so i built my own front mount setup for my s/c. i used all 2.5" mandrel bent aluminum and quality silicone couplers. now i can't get the car to boost at all. the gauge has trouble getting to 0.

now, before anyone jumps to conclusions....... i replaced the silicone couplers today and tested the piping for leaks @ 5, 10, and 15 psi using a compressor, regulator, and a few other little things. no leaks at all. before AND after the coupler change.

all this led me to believe that the intercooler is too much of a restriction, as it is tube and fin design, and slightly damaged. i called my friend who i bought it from..... he recently dyno'd his awd dsm with this IC, and it ran great. made 282 awhp @19 lbs on an evo III 16g.

why wont the car boost? it was fine before the fmic, and i could see maybe losing 3-4 lbs of boost MAX on a poorly designed system, and i happen to think this 'rough draft' of a setup isn't bad at all. i have turbo cars with worse systems. how could i not be boosting at all? what am i overlooking?

can u test the gauge?


pics man. pics!

Vacume lines installed correctly, actuater will not engage if it has no signal from the throttle body.

what vacuum lines? what actuator?

and i dont need to test the gauge.....butt dyno says no boost.

FWIW, the car runs and drives fine off boost. vac at idle is normal.

i posted some install pics in one of these threads in this forum. i will post completed ones after it works correctly. :)

My SC has a vacume actuator to control when I'm @ WOT ( I call it an actuator but no clue what the textbook name is) or close too, allowing all boost, otherwards it cycles back into the SC to keep fuel milage up.
Yours seems different but a pic would point it out.

are you talking about a bypass valve? that's the only thing the 'controls boost', per se'. it also has a vac line...... i take it you have a DASC. yeah, different setups, same idea. e

the bpv is fine..... of all things.

^^^ say this due to my cousin that had weeks of troubleshooting after rebuilding his 99 Dodge Cummings turbo D setup with same issue.
Did you forget a rag or something in the intake somewere?.....
Took him 3 weeks and a big bill to have the wrench toss the rag @ him when he came to pay his bill.
If you have boost and it's not getting into the engine something is stopping it.

You're still getting boost, you're just not seeing it on the gauge...but some of that pressurized air from the SC IS getting into the manifold.

Remember, even a well-designed FMIC can easily cost you a couple PSI in pressure loss, not to mention how much you'd loose on a poorly-designed setup.

Now, combine that 2+ PSI pressure drop with the RPM-bound nature of a centri SC AND a "low boost" setup to start with (8 psi?), and then add the slow response time of common analog gauges when dealing with low boost, and there's your problem.

You're probably only putting 5-6 PSI (if that much) into the manifold at redline now, and the boost gauge doesn't have much time to react (they barely start working until 5 PSI+), so by the time you shift, the boost gauge hasn't caught up.

Slap an electronic MAP sensor on there and see what happens. Or swap pulleys to make up for the pressure drop.

But before you do either of those things, find a nice stretch of road and make a 3rd or 4th gear run to see what happens....the longer time in gear might allow the boost gauge a chance to catch-up with what is happening in the manifold, compared to the much shorter 1st and 2nd gear runs.

You're still getting boost, you're just not seeing it on the gauge...but some of that pressurized air from the SC IS getting into the manifold.

Remember, even a well-designed FMIC can easily cost you a couple PSI in pressure loss, not to mention how much you'd loose on a poorly-designed setup.

Now, combine that 2+ PSI pressure drop with the RPM-bound nature of a centri SC AND a "low boost" setup to start with (8 psi?), and then add the slow response time of common analog gauges when dealing with low boost, and there's your problem.

You're probably only putting 5-6 PSI (if that much) into the manifold at redline now, and the boost gauge doesn't have much time to react (they barely start working until 5 PSI+), so by the time you shift, the boost gauge hasn't caught up.

Slap an electronic MAP sensor on there and see what happens. Or swap pulleys to make up for the pressure drop.

But before you do either of those things, find a nice stretch of road and make a 3rd or 4th gear run to see what happens....the longer time in gear might allow the boost gauge a chance to catch-up with what is happening in the manifold, compared to the much shorter 1st and 2nd gear runs.

... so he has a FMIC, his supercharger is making positive psi, but his gauge is not showing it? Man... these forums are getting whackier and whackier by the moment.





Bro - a CF makes linear boost over 0 - you can make 2 psi and read it on a gauge - the gauge is not "slow" to keep up.

yeah, what the hell are you all talking about? lets get this straight. before the fmic, the gauge showed 8psi or so at redline. i added the fmic, and now it doesnt boost.

its a very simple concept. i have taken it to redline. there is no power and no boost. i know how a centri works.

the gauge is not the problem here. it feels like there's no boost.......the gauge shows no boost..... see a trend?

all i am asking is for something i may have overlooked or the possibility that i could've lost THAT MUCH boost or not. this all doesn't make any sense, so i am asking you guys.

i'm not an idiot. i know how the system operates, i know how much boost i should be getting and where in the powerband i should be getting it.

