boost problem..... - Boost Forum

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boost problem.....
Saturday, October 14, 2006 10:04 PM
ok let me get you guys some background on this. last year i couldnt boost my car over 10 pounds. i had a manual boost controller from turbosmart, figured it may have been the cause. so this year i baught a blitz electronic unit, also got rid of my dsm bov and put on a greddy type rs. ive turned the screw a few turns in on it aswell.

now heres whats going on, last yeah i coudnt boost over 10 pounds, this year im having the same problem. all my clamps are tight, everything is sealed up and theres no leaks that ive seen or heard. ive been playing with my boost controller, the gain ive played around with and ive gone as far as 80% on one of my boost settings and still, i hit only between 8 and 10 pounds. my turbo is internally gated, good for over 20 psi according to herman at cherryturbos.com wh obuilt it but the wastegate has a 5.5 pound spring in it. i thought this could have been the problem. i preloaded the spring as much as possible with the wastegate actuator arm and still nothing. heres my question. im using a nipple on the compressor housing of the turbo for my wastegate. would me getting a signal from there in any way affect the boost issue im having or is this definatly a wastegate problem?

tomorrow im gonna unhook the line and see how the car boosts without a vac line on the wastegate. would me running a line from say the tb help me out? this has been bugging me for a long time now and im about out of ideas as to what could be the cause. and rather than replacing the wastegate id like to eliminate what i can.




parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list

Re: boost problem.....
Saturday, October 14, 2006 10:20 PM
ok is your wastegate vaccum line connected to the turbo or do you take your vaccum from the intake manifold?? I had a similar problem wich was that!! is your manifold leaking???? if you manifold leak it's normal you connot have much boost!! your turbo is too small maybe??? it says 20psi but on wich engine?? maybe on a 1.5 12 valve civic engine, lol .... are you sure your wastegate isnt broken??? maybe the flapper keeps open... that only supposition i'm trying to help you out






http://cavalierdomination.monchar.com
Re: boost problem.....
Sunday, October 15, 2006 6:38 AM
the flap opens, its a brand new turbo, ive preloaded it as far as i can go and nothing. its on a twincam motor. the turbo was built to make 420 hp by cherryturbos for my car

the wastegate line is connected to the compressor housing of the turbo. im thinking of getting my feed from the tb and seeing if that makes a difference at all although i dont think it really should because alot of turbos i see run like that




parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
Re: boost problem.....
Sunday, October 15, 2006 6:42 AM
I thought internal wastegates could only double their spring pressure? so if you wanted to go over 10 you'd need a stronger spring/actuater whatever?

Maybe I am wrong but I remember hypsy explaining this in soemones post a while back



LE61T PTE6262 Powered

Re: boost problem.....
Sunday, October 15, 2006 6:57 AM
if thats the case then that definatly makes sense, ive got a 5 pound spring in there right now and it would definatly explain why i cant go higher. although with a preload i should be able to take it up a notch id imagine.

also with the electronic controller its gonna try to keep the gate closed until it gets to the set %. @!#$ it im just gonna go unhook the little bastard and see what happens

any more input would be great, thanks for the help




parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
Re: boost problem.....
Sunday, October 15, 2006 8:51 AM
That's BS. I had a 5 lb spring in there last year, preloaded, and a TurboXS Controller and I hit just under 16 psi.

Uchi, you either have a leak, or a restriction. Something is stopping you... earlier this season I was maxed at 10-15 psi but I found out it was a leak and fixed it, and immediately hit 18 psi and let off (at 3500 rpm)... not enough fuel for that yet haha.

Do you have a cat? How is your connection from engine to manifold and manifold to turbo?

Sorry I missed your calls today bro.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: boost problem.....
Sunday, October 15, 2006 10:09 AM
hey bud,

