Boost pressure change

[Irish_86]

I have a 93 awd talon tsi. I was wondering if the boost pressure can be changed with all stock parts? if so how. and how can i find out what pressure it is runnig at/ return it to normal.

 

[LiquidX]

Boost pressure will only go to a minimum that the wastegate spring is set at unless you add in a boost controller which can only raise it above said spring pressure. Having boost, vacuum, and pre turbine exhaust leaks will affect the over all performance or pressure in the system.

To check your boost pressure, you need a boost gauge.

What do you mean "boost pressure can be changed with all stock parts?"

 

[O HAI]

The easiest way to do it is with a manual boost controller and a boost gauge, The controller goes in the vacuum running to your wastegate. You can turn it up a little, dont remember exactly what all stock parts can handle.

 

[Irish_86]

I dont want to go up. I just want to make sure its not jacked or something. if i dont have a controller can i change it? like am i able to change it.

 

[LiquidX]

No, but you would still be good having a boost gauge to see where it's sitting as the stock gauge isn't accurate for anything.

You will want to a a boost leak test to make sure everything is sealed up fine too.

 

[gusu]

If you are on a tight budget and aren't really worried with turning it up right now I'd just go with a cheap boost gauge like a glowshift. It's accurate enough to let us know if it's over or under boosting but other than that they aren't that great. But then again they aren't total trash either, it's just some people's preference to have a more accurate gauge. I've only ever heard of them being off by like 1 or 2 PSI which does not sound like much, but that can be the difference between a blown motor or not. So yes, it is a big deal.

Anyway, if you want a boost gauge that will be useful up until 30 PSI which you may never even run. For a bit more you can get a more accurate Prosport gauge. Which I haven't had any problems with accuracy with until around 25 PSI when testing and it only drifted maybe .5 PSI passed where it should have been. But by this time I'd honestly be looking at some other way of gauging boost than cheap boost gauges.

If you do get a boost controller I'd go with a Joe P. His boost controllers are great and only around 60 bucks compared to the more expensive Hallman Pros which go for 95-135 bucks depending on the vendor or sale. Hallmans do look better though if you are looking for a clean engine bay look.

As for turning up the boost you always want something to monitor knock. So a data logger like a Palm or a tuning solution like ECMlink that also logs is needed. Not all motors have been treated the same. But generally most people don't have a problem with a HEALTHY engine running 15 PSI on a stock fuel system. But then again I'm sure someone has so saying that most don't have a problem isn't worth destroying a motor when you could have spent a couple hundred on at least palm logging to make sure you aren't getting knock, leaning out, etc.

I'd also consider getting a wideband like AEM EUGO or LC-1, the LC-1 is more accurate apparently and most prefer it. I have the AEM and it's a nice gauge and even looks pretty good, but I would have gotten the LC-1 but it came with the car.

I'll also agree with everyone else you MUST test for boost leaks. At least spray soapy water on the intercooler piping, the throttle body (to check for leaky gaskets), and anywhere else you may be thinking boost from the turbo. When you turn the car on you should notice huge bubbles forming or bubbles forming in certain areas only. The best way to test though is with a boost leak tester and a air compressor, if you don't have these the soapy water test will help. Also simply listening for the hiss of leaking air can help.

 

[Irish_86]

What do you mean "boost pressure can be changed with all stock parts?"

What i mean is i heard/read somewhere that the boost can be changed by changing the waste gate. So what the meant to me was the boost could only be changed if you got a boost controller or changed the waste gate. I'm new to turbo's but experienced mechanically. This car was truly screwed over by prevoius owner. So i just want to know that on start up i dont blow the engine i just redid all the gaskets on.

 

[LiquidX]

How are you going to blow the motor on start up? The wastegate only opens up when a specific pressure is met to overcome the internal spring which then allows exhaust gas to be routed away from the turbine.

The only way to raise your boost is by using a boost controller to hold back air pressure before it reaches the wastegate, install a heavier spring in the wastegate (external gated), or a combination of both. Internal gated use an actuator which you can (if available) get a stronger gate or just use a boost controller.

 

[Irish_86]

OK. Then i pretty much would be safe. Like i said i just dont know turbos. Im learning.

 

[LiquidX]

It's all good, that's what the community is for

Just in case you are un aware, on a stock MAF intake, keep the BOV recirculated and do NOT tee the wastegate pressure line into the BOV line. Both should have dedicated lines.

Also, boost leak testing is your best friend and it's always good to do when you mess with your intake system to ensure that everything is sealed up tight.

 

[Irish_86]

ok with the leak test how would i go about that just take off something before the turbo seal it and throw some pressure on it with a gauge?

 

[LiquidX]

http://www.dsmtuners.com/forums/art...-boost-leak-test-how-boostpro-net-tester.html
Be sure to use soapy water.

I personally use one of these.
Intake Leak Pressure Tester

If you need to change to a different size pipe, just the a new coupler.

 

[pos4g63]

I think with the factory boost solenoid you could drill out one of the pressure inlets to get a little more boost maybe 2 to 3 psi. If my memory serves me correctly.

EDIT yeah did a quick google search and found it, also I just took my stock one off looked at. Screwed a drywall screw into the nipple and pulled out a tiny restrictor

 

[Irish_86]

thanks for the blt info.