NA Engine for Rally "Open Light" class?

REDrum · 08-25-2010, 09:14 PM

So I'm exploring going from Rally America PGT class (turbo) to Open Light (NA). Lots of good reasons to due so, too many to list/compare here... No going open or super production either, so lets not go threre.

So the challenge is how to get a decent NA EJ25X and get it into my 2002 GD?

My performance goals: are ~140 WHP (i.e. ~30 hp over stock), durable enough for 10 events or so, low end Tq and top end powah. Hi flow headers are a given (like TWE 4-2-1)

Phase II SOHC seems to be the most modded with peeps, (plus I have contempt for the Phase I short blocks; (cost me plenty in the late 90s)... I'll be running standalone ECU (Vipec) so OBDII ain't an issue.
Options under consideration:

EJ254 w/ <50K on SB (w/AVLS) then add some cams and bolt on mods.
Buy any old EJ253 rebuild w/ cams, opened up bearings/rings, hi comp pistons, mild PnP...
Or...lurk for decent flowing SOHC heads (PnP'd, AVLS or something JDM) add cams and bolt up to a EJ257 SB with opened up rings/bearings and hi compression pistons, blah-blah-blah

Would like to keep long block costs <$4,000.00.

Not considering E85 or anything higher than 93. Don't want to go much greater than 11:1 compression.

Ideas welcome!

* Registered users of the site do not see these ads.

bhilly82 · 08-25-2010, 09:49 PM

i would say with a good built bottom end and cams headers and a good exhaust and a good tune you would be were you want to be. I use to race a scca 240sx with the ka24e sohc motor, the stock output was around 130 to the wheels, we ran a FCW crank and 11.5:1 Compression and 4 down draft carbs and race cams and we put 200+ whp to the ground and spun it to 9000 rpms. SO if this can happen on a non computer controlled motor i am sure you can hit that mark with your computer controlled motor. Also we built one with ITB intake and a Aem standalone and put down 237whp around 30 more with the computer. Good luck with your build.

bhilly82 · 08-25-2010, 10:00 PM

Somthing else to think of the ne 09-10 na motors are putting that much power down stock.

flightwatch · 08-26-2010, 07:07 AM

I hate to be the bearer of bad news but the 09-10 N/A engines don't put out any more hp than the 06-07's. As a mater of fact, the '10 makes 3hp less than the '06...although it does make 4lb/ft of torque more. Unfortunately, our cars only put about 110hp to the wheels in their stock form. You can thank our wonderful awd for that.

sniper1rfa · 08-26-2010, 07:17 AM

I would dodge AVLS and get a motor with normal cams. You won't see any benefit, especially if you're using a 6 speed or rally-geared 5, and it's another complication for tuning and maintenance.

Plus, the AVLS pressure sensors are known to start leaking on a motor which sees high revs/abuse often. I've replaced both mine already, they were leaking a quart per change at 60kmi.

I would also use an NA block, rather than the beefier turbo blocks, because it's a bit lighter and the extra reinforcement won't be necessary, especially if you don't plan to build for race gas.

Definitely focus on the heads, increasing redline as much as possible. Even moreso if you're sticking to a 5spd.

EDIT: bhilly - a factory EFI motor is much harder to get more performance out of, because they're already so good at everything right off the bat.

REDrum · 08-27-2010, 07:45 AM

Thanks guys, please keep it coming.

FuJi K · 08-27-2010, 09:35 AM

Is this a 2002 WRX you're turning into NA?

REDrum · 08-27-2010, 10:03 AM

Quote:

Originally Posted by FuJi K

Is this a 2002 WRX you're turning into NA?

Yup!!!!

ballitch · 08-27-2010, 06:35 PM

I ran 10.8 CR on pump gas (91 octane) so I think with 93 octane you could get away with 11.5:1 easily.

Stick with a N/A block, no need for extra strength. Call Delta cams and see if they have any recommendations for you. I love my 2000 grind in my SOHC EJ25 heads with no port work done, I can only imagine what they could do if properly ported and rev'd out to 8k with good springs and retainers. I'm not an expert in AVLS, but I don't think I would use it in your case.

~Josh~

FuJi K · 08-29-2010, 01:28 AM

Quote:

Originally Posted by REDrum

Yup!!!!

if that's the case, don't worry about going SOHC. Get a set of EJ255 heads like '06+ WRX/FXT or '07+ LGT. Mate that with a higher CR piston'd EJ25 lighter rods motor. Tune via OpenSource with your WRX ECU.

Storm · 08-29-2010, 08:59 PM

^^^ This.

It's already been done if I remember correctly. Might have to search the built motor section or engine management section. I remember reading of a project where someone removed his turbo and added higher compression pistons, then open source tuned the ECU for NA fueling and timing.

