Help! BOV on Evo 7

waikeatyeo

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To all evo 7 sifus , is there any problem to install a bov on a evo7? ive heard tht it will make the engine lag or something like tht.. anyone experienced this b4 kindly feedback me pls.. thank u very much!
 
hello all sifus out there.I have also been told the same thing i.e that the airflow sensor cant read after installing bov on E7..so have been holding back installing on my car.Can anyone pls help us out?
 
EVOs use a MAF, which meters air into the intake loop prior to the throttle body, what goes in, stays in as far as the ECU is concerned.

This is why the EVO uses a recirculating valve, that is you already HAVE a blow-off valve, just that it doesn't do an atmospheric dump to make that 2F2F sound so many people expect from a turbocharged car.

If you install an atmospheric BOV, what you do is allow air that the system thinks is still in the system to escape, which means that when you shift, you run rich. You may also stall if you jump quickly from the accelerator to the clutch, for example in slow traffic or at intersections.

Some people experience relatively few problems, some people experience more, so your mileage may vary if you decide to install an atmo BOV as long as you maintain the MAF setup.

The only real way to make sure no problems will exist is if you have either a blow-through or MAP intake metering system. Otherwise, make sure you don't throw away your original valve ;)
 
thanx cannonfodder,.. wat about the hks ssqv kit for evo 7-9? is it meant for the evos? i tried asking my fren who has the kit on his evo 7, he said nuthins wrong since two years ago.. but it does happen to other evo 7 out there.? thanks
 
actually is the sqv got horror stories.. the ssqv is an improve version of the product... there are many types of BOV in the market.. each has their own specs and limitations.. like some BOV can only withstand only a certain boost presure only.. for instance 1.5bar.. above 1.5 bar will need a bigger BOV or "Racing type"..
 
guys.. just installed ssqv kit bought from N1... only for a week... got horror stories on this product??????? well i have to experience myself to know the truth.. hope nothing happen... god bless me..
 
nothing should happen unless it's installed wrongly..hehehe... the new ssqv is now quite stable compared to the older model sqv
 
The SSQV's positive pressure design is a good and bad thing. Good in that there is no limit to the amount of boost that it can hold. If you can make 2Bar, it will hold 2Bar.

The bad thing is that because it uses positive pressure to keep the valves closed, it is slow to vent when it needs to and this leads to compressor surge, the very thing that a BOV is meant to prevent.

If you install an atmospheric BOV into a stock EVO, there is no such thing as no problems. You will have issues, just a matter of how minor or how severe. If you're lucky enough, you may just have a problem running rich so you won't see any noticeable problems beyond the occassional pop in the exhaust.

If you are unlucky, you may experience stalling under throttle transition, stalling at idle (all BOVs execpt SSQV are designed to leak at idle), bucking when trying to modulate the throttle under boost, etc.

Again, your mileage may vary as each car is different.
 
cannonfolder is correct, my E9 at when running at 6 speeds, when i release my throttle, i can feel like a bit chock, donno is my imagination or not after reading so many case... kekekeke

FYI, i am using SSQV now.

ANy sifu can advise more?
 
saiyuke,

What you can do is put your car into 4th/5th gear, drive it up to around 4500-5500 rpm and then try to modulate your throttle by gently lifting and reapplying pressure on the accelerator.

If you are having issues with the SSQV, your throttle inputs will be juddery rather than smooth. There really is nothing you can do if this is the case, it's just that the EVO doesn't like atmospheric valves. Don't go and adjust the SSQV (if yours comes with the adjustment screw) as this will only increase compressor surge, not a good thing with the IX's turbo. If it's smooth, then you're probably fine.

Did your car come with the SSQV or did you swap out the stock valve?
 
saiyuke,

What you can do is put your car into 4th/5th gear, drive it up to around 4500-5500 rpm and then try to modulate your throttle by gently lifting and reapplying pressure on the accelerator.

If you are having issues with the SSQV, your throttle inputs will be juddery rather than smooth. There really is nothing you can do if this is the case, it's just that the EVO doesn't like atmospheric valves. Don't go and adjust the SSQV (if yours comes with the adjustment screw) as this will only increase compressor surge, not a good thing with the IX's turbo. If it's smooth, then you're probably fine.

Did your car come with the SSQV or did you swap out the stock valve?

Thanks bro... I will try it later. If really have juddery case(hopefully not & touch wood:mouth_closed: ), will it hurt my E9?
 
am using SARD R2D2...no probs for my CT9A...thinking of upgrading...its only 4 months old..anybody want?..

Rm200 hehehe...
 
Quick and simple:

MAF + VTA BOV = Engine Flutter or Stall (only problems with evo7, havent heard such issues on e8/9)

Possible solutions:
1. use re-circulate BOV like Greddy RS, SQV with recirc kit (hard to find) or ori BOV.
2. install HKS EIDS which cost around RM400+
3. change to a MAP (intake manifold pressure) ECU instead of MAF
4. don't use your aircond

I personally tested option 1, 2 and 4 and it works. But i am sticking with EIDS but removing soon after replacing my ECU. Let me know if anyone is interested in my EIDS.

Cheers!
 
re

Quick and simple:

MAF + VTA BOV = Engine Flutter or Stall (only problems with evo7, havent heard such issues on e8/9)

Possible solutions:
1. use re-circulate BOV like Greddy RS, SQV with recirc kit (hard to find) or ori BOV.
2. install HKS EIDS which cost around RM400+
3. change to a MAP (intake manifold pressure) ECU instead of MAF
4. don't use your aircond

I personally tested option 1, 2 and 4 and it works. But i am sticking with EIDS but removing soon after replacing my ECU. Let me know if anyone is interested in my EIDS.

Cheers!
My advise would be item 1. Cheapest and best way
 
Im using BLITZ bov currently.Sound is good..sound like people caughing..cough..coughhh...
 
Wat about HKS type 2 and Greddy Type R. Which one have the louder sound?

Am using Greaddy type RS but thinking of changing to either HKS Type 2 or Greddy Type R
 

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