any car that uses turbo/maf. i thought the point of recirculating was for better performance though? and an aftermarket bov provides the "better looks"... also, some aftermarket bov's and bypass valves can hold higher boost, right?
llaprad1 10-11-2002, 12:49 PM Has anyone tried one of these *hybrid* Bypass valves:
http://www.gofastbits.com/
newdimensions.com sells them for VWs and Audis.
They claim it recirc's enough air to eliminate rich scenarios, rough idles, etc., but allow some air to vent atmospherically for a PSSHHHT.
Just curious...
charlie2020 10-11-2002, 01:02 PM Originally posted by llaprad1
Has anyone tried one of these *hybrid* Bypass valves:
http://www.gofastbits.com/
newdimensions.com sells them for VWs and Audis.
They claim it recirc's enough air to eliminate rich scenarios, rough idles, etc., but allow some air to vent atmospherically for a PSSHHHT.
Just curious...
Yes, I've heard of them but you also have to remember that they are still more restrictive than stock CBVs so the safer route would be to get a full blown BOV and a SAFC to deal with the rich mixture during shifts (Dec. feature).
charlie2020 10-11-2002, 01:13 PM Originally posted by sonnypippo
i thought the point of recirculating was for better performance though? and an aftermarket bov provides the "better looks"... also, some aftermarket bov's and bypass valves can hold higher boost, right?
It is for better performance and gas milage. And your right almost all BOVs can hold higher boost pressures at the expense of not being able to open quick enough because of the higher spring rate and design to make the pssssh sound. Your walking a fine line between spring rate and vacuum if the spring rate is to high the vacuum won't be able to open it boost pressure inside the pressurized track will hopefully open it for you but by that time it has all ready started to surge on the turbo. Whereas a CBV with its weaker spring rates opens up immediatly.
sonnypippo 10-11-2002, 01:14 PM thanks for all the insight.
llaprad1 10-11-2002, 01:28 PM Originally posted by charlie2020
Yes, I've heard of them but you also have to remember that they are still more restrictive than stock CBVs...
But would this be suitable to run 7-9psi of boost (what I will run)?
Hybrid_DET 10-12-2002, 01:32 AM So from what I read, I need to replace my BOV since it makes that goose honking sound. Is that what you suggest Charlie?
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