I've seen a link before of the differences of the 1J revision 1 and 2, now all I can find is the pic showing the vent line. any help would be egsellent. thanks in advance
Differances in 1J revision
- Thread starter cruzinbill
- Start date
what all was changed, what i need to look out for... saw somthing bout possible bad valves blowby but thats bout it.
One has the pcv oil vapor-into-intake in the middle of the "T" connecting both compressor inlets to the intake tube
The other kind, the oil-in runs into the number 2 "T" to compressor air tube
The other kind, the oil-in runs into the number 2 "T" to compressor air tube
I think he's asking what the differance is between the two engines other than the PCV vent. In terms of the head and block.
Gen 1 has the defective vent tube that was recalled due to too much blowby causing turbine failure.
The main difference between gen 1 and 2 is the turbo outlet design with that pipe. Also most gen 2 do not have traction controll and have a cleaner throttle body.
I have nothing to back this, but just from experence and seeing the two motors in action, gen 2 ECU's have a different tune. Dyno for dyno even on here, gen2 motors put down more HP. It makes sence that it does have a remapped ecu, it's a whole nother generation of motor thats 3 years newer then the first design. Gen 3 motors got VVTI and single turbo, to say nothing changed but the vent tube is wrong.
Looking at dynos, most gen 1 motors stock put down in the 250-270hp range, and it's not uncommon for a gen 2 motor to put down nearly 300whp stock (5 spd trannys). My gen 2 bone stock with automatic transmission put down 275whp. A few mods later with stock boost, i was 300whp with the auto! You gen 1 supra guys with 5spds have a hard time doing that with a boost controller.
The main difference between gen 1 and 2 is the turbo outlet design with that pipe. Also most gen 2 do not have traction controll and have a cleaner throttle body.
I have nothing to back this, but just from experence and seeing the two motors in action, gen 2 ECU's have a different tune. Dyno for dyno even on here, gen2 motors put down more HP. It makes sence that it does have a remapped ecu, it's a whole nother generation of motor thats 3 years newer then the first design. Gen 3 motors got VVTI and single turbo, to say nothing changed but the vent tube is wrong.
Looking at dynos, most gen 1 motors stock put down in the 250-270hp range, and it's not uncommon for a gen 2 motor to put down nearly 300whp stock (5 spd trannys). My gen 2 bone stock with automatic transmission put down 275whp. A few mods later with stock boost, i was 300whp with the auto! You gen 1 supra guys with 5spds have a hard time doing that with a boost controller.
Sorry if this sounds noobish but how can i identify the generation of my motor? I just bought the car with the swap already done. Are there identification numbers somewhere or can i tell by certain parts?
edit: oops just noticed the picture link above.
edit: oops just noticed the picture link above.
The tune isn't generation related. All jza70 ecus are the same. The soarer and jzx90 (ithink) ecus switch over they received a better timing controlling system I assume. Similar to the mkivs which is much better then the jza70s.Ric said:
I have not seen any correlation linking cars with "1st gen" PCV valve and pipes blowing turbos any more often than cars with "2nd gen" valve and pipes. I've seen a car with the "1st gen" setup run a set of stock turbos without fail for more mileage than most people have probably put on their Supra, period. I've seen turbos fail on "2nd gen" motors just the same as a "1st gen" motor.
I don't think it's possible to do any kind of scientific study to prove any correlation(and dont even mention causation) that would say a "2nd gen" PCV setup will stop you from experiencing blown turbos. These engines and turbos have been used for quite a while before any of us got our hands on them. Unless you know the complete previous history, can find two cars with similar history using two different PCV setups, and can test them under the same conditions for some amount of time to see which one loses its turbos first, none of us can make a claim of anything. Even then, you would have to produce the same results multiple times and anyone else should be able to do the same. And the tests still would not be conclusive as far as I'm concerned. I doubt anyone wants to spend the money to completely rebuild 2 1JZs, 2 sets of turbos, and have them driven under the same exact conditions with different PCV setups to see what happens. And then do it a few more times to see if the results can be duplicated.
If you want to save your turbos, keep your EGTs in check, change your oil, and hope whoever drove your engine before did the same.
