tial wastegate for charge piping

[lamrith]

I wouldnt be surprised if it helped power a bit...everything is more efficient if the throttle is open

I am thinking (usually dangerous) this would also let you as a tuner tighten the screws a bit and push the fuel system to get more power out of it since you do not have to account for the pressure spikes and resultant fuel demands?

[derfdog15]

I wouldnt be surprised if it helped power a bit...everything is more efficient if the throttle is open

I am thinking (usually dangerous) this would also let you as a tuner tighten the screws a bit and push the fuel system to get more power out of it since you do not have to account for the pressure spikes and resultant fuel demands?

My tune for the regulator mod did allow for a higher commanded boost, as fuel control was a bit better. YMMV.

[StealBlueSho]

Brad tunes for it, so he would be the best to fill you in. But from what I can tell... it's a balancing act between boost, IATs, and wastegate duty cycle...

[Brewineer]

I used an ebay 38mm wastegate from E Motor USA, it was only $70 with a dump tube! I swapped in a lighter spring so I could use an MBC to dial in the wastegate to just catch the boost spikes without having to find the exact combination of springs to work with the tune.

[SHOdded]

How long have you been using this setup and how is it working so far?

[AJP turbo]

I used an ebay 38mm wastegate from E Motor USA, it was only $70 with a dump tube! I swapped in a lighter spring so I could use an MBC to dial in the wastegate to just catch the boost spikes without having to find the exact combination of springs to work with the tune.

That may be giving you the result that you are trying to achieve but a problem with that, depending on where you are getting your boost reference, is that you are bleeding off the boost reference when using a manual boost controller. And the wastegates duty cycles are dependant on how much signal is coming in and out of the solenoids

Which is why some people may think the wastegates mod makes the car run hotter or makes the turbos run harder due to seeing higher wastegates duties ...

There really is no way it would make things run harder or hotter unless you have a spring pressure too low or bleeding excessive boost reference and affecting what is going in and out of the solenoids

It really was meant to be a simple passive setup

Think of the boost reference line that goes in and out of the boost solenoids as being metered air....you don't want to lose any of it

[Brewineer]

I installed it last night!

I had tested the system with a bike pump to see that it was actuating correctly and changing with the MBC adjustments. I ended up plugging the bleed port on the MBC and got the boost reference right at the 3-port.

At First it was set too low and was a reliable boost leak at 10 PSI, and then turned it up to start opening around 12 PSI. I will tinker with it a bit more today. I may end up installing the 14 PSI springs and not mess with the MBC as the commanded boost is 12 PSI (I'd better double check).

[AJP turbo]

I installed it last night!

I had tested the system with a bike pump to see that it was actuating correctly and changing with the MBC adjustments. I ended up plugging the bleed port on the MBC and got the boost reference right at the 3-port.

At First it was set too low and was a reliable boost leak at 10 PSI, and then turned it up to start opening around 12 PSI. I will tinker with it a bit more today. I may end up installing the 14 PSI springs and not mess with the MBC as the commanded boost is 12 PSI (I'd better double check).

Yeah buddy I would try that...look at your "dsd tip" and put a spring rates for 2 psi higher ...remember wastegates generally "crack" a bit lower than their spring rating .

If your desired tip is less than 190 kpa then a 14 psi spring should work...if you are 190 kpa or more then the 14 isn't high enough...just roughing that in my head at the moment

[StealBlueSho]

Being as someone who had this modification... and added a MBC...just put the correct springs in it and ditch the MBC...

You will never quit tinkering with it... you get it set right and then a week or so later it needs an adjustment... I think it drove Brad nuts..

[AJP turbo]

I think it drove Brad nuts..

Yeah but it was fun....We did some pretty extensive back and forths!

[Brewineer]

Did a quick log last night and I would need to lower the limit on the MBC to catch the boost spike at WOT shift (you can see the typical boost spike and throttle closing). I did hear the wastegate woosh a little, but clearly not enough.

Doing another WOT pull from a lower speed and just smashing the pedal resulted in significant oscillations (I heard the wastegate woosh intermittedly) when it "tried" to "catch" the initial boost spike (13.9PSI).  Of course, the plots lines are all over the place in the 2nd log photo.

