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hello, i want to know how much psi of boost the ludespeed kits can handle and what other kits are there that are capable of running over 15 psi of boost. I know would will have to get new lower compression pistons, new rods ect. Thanks
 

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1. now we're talking!
2. i wish! i have rods, 8.5 to 1 pistons etc but that's where i start calling it "big" boost. some day.
3. transmission. a big trans mod will be necessary
 

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5252 said:
1. now we're talking!
2. i wish! i have rods, 8.5 to 1 pistons etc but that's where i start calling it "big" boost. some day.
3. transmission. a big trans mod will be necessary
???:confused: :confused:
 

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did anyone here do an engine build up where they can handle that much boost? I am really serious about this cuz thats what i am thinking of doing. Im looking for engine builders like cobb but there are lots of $$$. Parts like rods,pistions ect. What kind of set up can i run. thanks
 

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What's your goal for the engine/car? 1/4 mile times? Drivable in city with torque... there are a few factors to consider before just getting boost.

And yes, you'll need a much beefier transmission. The standard Subaru trannys fall apart with only a few pounds of boost over 10psi.
 

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RS25.com said:
What's your goal for the engine/car? 1/4 mile times? Drivable in city with torque... there are a few factors to consider before just getting boost.

And yes, you'll need a much beefier transmission. The standard Subaru trannys fall apart with only a few pounds of boost over 10psi.
i want a street car that can haul ass. Both 1/4 and track use. Thanks
 

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5252 said:
1. now we're talking!
2. i wish! i have rods, 8.5 to 1 pistons etc but that's where i start calling it "big" boost. some day.
3. transmission. a big trans mod will be necessary
Like he said, nevermind the strength of the factory pistons: you'll definately need a lower compression ratio than the stock (almost) 10:1! Approximately 8.5:1 is suppossed to be the ideal CR ratio for a super charged application (yes, a turbo is a form of supercharger).
 

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There are a few. Hayscoob runs 15 I think, and kastle has run up to 20 psi I think. You should contact them or wait for a reply.



Graham
 

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there's like maybe three cars in the usa running that much boost on the street. that is alot of boost. the first thing you are going to need is a transmission. your stock transmission is useless at those boost levels. even if your clutch could hook up. i have a built engine( rods pistons decked block extreme attention payed to the sealing abilities of the headgaskets. etc. i also have a transmission that has gears overtwice as wide as stock. i am at 12 lbs of boost and it is stellar. i want to go big boost (16lbs plus) but i would have to rethink my blower. into a t34 ceramic...... sorry about the short answer earlier. read t-rex-450's combo;
Engine:
Block: EJ25 Block Mahle Sleeved/ Bored to 100mm w/ Welded semi closed deck, Magged & Deburred
Crank: Magged, Nitrited & Micropolished
Rods: Custom Crower
Pistons: Custom Ceramic-coated Mahle
Rings: Total Seal w/ Ceramic-coated Top Comp
Bearings: Clevite Ceramic-coated
Heads: EJ25 SOHC (Phase II) Ported, Polished, Flowed & Port Matched
Valves: Custom Ferrera Valves, Springs & Retainers
Cams: Cobb Tuning Stage III
Intake: EJ25 Extrude Honed, Matched, & Reversed
Throttle Body: Bored & Polished
Fuel: 850cc injectors
STi Fuel Pump
Exhaust: MRT Manifold w/ Custom Turbo Adapter Jet Hot Coating
MRT Custom 3�EStainless Pipe and Muffler
Turbo: Garrett TO4E (to 600HP)
MRT Giant Front Mount Intercooler
Go Fast Bits Blow Off & Wastegate
Nitrous: NOS 20HP shot kit
Management: Motec

Drivetrain:
Clutch: Exedy Hyper Twin Plate
Transmission: MRT Full Dog (500HP)
Differentials: F: Cusco MZ w/ 3.90 Ring Gear
C: Cusco Tarmac 35/65
R: R180 w/ Cusco MZ
Mounts: STi Engine and Trans
Shifter: STi w/ Cusco Bushings
Axles: STi
those are big injectors. how much is your budget?
 