Jay

sniper1rfa · 08-29-2010, 09:15 PM

you're probably thinking of carl seigler's car. Carl or carl s. on the forums, depending on which forum.

11:1 wisecos, stock STi everything else. It worked OK, but i wouldn't go that route if you're going from PGT to open light, rather than starting in open light and moving to SP or open. Sounds to me like the OP wants a more competitive car, since he's already got a good bit of experience.

dirty · 08-29-2010, 09:19 PM

You don't need anything exotic for the class. Get a salvaged SOHC engine with delta cams, good equal length headers and exhaust then tune it and learn to carry more momentum in the turns. The best thing about the class is that you don't need a crazy build to be competitive in it.

We tried to run TWE headers and there was no way without dropping the skid plate really low.

J.

AQ Motorsports · 08-29-2010, 09:23 PM

It might be easier to use the stock heads and put money toward building them. There are a few places that offer CNC combustion chamber work to match up to the 2.5 bore.

Y_I_K_E_S · 08-31-2010, 12:57 PM

I've never used them but I've heard a lot of people complain that delta cams in the SOHC motors really push the powerband to the high end. If that's the case, I would try to stay away from them for this type of build.

I'm liking Fuji K's suggestion quite a bit.

sachilles · 08-31-2010, 02:27 PM

Too bad they limit the displacement to ~2650cc's. I'd like to see some of the subie 6 cylinders get some competition duty. Open light would be the perfect spot.

Looking at open light results for this past year, certainly looks like the class doesn't have huge numbers. I think a midly modified stock motor, would make YOU more than competitive. I think head work, and equal length headers would put you in pretty good shape, so long as you make sure you are running as light as possible. As your chassis is a bit heavier out of the box than the gc's.

REDrum · 08-31-2010, 04:02 PM

Thanks guys, please keep it coming, all good.

Quote:

Originally Posted by sachilles

As your chassis is a bit heavier out of the box than the gc's.

By the time the NA engine goes in it will no longer be "my" chassis... Gunna be swapping seats w/ my 5'-2" co-driver for a year...

bp_968 · 09-01-2010, 03:24 AM

Quote:

Originally Posted by REDrum

Thanks guys, please keep it coming, all good.

By the time the NA engine goes in it will no longer be "my" chassis... Gunna be swapping seats w/ my 5'-2" co-driver for a year...

I'd have to agree with a couple of the other posters here. your fighting against a couple other cars at most events. Some events (the ones not on the national calendar) recently have only had one OL car at all. If you car about fighting it out with other people in the same class as you consider going G2 (since you said you didnt want to do SP/OC). I'm just not sure spending a whole bunch for a few more HP is really worth it..

I guess if your just doing it for fun then that's cool. Anythings worth doing for the fun of it

I was told PGT was more expensive to run the SP, plus SP has some pretty decent contingency money and OL seems to have jack (sadly).

westu37 · 09-01-2010, 06:44 AM

Hey, Have you looked into anything about the intake manifolds? Everyone goes straight to the exhaust, but if theair going into the engine is restricted it won't help. I saw a thread about a N/A build using 05(?) (STI?) components including the entire intake runner and using a 65?mm mustang throttle body.

Just a thought...

Wes.

Y_I_K_E_S · 09-01-2010, 08:53 AM

Quote:

Originally Posted by westu37

Hey, Have you looked into anything about the intake manifolds? Everyone goes straight to the exhaust, but if theair going into the engine is restricted it won't help. I saw a thread about a N/A build using 05(?) (STI?) components including the entire intake runner and using a 65?mm mustang throttle body.

Just a thought...

Wes.

They used an 05 2.5RS intake. It seems to be the clear favorite of most N/A people for power builds.

Also, they used, I believe, 11.2 CR pistons which be the best choice for something like this if you are comfortable running 93 on that high of a CR. To my knowledge, no one makes a high strength 10.0 piston for these motors and you'll definately bust a stock cast RS piston if you try to use one of them.

sachilles · 09-01-2010, 11:04 AM

Quote:

Originally Posted by REDrum

Thanks guys, please keep it coming, all good.

By the time the NA engine goes in it will no longer be "my" chassis... Gunna be swapping seats w/ my 5'-2" co-driver for a year...

Oh, very cool. I bet she'll do well.

Will you do any more hill climbs?

bp_968 · 09-01-2010, 11:48 AM

Quote:

Originally Posted by REDrum

Thanks guys, please keep it coming, all good.

By the time the NA engine goes in it will no longer be "my" chassis... Gunna be swapping seats w/ my 5'-2" co-driver for a year...

