WJM Posted January 11, 2004 Share Posted January 11, 2004 Ok.... That is the down pipe i made. Now, ive checked the waste gate travel on a turbo with out a pipe, and then the turbo with the DP on it...the wastegate is NOT in anyway shape or form...being interupted with its opening/travel. I am getting boost creep of up to 16PSI with this DP...it did the same on my RX. I figured it was the cams/ultra free flowintake combo i had on the RX....but its doing the same with stock turbo cams as well... ok ok...heres my new intake for it too. Any ideas on why it boost creeps so bad? Quote Link to comment Share on other sites More sharing options...
WJM Posted January 11, 2004 Author Share Posted January 11, 2004 anyone? Quote Link to comment Share on other sites More sharing options...
Skip Posted January 11, 2004 Share Posted January 11, 2004 Will, . What make is the boost pressure control valve you are using? Quote Link to comment Share on other sites More sharing options...
the_bard Posted January 11, 2004 Share Posted January 11, 2004 You'll have to excuse my lack of turbo knowledge, and the potential of forcing this thread off-topic, but what's boost creep? I assume the boost pressure keeps "creeping" higher? Quote Link to comment Share on other sites More sharing options...
WJM Posted January 12, 2004 Author Share Posted January 12, 2004 Skip: i am using the factory stuff. No modifications intended for increased boost presures. Same for the RX. the_bard: Yes, it keeps creeping higher. In the case of my RX and the GL-10...it stops creeping at about 16 PSI. I want it at 8!! Quote Link to comment Share on other sites More sharing options...
Skip Posted January 12, 2004 Share Posted January 12, 2004 Are there two turbos / waste gates on these or did you swap the turbo unit? You could try just running a line from the small nipple on the turbo outlet to the waste gate control diaphram Quote Link to comment Share on other sites More sharing options...
Kamikaze Posted January 12, 2004 Share Posted January 12, 2004 I did the same thing (running from the nipple to the wastegate) and I am also getting boost creep to 15 psI. I am gonna try hooking the boost solenoid back up. Quote Link to comment Share on other sites More sharing options...
WJM Posted January 12, 2004 Author Share Posted January 12, 2004 Skip: two turbos, two wastegates. same issues on both. with stock exhaust, 7~8 psi all day long. but with my custom DP, both boost creep. and both cars had the wastegate/boost control as it came from the factory. and what do you mean exactly? You could try just running a line from the small nipple on the turbo outlet to the waste gate control diaphram you mean, actually hooking up the wastegate? or what? its hooked up. Quote Link to comment Share on other sites More sharing options...
Skip Posted January 12, 2004 Share Posted January 12, 2004 Will I ment by pass any other devises and run the line direct from the turbo outlet to the waste gate control diaphram. Kam, and Will, Please do what you want, but the waste gate duty solenoid's funtion is to allow the ECU to increase the boost when it deems necessary. You both have too much boost already. If I were confronted with this situation I would use a "MityVac" with a pressure output to see if the control diaphagms are ruptured or the control rods are bound somehow. My feeble mind tells me this is the only way that the boost can do what you say it is (aside from some physical limitation on the wastegate control rod, Will I know you say yours is not limited) is a blockage in the waste gate passage. Put Mity Vac pressure of about 10 PSI on the waste gate control diaphram and see if the control rod moves and stays moved. BTW My car with custom down pipe and free flow exhaust and intake sit right where I set the boost control valve pressure Quote Link to comment Share on other sites More sharing options...
WJM Posted January 12, 2004 Author Share Posted January 12, 2004 there is nothing but that line from the turbo to wastegate. I never messed with it. The RX always had the stock solenoid setup. Still...i dont understand how mine is boost bleeding. it only does that with that DP...and ive checked the wastegate actualtors. they are fine. I guess my DP design is flawed. Too much flow! Quote Link to comment Share on other sites More sharing options...
Skip Posted January 12, 2004 Share Posted January 12, 2004 As I said, you will do as you will, Will. But something tells me mine flows as well as yours, and mine sits at a seady 12 PSI. You say "and ive checked the wastegate actualtors. they are fine. Did you put a Mity Vac type tester on the WG control diaphram and see it hold pressure? BTW A small split or crack in a line to the WG will also cause this problem. Maybe the radical right turn at the top of your pipe, is causing the exhaust to bounce back keeping waste gate from opening -nah. At any rate, I firmly believe the problem is not "Too much flow!" Skipout Quote Link to comment Share on other sites More sharing options...
WJM Posted January 12, 2004 Author Share Posted January 12, 2004 no i did not use sucha tool on it skip... I will check that line and possibly replace it. I still dont get how it does it on two cars. one 1989 and now the 1986. This is only by changing to that down pipe. I made no other changes. Quote Link to comment Share on other sites More sharing options...
rallyruss Posted January 12, 2004 Share Posted January 12, 2004 I have noticed the same thing on both of my cars as well. under stock conditions boost was stable all the time. after custom exhaust and intake silencer removal with a K/N, they both do the boost creep. this happens at hight RPM or on a long steep grade. I hate to disagree with skip because he is a smart guy but there are to many people here that have experienced the same thing. I do belive its flow related. I have 1 subespeed down pipe with 2.5 out the back, intercooled on the wagon. custom modified down pipe with 2.5 as well on the RX. the waste gate just alows some exhaust to go around the turbo. what if our turbos are too small for the incerased flow? they cant dump excess exhaust fast enough. I read a verry good book on turbos once and he mentioned the possibility of this, espically with a internal wastegate. I think if you had a slightly larger turbo this would not be a issue. Quote Link to comment Share on other sites More sharing options...
