Tial 38mm Wastegate Plumbing

[944m3]

This might be semantics or I’m missing your point. But I would not think of it as vacuum.

This is how i understand it, please someone correct me if I’m wrong

If you put the pressure from the intake via the banjo bolt to the top of the Tial wg, you are adding pressure which helps to keep the wastage closed. Notice I say help. If your spring is 1 bar, and you produce 1 bar boost, the heat or gas pressure in the crossover pipe will need to be 2 bar to open the wastegate. The pressure at the top bar assists the spring. This a very simplistic explanation but both work together to keep the wastegate closed so the engine gets as much boost as possible. Note, this not a good thing in most situations.

If you put the pressure on the side port you are helping the spring “open”. You can control how much you “help” the spring with a boost controller.

The point of a dual port wastegate is that it allows you to more accurately fine tune the opening of the wastegate using a boost controller because you can control the pressure helping the spring or countering the spring. It’s a balancing act. The video I linked does a good job at explaining this

Applying vacuum to the top port would only be for testing purposes (verify spring pressure) with the wastegate off the car. While on the car, the boost source would attach to the side port and the top port would vent to atmosphere.

My goal is to have the accelerator and the spring be the boost controller since the manual boost controller isn’t very reliable and only accessible in the engine bay.

This gets confusing which is why I posted up for some advice.

Haha yes it took me a while to wrap my head around it.

I get what you’re saying about just using a spring, I’ve seen this same question on many other boards. But as I understand it, the danger is that your foot doesn’t react in time during a massive boost spike and you end up causing damage to the engine. A boost controller is a safety valve (a safety valve as in it provides a reference to the wastegate of what boost the engine is seeing/experiencing and can react by helping the spring open the wastegate), when working properly anyways. But I could be mistaken. Lots of information out there so you should be able to make an educated decision.

[NCGermerican]

This might be semantics or I’m missing your point. But I would not think of it as vacuum.

This is how i understand it, please someone correct me if I’m wrong

If you put the pressure from the intake via the banjo bolt to the top of the Tial wg, you are adding pressure which helps to keep the wastage closed. Notice I say help. If your spring is 1 bar, and you produce 1 bar boost, the heat or gas pressure in the crossover pipe will need to be 2 bar to open the wastegate. The pressure at the top bar assists the spring. This a very simplistic explanation but both work together to keep the wastegate closed so the engine gets as much boost as possible. Note, this not a good thing in most situations.

If you put the pressure on the side port you are helping the spring “open”. You can control how much you “help” the spring with a boost controller.

The point of a dual port wastegate is that it allows you to more accurately fine tune the opening of the wastegate using a boost controller because you can control the pressure helping the spring or countering the spring. It’s a balancing act. The video I linked does a good job at explaining this

Applying vacuum to the top port would only be for testing purposes (verify spring pressure) with the wastegate off the car. While on the car, the boost source would attach to the side port and the top port would vent to atmosphere.

My goal is to have the accelerator and the spring be the boost controller since the manual boost controller isn’t very reliable and only accessible in the engine bay.

This gets confusing which is why I posted up for some advice.

Haha yes it took me a while to wrap my head around it.

I get what you’re saying about just using a spring, I’ve seen this same question on many other boards. But as I understand it, the danger is that your foot doesn’t react in time during a massive boost spike and you end up causing damage to the engine. A boost controller is a safety valve (a safety valve as in it provides a reference to the wastegate of what boost the engine is seeing/experiencing and can react by helping the spring open the wastegate), when working properly anyways. But I could be mistaken. Lots of information out there so you should be able to make an educated decision.

I can see the argument about not being fast enough for overboost. However, I’m left with the following considerations:

1) what would cause an overboost if using WG springs to control boost? From what I’ve read manual boost controllers can fluctuate quite a bit with temperature and atmospheric pressure changes, which is in itself, a danger.

2) I really don’t have anywhere inside the car to mount the MBC. I run a double din Alpine touchscreen so I can’t mount it in the console. By having it in the engine bay, it guards against a passenger saying “what does this do” and turning it one way or another without me knowing. However, it makes it a huge pain for adjustment.

[NCGermerican]

Curious advice from Charlie at Evergreen. Legions of 951 folks have used a cabin-mounted manual boost controller and dual port wastegate over the last 2 or 3 decades, with good reliability and control. Much easier to dial in to your desired boost level too. You might need some trial and error with springs alone to get to an optimal boost level. I'm sure Charlie has his reasons, but sitting here I can't think of an advantage of eliminating the boost controller?

Tial makes various springs and designates their bar/psi level by size and color. Charlie said “optimal” and also “safe” boost level for the Raptor X on a stock motor is 16 pounds, or 1.1bar.

Since I really don’t have a good place to mount the MBC inside the car, it makes on the fly adjustments impossible anyway. I’ll never have a reason to go above 16 pounds of boost, so I figured using spring tension would be the easier and safer route. I could be wrong though.

[944m3]

Would be interested to hear your results.

Full disclosure, I have Tial 38mm and have also thought about just using springs. But decided against it and kept my mbc. Btw you can always just throw it in the glove box.

Always interested in learning different things about our cars.

[Spencan]

I have a Tial 38 as well. I started out using a MBC and I placed it next to the cruise control module in the engine bay. It worked fine there.

Then I decided that I wanted more precise boost control and I upgraded to an EBC. I went with the GoFastBits GFB Gforce III. They’re a company out of Australia and it was easy to setup and use. They have good customer support and there are some YouTube videos of people using them that helped me understand how the functions work; there are a lot of functions. Since their main language is English, the manual is pretty straightforward and easy to understand as well. If you decide to go that route, I highly recommend them.

I placed the digital controller over this vent. I removed the vent cover, used a heat gun to bend a piece and of thin abs plastic, attached the controller with some Velcro and used the same screw point as the vent cover to attach it. It works well in that spot.