That kinda explains the no SP/OC thing. If she's totally new to the drivers seat she won't have enough co-efficients.

I'm just shooting for reliability on our OL car. finish the race without kissing trees or breaking to much.

08-25-2010, 09:14 PM	#1
REDrum Scooby Specialist Member#: 61536 Join Date: May 2004 Chapter/Region: NESIC Location: Peoples Republik of Cambridge Vehicle: WRX' 04Road02gravel www.ToltecRally.com	NA Engine for Rally "Open Light" class? So I'm exploring going from Rally America PGT class (turbo) to Open Light (NA). Lots of good reasons to due so, too many to list/compare here... No going open or super production either, so lets not go threre. So the challenge is how to get a decent NA EJ25X and get it into my 2002 GD? My performance goals: are ~140 WHP (i.e. ~30 hp over stock), durable enough for 10 events or so, low end Tq and top end powah. Hi flow headers are a given (like TWE 4-2-1) Phase II SOHC seems to be the most modded with peeps, (plus I have contempt for the Phase I short blocks; (cost me plenty in the late 90s)... I'll be running standalone ECU (Vipec) so OBDII ain't an issue. Options under consideration: EJ254 w/ <50K on SB (w/AVLS) then add some cams and bolt on mods. Buy any old EJ253 rebuild w/ cams, opened up bearings/rings, hi comp pistons, mild PnP... Or...lurk for decent flowing SOHC heads (PnP'd, AVLS or something JDM) add cams and bolt up to a EJ257 SB with opened up rings/bearings and hi compression pistons, blah-blah-blah Would like to keep long block costs <$4,000.00. Not considering E85 or anything higher than 93. Don't want to go much greater than 11:1 compression. Ideas welcome! * Registered users of the site do not see these ads.

08-26-2010, 07:17 AM	#5
sniper1rfa Scooby Specialist Member#: 141040 Join Date: Feb 2007 Chapter/Region: NESIC Location: Designing things Vehicle: 07 2.5i wagon UGM	I would dodge AVLS and get a motor with normal cams. You won't see any benefit, especially if you're using a 6 speed or rally-geared 5, and it's another complication for tuning and maintenance. Plus, the AVLS pressure sensors are known to start leaking on a motor which sees high revs/abuse often. I've replaced both mine already, they were leaking a quart per change at 60kmi. I would also use an NA block, rather than the beefier turbo blocks, because it's a bit lighter and the extra reinforcement won't be necessary, especially if you don't plan to build for race gas. Definitely focus on the heads, increasing redline as much as possible. Even moreso if you're sticking to a 5spd. EDIT: bhilly - a factory EFI motor is much harder to get more performance out of, because they're already so good at everything right off the bat. Last edited by sniper1rfa; 08-26-2010 at 07:25 AM.

08-29-2010, 09:15 PM	#12
sniper1rfa Scooby Specialist Member#: 141040 Join Date: Feb 2007 Chapter/Region: NESIC Location: Designing things Vehicle: 07 2.5i wagon UGM	you're probably thinking of carl seigler's car. Carl or carl s. on the forums, depending on which forum. 11:1 wisecos, stock STi everything else. It worked OK, but i wouldn't go that route if you're going from PGT to open light, rather than starting in open light and moving to SP or open. Sounds to me like the OP wants a more competitive car, since he's already got a good bit of experience. Last edited by sniper1rfa; 08-30-2010 at 06:35 AM.

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08-25-2010, 09:49 PM	#2
bhilly82 Scooby Newbie Member#: 254417 Join Date: Aug 2010 Chapter/Region: MWSOC Vehicle: 09 Impreza Peperika	i would say with a good built bottom end and cams headers and a good exhaust and a good tune you would be were you want to be. I use to race a scca 240sx with the ka24e sohc motor, the stock output was around 130 to the wheels, we ran a FCW crank and 11.5:1 Compression and 4 down draft carbs and race cams and we put 200+ whp to the ground and spun it to 9000 rpms. SO if this can happen on a non computer controlled motor i am sure you can hit that mark with your computer controlled motor. Also we built one with ITB intake and a Aem standalone and put down 237whp around 30 more with the computer. Good luck with your build.

08-25-2010, 10:00 PM	#3
bhilly82 Scooby Newbie Member#: 254417 Join Date: Aug 2010 Chapter/Region: MWSOC Vehicle: 09 Impreza Peperika	Somthing else to think of the ne 09-10 na motors are putting that much power down stock.

