Part No: T9005

Respons T9005 Diverter / Blow Off Valve with sound adjustment system for Nissan GT-R R35 applications

Warning

GFB recommends that only a qualified automotive technician fit this product.

This product is intended for racing use only, and it is the owner's responsibility to be aware of the legalities of fitting this product in his or her state/territory regarding noise, emissions and vehicle modifications.

GFB products are engineered for best performance, however incorrect use or modification of factory systems may cause damage to or reduce the longevity of the engine/drive-train components.

Instructions

T9005 Instructions.pdf

Specific Product Information

What's Included

2 x valves
1 x 5mm hex key
2 x standard trumpets
2 x 30mm plumback adaptors

Product Range Information

Features and Benefits

Our Venting Bias Adjustment System allows you to fully adjust how much air is recirculated or vented to atmosphere by simply twisting the adjustment ring.
Direct bolt on kit for your car.
Fully adjustable sound from zero to loud.
100+ psi boost holding ability.
Get a blow-off sound WITHOUT causing stalling, backfiring, or any other BOV-related issues, even on a car with a sensitive airflow meter (MAF).
Faster boost recovery on gear shift, up to 30% faster than factory diverter valves.
Better throttle response.

FAQ

I’ve lost my spring preload screw, what do I do?

If you’ve accidentally misplaced or lost either your spring preload screw or installation tool, please do not hesitate to contact us to source a replacement. These are custom made screws and are not able to be obtained elsewhere.

I have a test coming up, and I want my Respons to pass as fully recirculating.

Purchase a screw-in plug via our website and simply unscrew the trumpet and screw the plug in its place.

Do I need to purchase a gasket with these?

Not at all! All of our flange-type Respons BOVs come pre-installed with an O-ring for a better seal, and improved reliability over the standard gasket.

How does a GFB Respons improve performance?

Boost Holding: Unlike factory bypass valves, or other brand valves that require different springs for different boost levels, a GFB valve CANNOT be forced open by high boost! The balanced piston design in a GFB valve uses boost pressure on either side to cancel out the forces. Therefore, it doesn’t matter how much boost you run; you can be sure a Respons valve will deliver all of it to the engine.

Throttle Response and Boost Recovery: GFB’s TMS (Turbo Management System) principle is based on an operating method that is different to all factory bypass valves, which can be summarised as: A factory bypass valve is open until required to shut. A GFB TMS valve is shut until required to open. This difference in operating methods means that the GFB valve only vents when required, and only enough air to prevent compressor surge. For example, during a gearshift it is possible to preserve a small amount of boost pressure for a short duration. Then, when the throttle is then re-opened, peak boost is reached faster than if all pressure is lost (as is the case with the factory valve that remains fully open too long).

I thought venting to atmosphere couldn’t be done on a car with an airflow meter, so how does the Respons do it?

We’ve all heard the stories and seen people get shot down on forums when they ask about BOVs. Common responses are “your car will stall, backfire, run rich, go slower, or rip a hole in the space-time continuum that will bring about the end of the universe”. Certainly, if the BOV is not designed or adjusted correctly, at least some of these may be true.

When you vent a BOV to atmosphere, you’re letting air out of the system that has been measured by the airflow meter, so the ECU will continue to inject fuel for that missing air, hence the issues with over-fuelling that can occur.

However, by controlling HOW MUCH the valve vents, WHEN it vents, and for HOW LONG, the Respons can be configured to vent a portion of air to atmosphere at a time and of a volume that least affects the fuelling to the point where there are no negative side-effects.

Since our competitors do not have a means for adjusting the amount of air that is vented to atmosphere, they are unable to achieve the same success that a Respons does on even the most sensitive engines.

Which type of blow-off valve makes the fluttering noise?

TLDR: There are no blow-off valves that make this noise.

Without a BOV, the pressurised air being pumped into the engine by the turbo will have only one path when the throttle is closed: back through the turbo compressor. The fluttering sound is the sound of this air against the blades of the spinning turbo compressor as it tries to flow through it the wrong way.

Car manufacturers fit recirculating (plumb back) BOVs to give the pressurised air an alternate path when the throttle is closed: back into the turbo compressor inlet. This eliminates the ‘undesirable in a brand-new car’ fluttering noise.

Aftermarket BOVs typically vent the pressurised air into the atmosphere for the purpose of making noise, and are characterised by the ‘standard trumpet’ sounds. Some other brands do different things with the air to make different noises, but this is not to be confused with the fluttering noise.

In some cases, aftermarket BOVs do not flow enough air either as a result of their design, or the way that they are adjusted. In this case, fitting an aftermarket blow-off valve will result in the fluttering noise being emitted from the turbo. While this is extremely popular, it is worth noting that if this is your objective, then simply removing the factory BOV and replacing it with a pair of hose plugs would have been more cost-effective!

Incidentally, fitting a pod air filter can make any fluttering noise that was already present more audible. Also, large front-mounted intercoolers can increase the likelihood of ‘flutter’ for any given BOV, due to the larger volume of air present in the intake system. If the BOV is any good, some adjustment of the spring preload would be all that is necessary to once again eliminate the flutter.

Finally, it is possible to set up your GFB blow-off valve to cause some ‘pigeon’ noise by increasing the spring preload slightly (turning the spring preload adjustment clockwise). The aim is to have the flutter occur at low rpm and boost, while allowing the BOV to vent freely at higher rpm and boost levels. Experiment with it; you can’t do any harm!

Tech Support and Warranty

Warranty Information

We offer lifetime warranty on all of our products, so provided that there is a genuine manufacturing or assembly fault with your product – please send us some photos of what’s going on so that we’d be able to assist with either replacement parts or components. It’s also worth noting that we our lifetime warranty does not extend to those who have purchased our parts second hand.

Contact Us: https://gfb.com.au/contact-us/

If you are still having some trouble, then the next steps are to contact our Tech Support team. Videos, photos and a clear description of the symptoms you are experiencing would give us a better understanding of what is going on and how to resolve this issue as quickly as possible. Remember, we can’t see your car or product, so our diagnosis is only as good as the information you provide us.

Downloads & Installation

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