Well ive been reading around and ive learn alot,but alot of guys have mods,my question is on my stock 07 sti how much hp gain would i get with a tune,keep in mind the only mod will be an apexi boost control.is this a good thing to do firts to my soobie or is there something better any help is welcome
I would get a downpipe and a catback exhaust along with a tune, though EM by itself is never a bad idea.
I started in your shoes...bought a Cobb AP (version 2) first and flashed stage 1. A few months later I bought a downpipe and flashed stage 2. I kept my stock catback because I wanted something a little more quiet than what most aftermarket exhausts provide. A tune by itself should help, but spend the extra couple bucks and get at least a downpipe first, then tune...should put you close to the 300whp mark. From there, it only gets more expensive
I would second the Cobb AP route. This makes it easy to go back to stock if you ever want to. You can also have it tuned via the AP. You should be able to get a Version 2 used for $400-550 depending on how paitient you are. The Stage 1 will net you a good noticeable gain. One word of caution - you will be voiding your powertrain warranty if that is a concern to you. Even if you flash back to stock, the dealer can detect it.
Slowwrx said throw a huge fucking turbo on that shit! lol Seriously tho what the siegel says is like the gospel.
Have to agree that the AP is a good way to start out. There are even off the shelf tunes to get you going till you are ready for a pro tune. However...none of these off the shelf tunes are designed to incorporate the Apex boost controller! I would try to wait on that till you are ready for that pro-tune.
There is no need for the Apexi boost controller. Save your money and get a Cobb APv2, DownPipe, Filter, and cat back.
On a stock car a tune is helpful, but not worth the money. Keep in mind you'll need to get an AccessPort in order to get tuned. So, you're already half way to... When it comes to tuning the general rule of thumb is: Do whatever Scott tells you to do. If you're strapped for cash (after being absolutely positive you're buying the correct part) buy lightly used parts. You can usually find exhausts and AccessPorts at a great deal.
Also the Apexi boost controller is nothing but trouble. A 3 port aftermarket one like the GM or Prodrive is the best. But for the mods that Siegel mention the stocker will work just fine.
The GM is a cheap mod, but it REQUIRES tuning before you can run it. When I put it on my stocker it really did not buy me a whole lot...100-200 rpm maybe? The nice part about those or any of the other interrupt style controllers is that you will be able to achieve target boost with lower WGDC when compared to the factory bleed style and generally hit target boost a little bit sooner. One thing I DO like about the Apexi unit is the ability to do gear specific boost. If you have it, get it tuned and use it. If not, I would recommend putting the money towards other parts.