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Old 04-25-2002, 12:19 PM   #1
SnortWagon
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Default Improve factory boost solenoid for $2.88

First off - credit to Kris and the folks at BoostMonkey because they discovered this: Replace the restrictive hose coupling that is in-line between the wastegate 'T' and the factory boost solenoid with a much less RESTRICTIVE 3/16" coupling available at any auto parts store - I bought two at NAPA for $2.88 each.

Here's what you'll notice due to improved airflow to the factory solenoid:
Faster boost build and very slightly higher boost levels as the solenoid now has a better physical connection to what's going on under the hood.
Boost will build a bit earlier and last a bit longer as well.

I believe all this occurs because the solenoid sees more air more quickly than stock, allowing the solenoid to work more quickly to prevent dumping boost through the wastegate (which opens at 8 pounds)

Prior to this mod, I NEVER saw second gear boost approaching 14 pounds (maybe 10-11 at best) - Now my car peaks momentarily at 14 pounds plus, and settles between 12 and 13 pounds in second gear - plus it holds boost a bit longer.

Subjectively, this feels comparable to running a stock WRX on 93 octane vs. 91. BTW, my WRX is stock except for the grounding mod. If you want pictures of what and where this piece is, look at the BoostMonkey website under 'install'.

Again, thanks to Kris for figuring out something we can all benefit from.
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Old 04-25-2002, 01:11 PM   #2
Evaider
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You have got to be kidding? This really makes a difference? Hmm. my as well try it.

Now to ask all the stupid usualy questions that havnt been asked yet. hehehe.

Will this void my warranty?

Is it possible that the aftermarket piece will melt because of the heat of the engine and somehow cause my turbo to blow up?

What is the best way to install this?

How long does this take to install? Should I maybe have my mechanic do it for me?



having too much fun here.. thanks for the info.
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Old 04-25-2002, 01:43 PM   #3
mlambert
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interesting, being that boost is still controlled by the stock EBC..you shouldnt get any overboosting, right?
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Old 04-25-2002, 02:04 PM   #4
SnortWagon
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Correct - no overboosting. The plastic piece I removed looked identical to the one I installed - only it was smaller. Think about how this works: the solenoid controls boost by managing boost(controlled electronically) pressure before the wastegate. The factory wastegate opens mechanically when it sees 8 pounds of pressure. By allowing the solenoid to 'see' and adjust to boost pressure more quickly (because the pressure passing to it is LESS restricted due to the larger coupling), the stock solenoid can prevent the wastegate from opening when it shouldn't. The stock 'restrictor' coupling causes the solenoid to behave more slowly, resulting in the wastegate momentarily/partially opening before the solenoid responds and gets the situation corrected.

The result of this modifcation means that precious boost (especially when the turbo first spools up) is saved at lower RPM, and that the solenoid does a better job of controlling boost at high RPM because it is more immediately tied to boost levels.

The part itself only takes about 10 minutes to switch (when the hoses are warm). Why not try it? You can always switch back if you don't feel a difference.
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Old 04-25-2002, 02:07 PM   #5
bluescoobywagon
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I asked this in the Boost Monkey thread, but didn't get a response. If you performed this mod with an EBC installed, would the EBC be better able to control boost and eliminate some of the weird problems I've read about?

Mike Robinson
2002 WRX Sport Wagon
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Old 04-25-2002, 02:14 PM   #6
6Pack
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If you read some of the first threads some people say it initially boosted slightly above the max of 17 then it quickly learned and now only go to 17. So that's going to be the max with everything else stock. If you're talking about using an extra EBC like the AVC-R or something then you're basically doing the same thing as the boostmonkey. No need to have both.
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Old 04-25-2002, 02:24 PM   #7
GM991
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SnortWagon
Do you have any pictures of the install and were it goes you could e-mail me??


gm991@excite.com
Thanks
Gary
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Old 04-25-2002, 02:44 PM   #8
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Old 04-25-2002, 02:54 PM   #9
Red Rocket
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Default Two questions...

1. Any effect on boost in 3rd, 4th or 5th on a stock car?

2. Is it reasonable (safe) to do this if you don't have a boost guage?

Kevin
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Old 04-25-2002, 02:59 PM   #10
VetteVert
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Default Re: Two questions...

If I can find one this evening, I'm going to try it. I have a boost guage and I'll try and document the changes as best I can. I'll post when I get it put in. If it doesn't raise peak boost that much, I think you would be OK

VV

Quote:
Originally posted by Red Rocket
1. Any effect on boost in 3rd, 4th or 5th on a stock car?

2. Is it reasonable (safe) to do this if you don't have a boost guage?

Kevin
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Old 04-25-2002, 03:17 PM   #11
Brad B.
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Can this be done on a stock setup? Or do you need a MBC?
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Old 04-25-2002, 03:39 PM   #12
VetteVert
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That's what this thread is about....

