Blow off valve on TD42

[BossGQ]

Hey guys just wondering if its worth fitting a blow off valve on my TD42, it's got a safari turbo kit running 6lbs of boost but im getting a full service and having dyno'd and all that and probably gonna crank the boost up to 12lbs, apart from it sounding awesome, would it there be any performance benefits, also is 12lbs to much to run if i still want reliability, cause it goes alright at the moment but it'd be nice to just have that little bit extra when towing and all the rest off it.

[nissannewby]

12psi will be fine. As for the blow off I'm pretty sure its a bit of a pain to set up as blow off valves are usually put in systems with a throttle body and diesels dont have these. and i reckon these sounds should be left for the rice boys lol.

[97_gq_lwb]

If you want everyone to look at you and think hmmmm what a tosser .
Other then that i can't see any benefit.

[aaron]

onley petrol's have them tho if you want to be a tossa and stuff your motor go for it. hahaha

[aaron]

sorry was a bit harsh your td4.2 dose not have negitav boost as if you fit 1 you will drcrease your power and cause the motor to blow up possably.... if i was you dont do it ull be sorry.... if you want 1 put a tb42 in it with a turbo kit they go quite well......
that is the differance between petrol & Diesel......:smileyvault-cute-bi

[HammerBuilder]

sorry was a bit harsh your td4.2 dose not have negitav boost as if you fit 1 you will drcrease your power and cause the motor to blow up possably.... if i was you dont do it ull be sorry.... if you want 1 put a tb42 in it with a turbo kit they go quite well......
that is the differance between petrol & Diesel......:smileyvault-cute-bi

I think but don't quote me on this aaron but most newer electronic injected diesels like the ZD do have a throttle body setup please correct me if this is not so, but on the D40 navara it has, not sure on 4.2 diesel ... so if you have the newer chances are you may already have some sort of blowoff system BossGQ my 2.8 GQ has 1 on the front of the intake manifold but is not adjustable & is set to 14psi to protect the engine, I run a turbosmart Boost T to adjust my boost on the line that goes to the wastegate actuator

Cheers TonyD

[Chaz]

Even though many diesel engines have a throttle body, no diesel engine is throttled so a blow off valve is useless. The so called throttle valves on diesels are for swirl control and engine shut down (ZD30) and boost control for EGR. None of them have anything to do with throttling.

[BossGQ]

oh ok sorry bout that guys i was unaware that you cant fit a blow off valve on a diesel, but i guess you learn something everyday eh

[HammerBuilder]

Even though many diesel engines have a throttle body, no diesel engine is throttled so a blow off valve is useless. The so called throttle valves on diesels are for swirl control and engine shut down (ZD30) and boost control for EGR. None of them have anything to do with throttling.

Ok then so there you go you can teach an ol' dog new things cool now I understand them a bit more
Cheers Chaz

TonyD

[dmgq]

it can be done but no real benifit on your diesel except the boy racer aspect , i have fitted one to a gu 2.8 using the live by wire throttle postion sensor on the pedal to activate a vacuum solinoid when throttle is in the closed postion thus suppling vacuum from the vacuum tank to the blow off valve . Worked well but no real benifit at all.

[Ben-e-boy]

the closest thing to a blow off type noise is to run no muffler. when you back off at high boost, the sudden decrease in impeller speed causes it to make a howling noise, apparently its much louder if you have a 2.5 indump pipe and 3 inch exhaust no muffler. mine does it with a full 3 inch exhaust no muffler 13 psi

[BossGQ]

Yeah alright thanks guys

[aaron]

just put on a big ass waste gate on and free dump it that will make some good noise lol..............................dump that exhaust pressure wosssssss!!!!!!

[Robo]

Complete waste of time.
A BOV is to reduce back pressure on a turbo when a throttle body and or carby is closed.
given most diesels don't have this system, there is no sudden restriction in air flow to put back pressure on turbo spool.

also the idea of plumbing back the waste boost back into the system between air cleaner & the turbo helps spool,
less neg pressure is placed upon the turbo inlet.
plumb back, not only the reduces noise, but any fuel vapors etc are also recovered.
keeps the enviro police off your back.