It seems the combination of a lighter wastegate spring and an MBC allows the wastegate to open too much too quickly and interfere with the car's boost control methods.

TIP DSD is 185 kpa at steady state boost (~11 PSI) so I'm going to try the 14 PSI spring set.

[AJP turbo]

Of course it's interfering....you are losing the boost reference...the ecu doesn't know where it went lol

Usually MBC's are used to increase boost and manipulate the reference on the wastegates...it just seems counterproductive to introduce another component as in the Mbc...they make wastegates springs about every 1.5 psi so why not simply select what you need?

Pick the spring that allows you to only hear the "whoosh" on wot upshifts and give it full reference that way you aren't losing the reference signal

[StealBlueSho]

So I did this a couple years ago, and if you are dead set on getting the MBC dialed in (weather dependent I might add) here is what I ended up doing...


I used a spring setup that was almost right at desired, and then used the MBC to dial it in the rest of the way. If I used a spring that was too heavy, I was unable to get it to crack open at the correct the time, and the MBC is only there to keep the wastge gate closed longer than the spring allows.

So.. used a spring that will allow the WG to crack earlier than you want, and then dial it in with the MBC... I was able to keep fuel rail pressure almost perfect, but run much higher boost than I would normally since I didn't deal with boost spikes...

This log is pretty gnarly... holding 16.5psi and almost perfect rail pressure even with the spikes... AJPTurbo tuned throughout this process..

[StealBlueSho]

Of course it's interfering....you are losing the boost reference...the ecu doesn't know where it went lol

Usually MBC's are used to increase boost and manipulate the reference on the wastegates...it just seems counterproductive to introduce another component as in the Mbc...they make wastegates springs about every 1.5 psi so why not simply select what you need?

Pick the spring that allows you to only hear the "whoosh" on wot upshifts and give it full reference that way you aren't losing the reference signal

I highly recommend doing it this way... the MBC is fun to play with, hard to KEEP dialed in... if the tial wg you purchased doesnt have the correct spring setup, you can order additional springs to dial it in correctly without adding an additional component. Being I have been down this road before with the MBC.. I will say it again. Just get the correct WG Springs and call it a day...

Also, not sure who is tuning this for you as your signature says unleashed, but Brad did a hell of a job getting mine tuned correctly, and there are tweaks needed for this modification. I highly recommended PMing him if you are not running his tune already..

[AJP turbo]

So I did this a couple years ago, and if you are dead set on getting the MBC dialed in (weather dependent I might add) here is what I ended up doing...


I used a spring setup that was almost right at desired, and then used the MBC to dial it in the rest of the way. If I used a spring that was too heavy, I was unable to get it to crack open at the correct the time, and the MBC is only there to keep the wastge gate closed longer than the spring allows.

So.. used a spring that will allow the WG to crack earlier than you want, and then dial it in with the MBC... I was able to keep fuel rail pressure almost perfect, but run much higher boost than I would normally since I didn't deal with boost spikes...

This log is pretty gnarly... holding 16.5psi and almost perfect rail pressure even with the spikes... AJPTurbo tuned throughout this process..

Using a lighter spring but using an mbc to keep it held shut is basically the same as using a heavier spring...but then as the weather changes you may not have the same consistancy which is what you had if I remember.....and I've thought a lot about this since then but you always believed that the mod made things run hotter and turbos harder because the wgdc was higher but in reality the turbos were not running harder...the increased wgdc was because the the reference was lost through the mbc and the ecu needed to increase wgdc to get the proper boost reference to the turbo wastegates to compensate for what was lost

1 psi springs are enough to give a beneficial difference...boost spikes don't have to be completely motivated to see a benefit you just need to take the edge off....you can see 4 psi spikes on the 2-3 shift...taking the edge off helps a lot without needing to complicate things with an mbc

2000 psi dead nuts even is not really critical ...people have been running 1000 psi on terrible tunes for years with very few failures...we all know who they are and have see them...id rather keep it simple and less components and if a spring makes it better I'd rather do that than continuously messing with an mbc

If the fuel pressure only drops to 1700 for a second without an mbc id do that  than to use an mbc and get the ecu upset because the boost reference is lost somewhere