Ok.. i mean ill try at least... gonna be a bit hard to video tape my a-piller boost gauge and tach, but ill give it a whirl.

i hope you understand too i wasnt trying to discredit you or make myself look smarter.. i just know how my boost comes on.

one thing i will say is since its been cold- in the mornings, it'll spike to like.. 25 or so and then drop back. but come midday and a normal temperature and definately in summer.. i hit max boost when i punch it, and it stays.. no tapering back for sure.

im just posting how my car is. i know stock it tapered, but i always credited that to the stock flash making it taper. once i did the dynoflash it always held.

anyways, ill see if i can videotape it tomorrow and show ya what i mean.

 

i'm not mad at you at all. I would like to see somebody is holding boost. what mods do you have?? what kind of boost gauge are you reading?? i don't care where it's spiking, just what's constant.

 

Well, I'm only hitting 17.5 and stayed at 17.5. The boost gauge was installed by the dealer. So it came equiped.

 

stock for me was 18psi on my E7

 

Did you buy your EVO 8 used? If so, install a MBC...I had the same problem.

 

ok bro here ya go:

I just filmed this after I got home. A couple things: #1 sorry its shaky... kinda hard to hold a camera to your boostgauge while punching it on the highway and then having to stop to shift. Also its kind of dark, but you can see it good enough.
#2 it was almost impossible to film both my boostgauge and my tach-- but you can clearly see in the video I am WOT for a good amount of time and it holds the boost the whole time. so i dont think you need to see my tach- but trust me, i held out til 6.5-7k.

That being said here ya go!

The first time i punch it is in 3rd gear- real short and choppy-
2nd time is 4th gear on the highway -kinda shaky and hard to see.
3rd time is 4th gear again - a little shaky but you are able to see it pretty good.
4th time is 5th gear WOT and its very clear. It goes straight to 22 and stays there the whole time!

Enjoy

http://jaredboy007.4t.com/movies/22psi_no_taper.avi

(i would probably right click > save as)

*edit* you asked about my setup so here goes:
HKS RS kit intake
HKS SS BOV
Megan racing 3inch turbo back exhaust- hi- flow cat.
Greddy Profec B boost controller (again just to control max boost)
Autometer boost, air fuel, and egt gauges ( lol only boost hooked up so far!)
walbro 255 lph fuel pump
Dynoflashed.

Again as soon as i got dynoflashed, no boost taper like stock.

 

Just saw the vid. 22, that's way beyond my boost range. I don't have a MBC, but mine always stay around 17.5. So I'll be the second to say that it's possible to hold boost.

 

do you have an exhaust?

if not thats probably why ur only getting 17.5

i mean stock i always got 19 then taper to 16, and then once i got my exhaust it went to 21 max without any other mods. so exhaust does make an amazing difference for our cars.

now my greddy profec b isnt a MBC, its an electric boost controller ( i say electric not electronic cuz theres no display or anything- just knobs to turn the boost up and down) and i cant stress enough- this is just to control my max boost-- it changes so drastically with the weather-- i have to turn it waaaay down in the mornings or else im boosting 25+

Lastly, I wanted to mention Ive had my car over 2.5 years now and i started to mod it about 6 mos after I got it. So ive had these mods and have been boosting 22 psi and more for about 2 years now and my car hasnt blown up yet! so I think its fairly safe. but I guess we'll see.. i just hit the 50k mark....

 

if you're getting about 12 psi on a stock car then your stock boost controller is not working and you're running wastegate only which would explain 12 psi or so

 

Looking at it frame by frame:

It seems like you spike to 23 and taper a bit.

First sequence hard to judge because the camera moves, the gauge falls and you lift all around the same time.

In both the second and third sequence going if you look frame by frame it looks like spike as high as 23psi and taper to about 21 psi. (At the start of the pull there is a significant gap between the needle and the 20psi mark - by the end of the pull there is no gap - the needle sits just off the 20 psi mark).

Fourth sequence in fifth gear I dont think you would have too close to 7000rpm - 7000rpm in 5th is somewhere around 180mph. It doesnt look like you are going that fast.

So I suspect there is still some taper there. But seeing as you are holding 20 psi or more I think it makes bugger all difference. I am assuming of course that your boost gauge reads correctly throughout.

Feel free to disagree with me if you think Im seeing things!!

 

No offense but... are you driving the same car i am???

in any event, i shifted into 5th at a lower speed-- maybe like 60 or so - so the rpms were really low. i punched it and held the boost- shifted at LEAST 6500 or more.

You do realize it takes the evo a while at 7000 rpms to get up to a really high speed-- fastest i topped my evo out was 150. (180?? wtf) lol anyways

i think i got up to maybe 110-120 on that.. i only let off cuz i came up on a car i think.

Its possible theres a little bit of taper, but i think #1 the video isnt all that great-- again its hard to drive and hold that--
and i was letting off.

i promise you.. i punch it WOT and it holds. maybe tomorrow i can get someone to sit in the back seat and tape over my shoulder so they can get both the tach and the boost gauge. this way i can focus on driving too

oh and im pretty sure my gauge is accurate.. i had put it in while stock and i remember it would hit 19 and taper to 16 as advertised. ( when really hot in the summer more like 17 down to 15 and in the winter sometimes 20 or 20.5)

 

Sorry I live in a metric country and Im converting kilometers per hour to miles per hour in my head - obviously a bad idea. How about 140mph at 7krpm. Does that sound better? =)

And yes Im well aware of how long it takes to get an Evo up to the top of the tach in 5th gear - Ive topped out at 240km/h (149mph) and that took ALOT of road. Which is part of the reason I wasnt sure you were getting that high - you dont seem to be hard on boost in 5th for that long.

And Im not meaning to be offensive - Im genuinely puzzled by this. All the dyno graphs that I have seen show tapering boost. And Im not sure whether this is because of the tuners, the dyno or the turbo. Your video here is the first real indication that I have seen that the effect is not as much as I think. Im just trying to understand this....

 

oh no im not offended- i was saying please dont be offended by my comment back!

ok the 180 comment makes more sense now. whew.

yea i'll try this again tomorrow with a friend and get both tach and boost gauge on tape.

 

Cool thanks. I would do it myself but I dont have a boost gauge and dont have logging enabled.

 

12psi = bad stock boost controller... it happens....slap a boost gauge and manual boost controller on and crank it up to 20/21 and call it a day.

what's the point of the 22psi vids again? ...i have a profec b spec II + dynoflash(+ more) and i hold 22.5-22psi all day....22psi stock...highly doubt it ...19psi stock w/ taper due to restrictor pill...u take out the restrictor pill boost may go higher than usual