Boost in neutral...a bad thing?

[notched86]

Ok, so it's not a 2.3, but it is a turbo. Besides, I'd rather trust you guy's word than the jack offs over on srtforums.


Anyway, I recently put a blow off valve on my SRT-4, and I noticed it now can build 5 PSI in neutral, even at a dead stop. It never did this before I put the BOV on. It boosts the same 13-15 PSI as it did before, and it certainly doesn't feel any slower. I asked the folks on SRTforums and they said "You don't want your car boosting in neutral. Something is very wrong."

Is it really a big deal? What is so bad about boost in neutral?

 

[My80Cobra]

BOV leaking causing a rich condition and creating a load therefore causing it to build boost..

 

[notched86]

Keep in mind this is not your normal external blow off valve either. It is actually a 1/2 inch thick aluminum plate with vents that bolts in between the turbo and the stock surge valve. The BOV goes off even in vacuume if you abruptly let off the gas. (however this is normal and all stock SRT-4s with this blow off valve do this for some reason)

I honestly don't see how it could be leaking...the bolts are all very tight, and I used a little grease on the gasket so it sealed good. If it is not leaking boost in a gear, I don't understand how it could leak in neutral.

And does this boost in neutral hurt the car at all?

 

[bhuff30]

How much do you have to rev it to build the boost? Normally, you won't be able to make boost in neutral becuase there simply isn't enough load on the engine, but if you rev it up high, and goose the gas some then I could easily see making boost. I bet the chevy put on an undersized turbo to get a fast spool up, so this makes it even more likely to build boost in neutral.
It won't hurt the car, but reving it up high in neutral isn't healthy for any engine.

 

[notched86]

Yeah it's a small mitsubishi turbo, spools almost instantly with full boost if your above 2,500 RPM. It hits the 5 PSI in neutral if you rev it about 3,100 RPM or higher.

 

[351wcoupe]

I was messing around today and the coupe makes full boost(20psi) by 2600 in 5th.

If I go WOT off idle I can make 2-3 psi just as it the green car sits. I would tend to believe the "releasing air, going rich idea"

 

[Stinger]

Sounds normal to me...I could blow off my RFL on the SVO without building boost...