Boost Leak Test Trouble

[bewstin]

Alrighty, so basically my problem is my turbo spools to 4-5psi, and wont spool to it's setting (12psi) until the RPMS get up to like 4500-5k. I feel I've narrowed down the problem to a Boost leak. Problem is, I've never properly been shown how to do a Boost leak test other than what I've read or seen on the forums. I made a boost leak tester a few months back, works good, and I've used it before to find major leaks. Right now I'm pretty sure I'm chasing down a small leak, but cant get the system to hold pressure. Now, when i fill the BLT with pressure using a air hose off my compressor, it pumps up the system great, But I cant get it to hold any psi. It just leaks out of my valve cover breather hose, pretty slow but enough to not let it even register 10psi on the air hose gauge. I imagine this is because the pressure from the intake manifold is leaking through the PCV valve into the valve cover. I can't really hear anything else leaking, but it's hard to tell because of the leakage from the valve cover. I've triple checked all my vacuum lines and inter cooler couplers.
The reason i think i have a small vacuum leak:
---Rough first 20 seconds after a cold start, w/ boost gauge bouncing between 5 and 15 vacuum, feels like it misfiring, AFR is solid 10.0. After about 15 seconds AFR goes up to 12ish and idle smooths out a little bit. after about 5-10 more seconds AFR goes up to 14.5 and car idle's smooth. Once car is up to temp, vacuum bounces between 19 and 21 vacuum slowly, with the AFR bouncing between 14.7 -14.3 constantly. I'm pretty sure the rough start is because of the EGR delete and its cold outside.
--- Front o2 is brand new and working, Coolant temp sensor is brand new and working, Brand new BPR7ES plugs, and NGK wires.
--- Brand new FP manifold, so no pre-turbo exhaust leaks. All bolts from manifold and head and manifold to turbo are on and tight.
---Boost lag, WOT in any gear other than 1st, the turbo will spool to 5psi. Then when the rpm's get up to 4500 -5k the boost climbs to 12psi, which is where i have the MBC set to.
---AFR's are 10.0 in boost, whether I'm lightly on the throttle in boost or WOT, the AFR is 10.0 the whole time, until i get to 5k ish it hits 10.8, 11 at the most.
---Cruising AFR is 14.7-13.5 depending on hills or flat.
---Stock fuel system

So I'm lost, does it seem like a boost leak?? I'm getting very frustrated, this seems to be my last little problem before i go to get tuned. I'm waiting to put in my DSMlink v3 full, FIC 1200's , walbo 255, and Fuel labs FPR until my tune date which is 1/5/13. It's a 2 hour drive and will cost me 600$ between gas and the tune, which is why i want my car perfect before I get down there. Sorry for the novel, but the more you guys know the more you can help. Thanks

 

[DeadlyScone]

Is there any oil in your intake pipe when you pull it off? Any in your compressor housing? If not you could have a number of other issues such as slightly bent valves, valves not seating correctly, piston rings garbage, ect.

Check play on your turbo first in and out and all around if its not pretty solid your seals could be shot. This also would be evident with the oil ine the aforementioned locations.

 

[bewstin]

Well my rebuild only has 2000 miles on it. I can't imagine the rings are bad. There was a little oil on the compressor inlet when i took the intake off to do the BLT. Although this was before i installed my oil catch can. The turbo is brand new as well, but its a cheaper GodSpeed turbo. No shaft play. It could be my head i suppose. When i did the rebuild i only had the head surface decked, i didn't have a valve job done. The exhaust valves had some carbon on them, but never jumped timing so i cant imagine i have any slightly bent valves. I hope that's not the case, but i suppose it could be head related.

 

[DeadlyScone]

Well my rebuild only has 2000 miles on it. I can't imagine the rings are bad. There was a little oil on the compressor inlet when i took the intake off to do the BLT. Although this was before i installed my oil catch can. The turbo is brand new as well, but its a cheaper GodSpeed turbo. No shaft play. It could be my head i suppose. When i did the rebuild i only had the head surface decked, i didn't have a valve job done. The exhaust valves had some carbon on them, but never jumped timing so i cant imagine i have any slightly bent valves. I hope that's not the case, but i suppose it could be head related.

Some air is acceptable during blt because the turbo seals arnt compressed both ways and so air enters the pcv system. Excessive air would be accompanied by loud gurgling.

 

[bewstin]

Just sounds like air leaking, no gargling. Is it possible that im running rich because i'm still on the stock fuel setup and tune, and upgraded to a 20g. Obviously the stock t25 spools much faster than a 20g, so could the computer be dumping fuel too early, causing the car to run very rich. And could running extremely rich (10.0) cause the car to have a hard time spooling the turbo??