Skip Posted January 12, 2004 Share Posted January 12, 2004 Well Russ thanks for chiming in here. Was that book Corky Bell's book "Maximum Boost" by chance? A very good point you make on waste gate size. The upper RPM thing also makes sense, could be the waste gate was not designed to dump that much exhaust gas at these elevated flow rates, thus enough gas still is passing through the turbine to let the boost pressure build. Will I'm sorry this does look like you are right and I am wrong. I will have a look at one of the turbos I have on the shelf and see if there is a way to make them open more. Once again Will I'm sorry for doubting you Quote Link to comment Share on other sites More sharing options...
WJM Posted January 13, 2004 Author Share Posted January 13, 2004 HAHA! It IS too much flow! Thats what I was trying to get to. I think I will throw a stock DP on it, that is cut at theend of the cat canister and the cat is gutted....thats what I had on the RX before. it didnt boost creep. But it was still an AWESOME sound and performance increase over what came on it from the factory. Its quite alright Skipper, we are all wrong at one time or another. You just happen to be right more often than not. I think the wastegate arm travel is the limiting factor. I was thinking, you could slot the bottom wastegate...so that when a secondary wastegate engages, it wont be fighting the first one, since its already bottomed out. Or somthing like that. or you could shorten the arm on the wastegate, athat the actuator arm attaches to...or something. Quote Link to comment Share on other sites More sharing options...
rallyruss Posted January 13, 2004 Share Posted January 13, 2004 yeah skip that was the book. lots of good info. I read it first then started modifing afterwards. as for the boost creep. put a intercooler on and let it go. I like it. just have to watch the boost gauge. mine has a warning tone set to go off at high boost. still looking for a legacy or WRX turbo. anyone have a spare? I feel this would do the trick. and yes I know there is fabrication involved. I will make more parts if I could get a sample turbo. Quote Link to comment Share on other sites More sharing options...
electryc_monk Posted February 15, 2004 Share Posted February 15, 2004 yet another victim of "boost creeping" .... Had the (embarassed giggle) exhaust leak fixed last week (looks to Calebz and Okami down in Denton) - yeah that slight exhaust leak sound we heard from Silver D/Ragon... well the plate the turbo mounted to had com completely seperated from the uppipe but, the surrounding heatshield and the factory clamping points kept the tubo to the exhaust and it still had boost albeing only up to about 7PSI (thanks to the gauge) anywho went out to do a few errands and the nice long 3+mile straightaway I desided to do a few "drop to 4th" and gun-it's..... watched the gauge go right to 7-8 then start slowly climbing higher and higher... then at about 82MPH the 12PSI line was crossed and WHAM! the ECU did its fuel cut... wow was it harsh... just like the ignition was killed for a split second. So I did it a few more times to "really make sure it was boost creeping and hitting that cut-off... yuppers just , and i mean *just* above 12PSI and it hits hard...... needless to say I have yet to install the MBC sitting in the passenger seat yet..... funny how 2.5 pipe from the turbo back with that 3-way cat are appearantly too much flow for the VF4? stock turbo..... looks like I should be saving up the nickels and dimes for a (thanks to Deniis's tinkering and advice - the most recently) looking for a VF-10 or 11 or maybe a VF-28 or 30????? but aside from that... I'll keep track of the data on this end and keep ya posted... i hope as good as you guys are doing.... Quote Link to comment Share on other sites More sharing options...
WJM Posted February 16, 2004 Author Share Posted February 16, 2004 The factory turbo for the EA82 is the VF7....unless other sources tell me differently, that is what it is supposidly. Not too terribly much difference with the VF11...just very slight enlargement of things, and different turbines, and the exh. housing is different. 5 bolt pattern...oh, the intake exh. housing is a little different too...bolt pattern again. Ive never hit fuel cut...even with it boost creeping to 16psi. That was on the RX, with no mods on the fuel system at all. The wagon never hit it when it boost crept cuz the switch is unplugged. I DID recently fix my exhaust leak on the crossover pipe, and install a factory turbo back system again...minus the muffler. I have to say that I like it like that, the low end is great, and mid range is about perfect. The high end sucks. Detonation. I think once i get the IC installed, cams....oh, and throw in some new t-belts, that problem will hopefully be solved. The number one thing to open up the high end on these engines is the crossover pipe, and turbo back exhaust. Then i all of us will run into the boost creep situation...in that case, more backpressure, aka muffler, will fix that...but high end will suffer...OR...either more travel on the wastegate, OR a larger turbo, such as the TD04...mind you the TD04 set for the stock 8 PSI...to start with. Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted May 16, 2008 Share Posted May 16, 2008 yeah that slight exhaust leak sound we heard from Silver D/Ragon... well the plate the turbo mounted to had com completely seperated from the uppipe but, the surrounding heatshield and the factory clamping points kept the tubo to the exhaust and it still had boost albeing only up to about 7PSI (thanks to the gauge) You mean like this? This happened to me on the way up to Whistler B.C. Thankfully it didn't crack the entire way through until I was back in the States. After this, I decided to do away with the factory pipe. It had proven its self not up to the task. Installed this: I have also cut the silencer off my EA81Ts airbox, but have not had any boost creep. Pretty much everything besides the intake and exhaust is stock. Quote Link to comment Share on other sites More sharing options...
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