Nor do I believe anything about any changes in the ECU to make a "2nd gen" ECU any better. Now changes between different factory 1JZ equipped cars, I might be more likely to believe that. But between the Supra itselt, I don't think so.
Ric, I don't think you have any proof that early 1Js and later 1Js from the same model car had any significant changes to them other than the PCV valve and pipes.
I don't think it's possible to do any kind of scientific study to prove any correlation(and dont even mention causation) that would say a "2nd gen" PCV setup will stop you from experiencing blown turbos. These engines and turbos have been used for quite a while before any of us got our hands on them. Unless you know the complete previous history, can find two cars with similar history using two different PCV setups, and can test them under the same conditions for some amount of time to see which one loses its turbos first, none of us can make a claim of anything. Even then, you would have to produce the same results multiple times and anyone else should be able to do the same. And the tests still would not be conclusive as far as I'm concerned. I doubt anyone wants to spend the money to completely rebuild 2 1JZs, 2 sets of turbos, and have them driven under the same exact conditions with different PCV setups to see what happens. And then do it a few more times to see if the results can be duplicated.
If you want to save your turbos, keep your EGTs in check, change your oil, and hope whoever drove your engine before did the same.
Nor do I believe anything about any changes in the ECU to make a "2nd gen" ECU any better. Now changes between different factory 1JZ equipped cars, I might be more likely to believe that. But between the Supra itselt, I don't think so.
Ric, I don't think you have any proof that early 1Js and later 1Js from the same model car had any significant changes to them other than the PCV valve and pipes.
Joe, there has to be ECU tune changes. I'm sorry but Toyota like all engine manufacturers fine tune their base tunes as years go by. In fact, it's probably safe to say that nearly every year released has some kind of revision.
As other people are saying, the Soarer and Chaser also got different tunes. The Chaser I believe to be the best. I've run both Chaser and Soarer ecu's in my car and there is a SOTP difference. The Chaser ECU also has higher shift points. The only physical different between the two is the location of the ECU plug. Top = Chaser, Side = Soarer.
The Gen1 PCV design is defective and causes turbine failure. It's a factory recall, look it up.
As other people are saying, the Soarer and Chaser also got different tunes. The Chaser I believe to be the best. I've run both Chaser and Soarer ecu's in my car and there is a SOTP difference. The Chaser ECU also has higher shift points. The only physical different between the two is the location of the ECU plug. Top = Chaser, Side = Soarer.
The Gen1 PCV design is defective and causes turbine failure. It's a factory recall, look it up.
Maybe small changes in ECUS but nothing significant between say the JZA70 years. I highly doubt you would be able to take a Supra with a 90 1JZ, dyno it, change the ECU with a 93 ECU and see any difference that could be attributed to the ECU. It's not like there was an OBD1/OBD2 crossover like the MKIV.
Just because a change was made to the PCV setup does not mean the problem went away. CT12s blow just the same on cars using early or later style PCV hose and pipes. Again, I've seen a car with the early style PCV setup run stock turbos for a very long time without problems. I've yet to see any conclusive evidence showing any difference in the longevity of turbos between the two setups. If the early style is defective, the later style is equally defective as far as I'm concerned. The only difference I see is when the PCV, or something else, fails and blows oil into your intake, only the front turbo would be killed. But you would still have to get in there, yank them out just the same, and might as well assume both were affected and change them both. Even if an original Toyota 1JZ engineer posts and says the problem was "fixed" it still wouldn't make a difference because later style PCV engines STILL blow turbos. And that is fact.
And again if someone wants their stock turbos to last, keep EGTs in check, change the oil, and hope your particular engine wasn't thoroughly abused previously.
Believe whatever you want.
Just because a change was made to the PCV setup does not mean the problem went away. CT12s blow just the same on cars using early or later style PCV hose and pipes. Again, I've seen a car with the early style PCV setup run stock turbos for a very long time without problems. I've yet to see any conclusive evidence showing any difference in the longevity of turbos between the two setups. If the early style is defective, the later style is equally defective as far as I'm concerned. The only difference I see is when the PCV, or something else, fails and blows oil into your intake, only the front turbo would be killed. But you would still have to get in there, yank them out just the same, and might as well assume both were affected and change them both. Even if an original Toyota 1JZ engineer posts and says the problem was "fixed" it still wouldn't make a difference because later style PCV engines STILL blow turbos. And that is fact.
