late ej20g (20k) engine timing

rs182 · 10-01-2009, 07:22 PM

I am going to start up my swapped rs this weekend. As of now I have safc and sitc piggy backs. Seeing how it is a 97 forester it is the bastard late g motor. I know the 20k get bad wrap for spinning bearing because of low octane fuel and not pulling enough timing. So my question is how much should I retard the timing to make it safe for 91 octane. I will be getting it tuned next month (have to drive to phx, AZ)but I want to start driving her. It is completely stock so I should not need to mess with any a/f numbers. Being that is a forester late 20g(20k) it already has a less agressive timing curve than say a sti 6s ecu. (250hp vs 280). So all you g,k gurus school me on this

and yes i am ready to be flamed for not getting a pro-tune immediately.

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

Jaxx · 10-01-2009, 07:34 PM

so you are using the G ecu right...

if your worried i would direct connect the wastegate and take her easy
det under low load is not an issue

should be fine with 91

rs182 · 10-01-2009, 07:40 PM

yea it is a g ecu but it uses the k style plugs so I am not sure how much more aggressive the ecu is. Am i correct in thinking that using a knock light and the sitc I can simply retard the timing until there is no knock at the given rpm?

elislider · 10-02-2009, 12:17 AM

the late ej20g with 20k style electronics makes the least power of that year range (for turbo models). its got a td04 which is a small turbo (still larger than the usdm td04 though AFAIK). the real problem is with the jdm ej20k sti ECUs like the 6S ecu that i have, runs 17lbs boost stock, which is quite a bit from the factory. so if you get an ECU from a plain ej20k wrx (one that had a td05 for example) then you could push your current setup further but not so far as a vf22/vf23 jdm ej20k sti (which would have bigger injectors, fuel pump, shim under bucket, etc)

Audioexcels · 10-02-2009, 01:26 AM

Quote:

Originally Posted by elislider

the late ej20g with 20k style electronics makes the least power of that year range (for turbo models). its got a td04 which is a small turbo (still larger than the usdm td04 though AFAIK). the real problem is with the jdm ej20k sti ECUs like the 6S ecu that i have, runs 17lbs boost stock, which is quite a bit from the factory. so if you get an ECU from a plain ej20k wrx (one that had a td05 for example) then you could push your current setup further but not so far as a vf22/vf23 jdm ej20k sti (which would have bigger injectors, fuel pump, shim under bucket, etc)

How are the heads on this Forester EJ20G (EJ20K actually) vs. the ones found on the STI EJ20K's?

elislider · 10-02-2009, 02:06 AM

the late ej20g and plain ej20k is shim under bucket very similar to the USDM 1998 2.5RS and USDM 1998 forester. they are similar in valve train features but the jdm has slightly larger ports and better valves and cam profile for the turbo model. the v3/v4 STi is shim under bucket and sodium filled valves, overall tougher valvetrain which can endure higher and more sustained revs (within reason). hence why the factory fuelcut on a v3/v4 sti is 8250 and for the plain wrx its lower like 7800 or something

marnix/matt/jaxx could provide more specifics

Marnix · 10-02-2009, 02:10 AM

The head castings are identical to all MY97-98 DOHC heads including USDM EJ25D, JDM EJ20G, EJ20H, EJ20K and EJ20R. The differences are in valves (solid or hollow/sodium cooled), valve springs and shim arrangement (under - or over bucket) and cams. This all has influence on rev limit and power range.

Considering the rs182 is using a EJ20G out of a Forester, he should also consider that the engine has a higher compression ratio (9.0 vs. 8.0) compared to a EJ20K meaning he will have to be even more conservative regarding timing under boost.

When using the ECU that came with that engine, however, the engine should be fine on 91 gas as the maps are far less aggressive as the EJ20K's. Still, when driving, start carfefully and monitor knock.

Matt Monson · 10-02-2009, 08:36 AM

Quote:

Originally Posted by rs182

Am i correct in thinking that using a knock light and the sitc I can simply retard the timing until there is no knock at the given rpm?