I was browsing youtube and i found this video. It's like exactly what my car is doing as far as the boost not hitting til higher RPMS. His seems to hit 10psi, then climb to 18psi which is where he apparently has it set to. Mine just goes to 5psi, and then spikes at 11-12psi. Maybe it's normal and I'm just crazy?

[ame=http://www.youtube.com/watch?v=8MCEvZrZ4XU]Eclipse GSX (douglas) Boost Gauge - YouTube[/ame]

Does the car in the video seem like its spooling properly?

 

[DeadlyScone]

You should be hitting full boost by 3400-3600rpm based upon boost level of course.
The 20g flows more air than the stock straw-like flow abilities of the td05. Figure 20psi on a td05 and 20 psi on a 20g, you will be making more power at the same psi with the 20g than the td05 due to more airflow. However you need a greater rpm to achieve said power.

You need to be close to 11.1-10.9 a/f ratio, a leaner mixture is needed before you wash out your cylinder walls being at 10.0(pig rich)

Get a hold of MY1GDSM if you want a good tune. Who rebuilt your turbo btw? Iam no 20g or turbo expert for that(Justin is however) but my fp green with the 20g compressor housing hits full boost by 3300-3400rpm, so something doesn't seem right to me.

for now adjust you maf comp sliders at the given MAFRaw Hz. Up will make it more rich and down will lean it out.

 

[bewstin]

I don't have the DSMlink in yet. Also i noticed, if im in a higher gear, like 3rd or 4th, it will only hit 5psi, and stay there until the car gets up to a higher RPM around 5k then it jumps up to 12. I can hear the turbo spool up fast at the low rpm, but its just stopping at 5psi. I'm thinking it has to be waste gate related. The turbo is brand new less than 2k miles on it.

 

[ChiTownHussla]

cheap turbo are known to have faulty wastegate regulators. look up jafromobile and how he fixed it up on youtube

 

[bewstin]

cheap turbo are known to have faulty wastegate regulators. look up jafromobile and how he fixed it up on youtube

Yes i'm leaning towards just a cheap wastegate that's not working properly. The turbo otherwise is really good quality so far.

So if the arm coming off my actuator is adjusted too loose, the flapper is getting blown open and causing the turbo not to boost properly correct? Today im going to spin it in a couple times to tighten it up, hopefully that will help.

 

[WES_393]

You need to be close to 11.1-10.9 a/f ratio, a leaner mixture is needed before you wash out your cylinder walls being at 10.0(pig rich)

The factory fuel maps target an AFR in the high 9's/low 10's at WOT. While an AFR around 11:1 is better for making power, there is definitely no danger in running 10:1 AFR. It's completely normal.

So if the arm coming off my actuator is adjusted too loose, the flapper is getting blown open and causing the turbo not to boost properly correct? Today im going to spin it in a couple times to tighten it up, hopefully that will help.

Yes, if the wastegate is constantly sitting slightly open it will increase spool time.

 

[Archer Fabrications]

Could you have a boost leak at the boost gauge?

 

[bewstin]

So I just went outside and checked the adjustment on the actuator. Pulled off the e-clip and pulled off the adjuster rod. Turbo was pre-loaded fine. Turns out my boost controller was bottomed out, i forgot i had set it at the minimum setting when i put it in. So i turned it up a little bit and bam I'm getting a solid 10psi instantly now. All fixed for the most part. I haven't gotten on it yet but I'm guessing what I'm experiencing as far as getting an extra bit of boost up high in the RPMS, is boost creep? Hopefully the shop can tune it out when i go get tuned in january.

 

[Archer Fabrications]

Good luck with those ebay turbos... they don't have very good reviews.

 

[WES_393]

Boost creep is a mechanical issue, not something that can be tuned out. However, it may stop creeping once you crank up the boost. It really depends on the size and design of the turbine housing.

 

[bewstin]

Boost creep is a mechanical issue, not something that can be tuned out. However, it may stop creeping once you crank up the boost. It really depends on the size and design of the turbine housing.

Yea i will most likely end up getting an external waste gate setup if this one gives me more trouble. Just sucks I just put on my new FP manifold. How hard would it be to make an external flange on it??

Good luck with those ebay turbos... they don't have very good reviews.

My budget couldn't fit in a more expensive Genuine 20G, so I went cheap. But, in all honesty I had a Godspeed GT30R knockoff on my 87 RX7 TII and it was great for 9 months, and put down 418whp. Sold the car with it still working, not blowing smoke or having any issues at all. It was externally gated though...

