How much power will certain mods get me?
--- We cant give you an exact number. All cars are different and if you take 10 identical cars, and do an identical mod/set of mods, they will make 10 different HP levels. Some may gain a lot, some may gain nothing.
We can often give you a ROUGH
I want to make XXXwhp, what will it take? (or) What mods to get XXXwhp?
--- This is VERY dependant on what kind of dyno you are talking about. More specifically, find out what shop you want to make that number at, and find out what kind of dyno they have. Dynos vary as far as how much power a given setup will make. What makes 350whp on one dyno will struggle to make 280whp on another. Between the highest and lowest reading dynos there is litterally a 100whp spread. So if for instance we were to tell you that a certain set mods will give you 300whp, then you go to a shop with a way low reading dyno, you are going to be very dissapointed when you make 250whp, or go to a shop with a very high reading dyno and think we are nuts when you make 350whp.
Mods void your warranty
--- Unless you race the car or its a salvage title, there is no such thing as a "voided" warranty. They can flag it if they see obvious abuse or extreme mods, but this almost never happens. Not enough to concern yourself with anyway. However, mods can and as we know all too well, can result in denied coverage of certain things.
--- For instance, an aftermarket short ram, that looks designed just like the SPT, can result in any work in your entire powertrain being denied warranty coverage if the dealership wants to be "by the book" Just because it looks like the SPT, it wasnt designed and tested by Subaru. This means your engine has been taken outside of their approved design operating parameters. Which means internal damage, turbo damage, transmission/diffs/axles/driveshaft coverage can be compromised since more power than they were intended to handle is going through them. yes, it can be THAT bad. It varies dealer to dealer though, some are really mod friendly. Bottom line, if you are super worried about the warranty, your best bet is to leave it stock, with only SPT parts on it.
The Mag-Moss act will save me if the dealer tries to void my warranty
--- Very little chance. In fact, its best to just forget that act even exists. It was written a long time ago, and it was written to protect people from the dealership denying warranty coverage if the person used non OEM parts THAT WERE OEM LEVEL design. This means that aftermarket parts that change the operating parameters, are NOT included in this act, and its irrelevant to them. I have seen this in court, discussed it with more than one lawyer, as I was a "dealership expert" for 2 dealerships I worked for, going with them to arbitration in these types of cases. Basically look at it this way. It was written too long ago to really be relevant today from a legal standpoint, and it doesnt apply to performance modifications anyway.
But X mod doesnt void Y warranty
--- See above, its entirely possible, and if it goes to arbitration, its not hard to tie X mod to Y problem for the dealership, as the arbitrator usually knows nothing about cars, and tends to believe the dealership over the plaintif from the very beginning.
--- Yes it does. But its the reality of the situation unfortunately.
I want to lower my Subbie, how low can I go?
--- The first thing to know is that Subarus do NOT like to be burried. In general, unless you take some measures to correct geometry, you dont want to go more than about 1 1/2 lower in the front, and 1" lower in the rear. Honestly, 1 inch front and 3/4 inch rear is a better drop from a handling standpoint. There is a lot more to handling than center of gravity.
I still want to go low, what can I do to make it better?
--- Whiteline and a few other companies make a roll center kit for the front suspension that will fix the problem in the front, I THINK you can pretty much slam the front with this kit in place and not have problems. For the rear, there isnt much you can do other than use camber plates/bolts and/or adjustable lateral links
I am going to race/I may race/I want to race a buddy/boss/the guy up the street from me
Great. Dont tell us about it unless you are going to do it on a proper race track. This does not mean a dead end street that you blocked off and have scanners/CBs to listen for cops. While some of us wouldnt really care, the overall feeling on NASIOC about street racing is extremely negative. If you post a street racing story or plan, expect to catch a LOT of flack for it. For heavens sake if you need
to know if you would win THAT bad, lie to us
Say its going to be on a drag strip/track/whatever
Can you tell me what tuner/shop where I should have my car worked on?
Maybe. But you will need to tell us where you live. It would be far better to ask in your regional forum, as you stand a far better chance of getting feedback from people who may have actually used that shop.
Can I run 87octane fuel in my WRX?
NO!. Period. You cant. Ok you can have it tuned on a special map for 87, but you arent going to get any better MPG, probably worse actually, you are going to lose a ton of power, and you will save about 3 bucks per tank of gas. 91 minimum. 93 if at all possible. Or run 87 and damage your engine. To save @12 bucks a month. Think about that
What about race gas? I heard anything higher than 93 is pointless without a tune
--- Absolutely not true. The factory ECU can take advantage of up to about 100 octane with no additional tuning, and you will see power gains. Going from 93 octane to 100 octane unleaded will net you easily 10-15whp, if not a little bit more. (speaking of how an average dyno reads I mean)
Over about 103 octane you will need a tune, in fact, higher than that without a tune could actually cost you power.
What about alcohol injection?
--- There is an EXCELLENT sticky in the meth/alch/water/nitrous subforum. I wont cut and past the whole thing here, its enormous as its both my FAQ and another guys FAQ together. I will grab the link later. But its a sticky so go check it out. Its good stuff.
So what size injector do I need for my turbo upgrade?
There is no 100% rule here as it depends on a few factors, elevation, how much boost you want to run etc. My best advice is to talk to your local tuner, and try to find at least a couple people in your general area with a similar setup and see what they are running. Keep in mind they may be running smaller or larger than they need...
However, IN GENERAL
TD04=stock 440s on the earlier WRX, dark blue top feed 565s on the laters. In other words, stock.
--Some people REALLY push their turbo, and those people that have the light blue 440cc injectors, they will benefit from going to a 550-565cc injector
VF29/30/34/23/22/39/43/48, TD05-16G= 565CC injectors are fine for MOST people. Again, if you are pushing it hard, IE over 22PSI, you may benefit from 650cc injectors.
Big 16G= really, same injectors as the normal 16G. I dont give this particular turbo a lot of thought as honestly, its a waste of time. If you want a faster spooling 16G, get a normal one. If you want the big power 16G, get an EVOIII-16G.
EVOIII-16G=650cc injectors for most people. Same deal, some will benefit from 750s.
18G=650cc injectors for most, HOWEVER, this is a little more of a grey area. You will need the 750s way sooner than you would on an EVOIII or smaller. If you plan on running more than 18PSI, go straight to the 750s.
20G=I have always said 750s. Most people are fine on 750s. However, as of late many big name tuners have been suggesting 850cc injectors on these.
Larger than a 20G, 850s are a must. In some cases, 850s + a rising rate fuel pressure reg or even finding some 1000cc or larger injectors will be needed. Most 10 second cars are running injectors over 1000cc. Some are even in the 1600cc range!!!
Meth/Alcohol injection will give you a little more headroom, slightly reducing your injector requirements, provided you dont go adding a bunch of boost, you can get away with slightly smaller injectors. So if you are on the edge of needing larger injectors, meth/alch injection will get you back into a safer duty cycle.