Nope - something is off. Normal FMIC will loose like 2 psi @ 20, or like 5 @ 30... not 8 at 8 lol. Get a pic of your setup. I want to see how you managed to even get a FMIC on a V2SQ. A coupler has to be off somewhere - other places to check:

1) IAC valve - now that you have a FMIC that IAC has to be plumbed in there somehow.
2) Crank case ventilation system
3) Idle valve connections on the BACK/UNDERSIDE of the manifold.

The good thing about centrifugal superchargers is that they should "move" air in neutral. So, a semi ghetto way of finding a leak would be to hold the TB open some whilst running your hand around the engine bay feeling for air moving. It can be tricky with the drive fan, but you get the idea. Please get pics, it would help in getting an idea of where this bitch COULD leak from.

But, I bet you have an issue somewhere around the ICV plumbing - you did plumb the ICV back in to the charge pipe right? I am not calling you a moron by any means, but I am sensing that the ICV is just chilling open now that you did the FMIC...


Ok I searched your name for threads created and I found your issue:

http://i76.photobucket.com/albums/j40/turbosporttsi/DSC01217.jpg

Bro that definitely will not hold boost.

That looks like a Johnny Racecar intercooler which is only 6" tall and 2.25 - 2.5" thick - I know, I had one. If it is leaking, which I REALLY suspect, I would recommend you get an ebay unit for like $120

hey! some helfpul insight! :D .... ok, the icv has a nipple near the tb as does the bpv. as far as the icv goes, i have eric's m50 swap kit, so the icv isnt plugged directly into the manifold any more. it is attached to heater hose on both sides. nowhere to pull out from.

i posted pics in the other thread.... 'turbo guys, front mount question'..... but i dont remember if they were of the completed piping.

i really dont think it has anywhere to leak, man. i replaced all questionable couplers today and had a buddy help check for vac leaks.

i have an electric fan , so there is no air moving in the engine bay as long as its not on.

here's where i'm stuck...... all you guys who have been dealing with boosted cars for some time now would mst likely agree. i have never.... NEVER seen a boost leak where the boost didnt spike a little for a sec, or the car ran like crap. the fact that there is NO boost, but plenty of idle vac is very confusing.

i have gone to higher rpm (4-5k) at part throttle, and then went WOT quickly, to at least get the boost gauge to register a 'spike' of boost, but man, it held right where it usually does.

btw: the crankcase vent has been deleted. no probs there. :)

hey! some helfpul insight! :D .... ok, the icv has a nipple near the tb as does the bpv. as far as the icv goes, i have eric's m50 swap kit, so the icv isnt plugged directly into the manifold any more. it is attached to heater hose on both sides. nowhere to pull out from.

i posted pics in the other thread.... 'turbo guys, front mount question'..... but i dont remember if they were of the completed piping.

i really dont think it has anywhere to leak, man. i replaced all questionable couplers today and had a buddy help check for vac leaks.

i have an electric fan , so there is no air moving in the engine bay as long as its not on.

here's where i'm stuck...... all you guys who have been dealing with boosted cars for some time now would mst likely agree. i have never.... NEVER seen a boost leak where the boost didnt spike a little for a sec, or the car ran like crap. the fact that there is NO boost, but plenty of idle vac is very confusing.

i have gone to higher rpm (4-5k) at part throttle, and then went WOT quickly, to at least get the boost gauge to register a 'spike' of boost, but man, it held right where it usually does.

Can you please get pics or make a drawing of the ICV setup you are running. I need to know where the big 1" hoses are connecting. Also, I really think you're intercooler is leaking something nasty. I found that same one on ebay for $79 - i'd replace it.

could it be a huge coincedence that the bpv is screwed up in any way? that might cause a lack of boost, but the presence of good idle vac......

it seems to be that it can only be the bpv or a huge loss b/c of the fmic system, which is unlikely.

oh, and urinemachine..... like i said, i pressure tested the piping, and triple checked the couplers. i really dont see that being the problem. but i have seen weirder.....

yes, i plan on replacing the IC, but like i said, my buddy used it @ 19lbs with no probs, so....

the icv...... ok, it goes like this:

charge piping ---> heater hose--->icv--->hose (u-turn)--->main connection at rear of manifold.

