Legacy Turbo Camshafts

Trey · 08-25-2000, 03:31 PM

Greetings,

I've been contacted by Matt (Shik) about the possibility of designing camshafts for the Legacy Turbo (EJ22T) models. As you might be aware, the cylinder heads are an issue with these engines, and replacing them with higher flowing heads from a WRX and/or EJ25 would be beneficial.

Nonetheless, I'm willing to help work with you all to design a camshaft that will take maximum advantage of the cylinder head flow we have to work with. What I need to know from you all is:
1) How much interest is their in such a product. Cost will be similiar to the cams we offer for the SOHC EJ25 ($650).
2) What boost levels do many of you run and do any of you have backpressure per boost ratios for the turbos you use? (ie: stock turbo, 14psi boost, 18psi backpressure between turbo and exhaust port)
3) How critical is idle quality? Do the turbo legacy's have decent idle control/bac valves?
4) What max RPM do many of you rev to?

Sorry for my ignorance regarding the Legacy turbos, I'm not an expert by any means on these models. I am, however, interested in helping you all in your quest for more power.

I will also need to have someone volunteer for testing the camshafts. Someone will need to have the means to dyno before and after.

Please feel free to continue discuss here publically, so we can hash out the details.

Thanks,
Trey
CobbTuning.com

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

Flatfour · 08-25-2000, 06:14 PM

O.T a bit here, but I just moved down to Austin from the Northeast and had no idea you guys were in Dallas. I will certainly drop by. I am running a 92 Legacy-Turbo 5spd which is aching for better cams + heads.

I am also looking into building up another engine by starting with a brand new short block, so i am very interested in what you can come up with.

PeteH · 08-25-2000, 09:05 PM

Hey Trey!

It's been a while, you called me about a year ago when I was trying to bring WRX motors and trannys to the states. Anyhow...After thinking this through I believe it would be more benifical to just swap to either the new SOHC or the DOHC heads, we should see a hp gain just from doing this!

To be honest, I can't see sticking $6 to $700 on a set of cams for a set of poor flowing heads, I would rather buy a set of cams for some heads with potential.

Question #2, I am currently running at 12psi (8.5 is stock) with the stock turbo, actually stock everything except the drop-in K&N. I will have to admit though, I know very little and have read even less about backpressure per boost ratios, is there an 'ideal' ratio? I would guess it changes with respect to the goal you are trying to achieve (street/strip/rally/etc.)?

#3 As long as it will idle with the lights/air on I will be happy

Actually, once I get my EGT gauge and my homebuilt dual K-type thermocouple display installed the TDO4/intercooler/3" from turbo back exhaust installed I can give you a better answer

#4 Redline is 6250 or 6500, with the added boost pressure it actually pulls quite strong to redline.

Don't feel bad for not knowing much about the turbo Legacy, there is scarce little info around about these and even less about performance tuning, in this respect we are all newbies! Just this past week we finally found out what the factory boost cut is set at!

Hmmm, dyno............does a G-Tech Pro count?

I personally will upgrade to better flowing heads, which ones I am yet unsure of. Maybe you can help, my research tells me that the hydraulic lash adjusters become an issue as rpm's/boost increases. My question is this: did Subaru produce any heads with solid lash adjusters? I also heard that the heads from a STi type RA version 3(?) used better castings with improved cooling and more material around the ports (for future porting), true?

I have got to say, I am quite impressed with the work you have done to date with the boxer, keep the goods coming!

PeteH

Shik · 08-25-2000, 11:13 PM

Trey, again much thanks for the info.

As I mentioned to Trey earlier, I do agree that swapping the heads is surely the way to go if you are looking down the road invisioning big horsepower. But, I inquired if it was possible to make a set of cams that would be able to make improvements to the heads/airflow we are given from the start. Who knows, maybe the factory had an extremely conservative cam design and a set of aftermarkets would make vast improvements. Then again, on the flip side, maybe it would be found that a set of aftermarkets would be of little help. I'm sure this is stuff Trey would have to find out but I would definately be interested to know.

