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So i started out with a bone stock 06 WRX. Now a have a AEM short ram intake, STi tmic, Perrin Up pipe, and i am looking at a Cat back Exhaust. Do i need a pro tune? Its not that i dont trust local tuners for my car. But i dont think they have the experience of tuning a lot of cars and i wouldn't want to nuke my motor. Should i go to cobb?

Also i want to get a Catless Down Pipe but do i NEED a tune? The 02 sensor is what reads your air fuel mixture and without the cats it could cause it to run way rich or way lean right? posting.php?mode=post&f=7#

The answer would be YES, YES, and YES.

You need SOME sort of engine management with all of these mods done to it. The way most "learning" ECU's work is that they will drive way different when you first put the mods on, but eventually they will adjust values to compensate. This is NOT a good thing.

Even if you have to pay someone $100 to do even a "meh at best" tune on your car with all these mods, DO IT. You'll never be able to tap the potential of these parts without making the necessary changes to your ECU mapping. If you ever do any mods to the engine/turbo/exhaust system, you really should get it tuned afterward. Kinda like how if you ever do any mods to the suspension system, you really should get a good alignment when you're done with the mod.




And that AEM intake might actually hinder your car's performance without that tune (especially as it is more or less useless if you're still on a restrictive/stock exhaust).

sweet man thanks! do you have any suggestions? Do you know of anyone to go to for a decent tune. i dont need to be Paul Walker i just wanna beat some mustangs and some rice burners!

COBB does tune i think it in $200 an hour

just go cobb!

ya, what kent said. if you are gonna be rockin an intake, up pipe, down pipe and catback, that is gonna be some real significant change there, you should definitely get it tuned.

I base my mod/tuning decisions on how much my car is worth. If its a beater, then who cares go to whoever will do it. If i had an 06 wrx like you do, i would definitely get it done professionally

I'm going to have to disagree with everyone here. A tune would certainly help out your performance, but without a bellmouth downpipe full TBE), you're not going to notice any real gains.

AEM intake - personally, they have been nown to cause MAF issues... I would remove it, and install a K&N drop-in. The stock intake can support up to 350whp. Or, go with a more tested and reliable intake like the SPT or Cobb.

Perrin uppipe - The 06+ WRX uppipes are catless from the factory.... adding an aftermarket catless uppipe is really irrelevant and probably didn;'t do a whole lot for you... maybe a couple lb-ft of torque..... maybe.

STI intercooler - a nice upgrade.... prevents against heatsoak..... but it really doesn;t change your car's "performance" at all.... just means that you've got a few more minutes in gridlock traffic.... and it will cool down a bit quicker after you get moving.

Catback - sounds great.... zero power gains though. Your exhaust isn't going to "flow" any better than stock, because you are still using the factory restrictive downpipe.

Regardless, "maybe" the intake would justify a tune, but the #s you are going to see aren't worth the $$ you'll spend ion a tune.

My advice?

Sell the intake on eBay.. re-install the stocker... buy a FULL TBE (Catback+Downpipe)... THEN get tuned.... you'll see 50-60 hp at the wheels

^seriously?

i'm no suby guru but...

you definitely are going to want a tune. maybe its not "necessary" but there is more to it than just running rich with a catless dp. and with an upgraded uppipe, you are pushing the limits with your turbo WITHOUT THE TUNE. If you get on it too hard, you are going to experience "overboost". which is BAD. i dont remember exactly how to describe it, but pretty much something/everything will go BOOM! and ESPECIALLY if you get a catless downpipe. I did that and had to be very careful with my car until i got it tuned. I didn't go above 4k rpms. and that was just with a catess dp. unless you have a boost gauge (i dont). if u do, watch that when u drive around

I say keep all that stuff, and drop $200 on the ebay Turboback exhaust. It is great for the price, and in combination with a good tune and everything else you just listed, I think you will LOVE the difference it makes.

The uppipe is catless from the factory on an 06...... an aftermarket catless uppipe does almost nothing. It's about as significant as changing a muffler

even an upgraded catless uppipe on an 02-05 WRX (that has a catted uppipe from the factory)... will not cause boost spiking.

Nor will it spool any higher than stock..... it just spools up a little quicker.

a bellmouth DP is what will allow your turbo to boost higher, and potentially boost spike if not tuned.

i'm gonna be honest, i dont really know much about uppipes. but if it spools quicker, that usually means that at higher rpms the turbo will be spooling more, so yeah.

ok sorry let me clarify for you. a "bigger" downpipe will cause a boost spike. i'm pretty sure the bellmouth is the part where the pipe connects to the turbo, so unless i'm wrong, all downpipes have bellmouths.

if its catless then it will definitely cause a boost spike if ur not careful. and since pretty much any after market catless dp is going to be 3", that means yay overboost!

but anyways, is a tune necessary? eh, its debatable. should you get a tune? YES.

Thanks guys! now i am sketched out! overboost is caused by the waste gate not releasing enough pressure, making it a mechanical issue right? can a tune fix that? should i get the turbo back off of ebay? will it sound ricy? i would love to go cobb or invida but i dont have 600 bucks to drop on one. as long as it doesnt sound ricy then its all good! I am trying to get my subi where i want it before i get married in feb. cuz after that i think the car will be on hold for a few years... do-i-need-a-tune-for-bolt-on-parts-t2724.html#

You're wrong. The top of a downpipe is where it attaches to the turbo. Bellmouth is just a shape, much like "divorced wastegate".
This is a good place to reference downpipes. You may want to read ALL OF Unabomber's mainfesto to get a little knowledge on those things...


You knew I was gonna nail you on this one, didn't you D?

shutup kent

why not retune man? if you can do it yourself that is. i dont know how tricky sub's are to tune, but i re tune EVERY TIME I FILL UP!!!! (mixing e85 and premium kinda sucks sometimes)

So on the subaru's they controll valve timing? kinda like v-tak or neo vvl?

also, when your on the gas, wouldn't it look at your maps instead of your o2 sensor readings??? and also put the cam's at a set map also?
the intercooler would not make a difference because of the maf. it knows how much air is in there, and how much is comming in. and it will compensate with fuel if there is more air. running out of injector is a common problem though, and not having fuel support. that depends on injector size though and other variables.

basically because when you are past a pre spesified thorottle point, it will ignore the o2 sensors and read the pre spesified map for timing, fuel, and cam's. having a cat, or removing it should not change anything with your tune because of this. but remember, im no expert when it comes to subby's.
dont your guys's factory ecu's controll the wastegate???


im with nine14er on this one.