I am considering trying the GFB valve at the tightest setting (I am at 2 turns out from full tight now) to see if the valve will hold boost a little longer between shifts in less aggressive driving as well. I really have no idea if that is how this valve works but I know it won't hurt to try it. I just wish the adjustment screw was easier to get at.
GFB Mach 2 BOV
I installed the GFB Mach 2 T9111 Recirculating valve this weekend.
GFB MACH 2 TMS RECIRCULATING VALVE - Forte GT — Panda Motorworks
Mach 2 T9111 TMS Recirculating Diverter Valve Direct Fitment - (gfb.com.au)
Amazon.com: Ucreative 5FT High Temperature Silicone Vacuum Tubing Hose Black (5/32" (4mm)) : Automotive
Amazon.com: Turbocharger Boost Control Valve - 7 28197 16 0 : Automotive
To do the install I took out the airbox and the lower engine shield. It was nice to have access from both top and bottom. At the same time I replaced the BOV solenoid with a Pierburg 7.28197.16.0. The factory plug fits this solenoid with no adapter. The vacuum line that goes to the intake manifold I left stock and it fits on the Pierburg with no issue. For the vacuum line to the intercooler pipe and the one to the GFB Mach 2 I bought 5/32 silicone vacuum hose and cut to fit. I secured the Pierburg to the stock bracket with two zip ties. I set the spring preload full tight but not actually tightened just until the adjusting screw stops. I do not want excessive turbo sounds so this setup uses the stock recirculating hose that attaches to the intake tube.
I was very pleased to get the results I was hoping for with this GFB Mach 2. The hesitation you get between shifts with the 6spd due to a drop in boost is gone when driving more aggressive and shifting quickly. The Mach 2 holds some boost so that when you get back on the gas after a shift the boost is immediate. I also seem to get a smoother application of power when accelerating hard which makes it easier to maintain traction. When shifting slowly at lower rpms there is a very slight delay in power still since the boost has not built up and bleeds off quick, but it is greatly reduced and depending on how quick you shift you could notice no delay. The sound is slightly louder and fractionally longer when pressure is released but not obnoxious.
This should be on the car from the factory - the slight hesitation (waiting for boost) between shifts when driving sporty was so annoying before this upgrade.
GFB MACH 2 TMS RECIRCULATING VALVE - Forte GT — Panda Motorworks
Mach 2 T9111 TMS Recirculating Diverter Valve Direct Fitment - (gfb.com.au)
Amazon.com: Ucreative 5FT High Temperature Silicone Vacuum Tubing Hose Black (5/32" (4mm)) : Automotive
Amazon.com: Turbocharger Boost Control Valve - 7 28197 16 0 : Automotive
To do the install I took out the airbox and the lower engine shield. It was nice to have access from both top and bottom. At the same time I replaced the BOV solenoid with a Pierburg 7.28197.16.0. The factory plug fits this solenoid with no adapter. The vacuum line that goes to the intake manifold I left stock and it fits on the Pierburg with no issue. For the vacuum line to the intercooler pipe and the one to the GFB Mach 2 I bought 5/32 silicone vacuum hose and cut to fit. I secured the Pierburg to the stock bracket with two zip ties. I set the spring preload full tight but not actually tightened just until the adjusting screw stops. I do not want excessive turbo sounds so this setup uses the stock recirculating hose that attaches to the intake tube.
I was very pleased to get the results I was hoping for with this GFB Mach 2. The hesitation you get between shifts with the 6spd due to a drop in boost is gone when driving more aggressive and shifting quickly. The Mach 2 holds some boost so that when you get back on the gas after a shift the boost is immediate. I also seem to get a smoother application of power when accelerating hard which makes it easier to maintain traction. When shifting slowly at lower rpms there is a very slight delay in power still since the boost has not built up and bleeds off quick, but it is greatly reduced and depending on how quick you shift you could notice no delay. The sound is slightly louder and fractionally longer when pressure is released but not obnoxious.