08-26-2010, 07:07 AM	#4
flightwatch Scooby Specialist Member#: 231058 Join Date: Nov 2009 Chapter/Region: South East Location: St Petersburg, FL Vehicle: 2012 Hyundai Sonata terbo	I hate to be the bearer of bad news but the 09-10 N/A engines don't put out any more hp than the 06-07's. As a mater of fact, the '10 makes 3hp less than the '06...although it does make 4lb/ft of torque more. Unfortunately, our cars only put about 110hp to the wheels in their stock form. You can thank our wonderful awd for that.

08-27-2010, 07:45 AM	#6
REDrum Scooby Specialist Member#: 61536 Join Date: May 2004 Chapter/Region: NESIC Location: Peoples Republik of Cambridge Vehicle: WRX' 04Road02gravel www.ToltecRally.com	Thanks guys, please keep it coming.

08-27-2010, 09:35 AM	#7
FuJi K Scooby Guru Member#: 3687 Join Date: Jan 2001 Chapter/Region: MWSOC Location: St. Paul, MN Vehicle: MY99 GF4 JDM 6spd NF Performance	Is this a 2002 WRX you're turning into NA?

08-27-2010, 06:35 PM	#9
ballitch Scooby Specialist Member#: 74907 Join Date: Nov 2004 Chapter/Region: NWIC Location: salem, OR Vehicle: 98 cam'd EJ251 Wrx Tranny,slowr than ish	I ran 10.8 CR on pump gas (91 octane) so I think with 93 octane you could get away with 11.5:1 easily. Stick with a N/A block, no need for extra strength. Call Delta cams and see if they have any recommendations for you. I love my 2000 grind in my SOHC EJ25 heads with no port work done, I can only imagine what they could do if properly ported and rev'd out to 8k with good springs and retainers. I'm not an expert in AVLS, but I don't think I would use it in your case. ~Josh~

08-29-2010, 08:59 PM	#11
Storm Scooby Guru Member#: 5218 Join Date: Mar 2001 Chapter/Region: MWSOC Location: SAUL'S Motorsports Vehicle: 96L Most Over- Developed Beater	^^^ This. It's already been done if I remember correctly. Might have to search the built motor section or engine management section. I remember reading of a project where someone removed his turbo and added higher compression pistons, then open source tuned the ECU for NA fueling and timing. Jay

08-29-2010, 09:19 PM	#13
dirty Scooby Newbie Member#: 23577 Join Date: Aug 2002 Location: Ca / Pa Vehicle: 01 Open Class Rally Car	You don't need anything exotic for the class. Get a salvaged SOHC engine with delta cams, good equal length headers and exhaust then tune it and learn to carry more momentum in the turns. The best thing about the class is that you don't need a crazy build to be competitive in it. We tried to run TWE headers and there was no way without dropping the skid plate really low. J.

08-29-2010, 09:23 PM	#14
AQ Motorsports NASIOC Vendor Member#: 60836 Join Date: Apr 2004 Chapter/Region: SCIC Location: Torrance, CA Vehicle: 2006 Mod Class STI TIMEATTACK!!	It might be easier to use the stock heads and put money toward building them. There are a few places that offer CNC combustion chamber work to match up to the 2.5 bore.

08-31-2010, 12:57 PM	#15
Y_I_K_E_S Scooby Specialist Member#: 159449 Join Date: Sep 2007 Chapter/Region: South East Location: Knoxville, TN Vehicle: 2005 WRX STi "Ali"	I've never used them but I've heard a lot of people complain that delta cams in the SOHC motors really push the powerband to the high end. If that's the case, I would try to stay away from them for this type of build. I'm liking Fuji K's suggestion quite a bit.

08-31-2010, 02:27 PM	#16
sachilles Scooby Specialist Member#: 115107 Join Date: May 2006 Chapter/Region: NESIC Location: Waitsfield VT Vehicle: 02 wrx wagon 61 Morris Mini	Too bad they limit the displacement to ~2650cc's. I'd like to see some of the subie 6 cylinders get some competition duty. Open light would be the perfect spot. Looking at open light results for this past year, certainly looks like the class doesn't have huge numbers. I think a midly modified stock motor, would make YOU more than competitive. I think head work, and equal length headers would put you in pretty good shape, so long as you make sure you are running as light as possible. As your chassis is a bit heavier out of the box than the gc's.

09-01-2010, 06:44 AM	#19
westu37 Scooby Newbie Member#: 223944 Join Date: Sep 2009 Chapter/Region: Tri-State Location: NJ Vehicle: 2005 Outback XT Shampagne	Hey, Have you looked into anything about the intake manifolds? Everyone goes straight to the exhaust, but if theair going into the engine is restricted it won't help. I saw a thread about a N/A build using 05(?) (STI?) components including the entire intake runner and using a 65?mm mustang throttle body. Just a thought... Wes.