(trust me when i say you dont wanna see me draw it)

the IC looks worse than it is. the tube is bent, and i removed the bent fins. like i said, i pressure tested the ic and piping today @ 15 lbs. it held that..... im sure it would hold 1 lb, which something is not.

... so he has a FMIC, his supercharger is making positive psi, but his gauge is not showing it? Man... these forums are getting whackier and whackier by the moment.








Yeah, pardon me, obviously I don't know shit about CF superchargers, inline charge coolers, and boost gauges on a S50/S52.

Yeah, pardon me, obviously I don't know shit about CF superchargers, inline charge coolers, and boost gauges on a S50/S52.

:lol

John...the only one who knows ANYTHING here, is UrineMachine...;)
Just ask him..he'll tell you himself...

Kobe 8 also have a SC w/ fmic...and is boost was off by 2 psi.

guys, lets keep this on topic and not turn it into a pissing match. k?

m3jokster- yes, kobe8's fmic was the cartech kit IIRC. and 2-3 psi is what i was expecting.

this is driving me nuts..... you would think that if the the car had a leak big enough to not boost at all, it would be present at idle as well. or at least part throttle. everything seems fine until i stomp it, basically. what could it be?

Yeah, pardon me, obviously I don't know shit about CF superchargers, inline charge coolers, and boost gauges on a S50/S52.

i know quite a bit about alot of things boost-related too...... but i would never imply that an analog boost gauge takes about 5 seconds to catch up with the actual manifold pressure.

what i got from your initial reply is that you didnt read my first post very well, because it's hard to see anyone reading that and thinking 'boost gauge'. IMO.

Bet that intercooler is pinched. Toss that thing in the garbage and replace it, bet your boost comes back.

like i said, im gonna be getting a new one shortly. i dont think i would lose all boost because one tube is bent, but i think today or tomorrow i will put a piece of straight pipe where the ic is and see what happens.

Bet your post comes back. That IC looks pretty f'ed up.

i dont know much about S/C and IC but I'm trying to learn, a suggestion for checking for leaks might be to spray WD40 on the area you think might be leaking an look for it to bubble. I dunno good luck.

well, thats along the right train of thought, but pressure testing the piping like i did is a much better way. it doesnt leak.

doc- im just gonna bypass the ic and if there's boost....... :D

The intercooler would not be so much of a restriction that it would prevent boost unless every tube was clogged. Your pressure testing, if done right, would show that the intercooler and plumbing are not leaking and can hold boost. Done wrong, it won't show you anything. A bad bypass valve will leak some boost, but probably won't prevent all boost (just cap it off in both directions to test). A bad blower or badly slipping belt will prevent boost. A huge leak that opens up only under boost that may be outside of the intercooler and plumbing that you tested is another possibility.

Let us know what you find.

Philip Bradley

while right, i think that is unlikely solely because the car ran and boosted perfectly before the fmic. the blower and all engine components should be fine.

the way i see it is.... my buddy ran 19 psi on a 2.0l with a turbo that flows under 500cfm at 15 psi. i am running 8 psi on a 3.2l with a compressor that flows 1000cfm at an assumed 20 psi.

maybe the ic just cant flow that high of a cfm, given its relatively small size. maybe it flows just enough that i can drive the car part throttle just fine, but the added flow under boost conditions is too much for the core.

like i said, i will either prove the ic as the problem or eliminate it as a possiblility hopefully tonite when i bypass it.

If the above is correct, very roughly you are flowing 8/20 of 1000 cfm, while your friend is flowing 19/15 of 500 cfm through the same IC. I doubt either of these numbers are accurate, so let's just use them for comparison purposes. You would be flowing 400 cfm while he would be flowing over 600 cfm. He has no problem with the IC, but you have so much of a problem that ithe IC that itt allows NO boost? Not likely. Overflowing an IC just reduces the efficiency and increases pressure drop, but you are far from stopping things up entirely. Either the boost is getting out somewhere or its not being produced in the first place. It is not being produced but being stopped up by the IC unless the IC is defective for some other reason. Since you are able to pressure test, pull the IC out and pressure test it. Plug in a boost gauge on both sides of the IC -- you will learn its pressure drop, and I doubt it is 100% even at far more boost than you will ever run.

