Evo X vs. Evo VIII and IX
Feb 12, 2008, 07:20 PM
#466
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i'd rather keep my VIII over the X because:
(i posted this in the evo x general section in "Evo X motor " thread)
(i posted this in the evo x general section in "Evo X motor " thread)
ok, i know i got this info from a subaru site but this write-up also applies to the 4G63T & 4B11T (& any car in general) in this situation concerning their closed & semi closed decks.
also this is the reason why i prefer the 4G63T over the 4B11T.
http://spda-online.ca/modules/newbb/...d=3116&forum=9
also this is the reason why i prefer the 4G63T over the 4B11T.
http://spda-online.ca/modules/newbb/...d=3116&forum=9
The deck is the surface where the head is bolted too.
The open deck design is for ease of manufacturing and not good for high cylinder pressures. This cylinder wall design is supported in 2 places. Many people will say that these engines cannot be turboed effectively but that is not the case. There are a couple here in the club that have run low to medium boost without issue. The problem is where the top of the cylinder where it meets the head will distort from high cylinder pressure and damage the head gaskets ability to seal in the combustion gases.
*A semi closed deck design is a little harder to manufacture, but supports the cylinder at the top, bottom and sides. (four places). This is stronger then the open deck design and therefore can take higher cylinder pressures.
*The fully closed deck design uses a different casting process that takes longer to manufacture and weighs more. These blocks have the most support to the cylinders, which will enable you to run the highest cylinder pressure of the available choices.
Subaru introduced the closed deck block for homologation reasons to be able to run it in their rally cars. This engine was made famous when a very similar version to it was installed in the limited edition 22B. With the casting methods and alloys available at the time Subaru chose this route to ensure a strong motor. With todays “modern” casting methods and alloys even the semi closed deck designed motors are very strong.
As a guide I would say the following;
Open deck blocks will work for all NA or low to medium boost applications.
Semi closed deck blocks are better suited for boost applications that are not extremely high or prolonged.
Closed deck block are best suited for applications where there will be very high boost for extended periods of time.
The open deck design is for ease of manufacturing and not good for high cylinder pressures. This cylinder wall design is supported in 2 places. Many people will say that these engines cannot be turboed effectively but that is not the case. There are a couple here in the club that have run low to medium boost without issue. The problem is where the top of the cylinder where it meets the head will distort from high cylinder pressure and damage the head gaskets ability to seal in the combustion gases.
*A semi closed deck design is a little harder to manufacture, but supports the cylinder at the top, bottom and sides. (four places). This is stronger then the open deck design and therefore can take higher cylinder pressures.
*The fully closed deck design uses a different casting process that takes longer to manufacture and weighs more. These blocks have the most support to the cylinders, which will enable you to run the highest cylinder pressure of the available choices.
Subaru introduced the closed deck block for homologation reasons to be able to run it in their rally cars. This engine was made famous when a very similar version to it was installed in the limited edition 22B. With the casting methods and alloys available at the time Subaru chose this route to ensure a strong motor. With todays “modern” casting methods and alloys even the semi closed deck designed motors are very strong.
As a guide I would say the following;
Open deck blocks will work for all NA or low to medium boost applications.
Semi closed deck blocks are better suited for boost applications that are not extremely high or prolonged.
Closed deck block are best suited for applications where there will be very high boost for extended periods of time.
4B11T (semi closed)
4G63T (closed)
l8r)
4G63T (closed)
l8r)
Last edited by pekpekbuster; Feb 12, 2008 at 07:34 PM.
Feb 13, 2008, 06:22 AM
#467
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So I talked to the product specialist at Mitsu the other day and asked them how to pull a nice 1/4 in a X MR. He gave me a very detailed blah blah about how the MR had the twin clutch yada yada like a ferrai and that it had a start off assist. I asked him how you preload a turbo with boost without a clutch and he said "uh... get a 5 speed evo". I'm pretty sure what he told me was that the value of my 06 MR just went up a little 
They are just people with a list of technical info and have never driven one so I'll kinda log that in the iffy file of my brain but I'm thinking the MR was designed for yuppies that don't know how to drive. Also It may be the answer to the weak stock evo clutches and people complaining about them. Rather than fix the problem they came up with a new one.
They are just people with a list of technical info and have never driven one so I'll kinda log that in the iffy file of my brain but I'm thinking the MR was designed for yuppies that don't know how to drive. Also It may be the answer to the weak stock evo clutches and people complaining about them. Rather than fix the problem they came up with a new one.
Feb 13, 2008, 08:16 AM
#469
Evolving Member
same what i think...i like the X but i wouldnt go for a change with my IX or even buy it...but you never know,,,maybe later....VII,VIII,XI, that and evo ...
Feb 13, 2008, 10:21 AM
#472
The flaw in your logic thought is that everyone buying an Evo X wants to drag race it. Thats not the reality at all though. The Evo VIII and IX got a "drag car" reputation, but it was given to it by the boards, not the world. The reality is this car is way more refined then a standard drag car. This is a drivers car now.
Feb 13, 2008, 10:43 AM
#473
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Being a noob i feel as give the new Evo X time....its only a matter of time till it proves itself as the new leader then its older brothers....but i read this on a other forum and wanted to ask "robi" does your "AYC" system react funny to brake mods? i could of sworn that the USDM IX came with "AYC" system....if the Evo X came with a lighter block and beefier internals then i would assume the output would be better and that Mivec is on the intake and exhaust side too....i guess well see...
Feb 13, 2008, 10:50 AM
#474
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Being a noob i feel as give the new Evo X time....its only a matter of time till it proves itself as the new leader then its older brothers....but i read this on a other forum and wanted to ask "robi" does your "AYC" system react funny to brake mods? i could of sworn that the USDM IX came with "AYC" system....if the Evo X came with a lighter block and beefier internals then i would assume the output would be better and that Mivec is on the intake and exhaust side too....i guess well see...
The Evo X engine is proving to be very friendly to initial mods. Ultimate capabilities are still a long way from being determined. From the factory, the X makes very close to the same amount of power as the IX, unfortunately the extra weight is 'dragging' down the acceleration numbers.
l8r)
Feb 13, 2008, 01:58 PM
#475
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No, USDM IX came with ACD, the X comes with SAWC, of which SAYC and ACD are components, among other things.
The Evo X engine is proving to be very friendly to initial mods. Ultimate capabilities are still a long way from being determined. From the factory, the X makes very close to the same amount of power as the IX, unfortunately the extra weight is 'dragging' down the acceleration numbers.
l8r)
The Evo X engine is proving to be very friendly to initial mods. Ultimate capabilities are still a long way from being determined. From the factory, the X makes very close to the same amount of power as the IX, unfortunately the extra weight is 'dragging' down the acceleration numbers.
l8r)
i dont care about little things...all i care is that the new Evo out performs the older brothers...if it doesnt then i wanna know why....you guys get me
Feb 13, 2008, 02:05 PM
#476
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^ I can address all of your concerns in a simple comment: go and test drive both an Evo IX and an Evo X. Then buy whichever one you like better. 
l8r)
l8r)
Feb 14, 2008, 07:11 AM
#479
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