We all know the white GC8 that JUN created. We all thought it was the ultimate EJ25.
Well, they are producing another Impreza powered by EJ25 turbo. This time it's GDB body and it's colored in their color, Hyper Lemon.

Mr. Koyama of JUN couldn't achieve his vision in the previous Impreza project, the white GC8, because it was a customer's car. This new GDB is JUN's car and Mr. Koyama created what he thinks the ultimate Impreza.

The engine spec of HyperLemon GDB is as follows
EJ25 export model (could be USDM)
C/R 8.1:1
BorexStroke 100mmx79mm
gasket 0.7mm
custom made parts by JUN
<piston/con-rod/crank/cam shaft (IN&EX 272degree, 1.3mm lift)/valve spring/and retainer>
turbine TD06SH-25G
boost 1.65 kg/cm2
max boost over 1.7 kg/cm2
600ps/7600rpm
torque 69.0 kg-m / 5100rpm

Ribs are added to the block for more strength and most of the internals are custom made in JUN.

Spec sheet is not the only part that this EJ25 impress us. The design of the intake is very unique. Hyper Lemon GDB has the huge turbo on top of transmission where we usually see intercooler. From there, intake pipe runs straight directly above the engine to the the top center of the front mounted intercooler. The intercooler has two cores in one and the compressed air will be cooled down through this massive intercooler before it comes out from the ends of the IC. This EJ25T has individual intake chamber on each bank, intake air will be provided from these two chambers through custom made Individual Throttle Body. For cooling purpose, IC is mounted behind the radiator slightly angled. This car is road race time trial car so the engine has to last 10 - 20 laps before overheat.

One of the weakness of Subaru is transmission. JUN is testing durability of the stock 6speed with this car and they report no problems at 500ps level.

I'll post pictures of this monster next month after I see it in person at Tokyo Auto Salon.

All the information in this post is from Option Magazine February 2003 issue. It has green S2000 on the cover. For more info buy the Option magazine. and the pic is page106-107 of the Option magazine that I took with digital camera.

Is this a nuclear reactor??? ;)

Wow that's the tightest thing i've ever seen.

Its almost odd they didn't relocate the alternator.

I guess i should go buy some magazines.

Hey I mentioned that project car a few weeks ago but had no access to a scanner at the time. The intake manifold is that way because they went with a four throttle body setup and had clearance issues with the intake manifold then being too tall. Eventually some of that should trickle down to the regular parts buyers.

kind of off topic, but relates to turbo EJ25 and Jun... wasn't their news on them making a turbo kit, or is it in production already?

those two videos are sooo tight. i can't imagine what it would be like to drive either one of those cars! i probably be able to control them in 3rd gear!

-PJ

They even moved the oil cap.:)

Hey! Where are the throttle bodies? I thought that they said there were two of them. Are there really four of them right where the TGVs used to reside? Are those barrel valves?

114.3mm bolt circle? How'd they do that?

From what I remember the orignal design was to have four 53mm throttle bodies to the setup. I'll finally be done moving on the 15th and I'll post up a scanned in pic of the throttle bodies they made.

yep it has individual throttle bodies.

The PCD is 114.3. If you look at the pics, the front and rear offset is different significantly.
I think they wanted wider track in the front and to do so they put wheels with more offset in the front.
I think what happened is, they couldn't find different offset wheel in PCD100 so they changed the PCD to 114.3 for more wheel selection.

How is that done? Do they just machine 5 holes next to the original 5 holes for the studs, and then press new studs in the new holes?

That might be the hot setup for the autocrossers. They might have a better selection of wheels to choose from. Better studs might also be available in the M12x1.5 vs. M12x1.25 size. I guess you could jump to M14 while your at it.:) Bring on the Porsche wheels!

Since they custom built the rest of the motor they likely just had a hob custom bult as well. Its not like in the Nissan world where you can just use the Attain front hubs to convert the holes and the pattern.

HOT DAMN! that car is soooo sick! Im gonna throw up!!!

If the Jun car can use ITBs, why can't the next STi use drive-by-wire ITBs? The TGV's need only be converted to drive-by-wire controllers and full plates screwed into place.

anyone else notice that it is a DOHC?

In the orignal Options Mag it says they had it shipped to Japan from the US so its likely they used the MY98's DOHC motor.

ok, that helps. i was wondering where else they would have gotten an EJ25 that was DOHC.

I just noticed that they also moved the power steering fluid bottle. I'd like to see a better picture of this engine bay if possible.

Originally posted by DJ 9iron
ok, that helps. i was wondering where else they would have gotten an EJ25 that was DOHC.
all the JDM EJ25 is DOHC. I think SOHC EJ25 only exists in US.
I wonder why they chose export model EJ25..?

I'd assume they used the best heads and best block they could use. That would mean using modified JDM STi heads and an EJ25 block that has been filled to have a closed deck. Maybe they had a shop in SoCal do the block. I'd imagine that few places in Japan do that kind of work, while US shops have a high volume/ low price advantage.

That's my speculation.

If JUNs doing a project it usually involves alot of custom done work at some of the top end machine shops in Tokyo. There are plenty of them around that area who could do the work. They did after all make their own four throttle body setup.

I thought JUN made everything in house? Oh, and the post about why they would use an exported ej25? They are abundant here in america..........liek the ej20 is there.

-scu

yeah JUN makes pretty much everything there. They are machine shop. They can make cams and such too. I heard piston were made by cosworth but not sure about this.

Yeah the pistons are made by Cosworth. Just flip them over, it's cast into the piston.

Jun is actually THREE divisions. Jun Machine Shop, Jun Auto Works, and Jun Body Shop. Of course these three are under another parent company.

-scu

wait. so the new usdm is DOHC right? and it has independent throttle body? or is that just the souped up jun WRX..?

No the discussion was about a one off production done by JUN. It in no way reflects an actual production car.

i c thanks.. but does the new sti have independant throttle body??

no