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Chris... question for you on that intake. I was under the impression that an intake doesn't do a lot for turboed 4 cylinder cars, especially cars like the WRX and STi?

I know an exhaust will help spool the turbo quicker, but am I way off base with my perception on the intake? - AB

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'14 Toyota Sequoia Platinum 4WD
Super Westerfield Bros - '93 Integra - LeChump Du Jour
STX 93 - Scion FR-S

I don't know about the STi, but everything I've heard indicates that a cai for a WRX is a "sound mod" - not a performance mod.



If it was up to me, I'd forget about the intake and put a Hoppe exhaust on it. Power AND sound.

Well, I'm new to performance oriented vehicles and do not know much yet. When I checked into the APEXi I looked at a filtration test:

http://www.mkiv.com/techarticles/filters_test/2/ with the testing done on a Skyline.

I also called Godspeed and was told that they dyno'd them and found approx a 10whp gain. So, I don't really know first hand. You guys got me thinking, though, so I'll call the owner of Godspeed and have a chat with him.

Just so ya know, 10 hp will be imperceptible on a 300 hp car. For autox, 10 hp won't even noticeably change elapsed times for a 165 hp car (Impreza RS). But if you like the sound it makes (I like the sound of my cai & evil exhaust, btw), go for it.

Yeah, gotcha. The best gains will come if I added a good downpipe in conjunction with the CAI. By itself it will probably not be noticeable. But, I've got to piece things together slowly as this is the first car that I bought for fun.

I ran DS all year nationally with the grounding mod. Believe it or not people, the WRX has SUCH poor grounds (dunno about the STi) that the extra grounding smooths out the power curve. We have 3 18 gauge grounds for everything...uhhm yea.

"I added a bunch of grounds so my stereo would sound better"

Everyone seemed to be OK with that.

As far as the CAI. PLEASE do NOT do that on the STi. They already run on the ragged edge of lean with the stock intake. Introducing a CAI into the system w/o proper dyno tuning will lean the car out dangerously. You *can* gain a few HP, no way its 10, with a CAI once you have the car dyno tuned. That way you can get a little more, and also colder, air into the turbo and compensate for the fact that you will have slightly more of it.

I've run my WRX w/o an intake and there are people running 10s on the stock intake. I *will* be trying a CAI when I go dyno tune the car the 2nd week in april. I expect a 3 or 4hp gain, but thats all I'm after.

-Tom

Tom,

My STi runs incredibly rich. Besides the visible black tipped exhaust, I have exhaust residue 'dots' all over the back of my car. The dirt comes off easy with soap but the dots take extra elbow grease. BTW, the owner of Godspeed Inc owns a STi and a dyno. He's dyno'd not only his car but lots of other STi's..He's confident it will not produce a lean and harmful condition. Regardless, your point is taken.

Where are you getting the dyno done? If it's local I'd like to get a run in as well.

Thanks, CHris

When I was into the S4 tuning scene I peeked around the EVO and STi stuff a bit. More so after I sold the S and was considering both. The EVO and the STi from what I saw both ran CRAZY rich from the factory. So rich that the wideband sensors at most dynos couldnt read it. Most guessed them to run 8:1 - 9:1 from the factory at some points. Most of the aftermarket tuning on these cars seems to be getting those fuel curves much more aggressive. Generally getting them around 11:1 which is still "safe" but doesn't really leave much room for error when it comes to bad gas and the like.

Again, no expert here by any means. Just sharing the little bit of information I have seen floating around.

Best of luck. That STi is one NASTY car. Almost makes me miss the ol S4. The ads are right. Turbo + AWD = FUN!

[quote="Vincent Keene
<whining mode on>

You definitely can't run in ESP. Any car with over 260 HP is just not allowed. I'm sure it says so in the THSCC rule book. Just look in the "Ryan, Art, Vincent, and Randy don't wanna get our ass kicked by a 300 HP AWD car" section. Go play with kids your own size (like Dan Ecclecstone) in AS.

<whining mode off>

:[/quote]

This is why I did not sign up for ESP open. Most folks do not think the STi should be in ESP and I am willing to oblige them.

Chris you should just sign up for NOV (ESP). You will get a better PAX than NOV (AS). Or even better, run in TIR, the ultimate thscc class.

Hopefully someone will start running in STU. In the mean time, I will stay in TIR.

Marcus

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Silver Honda
Green Ford
Blue/White Suzuki
Red Triumph
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"Never let life be shaped by fear of its end"

No, you're a towel!

Not to pick on Tom, but a word of warning

Any modification not permitted by the rules for perfomance related changes which is intended to be a perfomance improvement, no matter what the "cover story" is highly unlikely to survive a protest at a major SCCA event. This is true whether the modification actually works or not. I speak as a former protest committee member at several Solo II Nationals.

IF there is a grounding problem with some cars that just cleaning the connections won't solve, then look at the rules related to replacing hardware items, etc. Most parts of a car engine, including the fuel injection components and sensors, etc. are bolted together which leaves lots of opportunities for hardware changes per the rules. Those thin wires that Tom mentioned may not be the only ground paths. Presumably there is a big ground wire between the battery and the block.

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Dick Rasmussen

FS 50 2018 Mustang GT

You will be there with the WRB 03 WRX... driven by my wife. She will be there with you in ESP as a NOV until she trophies.

As for me, I have already trophied twice (that is not going to happen again for a long while ), so I am in Open. I will see you there in Open once you trophy this weekend (and you will). You are just too fast with AS PAX (if you stay there) to not.

If I were you, I would stay in AS, trophy, and see where you stand in the full field PAX before you go charging off into MOD land .

HOWEVER, I do understand the MOD bug. Oh, BTW IIRC (dont you just love acronyms? ), yes, in open loop mode, your car WILL run rich. HOWEVER, the rest of the time, the car runs REALLY close to lean. This is the reason for the Subaru reflashes on the STi and the DET problems. The CAI (even though I think the Apex i was one of the CAI's that didnt mess up the WRX's MAF) is decent, but it does nothing to improve the WRX. I doubt it will help anything on your car, and like the BOV I have (removed for this weekend), I am betting it will make things worse. At the novice event, I had to get out and adjust it before a run to 20% atmos. (that's what I was doing Kev! ) as it was causing stumbling at low rpm in my car by generally pissing off the MAF. After that, my car felt MUCH better, but it was still pissed with that SLIGHT change.

I would check that on NASIOC before taking my advice though. If you want to hear the intake, I would honestly do the intake silencer mod. That is the best free mod there is (should take you outta AS though ).

Hope to see you this coming weekend, and if you want to caravan, let me know. I am all about that .

Good luck, and have fun! Feel free to stop by our tent!

- Brian