Boost leak or what?

[TotallyNotAmused]

So I've been having continuous issues with how much boost I've been able to run as of late. Its been like this for a little over a month now, and its really starting to get annoying. I'm pretty sure its a boost leak, but I have no idea where.

I get the same thing when I get on it in third or fourth or fifth gear, all from 3k rpm or higher. Spikes to 15, drops right off to 14, climbs up to about 14.8 by 5krpm then starts falling off. By 6200rpm I'm at 12 pounds. I really don't think this is normal, as before I started messing around with all this BPV nonsense, I was spiking 17, holding 15.5 up to 5k rpm, and dropping off to 13.5-14 around 6k. This started happening back when I removed my TMIC the first time to try and get the HKS on. When we reinstalled the intercooler, the vaccum line was run under the intercooler elbow mistakenly, and I was hardly boosting ten pounds. It stayed like this for about a week till I realised that the connection was wrong and fixed it. It was this time that I started getting the curent boost readings I am getting.

Mods are CP-e intake, Forge BPV with blue spring+2 shims, Corksport Catback, CDFP, stretched coil springs.

When I first got the Forge, I ran it with just a blue spring, and the exact same thing happened. I'll try it with a red spring+no shims tonight. The only other thing I could think of is the tubes off the intercooler are loose, but I have tightend them to the point they wont go any tighter, so they may need to be tightend around the base. I'm getting new tires this weekend, the tire place is full service so I'll ask if they can do a boost leak check. I'm starting to get to the point where I want to say fuck it and just stop spending money on this car and start saving for something else.

Any advice/things to look for/I know whats wrong input would be awesome. Thanks.

[gsrtype1]

u definatly have a leak even if u had a stck bpv and u have the forge so its a leak for sure! I had this happen it was a whole the little pastic piece the directs tubing for the boost guage (rubbed away by the hood) i got another peice at oriely for a dollar

[TotallyNotAmused]

It can't be a hole in the line with the boost gauge because its a scangauge. I can't feel any air flowing out around from the two intercooler tubes. Possibility two (which I doubt) is that the gauge is messed up.

The only thing is, I raced two Speed3s, both with just intakes, and pulled on both of them. This was with loosing boost as described above. I don't think the catback adds enough to be able to noticably pull on them, and even with the CDFP letting me stay in it longer, I would think loosing boost would nix that?

I am almost positive its a leak, I just don't know where from, or if running it with the vaccum tube routed improperly for about a week may have something to do with it.

[Bravnik]

Check all your clamps - All 5 of them. 4 on the hoses to your TMIC and 1 at your Turbo Inlet.

[TotallyNotAmused]

Originally Posted by Bravnik Check all your clamps - All 5 of them. 4 on the hoses to your TMIC and 1 at your Turbo Inlet.

I'll re check the four intercooler hoses. That one in the back is a bitch...I have to pop off the intercooler to get to it, right?

[gsrtype1]

if your winning races then maybe you guage is wrong... messed up..

[SLS MS3]

Originally Posted by gsrtype1 if your winning races then maybe you guage is wrong... messed up..

Than it's several gauges (and ultimately his ECU) that are wrong. He's used a scangauge, and a dashhawk to check so far, and they both read through the OBDII port. I think he's also used a ProSport at one point before he got the scangauge.

And that brings up something else.... Robert, are you comparing the physical gauge readings to the OBDII port readings? If so, there's your discrepancy right there. Neither of the physical gauges I've used reads the same as the OBDII port.

[SLS MS3]

Originally Posted by TotallyNotAmused I get the same thing when I get on it in third or fourth or fifth gear, all from 3k rpm or higher. Spikes to 15, drops right off to 14, climbs up to about 14.8 by 5krpm then starts falling off. By 6200rpm I'm at 12 pounds.

I still don't think you have a leak. You're almost running the same boost levels now that i was back when i was closer to stock. My boost dropped off more than yours is doing now, but I didn't have the CDFP back then and I'm sure it's making a difference for you. I ran a 13.3 at that supposedly low boost level. *shrug*

[NYpest]

PM sent

[TotallyNotAmused]

PM replied to.

I never ran the Prosport, just the Aeroforce. I never really saw the readouts on that time I ran David's dashhawk, I wasn't watching it. I'm just confused because with the Forge, I should be holding boost marginally better. When I ran the Synapse for a few days, I wasn't falling off as much up top, but still was never getting more than 14.8psi. I really have no thought that it is the CDFP, because this was happening long before I picked the CDFP up, and nothing changed at all.

*shrug*

The only reason I think I have a leak is because back before I decided to mess with all this BOV nonsense, I was hitting high 15pounds pounds then falling off two pounds towards 6krpm. But, on that exact same note, I pulled on Juan and Sal, and I know a catback isn't going to add enough power to make up for a boost leak. Maybe its all in my head and I'm just used to the power/speed.

[Jesse MS3GT]

I spike then hold 13-14psi that falls off a cliff after 5600rpm so if you have a boost leak it must not be as bad as mine LOL

[Andrade08]

I have seen this.......on a 07/08 Speed3.
Cobb SRI, ETS 3.25" TMIC with SU boost tubes and T bolt clamps through out & Forge BPV blue spring 2 shims. On a Prosport mechanical boost gauge.......Spikes to just under 20PSi and slowly bleeds to about 16PSI and holds solid to about 4000rpms+(depends on gear) then drops slowly to about 13PSi and holds to 6000RPMs. Never below 13PSI in any gear at any RPM at WOT.
Check your Forge housing. I have seen loose ones.
Leave the BPV bolted to the cold pipe. Un hook the bypass vent tube from it. Grab the Forge vent tube in your hand and try to spin the top of the valve counter clockwise against the base. If the top on the unit spins on the bottom flange then you need to take it off and send it to Forge. Also check the vacuum fitting because it is screwed in and comes loose. Also check the vent tube itself as it screws in also and comes loose.

[NYpest]

Originally Posted by Andrade08 I have seen this.......on a 07/08 Speed3. Cobb SRI, ETS 3.25" TMIC with SU boost tubes and T bolt clamps through out & Forge BPV blue spring 2 shims. On a Prosport mechanical boost gauge.......Spikes to just under 20PSi and slowly bleeds to about 16PSI and holds solid to about 4000rpms+(depends on gear) then drops slowly to about 13PSi and holds to 6000RPMs. Never below 13PSI in any gear at any RPM at WOT. Check your Forge housing. I have seen loose ones. Leave the BPV bolted to the cold pipe. Un hook the bypass vent tube from it. Grab the Forge vent tube in your hand and try to spin the top of the valve counter clockwise against the base. If the top on the unit spins on the bottom flange then you need to take it off and send it to Forge. Also check the vacuum fitting because it is screwed in and comes loose. Also check the vent tube itself as it screws in also and comes loose.

good suggestions....