Boost and Hesitation Problem 2000 BE5B RSK

 A_J_T said:

Honestly it just sounds like your getting tangled up in the VOD/change over.

Good to see everything getting a good check over. Regarding the 4k gear change and boost hitting 0 then raising as in your video.. I'm standing by what I've previously said. 4k is bang on where it starts considering bringing the secondary online. I experience the exact same result in mine when changing consistently on or close to k4 rpm. When i first got my car i though it was the rudest thing. After owning it and driving it for 4 years i learnt how it responded and where to use the power and avoiding the VOD just became second nature. i actually have a love hate opinion on the twin setup and think it is pretty sweet when setup and running nicely. You can drive it very sedate and have all the down low you need to get the job done, just change before 4k. If you want to get on it then change at 5k minimum. id be keen to see a video of you just pinning it.. What’s the lag like coming back on boost between shifts once in Twin mode etc. also if you change at like 3.6k or near do you get the same lag between shifts or is it only when changing closer to 4k.

That all being said who knows maybe mine had issues all this time and I just delt with it haha I’m not sure dude. Ross what do you think regarding the gear shift at 4k and that video? I’m on my way to ST now but always fascinated by the TT setup.

Though its not at VOD yet when I shift, still at peak primary boost.

4k is only an example, if I shifted anywhere below, even at 3k there would be the same effect. Boost is at 0 at roughly 2800-3000 after the shift and only when im at full throttle after the shift. If I go about 1/2 throttle for a bit then full, boost will rise back up gradually and not get hung at 0.

When pinning it there is zero lag at 0 between shifts. My VOD starts at around 4300 and boost only drops to about 6psi. Here's a video

So I cleaned the BCS today and it seemed to help with the little lag. It no longer hangs at 0 for 1-1.5 seconds and only just slightly pauses on it for less than 0.5 seconds or so. Boost is much quicker to build back up after a shift as well.

Hey ross, I noticed you put a 1mm restrictor pill into hose 2 in the BBOD, would I gain anything from this if I tried it out?

Worth trying if you have a 1mm pill handy and can easily be changed back to 0.8mm if it doesn't help. It changes the ECV duty cycle which has an effect on primary boost. I had a bigger intake and de-catted exhaust at the time, changing the ECV duty cycle helped with primary boost spikes I was getting.

Don't have one handy, do you know where I could get one? I will be doing intercooler hose later this week and turbo inlet + decatting in a few weeks.

OEM pill part numbers in the BBOD thread, taken from here:

http://www.perth-wrx.com/vb/mechanicals/48287-restrictor-pill-what-why-you-need.html

If de-catting you'll most likely need aftermarket boost control too, MBC or EBC.

 Rome1017 said:

Don't have one handy, do you know where I could get one? I will be doing intercooler hose later this week and turbo inlet + decatting in a few weeks.

welding shop .8mm mig tip

Ok, I'm already looking into that, preferably ebc. Also with regards to the turbo inlet, what other things do you recommend replacing while everything else is apart?

Check out phenolic manifold spacers for when the manifolds off. Also the perfect time to check over or replace the OEM rubber fuel hoses under the manifold:

http://clubsub.org.nz/forum/showthread.php?40590-Rosssub-s-GTB

I would say a throttle body coolant bypass, but probably not a good idea in Canada (frozen TB).

Ok I'll check them out, but i dont think ill be doing the coolant bypass for obvious reasons lol. I replaced the intercooler hoses and my shifter bushings as well as knuckle. Noticed intake noise is quite a lot louder, especially with he resonator in the fender removed. The bushings were a pain to do even with a hoist.

I was wondering whether cleaning the differential pressure sensor by the intercooler would do any good, what's your opinion?

The differential pressure sensor is pretty much a double sided MAP sensor, so doesn't get any flow through it and should still be clean. There's two white inline air filters either side of the DPS that you could check, but should be sweet.

Am watching this thread with great interest as I have a BE5B. Ross, factory hose#2 has a 0.8mm pill yeah? Is there any gain from 0.8 to 1mm?

 B4 I was 250T']Am watching this thread with great interest as I have a BE5B. Ross, factory hose#2 has a 0.8mm pill yeah? Is there any gain from 0.8 to 1mm?

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