Vaccum hose setup: How should they be connected based on my setup?

[Prelude Guy]

Hey guys,

I have a Redtop in my S13 hatch. I am running an S15 T28 Spec-R turbo with an HKS adjustable wastegate actuator, Greddy Spec M FMIC kit, hotpipe with only an HKS SSQV BOV flange, HKS SSQV BOV, and an AEM Tru Boost boost controller.

I have been searching to see how I should connect up the vacuum hoses. According to some sources, I should have either a vacuum nipple welded onto my hotpipe or coldpipe. I'm hoping I don't have to do that, but if I do, I will.

Here's what I've gathered. I need to take the ugly-azz blue vacuum hose that came with my Greddy FMIC and connect it from the HKS actuator to the left input on the AEM EBC. Then I will use a T-connector to connect the top left vacuum output on the throttle body and the fuel pressure reguator. I will then run a hose off of that T-connector to the hose that connects to the back of the AEM EBC. Correct so far?

How do I connect up the BOV and the rest of it? Can I use another vacuum source to run the BOV? Does the vacuum line that connect up to the BOV then connect to the front vacuum input on the AEM EBC?

What are my options?

Also, does anyone know where I can get some black vacuum hoses for a good price? I hate those lame blue ones. :rolleyes:

Thanks!

[japslapsilvia]

here is what i did, on the I/M there are 2 vacume nipples the smaller one for the FPR/t-'d for Profec boost controller, bigger one for BOV. then on the bottom of the T/B there is a vaccume nipple conect that to you wastegate. the nipple under the t/b is getting a "boost only" source b/c if pre t/b butterfly (same as a nipple welded on cold/hot pipe)


oh and im using el-chepo hose from auto-zone, i will prob upgrade to sard hose

[jspaeth]

Ok you can get vacuum hose at your local parts store like pepboys.

You need a nipple on the hotpipe as close to the turbo as possible....this is your BOOST SOURCE....and needs to be run to the input of your EBC boost solenoid.

Then, run hose from the OUTPUT of the EBC boost solenoid to the wastegate.

Then run a hose from the intake manifold (vacuum source) to the BOV.

MOST people run the BOV on the hotpipe, but theoretically, it may be better to put it as close the throttle body as possible (on the coldpipe)..............you want the BOV to "recognize" the difference in pressure in the intake tract (between intake and throttle plate) and manifold that results from letting off the throttle ASAP.

Technically, when the throttle plate is closed it is the air closed to the throttle plate that reaches high pressure earliest....then as the air which is traveling towards the throttle body "stacks up", the high pressure wave goes back towards the turbo.

So, putting the BOV on the coldpipe is in a spot where it "detects" the closing of the throttle plate most quickly, but it is releasing air farther from the turbo.

So, all in all, I'm not sure which one is actually better .....

[jspaeth]

here is what i did, on the I/M there are 2 vacume nipples the smaller one for the FPR/t-'d for Profec boost controller, bigger one for BOV. then on the bottom of the T/B there is a vaccume nipple conect that to you wastegate. the nipple under the t/b is getting a "boost only" source b/c if pre t/b butterfly (same as a nipple welded on cold/hot pipe)


oh and im using el-chepo hose from auto-zone, i will prob upgrade to sard hose


huh? Why are you running a vacuum hose from the manifold to the boost controller first of all?

Secondly, you should really be using a boost source that is located pre-intercooler and as close to the turbo as possible as the "input signal" (it's air lol, not electricity, but i like this terminology) to the boost controller, not something far away from the turbo like at the TB

[japslapsilvia]

huh? Why are you running a vacuum hose from the manifold to the boost controller first of all?

Sorry...that was wrong....i have a profec e-01 and i have the boost pressure sensor connected to that line (vac & boost) and the boost solonoid connected to the boost source.

Secondly, you should really be using a boost source that is located pre-intercooler and as close to the turbo as possible as the "input signal" (it's air lol, not electricity, but i like this terminology) to the boost controller, not something far away from the turbo like at the TB

hmm i never though about the intercooler affecting it....oh well time to well on a fitting to the hot pipe

[jspaeth]

Yeah you can expect a solid 1-2 psi drop across the intercooler, if not more if you have a shitty intercooler.

BOV on hotpipe or coldpipe is debatable, but pressure signal should come off as close to the turbo as possible