Just got my HKS SSQV and it sounds great! No idle problems or CEL. Got it for $348.75 plus s/h. I've always loved the way the HKS BOV's sounded. Heres a link to where I bought it from.

http://www.advancespeedshop.com/ssqv-sequential-blow-valve-08up-mitsubishi-lancer-71004am015-p-7428.html

http://www.modyourcar.com.au/product_info.php?products_id=451

Anyone install the apexi twin chamber bov on their evo? or know of anybody who has?

Think you forgot about the cost, that was a sacrifice too! Glad to hear you like the bov. May I ask, do you have stock intake?
**Sorry for the delayed response**

Yes the cost was a pretty good sacrifice also....! :D

And yes I am still running stock intake......for now.

I was asked to record a video of the SSQV BOV on my car. Here it is. Please note, that the sound the car makes while standing is not the same as when it's moving. When the engine is under load the BOV sound is much louder and agressive. I've seen people trying to record it in motion, but there's always to much ambient noise and without special equipment it's hardly possible to reproduce it. But for what it worth (1.8 MB):
http://rapidshare.com/files/129961574/HKS_SSQV.wmv.html

And Youtube:
http://www.youtube.com/v/w9W8r4c81Cs

that sounds good. after i bought the agency power i saw this one. ill probably change. is it a quick buy or are there other parts that id have to order to get it to work???

Hum, the X does have a map sensor, but I am pretty sure it still runs off of metered air through the MAF. If this were the case, venting to atmosphere would essentially cause the ECU to dump a certain amount of fuel for how much air is being metered, but everytime you blow off there is air that goes un accounted for... so the ECU continues to feed the engine fuel for more air than is being introduced into the cylinders, causing a rich condition, causing the hesitation that people say "oh its not a problem," when in reality they just learned how to deal with it, and adjusted their driving habits, which I am not willing to do.

As for the advantage of upgrading your BOV, its a better seal, it responds quicker to boost allowing for a smidgen of quicker spool up, holds more boost and holds it longer. If you are buying a BOV because it "sounds" cool, then you really don't need to be driving an X.

Lastly, the BOV is much more noticable with a cone filter for a couple of reasons, the stock unit is quite restrictive and also a sound deadener, the majority of car owners don't want to hear the sucking of the turbo or the blow off of a BOV, they would have customers coming in left in right describing this "problem" they are having with this funny noise coming from the engine, and the cone filters always tend to resonate sound a little better, not sure why, maybe something to do with the design.

bahabhasha

Hum, the X does have a map sensor, but I am pretty sure it still runs off of metered air through the MAF. If this were the case, venting to atmosphere would essentially cause the ECU to dump a certain amount of fuel for how much air is being metered, but everytime you blow off there is air that goes un accounted for... so the ECU continues to feed the engine fuel for more air than is being introduced into the cylinders, causing a rich condition, causing the hesitation that people say "oh its not a problem," when in reality they just learned how to deal with it, and adjusted their driving habits, which I am not willing to do.

MAP sensor doesn't run off anything, it just measures pressure. As per the same MAF story everybody keeps repeating, it doesn't explain this:
- Reach or lean condition occurs in the actual engine cylinder where air is mixed with fuel
- Both BOVs (VTA and recirc) are venting the air AWAY from the engine because the throttle is closed and this air should be taken out to prevent it from hitting back on the turbo. Which means with both BOVs the amount of air entering the engine through the closed throttle is always the same.
- the only difference is that one VTA and the other vents into the intake BEFORE the turbo, which means the same amount of air is sucked by the turbo coz it's low pressure area.
- when throttle opens, both BOVs close and all air gets into the engine again, again same amount.
- so, where is this rich condition everyone is talking about and how can it possibly occur? Am I missing something?

Ok, Ill try and use numbers for a reference point.

Air goes through the MAF, reads 10 (for sake of explanation), with a VTA BOV when you let off the throttle, the air that is blown off into the atmosphere is lost, period... so now you have a reading of 10 (metered) and you lose 2 to the atmosphere, so that air going into the engine is now less than what was metered, air intake at 8 with fuel for 10, it is in a rich condition.

