|
|
|
|
Thread Tools | Display Modes |
09-11-2007, 12:13 PM | #1 |
Scooby Specialist
Member#: 113698
Join Date: Apr 2006
Chapter/Region:
MWSOC
Location: Locktucky, IL
|
Recommendation needed: 2.5 or 2.0 WRX heads better for engine build? (NON-AVCS)
I am in the midst of doing an engine build with an STi short-block to go into my WRX. I intend on running non-AVCS. Which is the better choice of heads? 2.5L or 2.0L WRX heads? I plan on porting and building the heads and pretty much going all out with the APS tumbler deletes, port and polish 20G most likely, perhaps a 30R. Just curious which provides the better platform for an engine build and which provides the most potential. Please speak with experience if you are going to respond. Thanks!
* Registered users of the site do not see these ads.
|
09-11-2007, 02:13 PM | #2 |
Scooby Guru
Member#: 12454
Join Date: Nov 2001
Chapter/Region:
Tri-State
Location: Vermont
Vehicle:10 Toyota Taco K8 SV650SF |
dont forget about 2.0l sti heads (v7/8), i dont think they are too expensive if compared to the 2.5l sti heads so consider those as well.
i only have a 2.0l so i cant really comment on these heads on a 2.5l since i dont have first hand experience just wanted to throw another option at you |
09-11-2007, 03:22 PM | #3 |
Scooby Specialist
Member#: 88322
Join Date: Jun 2005
Chapter/Region:
MWSOC
Location: Indianapolis, IN
Vehicle:2009 BMW 135i |
You really should get AVCS working if at all possible.
|
09-11-2007, 03:53 PM | #4 |
Scooby Newbie
Member#: 145138
Join Date: Apr 2007
Location: Stockton, California, 209
Vehicle:2002 Impreza WRX WR Blue |
very expensive to run AVCS.
If you can get 2.5L heads, go with those. If you don't have enough $$$ then the least you should do is upgrade the cams. I am running an STi shorty with my 2.0L wrx heads. I have great torque but power falls off a little past 5k rpm. With upgraded cams, you should be able to have good power through out the power band. just my .02 |
09-11-2007, 06:16 PM | #5 | |
Scooby Specialist
Member#: 113698
Join Date: Apr 2006
Chapter/Region:
MWSOC
Location: Locktucky, IL
|
Quote:
This is the type of response that I was looking for! Not some crap about recommending JDM heads. I don't intend on changing the ECU. Upgraded cams and port/polish are planned. I am just wondering what the better base is for these upgrades. Simple enough I thought. |
|
09-11-2007, 07:12 PM | #6 |
Scooby Specialist
Member#: 124252
Join Date: Aug 2006
Chapter/Region:
TXIC
Location: Houston, TX
Vehicle:0506 STI/Tribeca OBP/SGM |
heads
Wrx's heads can flow just as well with porting and polishing. I second the cam upgrade. i had a hybrid 2.5/ 2.0 heads. it does flatten out unless you PnP the heads and upgrade the cams. There is someone on here now sell wrx race cams for $400. which is a steal. Make sure you run a line from the extra oil vent on the top of the 2.5 block to one of the heads.
|
09-12-2007, 01:36 AM | #7 |
Scooby Newbie
Member#: 112072
Join Date: Apr 2006
Chapter/Region:
Tri-State
Location: nj
Vehicle:2004 wrx blue |
I have a built 2.5 bottom, p/p wrx heads, valves, springs and retainers with crower stage 3 cams.The car made 469 whp on pump gas. High compression makes it pull very hard.
