Issues with small pulley CRS - experienced opinion required

[bundysmurf]

Yet another question for the masses on these little blowers. I have a small pulley on order at the moment and was wondering what it was going to behave like with no clutch, so i bypassed the micro switch on the throttle body (ecotec) and turned it on .Besides constantly venting at idle (which i expected) the motor really dies in the arse and almost stalls after reving it and then backing off. The setup i am running is almost identical to IBLOWN's (intercooler, BOV in same position etc) and i was wondering if im missing something really obvious or if this is a common problem. I hear the early models of these kits used to run with no micro switch and obviously they worked ok, the only reason i can think of is possibly my aftermarket BOV is not right in some way

[VN_Luke]

dying in the arse at idle is an interesting issue, something to do with the IAC maybe? any tuning been done on the car?

constantly venting BOV doesn't seem like an issue, but it's damn LOUD and ANNOYING after a little - you'll propably decide to plumb it back, it really IS that loud.

so long as it's a metal BOV then you shouldn't have any issues - the plastic ones get VERY warm and i don't know how long they'd last.

[bundysmurf]

yeah it is bloody annoying. Seriously toying with the whole moving of the throttle body idea........but i like my faggy little blow off noise.

[bundysmurf]

It actually idles ok, its only when you rev it and back off it sorta chokes up and very nearly stalls

[IBLOWN]

ok. can u post a pic of where your maf sensor is? it must be as far away from the bov as possible. gimme a pic.

[IBLOWN]

note where mine is. as close the the tb as possible, away from the bov. ive played around with the maf position, so if u can post your pic i can tell u.

[bundysmurf]

Hey here is a photo that clearly shows the location of the bov, it does appear to be slightly closer than yours to the MAF sensor. What do you think, could this be the problem? Also i understand that you are modifying existing pulleys in order to run more boost while retaining clutch operation, could you give me a bit more info on the process cause i had mine apart the other day and couldnt work out how you could do it

[bundysmurf]

Hmm didnt work, maybe it will this time.......

[IBLOWN]

first things first. the bov is too close to the maf. the position mine is in, i found is the absoulute minimum distance from the bov. i dont modify cluch pulleys, although i can get 1psi more out of the standard clutch pulley. im a fitter machinist by trade with a machine shop at my disposal, which is where all my mods came from

[bundysmurf]

AHH i see....i misunderstood what you were doing with that pulley, makes sense now. Why does the postion of the BOV have such a large effect? Is it something to do with the pressure releasing and in effect having air flowing back thru the MAF sensor, thus making it think it needs a heap of fuel with no air to go with it? If im correct in this theory does that mean that altering the release point should minimise this problem (ie moving BOV as you suggested). Did you actually have this problem with your setup IBLOWN as its gonna be a bit of a pain to move the BOV, just want to be sure it'll fix it. Also is there any problem with having the BOV on the intake side of the intercooler. I read somewhere that one guy drilled a small hole in his throttle body to fix this....is that viable?

[IBLOWN]

I wouldnt be drilling a hole in the tb. Your exactly right about the bov confusing the maf. Like i said, i had the exact same problem on mine. Your gonna have to move your bov down further. Its the only way its gonna run right. My pulley looks different because i have designed them in a way that i can swap back to the clutch setup in 5 mins, also if something happens to the blower in the middle of nowhere, i can disengage the front section of the pulley (the part that goes on the splined shaft) by unscrewing 3 high tensile cap screws. I dont like the higher boost crs pulley one bit!

[IBLOWN]

also, where did you get the idea of the cooler configuration?

[bundysmurf]

I actually got the idea from looking at what a few others had done (mainly yourself and a couple of others) and changed a few different aspects in order to make it more suitable for what i wanted, like cutting holes for the piping instead of running them underneath. I may have gone overboard with the pipe size (3") because i lost a fair amount of power at standard boost (aprox 20rwhp) although im hoping to see a decent figure when i get it running right and maybe some water/meth inect. as well. Might also throw in a standard cam and see what it does for me......i understand that you hold constant boost thru the rev range, is your cam standard? cause i lose a fair percentage of my boost at higher revs due to overlap and so forth i'm led to believe.
PS excuse the dust and crap in the earlier picture........its not normally that dirty under there

[IBLOWN]

I actually got the idea from looking at what a few others had done (mainly yourself and a couple of others) and changed a few different aspects in order to make it more suitable for what i wanted, like cutting holes for the piping instead of running them underneath. I may have gone overboard with the pipe size (3") because i lost a fair amount of power at standard boost (aprox 20rwhp) although im hoping to see a decent figure when i get it running right and maybe some water/meth inect. as well. Might also throw in a standard cam and see what it does for me......i understand that you hold constant boost thru the rev range, is your cam standard? cause i lose a fair percentage of my boost at higher revs due to overlap and so forth i'm led to believe.
PS excuse the dust and crap in the earlier picture........its not normally that dirty under there

hahah, nah allgood. Ive got 2 1/2' from the blower to the cooler, then 3'' from the cooler to the tb. My boost hits full from low down then drops 2 psi midrange then comes back to full top end. Because of that i have shit midrange power which is pissing me off atm. What cam you running?

