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My link to the duck call BOV was a spoof. I didn't think that it would be considered as a comparison of what looks to be an excellent product with unique functional features. I have edited the link out of my posting.
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Someone thought the duck call was a real BOV?
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2014 Cayman S 2011 Cayenne Turbo 1979 930 (475 rwhp at 0.95 bar) |
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Ben 914-6 2.4s GT tribute. 914-6werkshop.com manufacturer of 914-6, GT, Conversion parts Last edited by mb911; 01-27-2008 at 01:36 PM.. |
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Forced Induction Junkie
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BOV should be around $100-125, a wastegate (Tail 46mm) is close to $200
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Dave '85 930 Factory Special Wishes Flachbau Werk I Zuffenhausen 3.3l/330BHP Engine with Sonderwunsch Cams, FabSpeed Headers, Kokeln IC, Twin Plugged Electromotive Crankfire, Tial Wastegate(0.8 Bar), K27 Hybrid Turbo, Ruf Twin-tip Muffler, Fikse FM-5's 8&10x17, 8:41 R&P |
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I am a tial dealer and BOV's sell for 200 and 46mm WG are $450 so your numbers are a bit off for real Tial products.. but your right they SHOULD be a bunch cheaper
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Ben 914-6 2.4s GT tribute. 914-6werkshop.com manufacturer of 914-6, GT, Conversion parts |
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Yea I was going to say the same thing. What the price should be, and the unfortunate reality of what they are tend to be a bit different. Average retail prices for the high quality line of diverter valves listed below: Tial 50mm $220 Syncronic $215 Turbosmart $259 APS twin vent $248 HKS SSQV $205
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Adam Hennessy |
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OMG! I got mine at a good time then. Two years before the dollar plummeted. ![]() Yes, it's a real Tial.....
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Dave '85 930 Factory Special Wishes Flachbau Werk I Zuffenhausen 3.3l/330BHP Engine with Sonderwunsch Cams, FabSpeed Headers, Kokeln IC, Twin Plugged Electromotive Crankfire, Tial Wastegate(0.8 Bar), K27 Hybrid Turbo, Ruf Twin-tip Muffler, Fikse FM-5's 8&10x17, 8:41 R&P |
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And for the CiS guys, Tial is coming out with a recirc version of the 50mm blow off valve. It uses what looks like the same flange as the 50 as well. The only problem with it is that it looks like a bong- but I imagine it would look cool mounted on the back of a Kokeln or B/6 Intercooler.
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Kris @ Tech9 86' 930/GT-40R Sold ![]() 94' Rustang GT daily (long gone) 2008 C6/Z51 Corvette |
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Macht Schnell
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Hello, How much of the Recirculating\Shuttle Valve\Bypass will it allow you to get rid of? Les
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---Les Garten---85 930, Andial IC, GHL Headers, Fabspeed Dual, K-27 HF2, 3.4 JE Full Finned 7.5:1 CR, 964 CAM'd, Carerra 3.2 Manifold Cut/Flipped, Tec3r, Siemans 55#, GSF Fuel Rails, Clewett Crank Trigger, Clewett Cam Trigger,Dual Plugged, ARP Head Studs/Rod Bolts, Clewett Wires.Tial 46mm WG, Tial 50mm BOV, WEVO Shifter,934 Boost Gauge, Wideband EGO Sensor/Gauge, C2T Head Gaskets, '88 MB 300TE,BMW R100RT |
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It's a BOV, for gods sake. A thing that should recirculate the air when you lift of the throttle. This is starting to sound like a thread from "Fast & Furious" forums
![]() BOV doesn't give any more power. It's shut when you boot it. OEM BOV works fine, it's just a bit overengineered. Also, I'm very sceptic about turning BOV into pop-off valve. As soon as you get bleeding metered air in a car equipped with anything else but MAP (of MFI) the engine runs richer than it should. You make turbo pump air that's being dumped overboard, essentially burning fuel to pump air oboard. Quote:
Wastegate is there to limit the massflow trough turbo, limit it's RPM and lessen the backpressure. You don't know if "turbo is working at it's peak efficiency" wothout knowing exact compressor map and the mass flow for turbo involved. I won't delve deeper into issue but let me say that regulating boost by pop-off valves belong to early days of turbocharging history and should stay there. Only production car that regulated the boost this way I saw was an old Mitsubishi Pajero Turbodiesel. It didn't have the wastegate and just let the turbo deadhead and then had the pop-off set slightly in the middle to get rid of excess boost if turbo should happened to boost little extra on a sunny day. So to wrap it up: You control the boost with wastegate, period. It's the best and most efficient way to do it. That makes sure it doesn't spin more than it should and that all metered air goes into engine. It also means you don't have uncontrolable air leak which must be compensated by fuel-injection should it occure. You control transient overrun boost peaks with BOV. That's why it's there. It's used only for that and it's main function is to prevent harmful boost peaks. It doesn't make more power otherwise. It's closed shut during WOT. Last ten years it found a new use, to make funny sounds which makes car sound "racey" which spawned a whole slew of cottage industry making "funny sounding thingies" that don't make any difference and if wrongfully configured, and sometimes cars run rich. Exuse me for sounding like all-knowing ingorant prick but there is a substantial reasoning behind manufacturers fitting wastegates and BOV's to their car and not making them sneeze or bleed boost into air. Regards,
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![]() Thanks Goran!