 

[WES_393]

The wastegate itself isn't the issue. You need to enlarge the wastegate channel and flapper hole. You could always just use an O2 housing wastegate setup and remove the internal gate. But, this is assuming that's actually the problem...

First things first, I would hook up a boost source straight to the watsegate actuator and see how much boost you can build. The Godspeed 20g should have come with a 1 bar (14.5psi) actuator. Like I said, a boost controller can't turn the boost down past wastegate pressure. So the slow spool and low boost are more likely caused by an issue with the wastegate flapper/actuator.

 

[DeadlyScone]

Yes i'm leaning towards just a cheap wastegate that's not working properly. The turbo otherwise is really good quality so far.

So if the arm coming off my actuator is adjusted too loose, the flapper is getting blown open and causing the turbo not to boost properly correct? Today im going to spin it in a couple times to tighten it up, hopefully that will help.

You have an internal wastegate since i have a dumped EWG i assume you would have heard if it was opening.

 

[Archer Fabrications]

It's not really recommended to weld on the FP manifold... It's doable though.

 

[bewstin]

Yea the problem is solved as of now. Boosts right up to 13psi and holds. I just had my boost controller set all the way down. Thanks for the help. If i run into problems when i get tuned ill be sure to look into an external wastegate setup.

 

[HOOCH256]

Good luck with those ebay turbos... they don't have very good reviews.

Godspeeds may be cheap but they are not "eBay" turbos, I know a number of people running them on SR20's in drift cars and they beat the piss out of them day in day out with no ill effects. All company's start at the bottom, and I think Godspeeds stuff has been coming along! Plus they offer a nice warranty as long as its installed by an ASE certified mech jut my 2 cents

 

[Archer Fabrications]

They are all over ebay they are cheap ebay turbos. Thats their main source
Of sales. Regardless of where they are sold they are Chinese pieces of crap. Your drift frienda might be having luck with them. (For now) but others havent been as fortunate. Like one of my buddies thay tried to go the cheap route.

 

[bewstin]

Urban is right when he says they are cheap turbo's, because they are. I was aware of what i was paying for before I purchased the product so I willingly took a chance. My history with GodSpeed was a gt3076 that I had on my 87 RX7 TII. Ran great for 9 months, no smoke, no problems. Even the oil line it came with held up fine. I sold the car still running and boosting strong. So I'm giving them another go around on my DSM. I'm already looking at FP turbo's, so I have a backup plan if it fails on me. You get what you pay for 100% of the time, sometimes you get more. I've seen honda kids run 125$ turbo's on their cars for over a year, and I've seen them smoke out of the box.

 

[Archer Fabrications]

How much boost were you running on the rx7? Honda kids only run like 5-8 psi so it's no wonder they last longer then a dsm trying to push 25+psi out of it. They are also cheap because no R&D went i to it and most likely wasnt even balanced for super high rpm (100,000+rpm) like lets say.... A holset? Which can be had for a very close price to a godspeed unit.

 

[habitatguy187]

Yea the problem is solved as of now.

What you first wrote is a major problem no one ever really adressed....

Right now I'm pretty sure I'm chasing down a small leak, but cant get the system to hold pressure. Now, when i fill the BLT with pressure using a air hose off my compressor, it pumps up the system great, But I cant get it to hold any psi. It just leaks out of my valve cover breather hose, pretty slow but enough to not let it even register 10psi on the air hose gauge. I imagine this is because the pressure from the intake manifold is leaking through the PCV valve into the valve cover.

Not being able to build just 10psi during a boost leak test is really bad. Have you tested your pcv valve yet? Unscrew it from the valve cover and see if you can blow through it, from the IM side to the valve cover side. If you can then you need to replace it. Be careful when torquing it back down not to tighten it too much I've cracked a valve cover doing that.

 

[bewstin]

Yea i was thinking my pcv valve was bad, even though it's only got 5k miles on it. Because when I do my BLT, i can hear air leaking from the oil catch can line that goes into the intake(valve cover breather hole). Obviously with the intake pipe off to do the BLT that line isn't hooked up to anything, and I couldn't get the system to hold pressure. So I figured a lot of air pressure was leaking through my PCV valve into my valve cover. As for putting in the pcv valve, I'm right there with ya, I've seen em crack before. I'll take it out tomorrow and check it, replace it if I have to, and redo my BLT. As of right now it seems to be fine, boosts up to 12psi. just seem to get fuel cut really easy even at lower rpms (3500+) under full boost in any gear other than 1st. Still on the stock MAF so I'm guessing that's why, either that or a boost leak somewhere i haven't tracked down yet. Runs fine if I'm not I'm just cruising. AFR's stay 10.0