bonestockevo8 - not my car... project car for someone that i'm working on

it's not so much the spike that's the problem...

it's how my boost can't hold at a certain setting... it seems to default at 1.2 bar... i want it to hold consistently at the setting where it's at... (1.3 for the time being... but would like 1.5)

 

Check the Greddy Type RS Bov. That might be the cause of your problems, try replacing with a the stock BOV .... and let us know ...

 

even though you have the boost controller in there, its still gonna taper a little. I think it depends on what gear you are in too. Usually gears 1,2 and 3 won't hold boost all the way. 4th and 5th gear usually holds boost because of engine load.

 

stock bov idea - no can do... had it off... sister stepped on it and it broke the lil pee pee part on top of it... no more stock bov...

evo949... when doing the pulls... shifting to 4th gear... it defaults back down to 1.2 bar... regardless if i had the boost controller to 1.5 or not

 

i say screw it... turn up the boost some more. if it spikes, thats fine as long as it settles to somewhere in the 1.3-1.4 region. My car spikes to 1.6-1.7 then settles to around 1.4.(then it starts dancing up and down around the 1.4 area)

could be BOV related too... switch back to the stocker just for $hits and giggles.

 

I'm sure someone here would sell you their stock BOV for cheap ...
Oh yeah! and put my tax $$ to good use damn it!

 

huh? tax dollars?

 

bump for more answers

 

do you still have the pill in it? a MBC shouldn't spike...

 

what pill?

 

boost pill

 

No pills in any of my lines and I spike 1.4 and taper to 1.3 on 4th gear. I've always had to set my MBC to .1 higher from where it settles. Currently using a 3rd brand of MBC and it still spikes. Maybe the reading is dependent on what type of boost gauge you have. My friend has an Autometer Boost gauge and he doesn't get any spiking. I have a Defi BF and mine spikes.

 

Well lets define spiking here.

Peaking at 1.4 and tapering to 1.3 isn't a spike. Spiking is a brief moment of 1.4 settling to 1.2 (for a good while) and then tapering to 1.0. (Obviously my numbers aren't accurate, but I'm trying to be clear about what we are talking about.)

Taper is normal. The whole reasoning behind the mbc is that it's physical limit, you don't have resampling to effect/control spiking. The pills on the other hand could cause the problems.

 

Gotcha. Our meanings were a little different. I agree that some type of tapering is normal.