bov a must?

[gtrte37]

hi new to the gtr scene, was wondering if my car needs a blowoff valve, its a single turbo hks
t04e, with external wastegate, but i found out the car had no bov, some people say its a must others say its good to have one, some ppl say its not needed?and how will it affect the turbo?

[gtrjon]

no you do not need one! infact im sure you have two they are just recirculating rather then atmospheric. The stock recirculating ones are actually better for the performance of your car then atmospheric ones. however they do sound sweet so i have a couple

[M13]

There are two bov stock because you have two turbos and they need to recirc to each inlet piping.


PPL don't get that and pay more money for 2 atmospheric. LOL


But as for NO BOV vs BOV, you can search. I haven't run one for a year and half and absolutely NO problem here. Response is amazing.

[DarkCaporaL]

What turbos are you running M13?

The only thing you will get with no BOV is off throttle surge, which is the surge you dont have to worry about.

[gtrjon]

lol look at his dp. hes running a rb20. big single not sure what one tho.

[rak123]

Go to nelsonmxmarc's build thread and look at his big write about how not running a bov doesn't cause problems. He has links and explains that the noise isn't compressor surge but merely a disruption of the air flow in the intake piping.

[M13]

lol look at his dp. hes running a rb20. big single not sure what one tho.

nah, a medium small single


Off throttle surge is ok. On throttle surge is bad.

Keep in mind, everytime you use your turbo, you are reducing its life (like any components) The off throttle surge does reduce its life, but it would be an overstatement to say it "kills" it. That's like saying working a 12 hour shift instead of an 8hr one kills a person.

[Skym]

My mates GTR racecar has no BOV's with 0 surge, but with non ballbearing turbo's you can do that. He floors it on the racetrack.

R35GTR is the same on racetrack, but is said to have non ballbearing turbo's. One thing you'll notice is the trans changes quickly, so turbo's are always spooled up.

BOV helps to increase transient response (transient hp). Basically keeps the turbo at optimum rpm, so engine, turbo responds quicker after a gear change. The slow down due to pressure wave reversing direction when throttlebody closes and going across compressor wheel, then having to speed up again is not good on CHRA.

My car has a BOV and is alot more responsive with transient response than my mates GTR racecar. But with single turbo, BOV, etc it should be.

[Dragon Humper]

My car never came with one either, there was a closed off piece of aluminum pipe plugged in to where the factory BOVs are supposed to go. I put one on and drove it for a year, took it off and drove it for a month, put it back on, took it back off........I can't tell any difference in response (which is very good by the way.....big single poo-pooers).

Apparently the T-88s and the T04s are very robust and can take alot of punishment, they were industrial turbos in a previous life. I'm leaving mine off, sounds bitchen.




Jon.

[gtrte37]

looks like ill leave it for now, my car is the same, just a closed off piece of pipe where the stock bov were

[nelsonmxmarc]

That's like saying working a 12 hour shift instead of an 8hr one kills a person.

Lol - that's good

[Skym]

Hub Dyno can measure transient hp.

[Bruizer]

Lol - that's good

Meh, I work 12 hour days, 3 days, 3 nights, 6'days off. Like a small vacation every 2 weeks. It's great and pays much more than 8 hour days.

[DreadedFist]

My crushed OEM bov was barely opening at all. When it wasn't crushed, there was a noticeable amount of time after a shift where the pipe work and cooler were being filled back up. When the crushed BOV wasn't opening, that "lag time" was nearly non-existent. After a few weeks I got a bit worried about tsu tsu tsu because I have the original RB20 turbo. Shaft play hadn't increased.

I say run no BOV just because tsu tsu tsu tsu.

Also I guess because response is much better.



















tsu tsu tsu tsu

[Skym]

My mates GTR racecar has a bit of lag before it moves when he puts his foot down after backing off throttle (no BOV).

I used to get similar lag with modifed stock BOV when transistioning from offboost to boost. But after I switched to Synapse BOV that lag disappeared (nearly instantly back onto boost and car accelerates while it transistions) and response of engine when pressing throttle is nearly instant. It's like a NA engine. It was something I wasn't expecting to happen.

Still have to tweek the ECU tune to suit, so it's just going to get better.