Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB - JDL Turbo Kit

Quote:

Originally Posted by DarkPira7e (Post 3468734)

He is inferring that CHRA technology and bearing type have significantly more of an impact than the kit does. The technology Garrett implements in the 18G's CHRA is quite old, and the journal bearing response is poor, in comparison to a similarly sized ball bearing assembly.

The issue OP is describing sounds like it is all tune based. There's mapping specific to input percentage vs actuation of the throttle. Example-0 15% throttle can be mapped to open the throttle valve 50%. It does not have to be linear either. The tuner may tune the throttle conservatively (50% input is 25% throttle) and map linearly to provide safety against input spikes causing other issues.

Mike wrote

Quote:

Originally Posted by CSG Mike (Post 3448834)

GReddy T518Z.

However, the response is not kit based. If anything, my car's response should be slower; I'm on a journal bearing 18G

Ok, he has the T518Z kit.

His response is kit based.

But it should be slower than it is.

Because(?) he's running an 18G.

Is the 18G the turbo that comes with the T518Z kit? Did he replace the original T518Z turbo with that one for some reason? Is the 18G a faster responsding turbo than what is typically included in the T518Z? (if so dear God what do they actually come with?) Why should his car's response be slower, or why is it faster? Is it faster because of an upgraded turbo, or is that the original turbo and its faster for some other reason? And what should it be slower/faster than? Should it be slower than OPs, or slower than it actually is?

I'm well aware the 18G is a slow old turbo, I just have no idea what Mike is trying to convey with his post.