I would also be very interested to know what the price of a total head swap would be and also any additional parts that would be needed(if any) besides the actual heads/pulleys. I know it would depend on what kind of heads you got, but still, a round about idea would be nice. I do agree with Pete, if the head swap was anywhere close to the price of just swapping cams, it would pay to do the heads. However, if we are talking 3 times as much for a head swap AND it is proved that cams alone can produced a very nice increase, I'd go with the cams in a second, simply because this car is my daily driver and I know it is never going to be a 12 second car. Respectable performance is all I'm looking for(especially on a "household" budget

).

I guess we wait and see what is found out about the stockers and then see if Trey feels a set of cams would be worth the effort. flatfour, we are depending on you

I'm with Pete on the redline, right around 6 grand is plently I would think. As far as back pressure per boost ratios, I am clueless. I can tell you I probably wouldn't run anymore then 15psi with a bit of work done to the turbo(or a different one all together). It would be nice to have a somewhat livable idle but on the other hand my idle has never been smooth as silk either

.

Trey, again, thanks for offering your expertise. It's nice to know you are an equal opportunity Subaru tuner

Trey · 08-26-2000, 08:49 AM

Thanks for the information thus far.

Our next step is going to be determining the stock camshaft's profile. From there, we'll be able to decide if a new profile will be worth our while.

As for swapping heads, I still think this is the ultimate option. Granted, it might end up costing a bit, but even with stock 2.5L NA SOHC heads, you gain 20-25% in flow!

In regards to the WRX heads, they uses thicker valve guides in their casting. Because of this, they actually flow worse, in stock form, than the NA 2.5L heads. They'd respond well to porting, yes, but you would have to put this extra time and money into them to get the benefits. Otherwise, the DOHC or SOHC 2.5L heads are a great buy I think.

I also need to cc the Legacy Turbo combustion side of the head to determine what will happen to our compression when we swap to different heads. Has anyone cc'd a piston, know the piston deck clearance and the head gasket compressed thickness? And I'm sure it's easy to find somewhere but what's the bore x stroke of this motor?

Thanks,
Trey
CobbTuning.com

Flatfour · 08-26-2000, 05:30 PM

According to the Subaru service manuals the only difference on the cams is of course the height,

N.A is 32.364---32.464
Turbo is 32.286--32.386

dont know if that helps. it also refers to the Turbo as having "closed" heads versus "Open" for the non.

I havent found to many other difference between the two. If the bore and stroke are the same,(absolutely right Shik ) its got to be deck height or pistons, no?

Will keep looking for more info. Big manuals, small reader

Shik · 08-27-2000, 12:22 AM

Well,the bore and stroke is 96.9x75.0( found at DLC's Turbo-Centric web site), can't offer much help on the others.

Trey, not to be a PITA, but since you had a pretty good look at the EJ22T, EJ25 DOHC, and EJ25 SOHC heads, does it look like everything is a completely direct swap from one to another? I just find it amazing that a head from '00 can bolt right on a different motor from as early as '91. I mean will all the coolant passages line up and everything? Hell, will all the bolt holes even line up?

I'm going to call around and see what places are getting for a set of the 2.5 heads just for curiosity, but I'm still very interested in your findings with the stock EJ22T cams. Looking forward to it.

