Boost Dropping

04-23-2006, 01:14 PM
'95 Civic, low compression b18c1 (9:1 pistons), Drag turbo kit (with fabricated extended dumptube).

I helped my friend put in the engine and put on the turbo kit a few months ago. When it left the shop it was running 14psi, and holding strong. The customer came back this week with it only boosting 7-8psi. We pressurized the pipes (pipe that connects the turbo all the way to the end of the charge pipe) to find any boost leaks, and the only one we found was a tiny pin hole one at the bov (hks ssqv) between the small gap of the clip that holds it on to the pipe. I thought that maybe someone played with the boost controller (turboxs high performance boost controller), so I did my best to reset it. On the way down the street it went to 10psi and held, but on the way back down the road it only would hit 7psi again. Tried upping the boost again and still only hit 7-8psi. We resealed the wastegate to the manifold (incase that was leaking), and it made no difference. Manifolds seem tight, injectors don't seem the be leaking (no drops of fuel under the injectors or being sprayed back on the fuel rail), t-body is tight, turbo isn't blown. Also forgot to mention that my friend took the boost controller out of the equation, and tied off one of the boost lines; and it still would only do 7-8psi.

Plan to double check the injector seals and IM gasket seal, as well as try to fix the tiny boost leak at the bov. Anyone have any ideas (i know no one posts on sundays :frown:)?

04-24-2006, 12:57 AM
well we took it for another test drive today (not touching anything since last night), and it's boosting to 12-13psi. I don't know what the hell to think.

04-24-2006, 08:05 AM
what are you using to register the boost?? If you're using a boost gauge it might be something wrong with it, but if you're using the MAP sensor, i dont know what the problem would be........let me think about this one and get back to you....

04-24-2006, 11:54 AM
We're using a boost gauge. The problem with that is when we first checked out the car 2 days ago, we pulled out the gauge to see if there was a kink in the line, and there was. The line was actually folded over it's self, I'm surprised it registered any boost at all. But we cut that part of the line off and redid it, but it still only read 7-8psi at the time.

04-24-2006, 02:31 PM
i would post this on Honda-tech so that you can get more than like 3 responses in a week...for some reason the Honda forum on AF is falling apart...

04-24-2006, 10:21 PM
[QUOTE]i would post this on Honda-tech so that you can get more than like 3 responses in a week...for some reason the Honda forum on AF is falling apart...

i would like to contribute, but, ive been so busy with work, law school, and a home loan to get lately, i only get to post when im at the office and have nothing to do. anyways, heres some essential questions.................

spring rate? turbo is spinning? any shaft play? leak in exhaust mani gasket? bov stuck open in idle, part throttle, wot? check all bolted connections, couplers, and clamps. wouldnt hurt to plug up a vac gauge you can rent at your parts store to verify there are no vacuum leaks. what boost controller? what wg? you are on an fmu? any wierd noise with the bov closed? are you still using the stock map sensor?

04-25-2006, 01:17 PM
I believe it's a 7psi spring in a Tial F38 wg. The customer did say that he popped his hood and saw some "air" spew out the top of the wg, though his story changed 3 times in a matter of 10 minutes; and finally said it may not have come from the wg at all (that's why we resealed the wg just to be safe). Turbo spins and there's no shaft play. Exhaust manifold is tight, was retightened about a week after it was installed. I'll have to check the BOV to be sure if it's getting stuck. It was making a slightly weird noise when it was only opened at partial throttle. But no weird sounds when it was completely closed, at least not that I heard. We checked all clamps and couplers, and did the old soapy water trick to check for leaks. It's a TurboXS "high performance boost controller". Using an FMU (until it's tuned with hondata by evans tuning in a week or 2). And using the stock MAP sensor with a missing link. And using a Blox IM, so there aren't as many vacume ports as the stock gs-r IM, and all lines are clamped down.

04-25-2006, 11:03 PM
i hate people saying different things. makes me not even want to help sometimes. all that is needed is some accurate facts. just the facts. anyways, lets move on.

so you have the basic drag different parts? what was the color of the spring................if you remember? do you know your elevation? where are the vac lines on the bov, wg, and mbc routed to? basically where are you getting your vac sources from? any fuel or vac lines mis routed? any cels? you sure you properly mounted and put in the map sensor, vac lines, and link? hows the wg O ring? other than that, all i can really think about is a leak somewhere.

also, you cannot boost 14 psi on the stock map sensor. go pick up a used gm 3 bar map sensor for $30 - $50 used somewhere. also, you cannot run the 3 bar map sensor on the stock ecu. but, if you run hondata, you will be fine.

04-27-2006, 12:56 PM
Color of the wg spring is red, but I don't know if it's tial's little or big spring. So it's either 5.80psi or 11.60psi. Elevation is right around 400ft (seen anywhere from 390-420ft). The BOV is running off a vacume T connected to the back of the IM and the boost gauge. The wg is run from the port on the compressor side of the turbo (I'm not up on my turbo terminology, but it's a vacume port on the inlet side of the turbo). The mbc is between the port on the inlet side of the turbo, and goes to the port on the back of the wg. As far as I can tell; all vacume lines, fuel lines, MAP, missing link; are all mounted correctly. The wg doesn't seem to have an O ring at all, just 2 gaskets that came with it. Infact the gaskets were the only hardware that came with the wg, not even the port that screws into the top of the wg (that would hit the hood anyways).

Last night we messed with it for hours and rechecked everything again. But this time the BOV didn't make a sound at all. It's back to 7psi again and it didn't make even the slightest chirp. And I found out that the BOV is used, so no one knows how well it's been working. But it was midnight by the time we started narrowing it down to that, so we'll have to check that today. We did get it to go to 10 psi again yesterday (earlier in the evening), but then it suddenly stopped again without touching anything. But the boost gauge was fluttering like crazy when it hit that high.

I knew about the 3-bar map sensor, but the customer just didn't want to buy it yet. But he also thinks that he can get 600+ whp with his Apexi WS2 exhaust. And he's been driving the car, since the break in period, with 7psi and only using an FMU for engine managment. I'm wondering if maybe bad rings (caused by the rich environment) could cause the problems we're having. I would assume that it would cause a loss in power (and obviously compression), but I don't know if it would effect the turbo at all. I hate this car...

Edit - we replaced the Tial wg with a delta gate one and it hit 14psi. But the BOV still wouldn't go off, so we replaced it with another ssqv. Everything seems to be working fine now, other than it running rich at 14psi. Idk...

04-28-2006, 10:58 PM
good job.

hows the wg ring?

04-29-2006, 01:01 AM
I'll try to check that out if I get a chance. The customer is going to try and send it back to Tial to get it replaced (who knows if they would). But in my last post I should have wrote that it's running lean at 14psi, and not rich. But I'm not really surprised, since he's only using an fmu and 310cc injectors.

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