Losing boost at high rpm

[robmustang201528]

I noticed when I was making a pull while in high rpm I noticed I was losing boost. I'm looking at my boost gauge climb then all of a sudden it started to drop down while in wide open throttle. I thought I was supposed to gain boost the higher I was in the rpm. What's wrong now smh. It's a vortech V7JT with id1000 boost a pump torque booster, 18 intake and boost controller and lund tune. Please help thanks

Sponsored

 

[jhatley7]

Belt slip or boost controller issue is where I would start. Have you sent a log to Lund?

 

[ahl395]

^ +1

What boost controller and what wastegate spring?

Check belt tension and look for signs of belt slip (black dust around pulleys). If nothing, it's probably your wastegate/controller. Either the boost controller needs to be adjusted to make more boost, or the wastegate spring is wrong and opening prematurely letting out your boost. 4 port boost control solenoids work best on wastegated centris to hold the wastegate shut until you want it to open and can manipulate the physical spring pressure.

 

[Lubner]

Belt slip

 

[robmustang201528]

I dont think it belt slip I have the 8 rib setup. But I do have a boost controller that I have no idea how to work. I need to find out what wastgate spring I have. I have the turbosmart e-boost street. The guy I bought it from says there is a high and low setting. I think it set to low. The most boost I've seen is 10 pounds then it'll start to drop. What wastgate spring should I have?

 

[robmustang201528]

Gonna send a log to lund next week. Gonna rain all week out here smh

 

[jhatley7]

Don’t discount belt slip without looking. I was skipping my Whipple 10 rib. You will see a fine black dust around the pully.

No experience with that setup, but I would assume you are on a 7.5 lb spring.

What happens if the controller is off? Others correct me, but if the controller is off it should default to the spring only for safety?

 

[robmustang201528]

I have no idea how any of this works lol smh. I'm new to boost. This boost controller thing.... I'm scared to touch it.

 

[jhatley7]

Lol we all started somewhere. 3 ?’s
Did you install?
Is the a new issue?
Has it always been wastegated?

 

[robmustang201528]

Is this the dust your talking about around the pulley? I hope this pic uploads

 

[robmustang201528]

Lol exactly. I didn't install it. Took it to a local speedshop. Got the kit from a guy a friend of a friend knew. I think I had this issue when I first got it but I just got the car back after sitting for 3 months. Yes it's always been wastegated

 

[jhatley7]

No it would be a lot worse. That looks like normal dust.

 

[robmustang201528]

Oh ok good. I'm hoping this just need to be adjusted

 

[robmustang201528]

I had it on the dyno once but the dyno was messed up. It wouldnt give show me my numbers but I recorded the boost gauge. As it was getting into the high rpm around 6 and 7 it started to drop. I'll try and post it

 

[jhatley7]

Well that doesn’t really help. Haha

So yes you are supposed to climb in boost with rpm. BUT you are gated. So once the controller sees “10psi” it will open the gate and bleed off pressure.

How much boost are you loosing and what rpm? After that pic I would say controller issue.

Sponsored