I'll try and post my results as soon as I find a connector (or whatever it's called...not real sure what to ask for)

VV

Quote:
Originally posted by Brad B.
Can this be done on a stock setup? Or do you need a MBC?
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Old 04-25-2002, 04:58 PM   #13
GM991
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SnortWagon

I just put one in and went for a ride. I have a stock wrx with just the ground strap mod scoop spliter and boost gauge.

I did not go up on the highway, but the short ride I did take
it seemed to spool up faster and my boost gauge did read 15psi at the top end of 2nd.
Normally in 2nd it goes up to 14-14.5psi.

Is that normal??? ANYONE

I guess what I'm saying is that it seemed more responsive on the low end and of cource 15 psi on the top end...

I'm going out later on the highway and I will let you guy's know if there is anymore differents

Snortwagon is this what you experenced???

Thanks
GM991

Last edited by GM991; 04-26-2002 at 09:31 AM.
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Old 04-25-2002, 05:06 PM   #14
bemani
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Yeah, where in the store do you find some connector like this?
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Old 04-25-2002, 05:12 PM   #15
VetteVert
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I just did the swap. Not a huge difference. Boost does jump faster, and peaks to a higher point (the most significant difference). It peaks right at .1 bar higher. It only holds around .05 bar higher. Definitely a worthwhile mod, though, for the $1.79 it cost me. (Advance Auto, btw) Here are some pics of both pieces, and a clearer picture of the installation area. I took the picture after installation so the white piece would make it more clear (hopefully).





VV
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Old 04-25-2002, 06:28 PM   #16
Brad B.
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Who's going to be the first to offer pink annodized ones with STi logos on them?
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Old 04-25-2002, 06:39 PM   #17
cvp71
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What about changing the T also? It looks like it may also be restricting flow.

Cody
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Old 04-25-2002, 07:11 PM   #18
Brad B.
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cvp: See this thread: http://i-club.com/forums/showthread....hreadid=176548

Basically, "Removing just #2 [the T fitting] and replacing it with a much larger 3/16" fitting causes the max boost to drop 2-3psi. " Not sure what the T + this mod will do however...
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Old 04-25-2002, 07:16 PM   #19
djerickd
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Anyone try this with TurboXS stage 2?
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Old 04-25-2002, 07:19 PM   #20
Mykl
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Okay, this is the first I've heard of this, and I'm about to read the other thread posted. If someone could be so polite as to post links to other threads on this subject or give me a keyword or two to search with it would be greatly appreciated.

Anyway, despite not having my boost guage installed I went and spend the $1.61 (I WIN!!!) at Autozone for a pair of connectors. Installed it in the parking lot in all of 2 minutes in a hot engine bay.

Butt dyno says "HOLY ****", but we all know how accurate the butt dyno is since it's controlled by the brain. Noticed a good improvement in 2nd gear, and spoolup in third seemed to be a bit quicker. 1st has always felt pretty quick so I can't really tell, and I haven't gotten on the highway to test 4th.

When I get my boost guage installed I'll swap the connector back out for the stock one, leave it in for a while, and pay attention to how it reacts. Then I'll install the larger one and see what I get.

One thing I did notice is that the 3/16th connector is closer to the actual size of the hose, while the stocker looks tiny in comparison.
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Old 04-25-2002, 07:31 PM   #21
bemani
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I keep looking at that picture and it looks like there's only one of those connectors, why do you guys buy a pair? Is there another one that isn't on the picture?
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Old 04-25-2002, 07:37 PM   #22
GOT_WRX
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Any EGT comparison before and after the mod?
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Old 04-25-2002, 07:49 PM   #23
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Got mine installed today and it seems like turbo spools up faster and reaches max boost quicker. Oh, it only comes in pairs for $1.69 if you are wondering why everyone's getting a pair
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Old 04-25-2002, 07:57 PM   #24
Darryl
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Thumbs up my 2 cents

Read the thread, went to Autozone ($1.57, and I win!!), popped it in, and took off. Butt dyno does not lie, and I got that funny feelig in my belly (from surprise). No boost gage, and it is very good turbo weather here right now (cool and dry) so maybe it's that. But I have the Cobb Club Spec kit, and I know I felt a stronger response off the line, plus, nailing it in 2nd feels a bit better too. I hope this won't conflict with the tuning on my Unichip. If not, my hearty thanks to you, Snort!
later all,
Darryl

Ps I'd have bought just one, but they came two per pack.
Ps(2x) When I said it felt stronger off the line, I meant it felt like the boost came on earlier, and that slight lag seems nicely diminished.
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Old 04-25-2002, 08:13 PM   #25
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Will there be a higer egt as a result of this mod? Any part throttle problems or will this not occur because the wrx is still using the factory boost control solenoid.
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