yes QBE is correct.........trying to get your turbo to hit that much boost with a 5 pound spring is a big no no.......SweetnessGT, yes it may be possible but not the best idea to do. your making your boost controller work extra hard to maintain the pressure that you want. anyone that is educated on internal gates will tell you that you always want to get a your spring pressure matched as closely as possible to the amount of boost you want to run. for your setup i would recommend going with a 10 lbs spring in your actuator... another thing to think about is running a dual port actuator. they tend to perform alot better, less problems with boost spikes. another thing that i realized with my internal gate was, cranking on the actuator arm didnt actually raise my boost pressure at all, the only thing that i noticed it did was help the turbo spool and make full boost sooner than it did with less tention on it. remember also that over tentioning the actuator arm is not the best idea, go with a stiffer spring thats why they offer different spring rates. i have my setup hooked up similar to yours, i have my vacume source coming directly from the compressor housing to the actuator along with my boost controller hooked to the other port. also most of the time the actuator will maintain a little less than what they are actually rated. as i stated earlier i have the 10 lb spring in my actuator. my autometer boost guage reads just under 10 psi when i run my calibration with the boost controller disabled but the AEM tells me im seeing about 7.5 psi which i believe over the boost gauge. anyway, just letting you know what i have experienced with this and what i recommend bud, good luck...any more questions just post....
Re: boost problem.....
Sunday, October 15, 2006 11:23 AM
^^ thats what I have learned and been told by a few people... and I ama ctually going to say that hahn/hypsy taught me that and for the reasons why I agree with them



LE61T PTE6262 Powered

Re: boost problem.....
Sunday, October 15, 2006 2:50 PM
hey thanks for all the help guys. i was out today and played around with it a little. heres what i found thats baffling the crap out of me.

i turned the boost controller down to 0 and it still hits the same boost level as before, i unhooked the vac line going to the wastegate and still the same thing, no spikes no creeps no jumps or anything. i seriously think this wastegate is screwed up, maybe the spring is cracked inside of it or something. im thinking that maybe the exhaust gases mixed withthe vac going to the actuator are forcing the flapper to open prematurly. i mean the damn thing should have gone skyhigh unhooked.

tomorrow im gonna remove some of the preload and try that out. right now im waiting for my buddy to find me his old srt4 wastegate and im gonna see if i can make that thing work for me its apparantly got a 7 pound spring in it and we'll see how that works out.

as for leaks, everything is tight as far as i can tell. ive got a greddy type rs bov and ive tightened it up about 4 or so turns already thinking that on its soft setting it might have been leaking. also im running silicone connectors with t clamps on all of them and ive got them cranked right down.

the cat on the car is high flow but thats been hollow for a while now

also theres no restrictions in the exhaust, 3 inch pipes mandrel bent, 40 series flowmaster muffler and all my charge pipes are 2.5 inches.




parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
Re: boost problem.....
Sunday, October 15, 2006 6:41 PM
Daniel, yes you're right you'll overwork it. I was commenting on the comment you CAN'T go higher than 10 psi (double it)... you can .

I am still running internally gated, ditched a 5 psi and an 11 psi spring that barely worked, and am running a 12 psi spring that sees about 10 at the manifold, no pre-load. I can effectively bring this up using the profec B, since this is what it's meant for. Should I need much more, I'll go to a 15 psi spring.

As for you uchi, you unhooked the vac line to the wastegate and STILL no more than 5 psi? Something's up, because that shuold have shot you to max boost (flapper kept shut tight)...

If it's not the actuator, check your movement on your flapper, and if not that, it's time to look deeper... something may be stopping it from building boost.

Gee, where are all those hot-talking boost "guru's" around here to help out? Only good for shooting your mouths off or something?

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: boost problem.....
Monday, October 16, 2006 6:07 AM
the flapper works fine, i unhooked the actuator arm the other day and the turbo made no boost whatsoever. the car sees about 10 pounds and tapers to about 8 n omatter what the boost controller is set to, unhooked the thing should have spiked. im not sure if the pressure is forcing the flapper open or what. im gonna tie the flapper closed and see what happens then.

also i cant figure out why i cant bring my boost level down, its 5 pound spring and i cant drop to any less then im at right now.

ive got the srt 4 wastegate in my hand, gonna see if i can make it work for me and if not then im gonn ahave to look into another wastegate i think




parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list

Re: boost problem.....
Monday, October 16, 2006 8:01 AM
I had that problem with my external wastegate, i figured out the exhaust pressure was too much for the little 5 pound spring and was opening the plunger despite any boost reference, so i could only hit ~10 psi. Shimmed the spring and problem solved.


Re: boost problem.....
Monday, October 16, 2006 9:19 AM
well i think i fixed the problem today, doesnt explain why my manual boost controller wasnt working on it but i sure think i know what happened.

one of the bolts that holds the wastegate onto the compressor housing had either backed out or wasnt tightened down. either or it was just sitting there and im guessing the wastegate actuator was moving under pressure. fixed that, got the wcar out and 15 pounds right away, tapers to about 12.5 - 13, gotta play withthe gain settings on ebc still to get it to hold boost where it should be but aside from that i think the mystery may be solved

thanks for all the help guys




parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
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