This should be on the car from the factory - the slight hesitation (waiting for boost) between shifts when driving sporty was so annoying before this upgrade.
1 - 19 of 19 Posts
Once you figure out the best spot let me know.. I gave up 6 months ago.I am considering trying the GFB valve at the tightest setting (I am at 2 turns out from full tight now) to see if the valve will hold boost a little longer between shifts in less aggressive driving as well. I really have no idea if that is how this valve works but I know it won't hurt to try it. I just wish the adjustment screw was easier to get at.
GFB also has a stiffer spring option, too.GFB Spares- Spring suits Respons TMS, Deceptor Pro II Valves, Mach 2
This is from GFB -
Specific Product Information
This is the standard spring that is supplied in all Respons TMS and Deceptor Pro II valves, and is an optional extra for all Mach 2 valves when being set up for atmosphere venting. Use this spring where the valve is set up for atmosphere venting and engine idle vacuum is greater than 19”Hg.
For full recirc venting and/or engine idle vacuum less than 19”Hg use the softer spring 6116.
Would the engine idle vacuum be the same as the intake manifold absolute pressure? My log file shows this at 9.5 inHg at idle.
Specific Product Information
This is the standard spring that is supplied in all Respons TMS and Deceptor Pro II valves, and is an optional extra for all Mach 2 valves when being set up for atmosphere venting. Use this spring where the valve is set up for atmosphere venting and engine idle vacuum is greater than 19”Hg.
For full recirc venting and/or engine idle vacuum less than 19”Hg use the softer spring 6116.
Would the engine idle vacuum be the same as the intake manifold absolute pressure? My log file shows this at 9.5 inHg at idle.
Are you sure 9.5 inhg? Map sensors typically measure in psi or voltage. 9.5 psi is around 19 inhgThis is from GFB -
Specific Product Information
This is the standard spring that is supplied in all Respons TMS and Deceptor Pro II valves, and is an optional extra for all Mach 2 valves when being set up for atmosphere venting. Use this spring where the valve is set up for atmosphere venting and engine idle vacuum is greater than 19”Hg.
For full recirc venting and/or engine idle vacuum less than 19”Hg use the softer spring 6116.
Since I am running it full recirc this does not apply to me but out of curiosity would the engine idle vacuum be the same as the intake manifold absolute pressure? My log file shows this at 9.5 inHg at idle.
It says inHg. At full throttle and boost the reading is 62 inHg (30.5psi)
full throttle psi (30.5psi) minus idle psi (9.5psi) comes out to 20psi boost from my math, sounds about right. 🤷♂️
full throttle psi (30.5psi) minus idle psi (9.5psi) comes out to 20psi boost from my math, sounds about right. 🤷♂️
Ok. I was think in gage pressure. Your reading is in absolute. I should have known, it's in the name. LolIt says inHg. At full throttle and boost the reading is 62 inHg (30.5psi)
full throttle psi (30.5psi) minus idle psi (9.5psi) comes out to 20psi boost from my math, sounds about right.
Found this which makes sense with the GFB numbers. Not sure what my reading is for sure. I need to learn more about this.
Vacuum at idle | Veloster Turbo Forum
Do I need to factor atmospheric pressure into the equation? 14.7psi or 30 inHg?
Vacuum at idle | Veloster Turbo Forum
Do I need to factor atmospheric pressure into the equation? 14.7psi or 30 inHg?
Correct. There is no way you're running 30 psi unless your wastegate is stuck closed. What does it read with the engine off? If im guessing right, it should read around 29-30inhg.Found this which makes sense with the GFB numbers. Not sure what my reading is for sure. I need to learn more about this.
Vacuum at idle | Veloster Turbo Forum
Do I need to factor atmospheric pressure into the equation? 14.7psi or 30 inHg?
I might have this figured out. If I factor atmospheric pressure into the absolute manifold pressure it is 20.4 inHg at idle and 32.1 inHg at full throttle which is 15.8 psi. That makes more sense now.
