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sperry · 2005-07-28, 10:29 AM

I'm a little confused as to who's who and when this happened. Is that an email from back when you were tuning the WRX, or is that regarding the STi?

If that's from '02, then most of what's in there matches the body of knowledge from back then. In '02 a BOV was unecessary, since all the ones out at that time were vent-to-atmosphere and nobody was really running that much boost to really need it. Now with the STi, things have changed a bit, but I'd still stick to only 100% recirculating BOVs.

Also, in '02 CAI's didn't make more power than stock... at least not safely. The early CAI's only leaned out the car, so they felt faster and sounded cooler, but were in fact risking the motor. Newer CAI's have been flow tested to be safe and provide additional power, especially on the STi w/ its larger displacement. Regarding tuning for a CAI... if the tuner is going to do it the right way, which includes scaling the MAF voltage for all rpm ranges, it will take a long ass time.

Turbo inlet hoses on WRX's don't make more power. My car is living proof. It's only with the install of the 2.5L that I'll finally be getting use out of that thing. But hell, sometimes you gotta try some stuff to see if it works, or we'd all be running the same shit we were running back when the WRX 1st came out.

Regarding the grounding kit... you've certainly shown that they do something, but we've yet to quantify what that something is. So it's a valid argument at this point to say that a grounding kit isn't worth the cost. It probably won't hurt anything, and it does seem to have some positive effects, but until we've got independent dyno data that shows the grounding kit does help performance in some way, you can make an argument for either side. Personally, I think the grounding kit won't add peak power or torque, but I believe it will help to smooth out the power curve due to more consistant sensor readings for the ECU.

You're dead on about cat backs and performance. If you're only gonna run a cat-back, just get the one that sounds the best. However, if you plan on later going to a full turbo-back, there's a chance that if you pick a shitty cat-back, it might hinder performance once the rest of the exhaust is replaced. However, I haven't heard of a cat-back that's that shitty yet.

So, if that email isn't from 2002, it sounds like this tuner is just living in the past, and still promoting what was considered to be the "right" way to tune from a few years back. Newer, better designed parts, and the differences due to the 2.5L STi motor have changed the tuning landscape a bit, which means things that didn't used to work are now useful like BOV's and CAIs.

(PS: Phil, I understand this is all stuff you already know, I'm posting it mostly for people that haven't been around Suby tuning for the last few years. Plus, playing devil's advocate is fun.

)

2005-07-28, 10:29 AM	#4
sperry The Doink Real Name: Scott Join Date: Nov 2002 Location: Portland, OR Posts: 20,335 Car: '09 OBXT, '02 WRX, '96 Miata Class: PDX/TT-6 The way out is through	I'm a little confused as to who's who and when this happened. Is that an email from back when you were tuning the WRX, or is that regarding the STi? If that's from '02, then most of what's in there matches the body of knowledge from back then. In '02 a BOV was unecessary, since all the ones out at that time were vent-to-atmosphere and nobody was really running that much boost to really need it. Now with the STi, things have changed a bit, but I'd still stick to only 100% recirculating BOVs. Also, in '02 CAI's didn't make more power than stock... at least not safely. The early CAI's only leaned out the car, so they felt faster and sounded cooler, but were in fact risking the motor. Newer CAI's have been flow tested to be safe and provide additional power, especially on the STi w/ its larger displacement. Regarding tuning for a CAI... if the tuner is going to do it the right way, which includes scaling the MAF voltage for all rpm ranges, it will take a long ass time. Turbo inlet hoses on WRX's don't make more power. My car is living proof. It's only with the install of the 2.5L that I'll finally be getting use out of that thing. But hell, sometimes you gotta try some stuff to see if it works, or we'd all be running the same shit we were running back when the WRX 1st came out. Regarding the grounding kit... you've certainly shown that they do something, but we've yet to quantify what that something is. So it's a valid argument at this point to say that a grounding kit isn't worth the cost. It probably won't hurt anything, and it does seem to have some positive effects, but until we've got independent dyno data that shows the grounding kit does help performance in some way, you can make an argument for either side. Personally, I think the grounding kit won't add peak power or torque, but I believe it will help to smooth out the power curve due to more consistant sensor readings for the ECU. You're dead on about cat backs and performance. If you're only gonna run a cat-back, just get the one that sounds the best. However, if you plan on later going to a full turbo-back, there's a chance that if you pick a shitty cat-back, it might hinder performance once the rest of the exhaust is replaced. However, I haven't heard of a cat-back that's that shitty yet. So, if that email isn't from 2002, it sounds like this tuner is just living in the past, and still promoting what was considered to be the "right" way to tune from a few years back. Newer, better designed parts, and the differences due to the 2.5L STi motor have changed the tuning landscape a bit, which means things that didn't used to work are now useful like BOV's and CAIs. (PS: Phil, I understand this is all stuff you already know, I'm posting it mostly for people that haven't been around Suby tuning for the last few years. Plus, playing devil's advocate is fun. ) __________________ Is you is, or is you ain't, my con-stit-u-ints?