grillpt: Agreed that the 25 PSI log is better spoolwise than the wimpy 20 PSI log. My question is whether both logs were done everything else being equal EXCEPT for adjusting the MBC. If both tests were in fact performed with the same exact amount of "light" preload and the only difference was two or three rotations of the MBC knob, then.....

Then, comparing honda-guy's two comparative logs would show how much a mere 3 turns of MBC adjustment can alter turbo spoolup as the two boost curves are about 1000 RPM apart with respect to turbo spoolup. So, honda-guy were both logs mad under the same conditions, the only difference being MBC adjustment, or did you tinker with the preload of the WG, between logs, as well?

I didn't think that three turns of the WGA turnbuckle would result in a 1000 RPM difference in turbo spool. It is food for thought.

 

all three pulls (17psi, 20psi, 25psi) were done back to back, only thing changed was turning the knob on the MBC. same light preload on the wga.

as you can see from the graph, it holds a steady 17 psi or 20 psi then starts to creep at 4800 rpm, and finally reach 25 psi by redline.

Sparky, not sure what you mean by the 25psi log spooling 1000 rpm faster than 20psi log. as you can see from the logs, all three settings hit 17 psi @ 3500 RPM. if you compare 17 vs 20, you can see they both hit 17 psi at the same rpm then the 20 continue to climbs. if you compare the 20 vs 25, they both hit 20 psi at the same rpm then the 25 continue to climb. fyi, the 20 psi graph used to compare with 17 and 25 is the same log.

i got the FP 18 psi wga two years ago and it was used, but as you can see, there is no spike issues with 17 psi or 20 psi, it was able to maintain a flat boost curve up till 4800 rpm where it starts to creep. also, i've used this 18 psi wga for two years on stock turbo and didn't have any spiking issues with it.

i do have a stock wga that i can put on but i'm starting to think that waste gate port on the turbine housing needs to be ported. i wish i would have known that while the turbo was out so i don't have to do all this again, hate draining and removing the radiator. :/

not sure where i clocked the vband bolt when i resembled it, might not be able to reach it without removing the whole turbo. the center section of the BB turbo is not oem but it does use a vband clamp like oem.

 

if anyone has a FP Red, could you turn your boost down as low as it can go and see if it will creep. thanks.

 

Mine creeps as well. I heavily preloaded the WG looking for spool(even trimmed the end of the stud some) and it would hit 26 psi up top. Backed it off two turns and not it climbs to ~21-22, which is about where I wanted it for my road race tune so I left it there.

I have a bigger o2 housing/dp setup, and ported the housing and around the WG area. I did not however port the actual WG holes.

 

^ what psi WGA are you using? so you're able to keep it at 22 psi when you have a light preload on the wga, but it would creep when you have a lot of preload?

 

i have the fp black, and with as little preload as possible without flapper opening, i get boost creep, and my black is ported, thinkin it may b the o2 dump

 

Mine seems to have the stock actuator on it. At normal preload levels(in this case slightly over half a hole) it hits ~16psi then creeps to 22.

 

so i did a test and mocked up my stock turbo and stock o2 housing from my old setup to see where the flapper was stopping and it stops the exact same place my fp black and o2 dump flapper stop at, so i guess i can rule out that its not the wastegate opening the whole way

 

dont chu worry about driving my car, worry about having my ice cream money ready

 

Next time out when I kick your butt in karts (again!), payment will be collected in form of seat time in the RS. I'm growing tired of taking ice cream from you all the time.

 

....Sparky, not sure what you mean by the 25psi log spooling 1000 rpm faster than 20psi log. as you can see from the logs, all three settings hit 17 psi @ 3500 RPM. if you compare ........[/QUOTE]

My bad. I am virtually illiterate as far as reading graphs...sorry buddy

 

i put the oem WGA on and did some logs. the wga was set with minimal preload, enough so it doesn't rattle. both pulls were done back to back and only changing the mbc.

first pull was set at 19 psi, it stayed flat till 5500 rpm then creep to 21 psi at redline. second pull was set at 24.5 psi and it stay flat till 4500 rmp then dropped to 23 psi at redline. also, looks like boost was not laggy at all even with minimal preload on the stock wga.

when i had the 18 psi wga and oem wga out, i tested them with compress air and notice that when they fully extend, the oem wga tends out about 1/8" farther than the 18 psi one. maybe that 1/8" is enough to reduce the boost creep from 25 psi to 23 psi.

so it looks like i can reduce boost creep to 23 psi if i use the oem wga, but then i cant run pass 23 psi either.

so, i'll have to find a way to make the 18 psi wga work cause i want to run 25 psi for TT, and 20 psi for HPDE.

 

the dotted line is the boost curve and the solid line is the AFR

 

I have a ported 64mm red with map o2 and fp 25psi wg and i dont creep. What type of boost controller are u running again?

 

Ok i read back and saw that you have a hallman mbc. Thats the same mbc im using. I would double and triple check your vacuum line that runs from the turbo to the mbc as well as the one that runs from the mbc to the j-pipe. Even the smallest leak there would cause a creep/overboosting issue.