2nd Gear Boost Issues

[LarryJoe]

So I finally installed my evo316g. I am using a 14b wastegate on it so wastegate pressure was around 7psi. Well I put in a Walbro 190 pump and wanted to up it a little. So I took my boost controller which was allowing me to boost at 12psi on my t25 and put it on. Well my boost will only build to 8 in 3rd, 4th, and 5th. Now if I mash it in 2nd it will sit at 8 until high rpms then it goes right to 11 and the car bucks. Does this sound like a boost leak to you guys?

 

[bryanwheat]

Do a boost leak test before anything. It would have to be a pretty big leak to physically hold the turbo from making more boost. Are you using an aftermarket gauge?

 

[LarryJoe]

Yeah I am. I think it is a boost leak though. I'm also down 3 vacuum after the install.

 

[Empyre]

If you end up removing the turbo to do a leak test, I would also try to manually actuate the wastegate by hand and make sure that the wastegate flapper is closing against the turbo. But thinking about it, the leak test should tell you that. If you find that you do have a leak, that is the first place I would look to repair/fix the problem.

 

[bryanwheat]

If you end up removing the turbo to do a leak test, I would also try to manually actuate the wastegate by hand and make sure that the wastegate flapper is closing against the turbo. But thinking about it, the leak test should tell you that. If you find that you do have a leak, that is the first place I would look to repair/fix the problem.

Why would someone remove the turbo to do a boost leak test? Also a boost leak test won't tell you anything about the wastegate whatsoever.

 

[GSTurbo1]

sounds like a boost leak... especially if it bucks like that, it must not be getting enough air causing the car to run way too rich from not enough air compared to what it is set up for.