|
09-12-2007, 01:39 AM | #8 | |
Scooby Specialist
Member#: 111268
Join Date: Mar 2006
Chapter/Region:
SCIC
Location: The Mullet Mafia
Vehicle:.... MLTMFA2 \,,,/ |
Quote:
The one thing I wish I could've done over for my engine was to throw on a set of cams... |
|
09-12-2007, 02:29 AM | #9 |
Scooby Specialist
Member#: 14164
Join Date: Jan 2002
Chapter/Region:
TXIC
Location: 32.9765°N 96.8867°W
Vehicle:2023 Model S Plaid Hailed 02 WRX Wgn |
Last edited by wrxdaddy; 09-12-2007 at 09:19 AM. |
09-12-2007, 12:54 PM | #10 |
Scooby Guru
Member#: 64908
Join Date: Jun 2004
Chapter/Region:
Tri-State
Location: Tuning 8/9sec Subies all over
Vehicle:10.8 XT+9.2@155 GR+ 9.1/157mph 2015 STI |
Bakka has standard STI head gaskets and 2.0 built WRX heads. Turbo is a FP 3065. The car hauls major ass
|
09-13-2007, 09:52 PM | #11 |
Scooby Specialist
Member#: 44629
Join Date: Oct 2003
Chapter/Region:
Tri-State
Location: '04WRX-Axis ej257, IPT 4eat.
Vehicle:CNC 'd heads, cams DB18g/EWG - F/S $8K |
USDM WRX (2.0) and USDM STi have identical ports but the STi has a slightly larger combustion chamber. It's very easy to have the chamber enlarged on the 2.0 heads to keep compression down and still use the proper sized head gasket (piston to head clearance should never exceed 1.2mm) if that's what you're interested in. Keep in mind the higher CR will help retain low end torque with the ported heads and larger cams - and spool a turbo faster.
|
03-28-2011, 08:56 AM | #12 |
Scooby Newbie
Member#: 277865
Join Date: Mar 2011
Location: OhIo
Vehicle:02 sanded down |
what kind of hp can I expect to get from a non built sti SB and wrx heads with the chamber enlarged to match the sti heads, running all stock internals?
|
03-29-2011, 03:02 PM | #13 |
Scooby Specialist
Member#: 115070
Join Date: May 2006
Chapter/Region:
MAIC
Location: Northern VA
Vehicle:2009 DGM LGT Spec.B 08 Audi Q7 4.2 PRM |
The S20 heads will give you the most flexibility to port for your application. They are small port to start with but have enough meat to enlarge to the same size as JDM big port heads.
I went huge on mines: -soobaviator Last edited by soobaviator; 06-15-2011 at 10:36 AM. |
03-29-2011, 04:01 PM | #14 |
Scooby Guru
Member#: 3687
Join Date: Jan 2001
Chapter/Region:
MWSOC
Location: St. Paul, MN
Vehicle:MY99 GF4 JDM 6spd NF Performance |
|
03-29-2011, 04:29 PM | #15 |
Scooby Guru
Member#: 178811
Join Date: Apr 2008
Chapter/Region:
MAIC
Location: MoCo
Vehicle:2011 White Corolla Over 400hp |
You'll want to at least pick up STI cams and plug them if not upgrade to something like a Kelford 264 or bigger.
|
03-29-2011, 09:17 PM | #16 |
Scooby Specialist
Member#: 191514
Join Date: Oct 2008
Chapter/Region:
NWIC
Location: teh bremerton
Vehicle:'05 FXT 6spd, 98 Fozzy lifted,'01 RS 6spd |
I have a set of ported B25 heads that have been modified for non avcs. Plugged sti cams, wrx cam sensor mounted, you'll need new seals. Too lazy to rewire the hydra in my '95 so I'm going to run the phase 1 dohc heads that are in it on a ej257. PM me if interested.
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
wtb:fp green or blouch dom 2.5 or 3.0 | Derek C | NESIC Private Classifieds | 0 | 04-01-2009 04:47 PM |
WTB: 2.5 or 2.0 wrx heads. | mvcsk8r | NESIC Private Classifieds | 0 | 03-12-2009 11:41 AM |
Wtb Short Block 2.5 Or 2.0 | twrxmess | Private 'Wanted' Classifieds | 6 | 02-09-2009 02:37 AM |
help! which knock sensor 2.5 or 2.0? | WRB04 | Service & Maintenance | 2 | 10-30-2007 02:20 PM |
2.5 or 2.0 | DausWRX | Built Motor Discussion | 10 | 09-06-2007 09:48 AM |