[bundysmurf]

Im not entirely sure what cam im running......it was already in the car when i bought it. You can really notice when it starts working at around 3.5 - 4 thousand rpm and it has a chip as well that prob came with the cam. Did you run the charger at higher boost levels without the intercooler, and if so did you notice any improvement with it? Also any idea what power you are making now? (connection is too slow at the moment to check your info). Ill post some dyno results when i get home tommorow arv for interests sake

[bundysmurf]

Oh yes and as you can see from my avatar picture my ute gets a bit of rough treatment which explains the dust etc.

[IBLOWN]

i ran 8psi with no cooler. it hauled ass, but pinged its brain off when the blower got hot. as soon as i installed the cooler i noticed a big difference in power without increasing boost level. as for power, i havent dynoed it since ive put the cooler in, but it ran around 230 hp atw

[bundysmurf]

Bad news......got bov moved to the other side of my engine bay (ie cut off and welded back on another pipe) and still no joy. Still does the same thing as before, now im really stumped. Spewin too cause it seems to go nicely under throttle, just dies and sometimes stalls when i back off. any other ideas??

[IBLOWN]

gimme a pic?

[bundysmurf]

Hey sorry for the delay, im back online finally. No pic at the moment (will endevour to get one in the morning) but the BOV now sits on the passenger side pipe facing toward the center of the car and slightly downward (just clears the radiator shrowd). I am thinking my problem may actually be with my cheap arse piece of shit BOV cause i got the shits and took it for a run the other day and i keep blowing silicon hoses off! Maybe its too stiff and/or there is a vacum issue......gonna try get it on the dyno to suss it out. I think its not releasing enough pressure causing load on the engine when i back off........maybe

[bundysmurf]

Long time no post but ive had varying levels of success with my problems. my initial problem of the boost falling off at high revs has been fixed (not sure how exactly but its constant six psi thru intercooler now) and my other issue with the stalling and so forth is aorted also. i have found that it was due to my BOV being unable to flow enough air which led to the whole system holding presuure at idle. Unfortunately when it was on the dyno the pressure was being read from the plennum and therefore it was showing a vacuum as it should, with the unwanted pressure being on the charger side of the TB. Fitted a second BOV just to test my theory and it seems to have fixed it.
Unfortunately when i tried to take it for a decent run i fried my clutch so i dont really know - it pulled 225rwhp on dyno but it had other issues at the time.
My next question is in regards to throttle body positioning. How much does moving the TB help the noise levels and driveability? I dont know how anyone can drive a car with the level of noise and so forth that i have experienced mine, some of the driveability issues obviously stem form my clutch problems but how much im not sure. So i would like to hear from anyone who has moved theirs and what difference it made, cheers

[IBLOWN]

Long time no post but ive had varying levels of success with my problems. my initial problem of the boost falling off at high revs has been fixed (not sure how exactly but its constant six psi thru intercooler now) and my other issue with the stalling and so forth is aorted also. i have found that it was due to my BOV being unable to flow enough air which led to the whole system holding presuure at idle. Unfortunately when it was on the dyno the pressure was being read from the plennum and therefore it was showing a vacuum as it should, with the unwanted pressure being on the charger side of the TB. Fitted a second BOV just to test my theory and it seems to have fixed it.
Unfortunately when i tried to take it for a decent run i fried my clutch so i dont really know - it pulled 225rwhp on dyno but it had other issues at the time.
My next question is in regards to throttle body positioning. How much does moving the TB help the noise levels and driveability? I dont know how anyone can drive a car with the level of noise and so forth that i have experienced mine, some of the driveability issues obviously stem form my clutch problems but how much im not sure. So i would like to hear from anyone who has moved theirs and what difference it made, cheers

just run a cai setup like mine and it will bring the noise down alot. i wish i had have know you were running a bosch bov, because your exactly right in what you said. its beat to run a plumb back aftermarket one. i still wouldnt mind a pic of your setup to solve some more probs for you.

[bundysmurf]

cheers IBLOWN ill get a photo of my engine bay soon (bit of a mess but, ive been 'problem solving' for the last two months). I wasnt actually running a bosch BOV but just a cheap atmo one which couldnt keep up, two seems to help tho (just a temp measure to make sure that was the prob), i dont think many people myself included comprehend just how much air these little bastards blow! Its a surprising amount even just at idle.
I have been considering my options in regard to the whole throttle body positioning dilema, not sure which way im gonna go yet. Have you ran yours with the TB on the intake side of the blower? Definitely need to hook up my cai and so forth too! New clutch next week so hopefully ill be able to suss it out a lot better then

[pandacav]

hey bundysmurf or iblown did putting the 2nd bov in stop it from stalling cause i got the same problem but im not running an intercooler(entend 2). I'm only running 3 psi though.

[IBLOWN]

pandacav: you dont have to run 2 bov's, only one good quality one like turbosmart or capa. it has to have a large plumback port to flow the unwanted boost.

bundysmurf: i havent ran the tb infront of the blower, but cant see any real improvement in doing so, other than maybe quietening the intake noisewhile cruising. anything after 1/4 throttle will only let the noise of the blower out anyway.