08-25-2000, 03:31 PM	#1
Trey Scooby Newbie Member#: 670 Join Date: Dec 1999 Chapter/Region: TXIC Location: Austin, the Republic of Texas	Legacy Turbo Camshafts Greetings, I've been contacted by Matt (Shik) about the possibility of designing camshafts for the Legacy Turbo (EJ22T) models. As you might be aware, the cylinder heads are an issue with these engines, and replacing them with higher flowing heads from a WRX and/or EJ25 would be beneficial. Nonetheless, I'm willing to help work with you all to design a camshaft that will take maximum advantage of the cylinder head flow we have to work with. What I need to know from you all is: 1) How much interest is their in such a product. Cost will be similiar to the cams we offer for the SOHC EJ25 ($650). 2) What boost levels do many of you run and do any of you have backpressure per boost ratios for the turbos you use? (ie: stock turbo, 14psi boost, 18psi backpressure between turbo and exhaust port) 3) How critical is idle quality? Do the turbo legacy's have decent idle control/bac valves? 4) What max RPM do many of you rev to? Sorry for my ignorance regarding the Legacy turbos, I'm not an expert by any means on these models. I am, however, interested in helping you all in your quest for more power. I will also need to have someone volunteer for testing the camshafts. Someone will need to have the means to dyno before and after. Please feel free to continue discuss here publically, so we can hash out the details. Thanks, Trey CobbTuning.com * Registered users of the site do not see these ads.

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08-25-2000, 06:14 PM	#2
Flatfour Scooby Newbie Member#: 906 Join Date: Feb 2000 Location: Austin TX	O.T a bit here, but I just moved down to Austin from the Northeast and had no idea you guys were in Dallas. I will certainly drop by. I am running a 92 Legacy-Turbo 5spd which is aching for better cams + heads. I am also looking into building up another engine by starting with a brand new short block, so i am very interested in what you can come up with.

08-25-2000, 09:05 PM	#3
PeteH Scooby Newbie Member#: 431 Join Date: Oct 1999 Location: Baraboo WI, USA	Hey Trey! It's been a while, you called me about a year ago when I was trying to bring WRX motors and trannys to the states. Anyhow...After thinking this through I believe it would be more benifical to just swap to either the new SOHC or the DOHC heads, we should see a hp gain just from doing this! To be honest, I can't see sticking $6 to $700 on a set of cams for a set of poor flowing heads, I would rather buy a set of cams for some heads with potential. Question #2, I am currently running at 12psi (8.5 is stock) with the stock turbo, actually stock everything except the drop-in K&N. I will have to admit though, I know very little and have read even less about backpressure per boost ratios, is there an 'ideal' ratio? I would guess it changes with respect to the goal you are trying to achieve (street/strip/rally/etc.)? #3 As long as it will idle with the lights/air on I will be happy Actually, once I get my EGT gauge and my homebuilt dual K-type thermocouple display installed the TDO4/intercooler/3" from turbo back exhaust installed I can give you a better answer #4 Redline is 6250 or 6500, with the added boost pressure it actually pulls quite strong to redline. Don't feel bad for not knowing much about the turbo Legacy, there is scarce little info around about these and even less about performance tuning, in this respect we are all newbies! Just this past week we finally found out what the factory boost cut is set at! Hmmm, dyno............does a G-Tech Pro count? I personally will upgrade to better flowing heads, which ones I am yet unsure of. Maybe you can help, my research tells me that the hydraulic lash adjusters become an issue as rpm's/boost increases. My question is this: did Subaru produce any heads with solid lash adjusters? I also heard that the heads from a STi type RA version 3(?) used better castings with improved cooling and more material around the ports (for future porting), true? I have got to say, I am quite impressed with the work you have done to date with the boxer, keep the goods coming! PeteH