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Discussion Starter #13
kastle said:
I run 14.5 psi on my RS-T, on a normal basis (daily driver). I have run 20+ psi though my engine (built bottom end) without problems.

whats your set-up
 

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There are a few. Hayscoob runs 15 I think, and kastle has run up to 20 psi I think. You should contact them or wait for a reply.
Well, actually, I am at 14 psi at initial onset and settles to 12 psi. This is also NOT how I drive my car however. I have yet to floor my car. I am too paranoid on breaking again. On the dyno, I didn't push it. Shiv did. Plus it is a controlled situation. On the street I am running up to 12 psi (looking at the gauge alot) Not WOT. It will go to 14 psi if I floor it. When I have a heat soaked TMIC, I ping a bit so I am careful to to push it too hard. I need to fine tune the TEC a little more. I have yet to have the EBC hooked up to the TEC. At the moment, I am using a MBC that Shiv hooked me up with. As for injector duty cycle... 72% at 14 PSI and I could easly go up higher in boost. With my built up block and such I really need to beef up my top end now. The engine needs to breath better to take advantage of those high booost levels. So, if you are thinking of going to 15 PSI and up, I'd get a good head builder to make the heads breath better. As for my tranny?... I am xing my fingers. Shiv stopped at 14 PSI because of my tranny. I will leave it at that.

Paul...
 

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I don't think I can understand your worry Paul. But then again, I have yet to blow a motor.

Just give it some time and you'll be back into the throttle like a mad man. I'm with you, as far as always looking at my boost gauge. I think I would be more paranoid if I had a MBC as well. Your using the Dawes Device unit, correct? I think that unit is worth trusting, but you never know.

Your getting pinging with heat soak?? Shiv must have tuned your car pretty liberal my friend, interesting.

I imagine that it would be in your best interest to get that EBC hooked up, then you can regain your confidence in what is argualbly already a bulletproof setup. Also, doesn't the TEC have a built in MAP ceiling you can set, where if it hits a certain kPa it will induce fuel cut? The Link 2 has this, to prevent overboosting and det.


Graham
 

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8000 bucks is the reason for my paranoia. As for the MBC thing... I would rather have the EBC hooked up, but my mechanic has yet to do it.

Shiv did indeed put a fuel cut at 14.5 psi in the TEC 3 program. So I have a safty measure in place. I am just not finacially recovered enough to feel comfortable about mashing down on the throttle yet. It still hauls ass though even without going WOT.

I will make plans soon to have the EBC hookup up and take the car back to Shiv and shell out more money for more tuning. I want the engine to be stable at 0 boost to max boost with no worrries at all.

I need head work and transmissoin replacement. So that's next on the roster. Transmission will be the next priority.
 

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I see your worry, now.

With aftermarket engine buildups, and especially Subaru's, its one thing after the next. You probably thought after the engine build you would be done with the car (well maybe the tranny). But, little do we know that the road to fast Subaru's, sorry to say, never ends.

Thats a great thought on having the car be able to run well at a wide variety of boost levels.


Graham
 

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Discussion Starter #18
Graham said:
I see your worry, now.

With aftermarket engine buildups, and especially Subaru's, its one thing after the next. You probably thought after the engine build you would be done with the car (well maybe the tranny). But, little do we know that the road to fast Subaru's, sorry to say, never ends.

Thats a great thought on having the car be able to run well at a wide variety of boost levels.


Graham

can you give me some examples of like that goes wrong on a weekly basis ect.?? thanks
 

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Well I'm not the one with the built engine, hayscoob is. Are you just curious what goes wrong with any Turbo RS, though?

If you are, then I would have to say, very little. This is my experience at least. The only problems I have really had are one of my gauges going out and some blowby from the turbo (this is when oil gets sucked into the intake from the valve cover). This is for the last nine months I have been driving my car, turbocharged.


Graham
 
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