boosted hybrid

I saw that Geoff posted this is a new option for his full-race kits. I am fabricating a kit up for my girlfriend and wanted to see what this would look like. If anyone has a link of a picture i could check out, or Geoff if you could post some pics. I am very interested in doing this.

Flamenco-T

okay, re-routing back to turbo inlet or intake piping...

for intake piping, depending on your BOV brand, you need to buy an adapter that you can clamp a hose and route back to intake piping..

for turbo inlet, I'd imagine you need the above and a one way check valves ( to prevent hot exhaust gas to go in your intake manifold) that can withstand high temp heat and to fab your manifold where the collector is located to the turbo inlet....

stan

Full-Race Geoff

stan said it... ill have some pics shortly of this setup.

Loco Honkey

Running it back into the TURBO side? If I'm understanding right, it'd help keep the turbo spooled between shifts, but what would that do to your A/F ratio assuming your O2 sensor is downstream of the turbo like 99% of us have it?

boosted hybrid

Awesome. I am still having some trouble imagining this. I drew out some pictures of how exactly this would work, I came up with venting it back into the exhaust manifold. BTW, I bought the Tial BOV for her car so i think that it has a big dumphole to weld a pipe onto it for recirculating. Where is the optimum place to have the BOV when doing this? I am thinking right after the turbo compressor..

DIRep972

iTrader: (1)

for the intake, you would want the bov after the intercooler so the air going back into the intake is cooled.

but if u routed it into the exhaust i guess u would want hotter air? I am curious also to how the cool air going through the exhaust would effect EGT's and 02 readings.


[Modified by DIRep972, 5:29 PM 11/15/2002]

racerxadam

I don't think you would notice a dramatic difference in the o2 readings because during a shift the injectors are already shut off giving a very high a/f reading. Maybe you would experience an extra .xxx seconds of lag between a peak a/f reading and the actual. It shouldn't really matter though because what the sensor doesn't realize is that gas hasn't acutally gone through the engine. Egt readings could change momentarily but it would depend on where the probe is located. My egt gauge doesn't move very fast so I don't think it would even register.

Vanilla Ic3

Why would you want to route your blow off air into the exhaust side? Sounds dangerous to me. Isn't there some way to damage your exhaust valves or turbine wheel by subjecting it to extreme air temp fluctuations? Not to mention the nasty backfiring you could cause, and risk of your engine injesting dirty exhaust air. I'm skeptical that this would actually help keep your turbo spooled seeing as how the bov air is only 5 to 20psi. The exhuast pressures that spool up the turbo are much higher than 20psi, arent they? I understand routing the air from the BOV back to the inlet side of the compressor... but the turbine inlet?? I don't get it.

Full-Race Geoff

find some pics of rally cars for more info on this. its not new, and yes it does work.

no damage to valvetrain. oxygen content doesnt matter becuase you are at zero throttle and the check valve is there to keep the motor from ingesting dirty air.

on a MAP car I always prefer that the BOV goes before the IC so that it vents hot air.

Full-Race Geoff

the EGT should always be mounted immediately in front of the port, preferably on cyl 3. The EGT will never see the fresh air.

prophet

common sense tells me you are right, however since I'm not very good with physics I can't really comment.

however wouldn't the sudden gush of air (from the bov) create turbulence ?

Full-Race Geoff

if airflow is what spins the turbo, turbulent flow is going to be better than no flow.

Full-Race Javier

correct, reusing some wasted energy is better than not using it....but wait, isnt that what turbos are all about

Flamenco-T

yeah true, the EGT should be on the runer to read almost the exact temp when it comes out of the head...

and I don't think that air would vary much on the O2, besides at that point, the throttle is at zero and the temp is dropping anyhow....and it would not have caused any damage due to different temp

stan

geoff, Javier and Jon :

Vanilla Ic3

Hrrms, I think I understand what you are saying Geoff. The throttle plate being completely closed means that, basically there is no airflow coming out of the exhuast vavles to the turbine inlet. I've heard about the "bang bang" setup the rally cars use, but I've always assumed that they simply injected fuel into the exhuast manifold, I had no idea they "injected" air instead/also. Your prefrence for mounting the BOV on the hot side of the IC has me thinking too now. I had originally planned on mounting it as close as possible to the throttlebody. I've learned something new today. Two things actually.

xci_ed6

They don't need to inject fuel into the manifold, they just run an overly rich mixture instead. I know 1G talons do this when you vent the BOV, because air keeps comming through the MAF sensor. If you were to vent the BOV into the mani they would have a built in anti-lag system.

For a ghetto system you could use EGR parts because theye are designed to handle the heat.

-Dustin