NOW, when you recirculate, this 2 that you blew off into atmosphere with the VTA BOV actually gets recirculated (hence the name), back into the turbo suction, so you meter 10, and you still have 10, because it is STILL accounted for.

I hope this helps.

The engine gets as much air as throttle will allow (which is closed or half closed when BOV goes off). The rest is blown off by the BOV, VAT or recirc - doesnt matter. In either case only 8 gets mixed with fuel.
And recirculating into the intake doesn't change the amount of air sucked by the turbo unless your filter is VERY restrictive.

Ok, I give up. When someone is convinced they are right, it doesn't matter what anyone else says...

I guess, same applies to you.
I heard that explanation before, but when I try to dig a little deeper, it doesn't go anywhere.

The engine gets as much air as throttle will allow (which is closed or half closed when BOV goes off). The rest is blown off by the BOV, VAT or recirc - doesnt matter. In either case only 8 gets mixed with fuel.
And recirculating into the intake doesn't change the amount of air sucked by the turbo unless your filter is VERY restrictive.

It's pretty straightforward. The recirculating valve is a closed system, so airflow that passes through the MAF also enters the engine, so it can be accurately used as an input for calculating necessary fuel.

The BOV (vent to atmosphere) is not closed, and therefore any air lost to the atmosphere is also detected by the MAF and assumed to be entering the combustion chamber, hence causing too much fuel to be injected.

In the same simple numbers:

BOV (to atmosphere):
- 8 enters combustion chamber
- 2 is vented to the atmosphere
- MAF reads 10 (= 8+2)
- Mixture is RICHER than expected since ECU injects fuel for 10 (based on MAF), but there is only 8 present

Diverter valve (recirculation):
- 8 enters combustion chamber
- 0 is vented to the atmosphere
- MAF reads 8 (= 8+0)
- Mixture is as expected since ECU injects fuel for 8 and 8 is present

Diverter valve (recirculation):
- 8 enters combustion chamber
- 0 is vented to the atmosphere
- MAF reads 8 (= 8+0)
- Mixture is as expected since ECU injects fuel for 8 and 8 is present
AFAIK MAF is located upstream from the valve, so how come it reads 8? Also, diverter still vents away from the chamber, so it's not a 0 vent, it's the same 2 vent. Therefore MAF still reads 10 and chamber gets 8.

AFAIK MAF is located upstream from the valve, so how come it reads 8? Also, diverter still vents away from the chamber, so it's not a 0 vent, it's the same 2 vent. Therefore MAF still reads 10 and chamber gets 8.

Ah, but you're missing the fact that it's a closed system.

The input is at the air filter, and the output is to the combustion chamber. On average, the amount of air entering the combustion chamber has to be equal to the amount passing through the air filter.

This is how the MAF reads the correct amount of air regardless of what the diverter valve is doing. The diverter valve is simply recirculating air.

Perhaps it's easier to understand with some further breakdown through every part of the intake system, as well as some new numbers (using grams per second of air) so that the number entering the combustion chamber is the same in each case:

Diverter Valve Config:
1) Air Filter: 10 g/s of air
2) MAF sensor: 10 g/s of air
3) Intake pipe just BEFORE diverter valve return connection: 10 g/s of air
4) Intake pipe just AFTER the diverter valve return connection: 12 g/s of air (10 from upstream in the main pipe, and 2 coming from the return connection)
5) Low-pressure side of the turbo compressor: 12 g/s of air
6) High pressure side of the turbo compressor: 12 g/s of air
7) Intake pipe just BEFORE the diverter valve: 12 g/s of air
8) Intake pipe just AFTER the diverter valve: 10 g/s of air (2 left through the diverter valve towards the return connection)
9) Entering the combustion chamber: 10 g/s of air

Blow-off Valve Config:
1) Air Filter: 12 g/s of air
2) MAF sensor: 12 g/s of air
3) Intake pipe: 12 g/s of air
4) Low-pressure side of the turbo compressor: 12 g/s of air
5) High pressure side of the turbo compressor: 12 g/s of air
6) Intake pipe just BEFORE the Blow-off valve: 12 g/s of air
7) Intake pipe just AFTER the Blow-off valve: 10 g/s of air (2 left through the blow-off valve and lost to the atmosphere)
8) Entering the combustion chamber: 10 g/s of air

In both cases we get 10 g/s of air entering the combustion chamber, but in the Diverter valve case we correctly read 10 g/s of air, but in the Blow-off vavle case we incorrectly read 12 g/s of air. This is because additional air needs to enter through the air filter to replace the air lost to the atmosphere through the Blow-off valve.