You don't want to just wire in a knock light in series. This will interfere with the voltage of the signal that is sent to your ECU for it's reference with respect to knock. If you want to do this, you will want to purchase a seperate knock sensor and mount it.

Maybe that's what the sitc is? (I hate when people throw out random abbreviations that aren't in common usage). Obviously sitc is some sort of timing controller, but exactly what that is isn't clear to me...

Jaxx · 10-02-2009, 08:43 AM

Quote:

Originally Posted by elislider

the late ej20g with 20k style electronics makes the least power of that year range (for turbo models). its got a td04 which is a small turbo (still larger than the usdm td04 though AFAIK). the real problem is with the jdm ej20k sti ECUs like the 6S ecu that i have, runs 17lbs boost stock, which is quite a bit from the factory. so if you get an ECU from a plain ej20k wrx (one that had a td05 for example) then you could push your current setup further but not so far as a vf22/vf23 jdm ej20k sti (which would have bigger injectors, fuel pump, shim under bucket, etc)

late ej20g=td04
ej20k=vf22
ej20ksti=vf23/vf24

all have the same injectors

Marnix · 10-02-2009, 09:41 AM

Eh no, not the late EJ20G they have the dark grey tops, same as all pre-1997 EJ20G (except some STI versions). Only the EJ20K had the yellow top injectors.

elislider · 10-02-2009, 04:26 PM

Quote:

Originally Posted by Marnix

The head castings are identical to all MY97-98 DOHC heads including USDM EJ25D, JDM EJ20G, EJ20H, EJ20K and EJ20R. The differences are in valves (solid or hollow/sodium cooled), valve springs and shim arrangement (under - or over bucket) and cams. This all has influence on rev limit and power range.

Considering the rs182 is using a EJ20G out of a Forester, he should also consider that the engine has a higher compression ratio (9.0 vs. 8.0) compared to a EJ20K meaning he will have to be even more conservative regarding timing under boost.

When using the ECU that came with that engine, however, the engine should be fine on 91 gas as the maps are far less aggressive as the EJ20K's. Still, when driving, start carfefully and monitor knock.

thanks for the correction on head castings. i thought the jdm ones were better flowing though? or am i thinking of these DOHC heads vs. usdm wrx heads?

Quote:

Originally Posted by Jaxx

late ej20g=td04
ej20k=vf22
ej20ksti=vf23/vf24

all have the same injectors

i know td05 was on some of early ej20gs but when was the td05 straight-inlet? or was there ever one stock

Quote:

Originally Posted by Marnix

Eh no, not the late EJ20G they have the dark grey tops, same as all pre-1997 EJ20G (except some STI versions). Only the EJ20K had the yellow top injectors.

werent there different variations (i heard up to 3 variations) of yellowtops? some say 440 some say 480

Marnix · 10-02-2009, 04:29 PM

There are different yellow tops on the MY99> engines, they're supposed to be 440cc whereas the earlier yellow tops (EJ20K and EJ20R) are 550cc.

Matt Monson · 10-02-2009, 05:06 PM

Straight inlet td05 was never a factory thing. Starting with v3, all STi's and 5MT Sedans got IHI VF series turbos while all the others got td04s. Straight inlet td05 are an aftermarket thing.

elislider · 10-02-2009, 05:29 PM

Quote:

Originally Posted by Marnix

There are different yellow tops on the MY99> engines, they're supposed to be 440cc whereas the earlier yellow tops (EJ20K and EJ20R) are 550cc.

interesting. i was told idk how many times my v3 sti r/ra had 440 or 480cc yellowtops. good to know they are 550

Quote:

Originally Posted by Matt Monson

Straight inlet td05 was never a factory thing. Starting with v3, all STi's and 5MT Sedans got IHI VF series turbos while all the others got td04s. Straight inlet td05 are an aftermarket thing.

I knew about the VF series stuff but thats more good info, thanks

rs182 · 10-02-2009, 06:14 PM

Quote:

Originally Posted by Matt Monson

You don't want to just wire in a knock light in series. This will interfere with the voltage of the signal that is sent to your ECU for it's reference with respect to knock. If you want to do this, you will want to purchase a seperate knock sensor and mount it.