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Ben 914-6 2.4s GT tribute. 914-6werkshop.com manufacturer of 914-6, GT, Conversion parts |
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![]() So please, have a little more faith in a fellow Pelican member. It's why we are here anyway...to collaborate and discuss different ways of producing power, tuning, different setups, helping each other out, etc....even if they're not always P-car related. I admit that I too have been skeptic on topics in the past but just sit in and ride it out to the end to see if anything actually becomes of it rather than shoot the ideas of soemone right to the ground based on what "I" know or have heard. ![]() Regards,
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Adam Hennessy Last edited by BoxxerSix; 01-28-2008 at 06:01 AM.. |
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Hello Adam!
We are here to "collaborate and discuss different ways of producing power, tuning, different setups" but critical remark on fundamentaly wrong strategy of venting boost pressure into athmo at WOT is "irrogant/sceptic"? ![]() Well I guess I have to talk from Porsche perspective then. It's simple physics. You are wasting fuel pressurizing the gas by spinning turbocharger. What's even worse, gas that has been metered up by fuel injection which will inject the bookmarked amount into fuel into engine. So instead of using this gas to raise VE, you dump it overboard but still inject the fuel? Of course, air dumped aboard is also warmed up by inefficient compression process and then cooled by intercooler. Turbo is also demanded to compress more air than it should, as part of it is vented overboard. Results on otherwise stock car (be it CIS or any other non-Speed/density system): Higher turbo RPM, more heat soak into intercooler, lower MPG, higher backpressure (as turbo isn't bypassed), richer mixture. Frankly, I don't see the benefits except maybe (and this is a strech) the fact that turbo is spinning faster and it's inertia might let it lag less between the shifts. Thus this might work on a one-off drag-racing car with gigantic turbo, with lot's of shaft-inertia and typical working point to the left of efficiency island. Then it needs to be custom-maped to compensate for VE-missmatch due to bleed. It's not a scenario that can be applied to typical P-car. Potential problems are much bigger than eventual gains. Let's take a look at typical K27 compresor map, should we? The pressure ratio is vertical, the mass flow is horisontal. What cold side bleed does is effectivly pushing the working point on the map to the right. As turbochargers are most often sized to have most effective working point somewhere in the middle range, and then allow some extra huffing on the high revs (w/o surging or overreving the impeller), pushing the point to the right (while retaining the same pressure ratio) will only make efficiency drop even more. Let the bleed open too much and you will punch trough Vne of compressor blade tips or a stall, with damages to follow. Call me ingorant but I really fail to see benefit of bleeding the air from pure efficiency point of view (and then there are the fueling issues on the top of it). ![]() You are of course welcome to explain the special ordeal that makes popper better than ordinary BOV/Wastegate combo and/or debunk my analysis of it. We might learn something from it. Regards, Goran
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Thank you for your time, Last edited by beepbeep; 01-28-2008 at 07:09 AM.. |
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Maybe I missed it, but could you describe the problem and how you solved it exactly? Where do you plave a BOV where it can do both functions? Les
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---Les Garten---85 930, Andial IC, GHL Headers, Fabspeed Dual, K-27 HF2, 3.4 JE Full Finned 7.5:1 CR, 964 CAM'd, Carerra 3.2 Manifold Cut/Flipped, Tec3r, Siemans 55#, GSF Fuel Rails, Clewett Crank Trigger, Clewett Cam Trigger,Dual Plugged, ARP Head Studs/Rod Bolts, Clewett Wires.Tial 46mm WG, Tial 50mm BOV, WEVO Shifter,934 Boost Gauge, Wideband EGO Sensor/Gauge, C2T Head Gaskets, '88 MB 300TE,BMW R100RT |