Philip Bradley

well, people... the results are in. i bypassed the IC with another pipe... and voila. 8 lbs of boost. my piping loses less than .5 psi, so that combined with my new IC should be about a pound.

and phonsalb, when you said my friend is flowing 19/15 of 500 cfm, that's not correct. the cfm measurement is taken at the compressor's peak efficiency, so he is prob flowing roughly 450 cfm at 19 psi. and also, im not sure how s/c's cfm are measured. the 1000cfm may not necessarily be at 20 psi, that's just its peak flow and peak boost pressure. im not sure how they correlate.

regardless, the ic was the problem. my buddy and i are confused as to why it was fine on his car and is not on mine.....without leaking.

on to bigger and better. i think im gonna go with a bar and plate ebay one like everybody else... :) im FWIW i am looking at ones sized about 24x7x3 or 3.5. im not sure how the taller 12ish inch ones will fit. also, if i can get a shorter one, that would be good.

well, people... the results are in. i bypassed the IC with another pipe... and voila. 8 lbs of boost. my piping loses less than .5 psi, so that combined with my new IC should be about a pound.

and phonsalb, when you said my friend is flowing 19/15 of 500 cfm, that's not correct. the cfm measurement is taken at the compressor's peak efficiency, so he is prob flowing roughly 450 cfm at 19 psi. and also, im not sure how s/c's cfm are measured. the 1000cfm may not necessarily be at 20 psi, that's just its peak flow and peak boost pressure. im not sure how they correlate.

regardless, the ic was the problem. my buddy and i are confused as to why it was fine on his car and is not on mine.....without leaking.

on to bigger and better. i think im gonna go with a bar and plate ebay one like everybody else... :) im FWIW i am looking at ones sized about 24x7x3 or 3.5. im not sure how the taller 12ish inch ones will fit. also, if i can get a shorter one, that would be good.

Here's a thought - you're pressurizing the FMIC, maybe its blocked - its not leaking but its also not letting shit thru.

like i said, it runs fine part throttle..... even accelerates nicely. it almost felt like it would if the gas pedal were to only open halfway. after halfway, the car never accelerated harder no matter what.

but after reading one of the other guy's posts, i did pull the 90 deg bend off the inlet side and checked for maybe a shop rag or something, but since i didnt use one, i didnt really expect to see one. :D

but no, nothing was blocking it. my guess is that my car moves alot of air, and between the small size and the slight damage, it was too much.

thanks for all of your help, guys. really. i never expected the ic of not flowing, especially since it is a known working ic.....at least, on a different application.

An IC simply does not work that way. Maybe it is full of congealed oil or something like that or it is otherwise defective. Buy a brand new one of the same IC, and it will flow air to make boost. For example, do you make so much airflow at 2 psi (or any level of boost beyond vacuum, however low) that it overwhelms this IC that flows enough air to put 19 psi into another motor -- no.

Philip Bradley

i flushed the ic with paint thinner before i installed it, just like i do every other used intercooler.

It is a small IC, and not the best choice for that reason on a 3.0 or 3.2L that should be making 8 psi+, but its size is not what was preventing you from getting no boost whatsoever.

Philip Bradley

glad you have your boost back

thanks!

fyi, i went ahead and ordered a bar and plate one sized 27x7x3.5. that should be plenty good. IIRC it flows 700ish cfm. cant wait til it gets here.

I am anxious for you to get a new IC, I know for a fact that the IC you currently had has to be defective.

yes, i too know that it is defective.

the only confusion here is that it worked a few weeks ago, and it doesnt leak. oh well, this gives me an excuse to go bigger and better. :)

I am anxious for you to get a new IC, I know for a fact that the IC you currently had has to be defective.

Yes, I'd say that is pretty obvious at this point.

I'm curious to see if you lose the usual 2 lbs through the ebay cooler.

yeah, so am i, seeing as how they advertise like a .2 pound drop at 15 psi. i didnt get the usual one most ppl get though. i believe it's the 24x12x3 and 4. i dont need one that big. the one i got shouldnt lose too much boost, and i've seen many successes with similar ic's.

on a lighter note, i am re-doing my piping the way i originally planned to, since i have the time and need to get beck in there anyways. it should eliminate 2 90 degree bends on the cold side. plus, because the new ic is smaller, i can eliminate 1 45 deg bend from the hot side. pressure drop? .......what pressure drop? lol.

this crappy ic is the best damn thing to happen to me in a while. w00t!

The way they do the psi drops is questionable. I think all the Ebay guys do is copy the numbers for similar Spearco or other established brands. And those numbers do not include any piping. Still, I think the Ebay IC are pretty good and probably don't flow much worse unless the welds are really botched up and bleed through into the core. Any 90s you can replace with a pair of 45s is an improvement, as are any bends you can eliminate. I think only one person measured pressure drop, with a Cartech kit, and that one measurement may not be enough to be reliable. I'll be interested to see what you get -- anything around 1 psi would be great.

Philip Bradley

agreed. 1 psi would most definitely be ideal. i personally think the ebay coolers, if bought with discretion, are just as good as the high dollar ones. im not worried. :)

hurry up UPS guy!!!