08-25-2000, 11:13 PM	#4
Shik NASIOC Supporter Member#: 132 Join Date: Jul 1999 Chapter/Region: Tri-State Location: Central PA Vehicle: 1997 LGT Wagon 5spd '06 LGT 5spd Ltd Sdn	Trey, again much thanks for the info. As I mentioned to Trey earlier, I do agree that swapping the heads is surely the way to go if you are looking down the road invisioning big horsepower. But, I inquired if it was possible to make a set of cams that would be able to make improvements to the heads/airflow we are given from the start. Who knows, maybe the factory had an extremely conservative cam design and a set of aftermarkets would make vast improvements. Then again, on the flip side, maybe it would be found that a set of aftermarkets would be of little help. I'm sure this is stuff Trey would have to find out but I would definately be interested to know. I would also be very interested to know what the price of a total head swap would be and also any additional parts that would be needed(if any) besides the actual heads/pulleys. I know it would depend on what kind of heads you got, but still, a round about idea would be nice. I do agree with Pete, if the head swap was anywhere close to the price of just swapping cams, it would pay to do the heads. However, if we are talking 3 times as much for a head swap AND it is proved that cams alone can produced a very nice increase, I'd go with the cams in a second, simply because this car is my daily driver and I know it is never going to be a 12 second car. Respectable performance is all I'm looking for(especially on a "household" budget ). I guess we wait and see what is found out about the stockers and then see if Trey feels a set of cams would be worth the effort. flatfour, we are depending on you I'm with Pete on the redline, right around 6 grand is plently I would think. As far as back pressure per boost ratios, I am clueless. I can tell you I probably wouldn't run anymore then 15psi with a bit of work done to the turbo(or a different one all together). It would be nice to have a somewhat livable idle but on the other hand my idle has never been smooth as silk either . Trey, again, thanks for offering your expertise. It's nice to know you are an equal opportunity Subaru tuner

08-26-2000, 08:49 AM	#5
Trey Scooby Newbie Member#: 670 Join Date: Dec 1999 Chapter/Region: TXIC Location: Austin, the Republic of Texas	Thanks for the information thus far. Our next step is going to be determining the stock camshaft's profile. From there, we'll be able to decide if a new profile will be worth our while. As for swapping heads, I still think this is the ultimate option. Granted, it might end up costing a bit, but even with stock 2.5L NA SOHC heads, you gain 20-25% in flow! In regards to the WRX heads, they uses thicker valve guides in their casting. Because of this, they actually flow worse, in stock form, than the NA 2.5L heads. They'd respond well to porting, yes, but you would have to put this extra time and money into them to get the benefits. Otherwise, the DOHC or SOHC 2.5L heads are a great buy I think. I also need to cc the Legacy Turbo combustion side of the head to determine what will happen to our compression when we swap to different heads. Has anyone cc'd a piston, know the piston deck clearance and the head gasket compressed thickness? And I'm sure it's easy to find somewhere but what's the bore x stroke of this motor? Thanks, Trey CobbTuning.com

08-26-2000, 05:30 PM	#6
Flatfour Scooby Newbie Member#: 906 Join Date: Feb 2000 Location: Austin TX	According to the Subaru service manuals the only difference on the cams is of course the height, N.A is 32.364---32.464 Turbo is 32.286--32.386 dont know if that helps. it also refers to the Turbo as having "closed" heads versus "Open" for the non. I havent found to many other difference between the two. If the bore and stroke are the same,(absolutely right Shik ) its got to be deck height or pistons, no? Will keep looking for more info. Big manuals, small reader

08-27-2000, 12:22 AM	#7
Shik NASIOC Supporter Member#: 132 Join Date: Jul 1999 Chapter/Region: Tri-State Location: Central PA Vehicle: 1997 LGT Wagon 5spd '06 LGT 5spd Ltd Sdn	Well,the bore and stroke is 96.9x75.0( found at DLC's Turbo-Centric web site), can't offer much help on the others. Trey, not to be a PITA, but since you had a pretty good look at the EJ22T, EJ25 DOHC, and EJ25 SOHC heads, does it look like everything is a completely direct swap from one to another? I just find it amazing that a head from '00 can bolt right on a different motor from as early as '91. I mean will all the coolant passages line up and everything? Hell, will all the bolt holes even line up? I'm going to call around and see what places are getting for a set of the 2.5 heads just for curiosity, but I'm still very interested in your findings with the stock EJ22T cams. Looking forward to it.