This is a well documented issue with fitting aftermarkt blow-off valves to cars whose engine management systems rely on MAF sensors.

The general solution for those that must have a blow-off valve (for the cool noise) is to move the MAF sensor to the high-pressure side of the intake (post blow-off valve). This would be putting it between numbers 7) and 8) in the Blow-off valve example above, and we would then get the correct reading of air.

Unfortunately the MAF sensor electronics are optimized to measure un-compressed air, so there is some error introduced when swapping it over to the high-pressure side.

Ah, but you're missing the fact that it's a closed system.

The input is at the air filter, and the output is to the combustion chamber. On average, the amount of air entering the combustion chamber has to be equal to the amount passing through the air filter.

This is how the MAF reads the correct amount of air regardless of what the diverter valve is doing. The diverter valve is simply recirculating air.

Perhaps it's easier to understand with some further breakdown through every part of the intake system, as well as some new numbers (using grams per second of air) so that the number entering the combustion chamber is the same in each case:

Diverter Valve Config:
1) Air Filter: 10 g/s of air
2) MAF sensor: 10 g/s of air
3) Intake pipe just BEFORE diverter valve return connection: 10 g/s of air
4) Intake pipe just AFTER the diverter valve return connection: 12 g/s of air (10 from upstream in the main pipe, and 2 coming from the return connection)
5) Low-pressure side of the turbo compressor: 12 g/s of air
6) High pressure side of the turbo compressor: 12 g/s of air
7) Intake pipe just BEFORE the diverter valve: 12 g/s of air
8) Intake pipe just AFTER the diverter valve: 10 g/s of air (2 left through the diverter valve towards the return connection)
9) Entering the combustion chamber: 10 g/s of air

Blow-off Valve Config:
1) Air Filter: 12 g/s of air
2) MAF sensor: 12 g/s of air
3) Intake pipe: 12 g/s of air
4) Low-pressure side of the turbo compressor: 12 g/s of air
5) High pressure side of the turbo compressor: 12 g/s of air
6) Intake pipe just BEFORE the Blow-off valve: 12 g/s of air
7) Intake pipe just AFTER the Blow-off valve: 10 g/s of air (2 left through the blow-off valve and lost to the atmosphere)
8) Entering the combustion chamber: 10 g/s of air

In both cases we get 10 g/s of air entering the combustion chamber, but in the Diverter valve case we correctly read 10 g/s of air, but in the Blow-off vavle case we incorrectly read 12 g/s of air. This is because additional air needs to enter through the air filter to replace the air lost to the atmosphere through the Blow-off valve.

This is a well documented issue with fitting aftermarkt blow-off valves to cars whose engine management systems rely on MAF sensors.

The general solution for those that must have a blow-off valve (for the cool noise) is to move the MAF sensor to the high-pressure side of the intake (post blow-off valve). This would be putting it between numbers 7) and 8) in the Blow-off valve example above, and we would then get the correct reading of air.

Unfortunately the MAF sensor electronics are optimized to measure un-compressed air, so there is some error introduced when swapping it over to the high-pressure side.

great break down of the problem. welcome to the site.

Thank you, MechEE. It's a very good explanation and it makes a lot of sence. The exact location of the MAF sensor is the key point there which I was missing.
However I can't agree with the concept of "average A/F ratio". IMO, average doesn't work here, there has to be a correct ratio at each point in time, without any spikes and drops which will not be visible if you just take the average.
Even with recirc setup, when you let off throttle, at that moment the meausred air was 12, but only 10 will enter the chamber. And then when it goes through the loop, you're at WOT again.
I guess, the throttle position and MAP reading should be taken into acount by ECU as well. May be that's why nobody with X had any issues running VTA setup (myself included)? I haven't noticed ANY difference in car's behaviour after i switched to VTA although, having read all the horror stories I was looking for it.

