how much damage do you think the venting has done to the car?

[appleyard777]

alright guys i should be getting another dsm very soon i hope!

i had a 99gsx around 400whp on race gas sold the car and i cant stand it got to get another

anyway found another 99gsx the car is very lightly modified, just exhaust and a few other little goodies, still stock t-25 and stock fuel, but the car has a ssqv BOV and does not seem to have the maft translator, now not all to sure how long the car has been ran this way i know the car is in great shape, strong motor, doesnt burn any oil, no smoking etc...

how much damage do you think the venting has done to the car?

 

[numlock666]

venting wont do any damage, just runs rich in between shifts and stumbles at partial throttle

 

[freshlane]

I thought the HKS works differently. Isn't it a pull type BOV vs the push type OEM bov?

 

[numlock666]

yhea, true. But as far as damaging to the engine, venting a HKS would just make u run rich between shifts or stalling when comming to a stop. But drivability shouldnt be too bad. As far as engine damage, none.

 

[1stGenRocks]

hks will mostly just run rich between shifts. because of its design it isnt open at idle like most bov's

 

[blazebolt]

You will probably need to replace those spark plugs. One of the hardest and expensive repairs to do on a DSM.

 

[Talesin]

CBVs are open at idle (under vacuum). BOVs are not. Our cars came stock with CBVs.

No engine damage, but you should pick up the recirculation kit and fix that venting problem ASAP, if you do end up buying it.

 

[DSMunknown]

Here is some good info on the HKS SSQV from Mike at Forge Motorsports:

HKS SSQV:

The HKS valve is neither [a "pull" nor "push"] type [valve]. Most other valves are both types.

The HKS valve is unique in that it's spring is used to keep the valve closed at idle/under vacuum, preventing it from being "pulled" open. And while this is great when used in an atmospheric configuration, so as no metered air is lost from the system through the open valve, this principle does not apply when the HKS valve is setup to recirculate. When recirculating, the valve needs to be "pulled" open at idle, so the spring is subsequently too stiff to allow this to happen.

Additionally, in an atmospheric configuration, when under load/boost, obviously the HKS valve will be "pushed" shut from a combination of the pressure reference from the intake manifold and the positive pressure within the piping holding the valve's "disk" against its seat, but at throttle lift, when there is a residual amount of pressure needing to be released, that pressure within the intercooler piping is still "pushing" the valve's disk closed. And though the intake manifold has also returned to vacuum, at least momentarily, and the valve should be "pulled" open, as mentioned above, the spring used in the HKS valve is designed to prevent the valve from opening under vacuum or at idle, so the HKS valve only opens in response to a change in the pressure differential between the intercooler piping and the throttle body.

In my opinion, this change takes such a period of time to occur before opening the valve, that the residual charge pressure has already backed up into the compressor wheel on the turbo, thus slowing it down, and potentially even creating lag, or worse, possibly compressor surging.

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OEM to HKS Comaprison:

HKS's valve, as can be seen in the diagram, has a separate chamber in which a diaphragm exsists. This is virtually idential in design to the OEM Evo valves, HOWEVER, there is one very important distinction related to my points above.

The intercooler piping pressure enters the HKS valve through the port at the bottom of the diagram, thus holding their valve shut when any amount of pressure or vacuum exists within the system until a certian pressure differential is reached.

The OEM Evo valves, however, have the intercooler piping pressure enter the valve through the port on the side of the diagram above, and this is better for three reasons.

One, the spring tension in the valve is not so stiff that the valve won't be "pulled" open at idle/under vacuum, thus it CAN open at idle maintaining proper function of the closed loop system.

Secondly, since the positive pressure enters the OEM valves from the port directly opposed to the main chamber, under load, the only pressure required to hold the valve shut is a combination of the spring pressure and the pressure reference from the intake manifold.

Lastly, at throttle lift, not only will the valve immediately open from the residual charge pressure "pushing" the disk off of its seat, but the return of the intake manifold to vacuum will also "pull" the valve open releasing the residual charge pressure before any lag or compressor surging can take place.

 

[FlatBlackTerror]

Here is some good info on the HKS SSQV from Mike at Forge Motorsports:

I drive my car daily with a vent tial wastegate and have no problems whatso ever. I actually like it more than a recirc because it backfires a little and i get a little bit of fire out the exhuast (ricey i know)

 

[Talesin]

Mike's explanation makes little sense... he's saying that the SSQV only opens when there's a certain difference in pressures between the manifold and IC piping. The same could be said for ANY BOV.

And a BOV being open at idle is 'neccessary' for proper recirculated operation? No it isn't! That just allows the compressor to be bypassed under low throttle operation for marginally improved response. Which is one reason our stocker is a CBV (compressor bypass valve) and not a BOV. It's open at idle.

Sounds like he was feeding you a pretty massive line, if you think about it. Sounds like an intentionally confusing explanation, intended to invoke smile-and-nod mode in those that are listening.
The actuation chamber of the SSQV still has manifold pressure on one side, and IC pressure on the other... far as I know, it isn't sealed from the 'release' section of the BOV, just baffled to reduce the chance of having the induced vacuum from the escaping charge potentially 'flutter' the BOV, if the induced vacuum was powerful enough to come close to the manifold vac pressure.