Maybe that's what the sitc is? (I hate when people throw out random abbreviations that aren't in common usage). Obviously sitc is some sort of timing controller, but exactly what that is isn't clear to me...

Wow I as at work all day and I come home to a **** load of posts lol Thats awesome. The SITC stands for super ignition timing converter. It is an apexi product that has now been discontinued but it still in wide use. Basicly it intercepts the cranks position senor and cams position sensors and allows you to advance or retard your timing up to 15 degrees either way at 5 different rpm levels. The knock light I am running is a turboxs knock light. They swear that it doesnt interfere with the stock sensor reading but maybe a different sensor is a good idea.

Thanks to everyone for all the input! I know these late g's are confusing to alot of people. It is great to have some suby gurus to clear stuff up for newbies

It sounds like I will go ahead and run this on 91 as is for a while and just take it easy.

thanks everyone
Jason

rs182 · 10-02-2009, 06:20 PM

One more thing.... I have heard various hp numbers for this motor ranging from 190 to 265 but 250 comes up the most. Is the 250hp number correct? I would like to think it is at least more that a usdm wrx

Cbgrandtheftauto · 10-02-2009, 06:27 PM

so theres a difference in the WRX 20K and the forester engine??...hmmm..thats something new

rs182 · 10-02-2009, 06:36 PM

I think they are the same? I am pretty sure the wrx wagons came with the late g as well as the forester. Mine has a 4w ecu. Not sure how that compares with the wrx guys.
Also I was not aware that the g had a higher compression ratio than the k either I was under the impression that the internals were the same. Im glad I posted before I threw on a 6s ecu and a vf23!

Matt Monson · 10-02-2009, 07:58 PM

Quote:

Originally Posted by rs182

The SITC stands for super ignition timing converter. It is an apexi product that has now been discontinued but it still in wide use.

Leave it to the Japanese. I'm surprised there's not an "extra special" in front of that making it the ESSITC.

I actually own one. I've just never heard it called that before. I've just always seen it referred to as an Apexi ITC.

Since we're going back into the dark ages of tuning these cars, the J&S Safeguard was a popular aftermarket knock sensor in it's day. Not only did it sense, but it also automatically retards when it gets knock, much like the stock ECU is supposed to do.

Jaxx · 10-03-2009, 01:08 PM

there is still disagreement on the ej20k yellow sidefeeds
i believe they are 480cc @ 3 bar

elislider · 10-03-2009, 03:17 PM

Quote:

Originally Posted by Jaxx

there is still disagreement on the ej20k yellow sidefeeds
i believe they are 480cc @ 3 bar

you and marnix should duke it out on this one

Marnix · 10-03-2009, 03:23 PM

No could be they are 480 cc; I only know they're bigger than the grey tops and the only other engine they were in besides all EJ20K, is the TwinTurbo EJ20R.

Matt Monson · 10-03-2009, 04:53 PM

IIRC i_c_the_light actually had a set tested and posted teh results. Though it could have been for the greys. Wouldn't hurt to search if people really care. I don't.

Marnix · 10-04-2009, 01:56 AM

It would be nice to test a grey top and a yellow top simultaneously to see the difference between them.

John at J&S · 01-09-2010, 06:29 AM

New version has headphone output and knock-finder LED's to show which cylinders are knocking.

Google "knock amp interceptor"

10-01-2009, 07:22 PM	#1
rs182 Scooby Newbie Member#: 197511 Join Date: Dec 2008 Chapter/Region: SWIC Location: Las Cruces, NM Vehicle: 1999 2.5RS Black	late ej20g (20k) engine timing I am going to start up my swapped rs this weekend. As of now I have safc and sitc piggy backs. Seeing how it is a 97 forester it is the bastard late g motor. I know the 20k get bad wrap for spinning bearing because of low octane fuel and not pulling enough timing. So my question is how much should I retard the timing to make it safe for 91 octane. I will be getting it tuned next month (have to drive to phx, AZ)but I want to start driving her. It is completely stock so I should not need to mess with any a/f numbers. Being that is a forester late 20g(20k) it already has a less agressive timing curve than say a sti 6s ecu. (250hp vs 280). So all you g,k gurus school me on this and yes i am ready to be flamed for not getting a pro-tune immediately. * Registered users of the site do not see these ads.

