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Old 10-10-2012, 01:00 PM   #1
HoboBob
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Default I know its a bad idea

Now I know this is a bad idea, and I know why I just need to hear it from someone else. I have a VF40 sitting in my driveway in need of a rebuild. I need someone to talk me out of putting it on my car.

Now I know the N/A motors are only good for ~3 LBS of boost which is fine I just think it would be more fun to drive. Since I've already 'confused' my car so much (4/2 Pots, Slotted rotors, COBB AP, etc.) It's far from an ordinary Impreza since I was going for the unique approach.

Good or Bad idea to put it on the car for a light turbo build. It would be rather unique but what could go wrong...
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Old 10-10-2012, 01:09 PM   #2
ScubyPhilly
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I believe that there are quite a few out there running 6psi without issues. The Raptor Supercharger does 6psi and offers a 9psi pulley (suggests to have some work done on internals). The biggest part would be getting all of the additional components to run and manage the turbo...

Oh, and a tune...
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Old 10-10-2012, 01:25 PM   #3
07VTRex
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im pretty sure vf turbos can not be rebuilt.

converting your NA suby to a forced induction suby is a terrible idea. it is a **** ton of work, and a **** ton of money. you are 1000x better off just selling it and buying a wrx or sti and building from that platform.

putting that turbo on your na suby is only 1 out of like 100 parts your going to need

unless you know exactly what neeeds to be done to turn your impreza into a turbo impreza, and by exactly i mean every part, the work it entails, and where you will source all these parts, and a ballpark # of $ of what your doing, then no. this is possibly the worst thing you could do to your car.

If you knew what was involve, and had the tools and experience to do it, then you wouldnt have to ask. Just having you have to ask, makes me think you are so far in over your head all i can do is laugh

heres a rough list of parts that come to mind (be warned, there are a LOT, i am misssing)

new exhaust manifold
new up pipe
new downpipe
turbo
intercooler
all silicone couplers and t clamps
possible new intake manifold, depening if its shaped the same as the turbo
correct ECU an associated wiring
some sort of boost control
DBW or DBcable makes another huge hurdle jump over
new tune


this is a very short list, and i am sure there is a lot i am missing, not to mention the labor involved.

you cant just "throw a turbo on" and have it work.... theres a LOT more to it than that

Last edited by 07VTRex; 10-10-2012 at 01:30 PM.
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Old 10-10-2012, 03:20 PM   #4
chazly413
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too many friction losses

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^ Nailed it.
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Old 10-11-2012, 12:04 AM   #5
mod maniac
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I would do it and run it on wastegate pressure, 6-7 psi and there are ways to rebuild vf turbo's.
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Old 10-11-2012, 04:58 PM   #6
spyrule
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You'd also have to swap your n/a x-member to a turbo x-member (it has the U shape for the up-pipe).
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Old 10-11-2012, 05:07 PM   #7
cal_look_zero
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Alex, I'll take "Huge waste of money and resources" for $1000
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Old 10-11-2012, 10:38 PM   #8
dead
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Default

turbo- free
headers/uppipe/downpipe- 200
double port heads (2 one each one)- 100
a timing belt kit- 250 : (
oil pump- 100-150
tune(honestly i dont know, ) not including custom map and ecu- 0-500
find out how to lubricate turbo- gerr factor
headgaskets- 150?
breaking triple digits in wheel horse power- priceless
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Old 10-11-2012, 10:44 PM   #9
cal_look_zero
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Quote:
Originally Posted by dead View Post
turbo- free
headers/uppipe/downpipe- 200
double port heads (2 one each one)- 100
a timing belt kit- 250 : (
oil pump- 100-150
tune(honestly i dont know, ) not including custom map and ecu- 0-500
find out how to lubricate turbo- gerr factor
headgaskets- 150?
breaking triple digits in wheel horse power- priceless

Orrrrr, he could swap a WRX engine in for $1200 or so if he finds a good deal, and not hassle with an open deck platform that will top out below my NA engine, unless he wants to risk kaboom kaboom.
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Old 10-11-2012, 11:31 PM   #10
beaviscih
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I considered this several years ago but by the time I did the math, assuming similar mechanical effort needed to to a turbo engine swap, I went with the swap.

When I looked at the effort required and the fact I could easily double the boost with a full swap it was a no brainer.
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Old 10-12-2012, 12:15 PM   #11
Patrick Olsen
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Default

I'm not advising HoboBob to undertake this endeavor, but there's an awful lot of inaccurate information being thrown out here. Before there were WRXs aplenty, guys used to turbo 2.5RSs using bits and pieces from the old turbo Legacys, or imported WRX bits. It can and has been done. Is it economical nowadays, with the much greater availability of used WRX drivetrains? That I can't answer.

Quote:
Originally Posted by 07VTRex View Post
new exhaust manifold - Bazillions of used WRX manifolds available for next to nothing
new up pipe - Same
new downpipe - Same
turbo - Already has it
intercooler - Certainly a very good idea, but not required at the low boost numbers he's talking about. And again, plenty of cheap, used WRX bits out there.
all silicone couplers and t clamps - T-clamps not needed at low boost, and WRX take-off plumbing should be plentiful and cheap
possible new intake manifold, depening if its shaped the same as the turbo - Not even sure what the hell that's supposed to mean (intake manifold the same shape as the turbo? ). But no, he doesn't need a new intake manifold
Comments added above.

Quote:
Originally Posted by cal_look_zero View Post
Orrrrr, he could swap a WRX engine in for $1200 or so if he finds a good deal, and not hassle with an open deck platform that will top out below my NA engine, unless he wants to risk kaboom kaboom.
You do realize the EJ205 and EJ257 are open deck, right?

Last edited by Patrick Olsen; 10-12-2012 at 12:46 PM.
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Old 10-12-2012, 12:34 PM   #12
07VTRex
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Default

thanks for clearing up my sloppy explanation. i was in a rush and i knew my post was full of holes. When you disect it like that it does look rather ignorant, but i was just trying to shed light on how bad an idea it was.

My main point is that it is A LOT of work, and unless you are really experienced at building cars and doing this type of thing i wouldnt even consider it. Its more work than the avg person would think, more parts than you think you would need, and lots of little stuff that adds up. Then you have the whole reliability issue of a frankenstein build vs. just swapping an oem turbo block.

Serious question though: can the ecu even handle the turbo? or do you need a factory turbo ecu? that alone, combined with all the wiring would make me say hell no.

IF you can find used parts at a good price AND
IF you know exactly all the parts you need AND
IF you can do ALL the labor yourself AND
IF you are ready and able to fix anything and everything that may break along your build and
IF you are fully aware that this is going to be a lot of work and headache, THEN it CAN be done. But it wont be cheap, easy, or economically feasible compared to other options like a swap.

i apologize for my misinformation. I was just trying to tell OP that it was a BAD idea. I will try to give a more thoughtful and accurate answer next time.

Quote:
Originally Posted by HoboBob View Post
It would be rather unique but what could go wrong...
A LOT!!!

Last edited by 07VTRex; 10-12-2012 at 12:39 PM.
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Old 10-12-2012, 02:20 PM   #13
spyrule
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Default

I think 07VTRex is right... its not a matter of IF it can be done or if it's plausible. Everything is possible and has been done. However, it's just not financially worth it at all. I know someone locally who is going through this process right now, and has spent well over $7k and isn't even close to being done yet. Mind you, he pulled his v9 2.5i engine/transm. and put a v7 STI full block and 6spd STi transmission as well. I think by the time he's done, it will have cost him almost 8-9k worth (I'm not sure of the exact amount of cash though, mind you).
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