And again if someone wants their stock turbos to last, keep EGTs in check, change the oil, and hope your particular engine wasn't thoroughly abused previously.
Believe whatever you want.
OneJoeZee said:
I believe Mr. Toyota, not you.
http://www.supraforums.com/forum/showthread.php?t=143293
It costs about $20 to fix, and the parts are USDM cross-reference.
Thank you, have a nice day
I knew you would pull that up eventually.
If the problem was "fixed" then why do later style PCV engines STILL blow turbos?
Again, because a change was made, does not mean the problem went away.
Notice the change mentioned is from a 2JZ-GTE NOT another 1JZ PCV valve. Also notice, Hams mentioned he did NOT change the exhaust side pipe setup. The longer later style 1JZ change is irrelevant.
The change made in the 1JZ was a longer hose that vents into the front turbo intake pipe instead of the middle pipe that would go to both turbos. The fix that hams posted about has nothing to do with the change Toyota made to the PCV hose vent.
Keep dancing around it all you want. 1JZs with early(short) and later(long) style PCV setup blow turbos just the same. I've experienced this with my own two Supras and 3 1JZ engines that I've had.
I'm not gonna keep going back and forth with you. It was really nice around here when you were gone. Nothing lasts forever I guess.
That thread doesn't help you at all.
If the problem was "fixed" then why do later style PCV engines STILL blow turbos?
Again, because a change was made, does not mean the problem went away.
Notice the change mentioned is from a 2JZ-GTE NOT another 1JZ PCV valve. Also notice, Hams mentioned he did NOT change the exhaust side pipe setup. The longer later style 1JZ change is irrelevant.
HamsMKIV;2197766 said:
The change made in the 1JZ was a longer hose that vents into the front turbo intake pipe instead of the middle pipe that would go to both turbos. The fix that hams posted about has nothing to do with the change Toyota made to the PCV hose vent.
Keep dancing around it all you want. 1JZs with early(short) and later(long) style PCV setup blow turbos just the same. I've experienced this with my own two Supras and 3 1JZ engines that I've had.
I'm not gonna keep going back and forth with you. It was really nice around here when you were gone. Nothing lasts forever I guess.
That thread doesn't help you at all.
onebad7m;3829657 said:
flubyux2;4355403 said:i just realized... no one in this thread, (except this guy /\), really gets how the PCV system works...
the PCV hose on the exhaust cam cover leading into the Front turbo inlet pipe/Y-pipe is primarily intended to draw fresh air into the crank case. as a secondary (and consequently, less important) function, it allows pressurized blowby gasses to escape into the turbo pipes. the PCV system is meant to allow fresh/filtered air to be pulled from the intake pipes, thru the cam covers and into the intake manifold. it doesnt matter if this fresh/filtered air is pulled from the stock twins inlet pipes, 4" intake pipe on a single turbo setup, K&N breather filter, GReddy catch can, or tubing flush-mounted w/ the hood creating a low-pressure effect at road speed. the vaccum of the intake manifold will pull air thru this PCV hose on the exhaust cam cover regardless. since the 1-way valve only allows vaccum, not boost, the air/blow-by gasses do not flow INTO the turbo intake pipes. on MKIV's, this is a metered vacuum leak and requires filtered air. turbulent air in a stock twins Y-pipe or fast moving air while the front turbo is under boost makes has no bearing on the functionality of this PCV hose. the PCV hose only draws air when there is sufficient manifold vacuum. if the check valve fails, it becomes a boost leak. if it becomes a boost leak, then the turbos will have to work harder to maintain the same desired boost level as before. this will result in over-spinning the turbos and more exhaust heat transferred into the turbos.
the placement of the PCV vent hose in the Ypipe or front turbo pipe is a moot point. this wont have any bearing on the check valve operation/failure, corrosive exhaust/blowby gasses or any of that talk.
it basically boils down to your PCV valve... make sure it has not failed and become a boost leak. you will most likely blow your turbos due to this leak.
im doing a swap w/ into a friends car using an early jza70, 1990 (heisei 1) with the "faulty" pcv valve. ive installed the later model 1991+(heisei 2+) intake pipes w/ the relocated nipple... the main intent was because these are powdercoated; the old ones werent
Would you like to keep going, Ric?