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10-01-2009, 07:34 PM	#2
Jaxx Scooby Guru Member#: 177 Join Date: Aug 1999 Chapter/Region: NWIC Location: Austin, Texas, USA Vehicle: The 93 W/EJ20K-sold Subaru-less :(	so you are using the G ecu right... if your worried i would direct connect the wastegate and take her easy det under low load is not an issue should be fine with 91

10-01-2009, 07:40 PM	#3
rs182 Scooby Newbie Member#: 197511 Join Date: Dec 2008 Chapter/Region: SWIC Location: Las Cruces, NM Vehicle: 1999 2.5RS Black	yea it is a g ecu but it uses the k style plugs so I am not sure how much more aggressive the ecu is. Am i correct in thinking that using a knock light and the sitc I can simply retard the timing until there is no knock at the given rpm?

10-02-2009, 12:17 AM	#4
elislider Scooby Specialist Member#: 133923 Join Date: Dec 2006 Chapter/Region: NWIC Location: Portland, OR Vehicle: 03 Legacy GT wagon I love goooollllllllddddd	the late ej20g with 20k style electronics makes the least power of that year range (for turbo models). its got a td04 which is a small turbo (still larger than the usdm td04 though AFAIK). the real problem is with the jdm ej20k sti ECUs like the 6S ecu that i have, runs 17lbs boost stock, which is quite a bit from the factory. so if you get an ECU from a plain ej20k wrx (one that had a td05 for example) then you could push your current setup further but not so far as a vf22/vf23 jdm ej20k sti (which would have bigger injectors, fuel pump, shim under bucket, etc)

10-02-2009, 02:06 AM	#6
elislider Scooby Specialist Member#: 133923 Join Date: Dec 2006 Chapter/Region: NWIC Location: Portland, OR Vehicle: 03 Legacy GT wagon I love goooollllllllddddd	the late ej20g and plain ej20k is shim under bucket very similar to the USDM 1998 2.5RS and USDM 1998 forester. they are similar in valve train features but the jdm has slightly larger ports and better valves and cam profile for the turbo model. the v3/v4 STi is shim under bucket and sodium filled valves, overall tougher valvetrain which can endure higher and more sustained revs (within reason). hence why the factory fuelcut on a v3/v4 sti is 8250 and for the plain wrx its lower like 7800 or something marnix/matt/jaxx could provide more specifics

10-02-2009, 02:10 AM	#7
Marnix Scooby Specialist Member#: 51480 Join Date: Dec 2003 Chapter/Region: International Location: The Netherlands Vehicle: 1984 AM5, 1984 AF1, 1994 BC4, 2015 Outback	The head castings are identical to all MY97-98 DOHC heads including USDM EJ25D, JDM EJ20G, EJ20H, EJ20K and EJ20R. The differences are in valves (solid or hollow/sodium cooled), valve springs and shim arrangement (under - or over bucket) and cams. This all has influence on rev limit and power range. Considering the rs182 is using a EJ20G out of a Forester, he should also consider that the engine has a higher compression ratio (9.0 vs. 8.0) compared to a EJ20K meaning he will have to be even more conservative regarding timing under boost. When using the ECU that came with that engine, however, the engine should be fine on 91 gas as the maps are far less aggressive as the EJ20K's. Still, when driving, start carfefully and monitor knock.

10-02-2009, 09:41 AM	#10
Marnix Scooby Specialist Member#: 51480 Join Date: Dec 2003 Chapter/Region: International Location: The Netherlands Vehicle: 1984 AM5, 1984 AF1, 1994 BC4, 2015 Outback	Eh no, not the late EJ20G they have the dark grey tops, same as all pre-1997 EJ20G (except some STI versions). Only the EJ20K had the yellow top injectors.