Thank you, MechEE. It's a very good explanation and it makes a lot of sence. The exact location of the MAF sensor is the key point there which I was missing.
However I can't agree with the concept of "average A/F ratio". IMO, average doesn't work here, there has to be a correct ratio at each point in time, without any spikes and drops which will not be visible if you just take the average.
Even with recirc setup, when you let off throttle, at that moment the meausred air was 12, but only 10 will enter the chamber. And then when it goes through the loop, you're at WOT again.
I guess, the throttle position and MAP reading should be taken into acount by ECU as well. May be that's why nobody with X had any issues running VTA setup (myself included)? I haven't noticed ANY difference in car's behaviour after i switched to VTA although, having read all the horror stories I was looking for it.

The ECU can only respond so quickly. There's a bandwidth limitation on most of the sensors (which are naturally averaging over some period of time). Additionally, there is only so fast that you can actually make changes to how the engine is operating. Given that two cylinder ignitions are occurring per revolution of the engine on these cars, it wouldn't make much sense to update injector timings more often than twice per RPM. That gets pretty fast up until the minimum injector on-time accuracy forces batch instead of sequential injection.

Most complaints from the MAF innacuracies from fitting a BOV to a normally closed system are from hiccups during shifts or when going on / off / on the throttle relatively quickly. It's likely not as pronounced on cars that also combine MAP sensor output for determining fuel injection.

totally unrelated to what you guys are discussing BUT from my limited experience im getting my Evo x MR in 2 weeks will the HKS SSQV make any noise since i have the paddle shift?

Im guessing that yes it will but only in idle while revving and only in gear if i take my foot off the gas...

sorry for such a newb question im new here so be nice

Cheers in advance

hmmmmmmm

The ECU can only respond so quickly. There's a bandwidth limitation on most of the sensors (which are naturally averaging over some period of time).
I don't think there's any averaging done by the sensor or there's any bandwidth isse on the sensor. The sensor feeds continuouse signal to the ECU. And if any, the averaging must be done by the ECU and there the refresh rate can be limited. But I think what's in between the readings just gets lost, which is right because any averaging would distort the actual readings.
Anyway,
Most complaints from the MAF innacuracies from fitting a BOV to a normally closed system are from hiccups during shifts or when going on / off / on the throttle relatively quickly. It's likely not as pronounced on cars that also combine MAP sensor output for determining fuel injection
That's probably why the X doesn't have the problems with VTA that IX and below had. Although I was reading about ppl successfully running VTA setups with SSQV on those cars also.
Anyway, let's try and see what happens :)

Im guessing that yes it will but only in idle while revving and only in gear if i take my foot off the gas...

Yes, it should be as you described.

I don't think there's any averaging done by the sensor or there's any bandwidth isse on the sensor. The sensor feeds continuouse signal to the ECU. And if any, the averaging must be done by the ECU and there the refresh rate can be limited. But I think what's in between the readings just gets lost, which is right because any averaging would distort the actual readings.

That's like saying your analog boost gauge has infinitely fast response. There is a time constant associated with the mechanical interface that's actually measuring and displaying the pressure signal that limits how quickly it can respond. You could spike to 100 psi for 0.00001 seconds and you'd never see even the slightest movement of the dial.

In the case of the ECU, since the ECU is sampling at a certain frequency, either the sensor itself or the front-end of the ECU needs to be bandwidth-limiting the sensor output to prevent aliasing.

That's like saying your analog boost gauge has infinitely fast response. There is a time constant associated with the mechanical interface that's actually measuring and displaying the pressure signal that limits how quickly it can respond. You could spike to 100 psi for 0.00001 seconds and you'd never see even the slightest movement of the dial.
Actually, no, this is not what I was saying. There's the sensor and there is the gauge. The sensor is your raw data, its accuracy and dynamic range is all your system is getting, it can't be more prcise than that. Then there's gauge, it can be slow and unresponsive in displaying what is being fed to it. If you don't see the spike on the gauge display, it doesn't mean it wasn't detected by the sensor.