It's funny how you post that thread but completely ignore the results found in the end that say the exact opposite of the point you are trying to make. But thanks for linking it for me so I didn't have to go through the trouble of getting it myself.
You're worse then my ex-wife, i swear your a girl.
This thread is about the differences between the two motors. The differences were posted, along with recall info about the GenI design. The recall from Toyota being posted about 17 years ago.
You can argue all you want about your personal opinion on 18 year old ceramic bladed turbos that are about 13 years past their designed lifespan. Here in the year 2007, you are correct... both designs blow up, why? Age. Being these turbos are 15 PLUS years old and still work for most people at 20psi is simply amazing. If you were to buy a brand new set of CT12A turbos from Toyota to install on your GenI, it would be smart to follow the recall suggestions.
This thread is about the differences between the two motors. The differences were posted, along with recall info about the GenI design. The recall from Toyota being posted about 17 years ago.
You can argue all you want about your personal opinion on 18 year old ceramic bladed turbos that are about 13 years past their designed lifespan. Here in the year 2007, you are correct... both designs blow up, why? Age. Being these turbos are 15 PLUS years old and still work for most people at 20psi is simply amazing. If you were to buy a brand new set of CT12A turbos from Toyota to install on your GenI, it would be smart to follow the recall suggestions.
You really are that dumb.
Did you read anything?
First you post that thread thinking it supports your point. Then you ignore the REAL WORLD posts that say the exact opposite of what you're trying to prove.
It's not personal opinion. Why don't you read the thread you yourself posted all the way through? Better yet, just read the two posts I pointed out from the thread. If you understood anything from that thread, you would not still be here trying to tell people that a longer PCV vent hose will save their turbos.
The problem has ZERO to do with the short or long vent hose and has EVERYTHING to do with the PCV 1-way valve which members found that the 2JZ-GTE valve is better. Or at the very least it is NEW.
If you really believe the change a longer PCV vent hose on the exhaust side is going to stop turbos from blowing, you are alot dumber than I think you are. All that hose is is the vent. That's it. It's not the faulty 1-way valve and it's not going to stop turbos from dying.
A longer hose won't do shit. An updated and new PCV 1-way valve WILL do everything.
The turbos can last a very long time if they are taken care of. Look above. Jose himself said it and he was the person I was referring to before. If age was the problem, everyone with a 1JZ would be blowing turbos left and right all day long.
Why is it someone is able to get over 200,000 miles out of a stock engine with stock turbos?
Change the PCV 1-way valve before it goes bad, keep your EGTs in check, change your oil, and you should be ok.
I'm done here. There's nothing more to say. Even your own evidence doesn't agree with you.
Did you read anything?
First you post that thread thinking it supports your point. Then you ignore the REAL WORLD posts that say the exact opposite of what you're trying to prove.
It's not personal opinion. Why don't you read the thread you yourself posted all the way through? Better yet, just read the two posts I pointed out from the thread. If you understood anything from that thread, you would not still be here trying to tell people that a longer PCV vent hose will save their turbos.
The problem has ZERO to do with the short or long vent hose and has EVERYTHING to do with the PCV 1-way valve which members found that the 2JZ-GTE valve is better. Or at the very least it is NEW.
If you really believe the change a longer PCV vent hose on the exhaust side is going to stop turbos from blowing, you are alot dumber than I think you are. All that hose is is the vent. That's it. It's not the faulty 1-way valve and it's not going to stop turbos from dying.
A longer hose won't do shit. An updated and new PCV 1-way valve WILL do everything.
The turbos can last a very long time if they are taken care of. Look above. Jose himself said it and he was the person I was referring to before. If age was the problem, everyone with a 1JZ would be blowing turbos left and right all day long.
Why is it someone is able to get over 200,000 miles out of a stock engine with stock turbos?
Change the PCV 1-way valve before it goes bad, keep your EGTs in check, change your oil, and you should be ok.
I'm done here. There's nothing more to say. Even your own evidence doesn't agree with you.
Last edited:
lol, i love when you two go at it. :biglaugh:
i agree with you joe, both styles blow turbos. replace the valve and you should be ok.
i agree with you joe, both styles blow turbos. replace the valve and you should be ok.