10-02-2009, 04:29 PM	#12
Marnix Scooby Specialist Member#: 51480 Join Date: Dec 2003 Chapter/Region: International Location: The Netherlands Vehicle: 1984 AM5, 1984 AF1, 1994 BC4, 2015 Outback	There are different yellow tops on the MY99> engines, they're supposed to be 440cc whereas the earlier yellow tops (EJ20K and EJ20R) are 550cc.

10-02-2009, 05:06 PM	#13
Matt Monson Scooby Guru Member#: 832 Join Date: Jan 2000 Chapter/Region: RMIC Location: Teh Ghetto Garage, CO Vehicle: 99 2.5RS, '85 911 '73 914 and 2012 BRZ	Straight inlet td05 was never a factory thing. Starting with v3, all STi's and 5MT Sedans got IHI VF series turbos while all the others got td04s. Straight inlet td05 are an aftermarket thing.

10-02-2009, 06:20 PM	#16
rs182 Scooby Newbie Member#: 197511 Join Date: Dec 2008 Chapter/Region: SWIC Location: Las Cruces, NM Vehicle: 1999 2.5RS Black	One more thing.... I have heard various hp numbers for this motor ranging from 190 to 265 but 250 comes up the most. Is the 250hp number correct? I would like to think it is at least more that a usdm wrx

10-02-2009, 06:27 PM	#17
Cbgrandtheftauto Scooby Specialist Member#: 184977 Join Date: Jul 2008 Chapter/Region: South East Location: TN Vehicle: 99 Impreza RS '13 BRZ	so theres a difference in the WRX 20K and the forester engine??...hmmm..thats something new

10-02-2009, 06:36 PM	#18
rs182 Scooby Newbie Member#: 197511 Join Date: Dec 2008 Chapter/Region: SWIC Location: Las Cruces, NM Vehicle: 1999 2.5RS Black	I think they are the same? I am pretty sure the wrx wagons came with the late g as well as the forester. Mine has a 4w ecu. Not sure how that compares with the wrx guys. Also I was not aware that the g had a higher compression ratio than the k either I was under the impression that the internals were the same. Im glad I posted before I threw on a 6s ecu and a vf23!

10-03-2009, 01:08 PM	#20
Jaxx Scooby Guru Member#: 177 Join Date: Aug 1999 Chapter/Region: NWIC Location: Austin, Texas, USA Vehicle: The 93 W/EJ20K-sold Subaru-less :(	there is still disagreement on the ej20k yellow sidefeeds i believe they are 480cc @ 3 bar

10-03-2009, 03:23 PM	#22
Marnix Scooby Specialist Member#: 51480 Join Date: Dec 2003 Chapter/Region: International Location: The Netherlands Vehicle: 1984 AM5, 1984 AF1, 1994 BC4, 2015 Outback	No could be they are 480 cc; I only know they're bigger than the grey tops and the only other engine they were in besides all EJ20K, is the TwinTurbo EJ20R.

10-03-2009, 04:53 PM	#23
Matt Monson Scooby Guru Member#: 832 Join Date: Jan 2000 Chapter/Region: RMIC Location: Teh Ghetto Garage, CO Vehicle: 99 2.5RS, '85 911 '73 914 and 2012 BRZ	IIRC i_c_the_light actually had a set tested and posted teh results. Though it could have been for the greys. Wouldn't hurt to search if people really care. I don't.

10-04-2009, 01:56 AM	#24
Marnix Scooby Specialist Member#: 51480 Join Date: Dec 2003 Chapter/Region: International Location: The Netherlands Vehicle: 1984 AM5, 1984 AF1, 1994 BC4, 2015 Outback	It would be nice to test a grey top and a yellow top simultaneously to see the difference between them.

01-09-2010, 06:29 AM	#25
John at J&S Scooby Newbie Member#: 2036 Join Date: Aug 2000 Location: Garden Grove, CA USA Vehicle: 2000 Intrepid silver	New version has headphone output and knock-finder LED's to show which cylinders are knocking. Google "knock amp interceptor"