I just bought my 99 2.5rs and wanted to get some advice on my mods that I have just purchased. This is what I have aquired since my new purchase. Stock WRX turbo with less than 3k, WRX injectors, fuel pump, uppipe, downpipe that have to be whacked, WRX tmic, y-pipe, bov, vortech rrfpr, apexi super afc II. I need some suggestions on what type of exhaust and intake for my new setup. What size exhaust is good for the stock WRX downpipe? Is there exhaust systems out there for a turbo 2.5rs? I plan on running safe boost levels around 4-6psi with proper tunning. Can you seasoned RST owners give me some feedback on these many questions I have? I also need to know do I need to upgrade to a WRX manifold or is the stock rs ok to use....Thanks

 

Your uppipe won't fit without hacking up your crossmember or buying one of those too. Your vortech rrfpr is a pile. custom build your exhause and custom build your intake.

3" on a turbo car with what you're running. Understand this: You aren't doing "proper" tuning right now, your piecemealing yourself together a turbocharger kit. Be prepared for extra costs that you didn't expect to creep their way in.

The stock intake manifold is okay. the WRX manifold won't fit on your heads anyway.

 

I understand what you are saying about problems creeping up. I have owned serveral turbo cars and this is my first subaru. I like the wrx, but it's a 4 door. The 2.5rs is the perfect 2 door platform for turbo. I will purchase a legacy crossmember. I was under the impression that if I'm only running 4-6psi boost a 2.5" exhaust system will be ok. My plan is to buy a used 2.5" aftermarket (Apexi N1, Greddy evo, etc.) and modify if I have to. Do you know what size the size of the stock WRX up and downpipe is? What type of hp over stock can I expect with proper tuning with 4-6psi of boost? And yes I plan to have it dyno tuned. Will I need to replace the stock WRX wastegate since I only plan on running 4-6psi of boost. I think the WRX runs about 14psi boost stock and the wastegate spring is set at no less than 11 or 12 psi. I'm not sure but is that about right. If my Vortech rrfpr is a pile what do you suggest. Thanx....

 

Im running 2.5" custom cat free piping all around at 5psi and Im having NO problems. As far as fuel, go with a Vortech FMU with a 4:1 calibration shim. I have that on mine, runs perfect with 5psi, and a friend of mine ran 14psi on a 99 RS-T with the FMU perfectly. Best solution is just go with a Link or a TecII and tune it....but that takes time and $$$, if you wanna go with just a low boost system like me, you dont even need the SAFC, just propperly tune the FMU and youll be cool.

Boki

 

Yeah, that'll be okay.

Nope.

plenty.

Yes. I believe the minimum it will run is about 10lbs, though don't quote me on that.

Aeromotive adjustable fuel pressure regulator. Adjusting your base pressure up will have the effect of a larger injector. Those rising rates are crap because they increase fuel pressure too much causing a different sort of ping then when you run too lean.

 

What type of hp do you have at 5psi boost. How is your tranny holding up and did you replace your clutch. I plan on going with a 2600lb ACT clutch upgrade, is this overkill. Did you build your kit with WRX parts or did you buy a kit? If so, are you using the stock wrx wastegate? How is the total package working for you?

 

I don't suggest the ACT, i've seen 4 transmissions blow up using that clutch.

 

ok what clutch then?

 

exedy double disk or the centerforce dual friction.

Reason: the ACT clutch is designed not to slip AT ALL, like the on/off switch of clutches. the two i mention allot for slippage, but do have a lot of grabbing force. the double disk is better, but obviously, more expensive.

 

Im making around 230-250Hp. My stock gearbox is fine and Im running the DPG Clutch. It the BEST F'n Cluch on the market. Dual friction, feels smooth and stock but when the boost kicks in it grabs for all life.

 

Hey darkangelgrafix, what type of set up do you have on your RST? Never heard of DPG, how much for the clutch kit?

 

DPG is a prototype and design company here in socal and somewhere in the East Coast. They produce clutch kits, brake kits, exhausts...well name it....and if they dont, show them demand and they will....all i know is that this clutch has never broken a tranny and never slipped, and its been in rally cars, rst's and....well.....name it. Chek em out: www.dpgperformance.com or email Phil Gonzales: philracer@dpgperformance.com

The setup im running:
TD04
WRX TMIC
Custom CAI
Custom upipe
Custom 2.5" downpipe/trackpipe
WRX Midpipe
2.5" Stromung Muffler
Vortech FMU
WRX fuel pump
Spit Second Voltage Clamp
Greddy TT
Blitz Powermeter ID

Im gonna add an SAFC, but just so it looks cool....it'll be pointless since the car is runnin wicked awsome without.

 

Thanks for the info. Did you have to modifiy the WRX midpipe. I'm using WRX stock up and downpipe modified. Do you know the diameter of the stock up, dn and midpipe for the REX. I've got a apexi super afc II, but I was told I would need it since I have a rising rate fuel press regulator. Is this true? But I will need it for the WRX fuel injectors. What do you think?

 

Not really, its slightly tilted but its stock. The uppipe and down pipes were custom 2.25" pipes and I thinks so is the WRX midpipe. I think the WRX upipe is 1.75" or 2" an the DP and Midpipe are 2.25" but I could be wrong....

The AFC is a useless piece of shiny plastic on the RST...you just need to install everything propperly and tune it and you need absolutely NO engine management. YOu dont need it.

Get rid of the RRFPR cause its a 1:1 FMU and to run a truly safe system that is flexible and can be expanded you need an FMU 4:1.

you dont need WRX injectors, but you will need either a wrx fuel pump or another aftermarket pump.

Dont waste your money on piggy backs, theyre more trouble than they are worth and Sean from Suby Specialties even told me that all great RST he ever worked on had NOTHING on them. If you adjust your fuel supply the stock computer will take care of the rest.

Oh yeah, if you have a 2001-newer you will need an Voltage Clamp, otherwise the ecu will freak out.

Lemme know if you have other questions.

 

I'll try my setup with the stock RS injectors with the REX pump too see how it does. I'll hold on to my REX injectors just in case. My brother was telling me the only reason I needed a afc was for the REX injectors. Guess I could have used that $320 some wheres else on the car. Brother was also telling me to get a rrfpr b'cause I am boostin. I will take your advice and stick with a standard fpr. I guess I some what lucky having the 99 2.5rs with the MAF cause it can compensate for the 4-6psi boost. Thanks for your help!!!!!!!!!!