Waste gate actuater

[DanielS]

Hi guys,

Im fitting my new turbo and PWR intercooler this week, and was hoping someone could help me out with the best place to ducted the piping for the waste gate actuater and boost compensator.

Is it better to fit it closer to the inlet or is better closer to the turbo housing? or does it not make much difference??

Any info would be great, thanks

Daniels

[HotFourOk]

My wastegate actuator line comes straight out of the inlet manifold.. coz that is the pressure that the motor is getting... If you put it before the intercooler or near the turbo housing.. it will compensate for extra boost (as boost is higher out of the turbo than the boost going into the engine) and overfuel. This is due to the pressure drop over the intercooler and the pipe lenth.

[DanielS]

thanks hotfourok, that makes sence.

Do you think the boost actuater piping should be located here too?

[stool]

If you run the boost compensator pressure line from the inlet manifold`

you could have problems with extra turbo lag .

As the whole pipe`line and intercooler needs to build pressure` Before the
boost compensator receives + pressure on the diaphragm.

Which gives you the extra fuel to make power to over come turbo lag

Just thinking out loud with no facts to prove my theory.

[DanielS]

good point stool- will have a look at it and try and work it out.

[HotFourOk]

If the pressure from the turbo is not yet at the inlet manifold, there is no boost entering the engine.. hence you will put fuel in before the boost has reached the motor... which leads to overfuelling issues.

Turbo lag is related to the extra time it takes for a turbo to spool up, mainly due to insufficient exhaust gas production for the turbine size. Eg - a stocko charade running a disco potato

You may be able to make the engine fuel up earlier to overcome some sluggishness before the turbo has spooled up, but you then have issues with the motor running too rich, and maybe not much extra power anyways.. as the boost compensator effects how much fuel goes into the combustion chamber... and without the air needed (because the compensator has been activated earlier) the motor can run rich.

It doesnt matter about the amount of boost anywhere except the inlet manifold... that is the amount of boost that enters the motor.. that's all you need to worry about.

[Rb25sil80]

You want it coming straight off the compressor housing to the wastegate actuator, every factory turbo and aftermarket turbo ive seen uses this setup and i'd imagine for very good reason. Stool hit the nail on the head really. You would definately face extra lag having the actuator gain its signal from further along the inlet tract. There are several things you can do to reduce lag even further, can shorten the wastegate actuator rod and i'd highly recommend fitting an electronic boost controller. Will hold your wastegate firmly shut until reaching your desired boost level and it will eliminate any nasty boost spikes that can occur in cooler conditions.

If you want anymore info gimme a yell, I pissed many a dollar into my turbo setup on the rb25 in the sil80

Cheers
Brad

[HotFourOk]

My Rocky comes off the inlet manfold

[HotFourOk]

After doing some reading I found this...

"When increasing the boost pressure to higher levels (15 psi or higher), you will get more accurate, responsive and stable boost pressure by using a pressure supply line directly from the engine inlet manifold after the throttle body housing instead of the pressure line from the pressure side of the turbo as stated in step 3 above. By supplying the pressure directly from the engine inlet manifold, pressure effects due to air being forced through the connecting pipes and intercooler are eliminated from the operation of the wastegate actuator system."
(http://www.turboxs.com/faq/turboxshigh.htm)

So for lower boost applications it looks like it doesn't matter..

[DanielS]

Thanks for all the info guys, I will let you know how I go.

Daniels