I just tested out the GFB Mach2 with the adjustment at the tightest setting. I did not actually tighten it, just turned it until it stops. Under full throttle with quick shifts (6spd) there is no drop in boost and I can control the wheel spin better with the traction and stability control shut off. This is with the Racechip GTS on 5 or 7 and the XLR at S or R+. This setting feels the best to me. I did try it with the Racechip shutoff and it works great that way as well, just not as much power obviously. Looks like I finally have this thing setup perfect. Now that I have the 235 tires it's time for 93 octane and try a some more Dragy runs. See if I can get the 1/8 mile down closer to 9.0 seconds
With mid level acceleration and easy shifting the boost does still drop slightly so there is that slight hesitation between shifts and then the big surge of boost that breaks the tires loose, but this does not happen at full throttle and a quick shift. The boost drop between shifts is greatly reduced with the GFB and is in a large part dependent on how quick you shift.
With mid level acceleration and easy shifting the boost does still drop slightly so there is that slight hesitation between shifts and then the big surge of boost that breaks the tires loose, but this does not happen at full throttle and a quick shift. The boost drop between shifts is greatly reduced with the GFB and is in a large part dependent on how quick you shift.
The crybabies are going to get really pissed if you hit a 9 second 1/8th with a Racechip GTS... please do it...please.
Last month before getting everything setup nice I did 9.5 with the 205 tires from my Forte lxs getting no traction until 3rd gear and Racechip on 5 with 87 octane and getting off the gas before the end of the run since I had the phone on the passenger seat. I seriously hope I can get close to 9.0.
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I drove the car to work today with all the Racechip stuff shut off and driving normal in normal mode to see how the GFB behaved on the stock ecu settings. I noticed no hesitation or drop in boost between shifts today. Last night I did notice a slight hesitation between shifts driving easy. I think part of that sensation may be related to climate conditions and the way the ecu controls the power delivery of the engine, but the GFB definitely reduces it to nothing in most situations assuming you shift quick and smooth to prevent the boost from bleeding off. For my setup it is working great
Are your plugs cutting out?I drove the car to work today with all the Racechip stuff shut off and driving normal in normal mode to see how the GFB behaved on the stock ecu settings. I noticed no hesitation or drop in boost between shifts today. Last night I did notice a slight hesitation between shifts driving easy. I think part of that sensation may be related to climate conditions and the way the ecu controls the power delivery of the engine, but the GFB definitely reduces it to nothing in most situations assuming you shift quick and smooth to prevent the boost from bleeding off. For my setup it is working great
No there is nothing wrong it is just between shifts when the boost drops off and it has to build boost again once your back on the throtle. Stock the hesitation from 1-2 and sometimes 2-3 is pretty annoying with the 6spd but the setup I have now I am barely getting that feeling anymore. I am so happy this product did what I expected.
You'll see the most vacuum on deceleration. I get around 22 inHg on decel. I actually emailed GFB a while back with the question about which spring to use. They replied, on this platform they recommend the softer spring since the ecu determines when the valve opens and closes.This is from GFB -
Specific Product Information
This is the standard spring that is supplied in all Respons TMS and Deceptor Pro II valves, and is an optional extra for all Mach 2 valves when being set up for atmosphere venting. Use this spring where the valve is set up for atmosphere venting and engine idle vacuum is greater than 19”Hg.
For full recirc venting and/or engine idle vacuum less than 19”Hg use the softer spring 6116.
Would the engine idle vacuum be the same as the intake manifold absolute pressure? My log file shows this at 9.5 inHg at idle.
I am not really missing the GFB valve since I removed it. I am actually realizing that by changing my shifting habits/timing I am not feeling the drop in boost as much as I used to, more often than not I am not getting any hesitation at all now that I realize what was going on. The stock bov and solenoid are more than capable of handling the boost that stock and Racechip on 7 can deliver.
1 - 19 of 19 Posts
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