High Boost

[MadTripper]

After about a year and a half, I finally have my Talon on the road. Well, I'm waiting for the paperwork and title to come back but that should be early this week. I have been doing little things to get it cleaned up and so on. Yesterday, I installed a boost gauge and mounted it to the steering column. I didn't want to drill my dash area up so I hacked up a gatorade bottle and used a nylon strap to mount it. Surprisingly enough, it looks decent. Anyway, I took it for a test drive and my boost is hitting 20 psi! It doesn't bother me too much but I thought the stock 2G setup was around 12-15. The only mod is the 1G BOV so I don't get it. If anyone has an idea, let me know.

Tripper

 

[dave99gst]

in a year and a half , your talon is totaly stock ?
mods you may have done may account for the hi pressure. (3" exhaust,no cat,etc)

 

[bushy]

From the looks of his avatar it looks like the talon was in a bad accident.

But there's nothing wrong with taking your time.

 

[iceman21221]

IF you can take some pictures of the engine bay, turbo, intercoler and maybe someone can tell if the car has any mods.

 

[MadTripper]

No mods other than what I have in my profile. It took a year and a half and a total of $5000.00 for the talon to be on the road. I didn't add any aftermarket parts because I want to run it for a while and make sure it will hold up before dumping more money into it. I have some pictures of the engine bay when it was wrecked up and I'll run out and grab some right now of the current look.

Here are the pictures from a while back:
http://www.madtripper.com/gallery/Talon


Here are the pictures from today:
http://www.madtripper.com/gallery/Rebuild

Thanks for the help.

 

[Turbo Talon 111]

is it hitting 20psi quickly and you are instantly letting off the gas or what? you don't list a boost controller. is this correct? it should not be getting 20psi without a boost controller and even with one i can't imagine a T-25 (stock turbo) hitting that high. it should hit boost cut long before that and would not last long at that high of a boost anyways. so either your gauge is reading wrong for whatever reason or you have a problem with the stock boost control system.

 

[VPrime]

mine also gets20+psi... but only after installing a boost controller.

 

[MadTripper]

It hits 20 and then drops off to about 15 or so. I'll try and shoot some video of it this week. No boost controller and the only leak I was able to find is on the TB shaft. Also, I verified the gauge works during my boost leak test.


Tripper

 

[zippyshoe]

This sounds like there is either a problem with your stock boost control (as mentioned by Turbo_Talon_111) such as a defective boost control solenoid or a missing/damaged vacuum line, or the turbo's wastegate is not functioning properly. You definitely do not want to be running your car at 20psi boost with the stock fuel system - you will be running very lean (bad for the engine). As an experiment, you could try connecting a vacuum line directly between your turbo compressor housing and the wastegate actuator. When you do so, you should only reach about 11psi. If this is the case, then this means that the problem is with either the boost control solenoid or one of the vacuum lines running to the solenoid. If you still reach 20psi, then you probably have a defective wastegate. Hope this helps!

 

[MadTripper]

I hate to be ignorant but where do I find the boost solenoid? Is it mounted by the firewall to the left of the fuel pressure solenoid? Let me know when you get a chance.

Tripper

 

[travislaw]

I hate to be ignorant but where do I find the boost solenoid? Is it mounted by the firewall to the left of the fuel pressure solenoid? Let me know when you get a chance.

Tripper

It is located by your Coolant Reservior on the passender side fender wall in the engine bay. If you have the stock turbo, just follow the rubber hose line coming out of the Turbo Intake Compressor Housing. It T's in one or two spots, but it will eventually get you there.

 

[MadTripper]

Well this could explain some things since that is the side that was crushed by the deer. I'll have to investigate after work and thanks for the help. Real quick, would the solenoid I described above be the EGR solenoid? I have another post where I added a block off plate but I also noticed a little leak on the this unit when doing a boost leak test. This may explain my odd idling. Here is a picture of the part in question. Thanks again.

 

[travislaw]

This is off of Vfaq.com

 

[MadTripper]

Should have known to look there. Just so I'm clear, the solenoid on the left is the EGR?

Thanks again

 

[MadTripper]

I found the BCS but I haven't had a chance to play with it yet. I did manage to take some quick video of my boost gauge and also of the engine idling.


http://www.madtripper.com/albums/Rebuild/talon_boost.wmv

http://www.madtripper.com/albums/Rebuild/talon_idle.wmv

Tripper

 

[Turbo Talon 111]

i can't tell whats going on with the idle from that video. the boost going up to 20 then dropping to 15 is known as boost spike though.

 

[GVR4592]

You shouldn't boost it until you get the problem fixed. You are going to destroy your engine. Start by bypassing the bcs and inspecting the wategate actuator and actuator arm for any problems.

 

[MadTripper]

I've put about 150 miles on it and so far no issues. Not that I want to invite any additional problems. I'll follow what zippyshoe wrote and see if its the BCS or the wastegate actuator. Thanks again for the input.

Tripper

 

[MadTripper]

Just to be clear, I should be able to block off the end of the T fitting going to the BCS and have all the pressure go directly to the WGA right?

 

[travislaw]

Just to be clear, I should be able to block off the end of the T fitting going to the BCS and have all the pressure go directly to the WGA right?

Or you can just take the T-out and have the hose going from the compressor housing go right into the wastegate actuator. Then just Plug the line going from your intake accordian tube thingy to the T. (Forgot the technical name for it.)

 

[MadTripper]

Ok, thanks again and I'll see what I can do with it this evening.

Tripper

 

[zippyshoe]

Good luck and let us know what you find. Also, make sure the vacuum line you use to connect between the compressor housing and the wastegate actuator is a good line (no leaks).

 

[MadTripper]

I did a vac leak test a few weeks back so I should be good to go. I'm going to block off the BCS side of the "T" and see what that does. By all things holy, the WGA should open at 11 or so PSI from what I understand. I'll post later this evening with my results.

Tripper

 

[oldman]

T25 as well as the stock BCS (any bleeder type valve really) are well known for boost spikes though usually about 3psi, 5psi is excessive so you should definitelylook into possible leaks, specifically the hoses going to the actuator. Bypassing the BCS or proper porting of the turbine housing should definitely help.

 

[MadTripper]

I used a worm gear clamp and pinched off the tube from the "T" fitting to the BCS. I am now maxing out at 14 and then it drops to around 10. I do know of a little boost leak around the TB shaft but other than that, everything was pretty sealed up. Correct me if I'm wrong but I should be able to put an MBC in place of the "T" fitting and keep it adjusted to a safe level right? The BCS can basically be removed and the intake nipple blocked. Let me know if this makes sense.

Thanks again for all your help.

Tripper