In the case of the ECU, since the ECU is sampling at a certain frequency, either the sensor itself or the front-end of the ECU needs to be bandwidth-limiting the sensor output to prevent aliasing.
Well, IMO limiting the bandwidth (refresh rate) would exactly result in aliasing. You can approximate (average values) between the readings, and you'll get a smooth curve. But in case of a spike you won't see neither the spike nor the actual reading at that moment because of the averaging. What's best for the system?

Doesn't the MAF measure the air passing it? If so the BOV is behind it so it shouldn't affect the readings.

Also I took my stock diverter and pointed it down. I plugged off the intake hole where it went. I have been driving a few days with no idle problems, no cel's, and no limp mode. Can someone explain why I'm having no problem.

Doesn't the MAF measure the air passing it? If so the BOV is behind it so it shouldn't affect the readings.

Oh sweet mother of baby Zeus read the whole dang thread!!!

Oh sweet mother of baby Zeus read the whole dang thread!!!

I tried.

The only experiance I have had with VTA VS. VTR is with my 1g talon and it had some real problems. I had to eventually switch to a 3" GM MAFS. so I could be real ricey. I still have an HKS Black edition BOV that i'm gonna switch out onto my evo. if it runs like crap I'll recirc. no biggy.


allthough the hardware/software they use nowadays is a bit more advanced, it doesn't suprise me that people are not having problems VTA on a setup originally setup to recirc.

I plan on run vta but i dont like hks because every kid have it i will go with tial

Oh sweet mother of baby Zeus read the whole dang thread!!!

Rhea?

I tried.

The only experiance I have had with VTA VS. VTR is with my 1g talon and it had some real problems. I had to eventually switch to a 3" GM MAFS. so I could be real ricey. I still have an HKS Black edition BOV that i'm gonna switch out onto my evo. if it runs like crap I'll recirc. no biggy.


allthough the hardware/software they use nowadays is a bit more advanced, it doesn't suprise me that people are not having problems VTA on a setup originally setup to recirc.


LOL, you tried? And failed? It's only 3 pages. LMFAO. :-P

Rhea?

LOL who? Is that really the mother of Zeus?

Yes. :nerd:

LOL, you tried? And failed? It's only 3 pages. LMFAO. :-P


what can I say... it either works, or it doesn't.

Forget the blow off valve. I put air intake on and I can now hear turbo and blow off now. Loud and clear. Also I know my car isn't running too rich, in fact it is running leaner. Better ratio then I ever had.

i was thinking of gettin a agency power bov, good or bad idea? ive been told not 2 by some, and some other say go for it. ima noob at this. also wat kind of intake and piping is good?

I have the AMS intake and the AP BOV. Works very well

did u get n e codes or check engine light? i keep reading they they have very sensative map sensors and if i do add a bov and or intake i have 2 tune and dyno it

do u have a video of how it sounds? im goin crazy lookin 4 a good bov and intake

I've been running the SSQV3 VTA for over 5000kms without any stalls misfires or cels. Then again I have a MR and it seems only guys with GSRs are having issues VTA.

Can you run an SSQV recirc? I don't think I've seen one done so (and remembering how it looked in my Celica, it doesn't seem built for it).

Can you run an SSQV recirc? I don't think I've seen one done so (and remembering how it looked in my Celica, it doesn't seem built for it).

On the MR, it is recommended that you run recirculated. Check out the Official Engine Bay thread and you'll see that few people are running it recirculated.

i was thinking of gettin a agency power bov, good or bad idea? ive been told not 2 by some, and some other say go for it. ima noob at this. also wat kind of intake and piping is good?
I got the AP bov, just don't go 50/50 cause when I go 50/50 I feel some power lost, the evo X don't like VTA and 50/50..
About the intake just get an open element and your good to go..

since this thread is back from the dead I'll post that my hks SSQV black edition works great.

I had a black SSQV and the innerseal on the purple part blew out, HKS did warranty it, after 4 months tho, was not happy

I had mine on my car for about 2 days until I took it off and sold it. Part throttle driving then letting of the gas slowly was a pain in the ass since it would occasional make the car buck hard. It also fluttered like kindawg chasing butterflies in the sun and got to be quite annoying.