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Hi Goran,
How does a WG limit backpressure on a Turbo? Seems like it would limit Feed Pressure? Les
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---Les Garten---85 930, Andial IC, GHL Headers, Fabspeed Dual, K-27 HF2, 3.4 JE Full Finned 7.5:1 CR, 964 CAM'd, Carerra 3.2 Manifold Cut/Flipped, Tec3r, Siemans 55#, GSF Fuel Rails, Clewett Crank Trigger, Clewett Cam Trigger,Dual Plugged, ARP Head Studs/Rod Bolts, Clewett Wires.Tial 46mm WG, Tial 50mm BOV, WEVO Shifter,934 Boost Gauge, Wideband EGO Sensor/Gauge, C2T Head Gaskets, '88 MB 300TE,BMW R100RT |
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What I mean with "backpressure" is the pressure engine feels opposing the gases as they exit the heads. As wastegate essentially routes gases around the turbo, it will also make backpressure drop somewhat compared to the case where wastegate is always shut and pop-off valve is utilized to controll boost.
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1 thing should be noted. if you look at Goran past post you will quickly understand he is far more knowledgable on this topic then 98% of us. He has done more with different cars then we hope to do so he is speaking from experience and knowledge both..
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Ben 914-6 2.4s GT tribute. 914-6werkshop.com manufacturer of 914-6, GT, Conversion parts |
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Macht Schnell
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Quote:
Clear as Crystal. I thought by the way that you worded it that you meant Backpressure on the Turbo itself. Thanx! Les
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---Les Garten---85 930, Andial IC, GHL Headers, Fabspeed Dual, K-27 HF2, 3.4 JE Full Finned 7.5:1 CR, 964 CAM'd, Carerra 3.2 Manifold Cut/Flipped, Tec3r, Siemans 55#, GSF Fuel Rails, Clewett Crank Trigger, Clewett Cam Trigger,Dual Plugged, ARP Head Studs/Rod Bolts, Clewett Wires.Tial 46mm WG, Tial 50mm BOV, WEVO Shifter,934 Boost Gauge, Wideband EGO Sensor/Gauge, C2T Head Gaskets, '88 MB 300TE,BMW R100RT |
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Wow, this string got lively today.
Adam, all of Goran's points are valid. I see his issue is your conclusion that the application of this BOV is "efficient". It is a compromise of efficiency to solve your problem. If the car won't run, you have a dissatisfied customer and that is reason enough to compromise but of the issue it's inefficient there is no doubt. Just ask a CART driver who has just cranked his W/G setting too close to the series mandated pop off valve pressure. Once that valve pops power drops immediately and this happens from increased negative differential across the engine - pumping and compressor efficiency loses. Based on your desired 24PSI manifold pressure your application is considered high performance. It's possible you are trying to use low-mid performance type hardware and techniques to tame the very high pressure spikes that are traveling back and forth in your racing engine's manifold. Could be you can relocate the sensing line and or snub their signal or better look to what Porsche and others did in this situation. If you fabricate a butterfly valve with mechanical linkage tied to the throttle you have positive mechanical, vs pressure, activation. Then you can go back to using your W/G in it's proper function. |
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hey, speaking of wastegates, does anyone in here have experience with the Tial 44 v-band gate with a large frame turbo? I am going to run a divided T-4 housing on my 37 for quicker spool-up and wanted to know if I should maybe purchase a second 44 wastegate to regulate it. I know that the V-band housing is much newer and more efficiant than our old 46 gates.
P.s Is anyone interested in a Tial 46 gate, I got one for sale.
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Kris @ Tech9 86' 930/GT-40R Sold ![]() 94' Rustang GT daily (long gone) 2008 C6/Z51 Corvette |
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