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1.8 Normal Aspirated and Turbo Differences.


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Hey Soobers;

 

Does anyone nkow what the difference are between the Turbo 1.8 that was put in the Loyale and the normally apirated one? Other than the Turbo being fitted I mean. If I work on my present engine then add the turbo to it, will that be different tha a factory Tubo 1.8?

 

Thanks

Gareth

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the different heads/pistons make a lower compression ratio. Turbos run at 7.7:1 compression where a carb is 9.0 and a SPFI runs at 9.5:1 ratio. I may have the carb and spfi numbers mixed up, but I'm positive that the turbo comp is 7.7.

 

The only way you are gonna make a N/A EA82 a turbo, is get a carb block, turbo heads, turbo intake, turbo x-over pipe, down pipe, turbo unit. then you are gonna have to switch wiring harnesses.

 

Better off just buying a car that came stock with a turbo.

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Hi:

Well I guess that means no mod s for the current engine beyond; hi-flow cat, better muffler and K&N filter in the airbox. I'll just buy one of those low-mile Japanese market imports (w/turbo) and have it installed.

 

Cheers,

Gareth

 

 

 

the different heads/pistons make a lower compression ratio. Turbos run at 7.7:1 compression where a carb is 9.0 and a SPFI runs at 9.5:1 ratio. I may have the carb and spfi numbers mixed up, but I'm positive that the turbo comp is 7.7.

 

The only way you are gonna make a N/A EA82 a turbo, is get a carb block, turbo heads, turbo intake, turbo x-over pipe, down pipe, turbo unit. then you are gonna have to switch wiring harnesses.

 

Better off just buying a car that came stock with a turbo.

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the different heads/pistons make a lower compression ratio. Turbos run at 7.7:1 compression where a carb is 9.0 and a SPFI runs at 9.5:1 ratio. I may have the carb and spfi numbers mixed up, but I'm positive that the turbo comp is 7.7.

 

The only way you are gonna make a N/A EA82 a turbo, is get a carb block, turbo heads, turbo intake, turbo x-over pipe, down pipe, turbo unit. then you are gonna have to switch wiring harnesses.

 

Better off just buying a car that came stock with a turbo.

 

 

I couldnt disagree more.. You dont need all of that.

I run a 9.5:1 now (SPFI) @ 8 psi without any problems

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yeah it may run at 8 psi, but bump it up to 10 psi. I guarentee you are going to start blowing hg's. And if it wasn't a problem, why did they make turbo motors lower compression? wouldnt it have been easier for subaru to just make all 9.5 comp motors and just use different heads?

 

romcat for the price you are going to pay for a JDM motor, I would just sell the soob you have now and find a turbo wagon/sedan in the US. No work involved for that. If you get a JDM motor, EVERYTHING is on the other side of the motor. You dont want to get me started on how much of a PITA it is converting a JDM motor. You are going to have to strip the motor down (intake, motor mounts, exhaust, turbo) and then get US parts to make it work. I did a JDM carb swap a few weeks ago, and I will never EVER get a JDM motor again for a soob. Too much work is involved for the price you are paying for a complete motor.

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HI;

 

Problem is I'm moving back to Canada in about 10 days. The Loyale Wagon I have "Pockets" is in great shape but the motor sounds like a Combine or a Stearman bilpane. The motor only has 135,000 miles on it, way less than my last one an 86 4wd wagon got to 288,000 before the floor fell out, well actually the subframe. The extra 2-25 HP would make a huge difference but maybe the hi-flow cat, higher flow pipe and a K&N and possibly a biy of porting will give me another 10-20 hp. That would be enough. I'm going to get a Legacy 2nd generation wagon probably in the next two years. What about cams, whats available for good low end power? I shift at around 3200-3500 rpm normally.

Open to ideas???!!!

 

BTW, why won't the Turbo drop in "as is" after all it was offered in the same car? I love simple answers, don't you love simple answers?! Now where did they go! ;-)

 

Gareth

 

yeah it may run at 8 psi, but bump it up to 10 psi. I guarentee you are going to start blowing hg's. And if it wasn't a problem, why did they make turbo motors lower compression? wouldnt it have been easier for subaru to just make all 9.5 comp motors and just use different heads?

 

romcat for the price you are going to pay for a JDM motor, I would just sell the soob you have now and find a turbo wagon/sedan in the US. No work involved for that. If you get a JDM motor, EVERYTHING is on the other side of the motor. You dont want to get me started on how much of a PITA it is converting a JDM motor. You are going to have to strip the motor down (intake, motor mounts, exhaust, turbo) and then get US parts to make it work. I did a JDM carb swap a few weeks ago, and I will never EVER get a JDM motor again for a soob. Too much work is involved for the price you are paying for a complete motor.

