fuel cut and boost spike during engine break in

[gst96spyderman]

Alright.. Just drove the car a few hundred miles after rebuilding motor. Then I noticed under load that the boost would spike to around 25-30 psi. This is after installing a hallman pro mbc. I'll assume that its being caused by the wastegate since i'm still internal. What really had me concerned is hitting fuel cut during the break in process. I've got 150 miles on her so far and the motor is very strong. This is only my 3rd 4g63 motor break in and never ran into this issue before. any thoughts or opinions?

 

[LiquidX]

Being on a 16g I hope you are on wastegate pressure as anything above that really needs larger injectors to keep out of extremely high IDC% (90-100%). Also why did you let your motor get up to that high of PSI as you aren't supposed to go WOT right away? The boost gauge is there for a reason, you see the boost going higher than it should, you need to get your foot off the pedal.

 

[gst96spyderman]

I was @ 10lbs w/ mbc turned all the way down. The boost shot up w/o being in the wot. I was maybe 40-50% in the throttle. As soon as I saw this happening, I let off. As for the fuel cut, yeah, I need to get off the gas. I know that was caused by me being impatient and overeager.

 

[donniekak]

B

• you aren't supposed to go WOT right away?

• 
  
  While the op is doing it wrong, the only thing he is doing wrong is not being tuned for the boost he is running. Here is a quote from someone in the know, who feels the same way i do about a light break in recommended from a builder.
  
  "It is nothing to have a car with less than 10 miles on it at 40 psi of boost and 10,000 rpm. If it is going to fail then it is going to fail at that point and running it for 2,000 miles (whatever) easy is not going to change that. Running an engine for 2,000 miles to break it in is complete bullshit. It's most companies ways of getting you to take 6 months to be ready to run the car hard and by then they hope the warranty is over."
  
  David Buschur

 

[XiKeiyaZI]

While the op is doing it wrong, the only thing he is doing wrong is not being tuned for the boost he is running. Here is a quote from someone in the know, who feels the same way i do about a light break in recommended from a builder.

"It is nothing to have a car with less than 10 miles on it at 40 psi of boost and 10,000 rpm. If it is going to fail then it is going to fail at that point and running it for 2,000 miles (whatever) easy is not going to change that. Running an engine for 2,000 miles to break it in is complete bullshit. It's most companies ways of getting you to take 6 months to be ready to run the car hard and by then they hope the warranty is over."

David Buschur

I have to mostly agree. During break-in, I'd rather run an engine rough for the first bit opposed to running it gentle and babying it around. It's all about variable speeds, loads, and allowing the engine to see boost. It's designed to handle boost, correct?

 

[donniekak]

I was @ 10lbs w/ mbc turned all the way down. The boost shot up w/o being in the wot. I was maybe 40-50% in the throttle. As soon as I saw this happening, I let off. As for the fuel cut, yeah, I need to get off the gas. I know that was caused by me being impatient and overeager.

Check the lines to and from the boost controller, and check for actuation of the wastegate with compressed air.

 

[LiquidX]

While the op is doing it wrong, the only thing he is doing wrong is not being tuned for the boost he is running. Here is a quote from someone in the know, who feels the same way i do about a light break in recommended from a builder.

"It is nothing to have a car with less than 10 miles on it at 40 psi of boost and 10,000 rpm. If it is going to fail then it is going to fail at that point and running it for 2,000 miles (whatever) easy is not going to change that. Running an engine for 2,000 miles to break it in is complete bullshit. It's most companies ways of getting you to take 6 months to be ready to run the car hard and by then they hope the warranty is over."

David Buschur

I agree with a hard break in and am aware of dyno and track brake ins. However I haven't heard that they do full boost or full throttle for the first few passes.

More pressure and vacuum the better seated the rings are yes, but I don't believe a lot of people fully know how to prep for it by changing the oil out religiously and having it pre tuned.

 

[dsmboost84]

Read this first: -=MototuneUSA Car And Motorcycle Performance // PhotoBlog Break in secrets

 

[delta448]

I was @ 10lbs w/ mbc turned all the way down. The boost shot up w/o being in the wot. I was maybe 40-50% in the throttle. As soon as I saw this happening, I let off. As for the fuel cut, yeah, I need to get off the gas. I know that was caused by me being impatient and overeager.

Check your wastegate actuator. It sounds like you're not getting a good vac signal to it, but I'd also make sure the flapper arm isn't getting binded up in the closed position. You are using a dedicated vac line for the WGA aren't you?

 

[gst96spyderman]

Let me clarify something. This is my 3rd 4g63 build and the previous times, I used the drive it like a granny method. I've done extensive research on this and the majority of the users on here are use the motoman's method or something similar. I am trying this method even though I'm not 100% that this is the best method, but I;m kind of doing some independent research, hopefully not at the expense of the spyder.

The vaccum lines from the BC are snug and secure.

Yes there is a dedicated line for vaccum for the wastegate actuator... I think that is where my problem lies since the spike occurs at higher RPMs. That would also indicate that the flapper was not functioning properly on the WG itself. Correct?

 

[DSMTyson]

That would also indicate that the flapper was not functioning properly on the WG itself. Correct?

Yes, test the wastegate with compressed air and see how it goes.

 

[DJ23GSX]

I was having the same problem recently with my Hallman boost controller. Turns out that the spring inside was to stiff and was causing my boost to spike. I put the softer spring in it and now my boost is rock solid no more spike. I also noticed when I opened up the controller to change the spring that a little piece of the rubber seal on the barb made it inside the controller and was stuck on the ball bearing. I'm sure this too could cause the ball to stick and not open the wastegate causing a big spike as well.

 

[gst96spyderman]

where did you find a replacement spring? I'm assuming that the wastegate is the actuall culperate here, but would not rule out the spring in the hallman...

 

[laser5spdturbo]

my buddy's talon is having the same problem . We made the boost controller homemade , and are going to try a softer spring today . Also an internally gated 16g on 10psi , with a spiking problem .

 

[DJ23GSX]

where did you find a replacement spring? I'm assuming that the wastegate is the actuall culperate here, but would not rule out the spring in the hallman...

I found a softer spring at work out in our maintenance shop . I know my local hardware store has a spring drawer so just bring the hallman spring there for comparison. I replaced my wastegate too thinking that was the problem but it didn't help. The spring is easy to do and cheap I would start there.

 

[gst96spyderman]

roger that. Will be done tomorrow