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BTW, why won't the Turbo drop in "as is" after all it was offered in the same car? I love simple answers, don't you love simple answers?! Now where did they go! ;-)

 

Gareth

 

It will just 'drop in'

 

It just won't run that way ;)

 

Wiring is different, crossmember is different to deal with the fact that the exhaust is different

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Hi:

 

How is the crossmember different? Because of the way the exhaust hangs. I assume we're talking about the manifold? Can the they be swapped? Is the rest of the exhaust pretty much the same?

By wiring, do you mean the igntion etc, computer?

 

Cheers,

Gareth

 

 

It will just 'drop in'

 

It just won't run that way ;)

 

Wiring is different, crossmember is different to deal with the fact that the exhaust is different

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re wiring the car isnt really that hard, i had to rewire my rx when i got it, i had to pull out what remained of the original harness and replace the whole front end wiring harness. the only thing that was hard was getting the harness throught the firewall under the dash, and that was cause i am not the smallest person out htere. if you get acomplete harness, you just get it through the firewall and every thing will line up where it needs to go.

 

as for the cross member, youll need the turbo unit due to the fact that hte turbo exhaust manifold passes over it instead of under like the n/a manifold.

 

i say that you should try for it, its fun and a great learning experiance and you get to know your car even more, you get closer to it.

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  • 1 month later...

Speaking of bumping it up...

 

I have a aspirated 1.8 loyale (9.5:1 comp, or even a bit higher according to haynes book) My Q is about turbo heads, intake setup on high comp without turbo. I cannot find chamber sizes for heads, exact info on pistons,

deck height at tdc, to feed an algorithm to help me figure that out.I want to open this EA82 up!:)

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Speaking of bumping it up...

 

I have a aspirated 1.8 loyale (9.5:1 comp, or even a bit higher according to haynes book) My Q is about turbo heads, intake setup on high comp without turbo. I cannot find chamber sizes for heads, exact info on pistons,

deck height at tdc, to feed an algorithm to help me figure that out.I want to open this EA82 up!:)

Combustion chambers are essentially the same for all of the EA82s. C/R variances are due to piston shape. Turbo heads are dual intake port, just like the N/A MPFI heads. The reason they are dual intake has to do with what happens with siamesed intake ports when you only squirt fuel into them simultaneously once every crank revolution. The turbo heads have existing bosses drilled to accept oil supply and drainback lines for the turbo, as well as the coolant supply line for the turbo.

 

The turbo block has an additional PCV line connected to an oil separator chamber on the engine bellhousing.

 

The exhaust system sweeps from the driver's side forward next to the oil filter, then back across the passenger side exhaust port and then up between the engine and the front crossmember; the turbo crossmember is notched to allow this pipe to pass, and this is the crossmember difference.

 

The Turbo and MPFI wiring is similar to each other, if not the same (I haven't looked yet). But the wiring is different from carb SPFI, as are the ECUs. The fuel pump is similar/same between turbo/MPFI and SPFI, but carb uses a different pump and fuel line configuration.

 

TurboSPFI, did you do a blowthrough on yours? If so, that woudl be interesting on several levels... And I am interested in a high-comp conversion of one of my turbos, and see little reason to run more than 5-8psi, mostly at higher rpm.

 

Regarding JDMs, the ones we get here could pretty much just drop in if it weren't for the common practice of cutting off the wiring harness connectors. I have yet to see anything on the wrong side, but that might depend on source. I have been very happy with my several used JDM experiences.

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since you all are on the topic, i was wonder if i could do the oppisite. put a carbed+exhaust in a turbo car. since i blew the head gaskets on the wagon and i want carbed wagon so i can put a lift on so its easyer to fix on the trail and a lot less stuff that can go wrong. like cold water on a really hot turbo. but i don't really want to swap wiring harness.

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yeah it may run at 8 psi, but bump it up to 10 psi. I guarentee you are going to start blowing hg's. And if it wasn't a problem, why did they make turbo motors lower compression? wouldnt it have been easier for subaru to just make all 9.5 comp motors and just use different heads?

I dont know if you noticed, but stock turbo cars are not really that fast. Subaru really didn't turbo these things for the POWA!!, they did it for fuel milage. The reason that they dropped the compression was so that one could run regular grade fuel in it to conserve. My buddy with fairly light foot in his turbo xt usually gets about 32MPG...... My point is that they made them high compression turbos... one would HAVE to use high grade fuel.

 

since you all are on the topic, i was wonder if i could do the oppisite. put a carbed+exhaust in a turbo car. since i blew the head gaskets on the wagon and i want carbed wagon so i can put a lift on so its easyer to fix on the trail and a lot less stuff that can go wrong. like cold water on a really hot turbo. but i don't really want to swap wiring harness.

Carb? Wiring harness? If you get the right carb you can throw all that wiring harness junk out the window. My 87 doesnt need no fancy wiring harness, but some of the older feedback carbs do since they have a really simple computer.... Get the 87 carb... hell my car doesn't even have an O2 sensor!:drunk:

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