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Old 11-11-2003, 05:54 PM   #1
BBrown
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Question How to improve the XT

I am a very recent proud owner of a Forester XT (Auto), and am looking at affordable ways of slightly improving the car's performance. This is really just a whim, since the stock performance is already pretty impressive to start with: with a little brake torquing I consistently get 6.1+/-0.2 for 0-60, and the 1/4 mile is always in the low-to-mid 14s. I want to keep the car as close to stock as possible, changing possibly only a few cables, etc. I am not interested in extensive/expensive mods that might void the warranty and/or change the look of the car. With this proviso, I have the following questions:

1. What is the best oil to use, to maximize performance and engine conditioning?

2. Does changing the alternator cables from stock to upgraded ones result in any noticeable difference in performance?

3. Anything else you experts know about, that can be done for no more than $300?

Thanks in advance for your help.
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Old 11-11-2003, 06:04 PM   #2
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Changing cables isnt going to do squat. The best thing you can do for under $300 is a downpipe, it wont change the look of your car at all and most dealers are cool with them.
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Old 11-11-2003, 06:07 PM   #3
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Thanks, Afpdl. Is there any downpipe you'd recommend? And what about the oil?
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Old 11-11-2003, 06:21 PM   #4
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A VF39 off of a STi will make a insane difference in performance. As will a STi intercooler, but I do not know if they fit. Even if they do you will need a custom IC to hoodscoop skirt.
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Old 11-11-2003, 06:29 PM   #5
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Thanks, XT6Wagon. Other than the potential fitting problem, I am not sure if the mods you suggest (even if they are within the $300 ballpark, which is highly unlikely) will void the warranty....

Thanks anyway. All and any info you guys provide is good education anyway, since I know nothing about aftermarket mods.
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Old 11-11-2003, 06:49 PM   #6
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Well the VF39 isn't in the $400 range yet, but should be a 0 warrenty issue if run on stock boost since.

A. is sold on a Subaru as a std item

B. Said subaru has the same exact engine.

C. they wouldn't be able to tell the difference unless the tech is a ultra ninja at that kind of thing.
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Old 11-11-2003, 07:00 PM   #7
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You made a strong case, XT6Wagon! I'll try to find the best price for it, and learn more about it before I make a decision.
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Old 11-11-2003, 08:05 PM   #8
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Quote:
Originally posted by XT6Wagon
Well the VF39 isn't in the $400 range yet, but should be a 0 warrenty issue ...
Guess again. SOA will assert that you've "re-engineered" the Forester powertrain. You should expect huge a "warranty issue" if you encounter problems that can possibly be blamed on the increased/excessive torque produced by such mods.

Last edited by Jon [in CT]; 11-11-2003 at 08:17 PM.
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Old 11-11-2003, 10:12 PM   #9
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I've had techs look right at my WRX with a VF-34 on it and not take a second look at the turbo... even with a FMIC and no heatshields to hide it. Trust me if the head tech of a dealership can't tell the difference between a STi and a WRX engine undertray.... there is very lvery little chance they could tell a VF38 from a mitsu 13b or whatever the stocker is.
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Old 11-11-2003, 10:24 PM   #10
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There not going to notice it when you go in for an oil change or somthing but if you blow something in the engine they will figure out pretty fast that its not a stock turbo.
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Old 11-11-2003, 10:58 PM   #11
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While I agree that most Subaru techs won't catch the difference in turbos, Jon is right.

If something major does happen you better bet that they will take a long hard look at your engine bay before they authorize a hefty repair like an engine replacement.
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Old 11-12-2003, 01:51 PM   #12
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OK, fellas... it seems that adding on a VF39 (or similar non XT stocker) might lead to warranty issues in the event something does happen to the engine or any other part whose problem might possibly be connected with the non-stocker turbo. I'll leave my XT as is for now. I still have a couple of minor questions:

1. What is the best (presumably synthetic) oil to use to maximize engine performance? Any suggestions?

2. Has anyone tried any of the Racing Fuels from 76? They offer four different blends, rated at 100, 110, 114, and 118 octane, respectively. Any recommendations, warnings, etc?
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Old 11-12-2003, 05:45 PM   #13
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Don't use any of the fuels that are leaded. The tetramethyl lead will clog your cat and more than likely foul your 02 sensors. Frankly, unless you have the boost turned up, or are running a program that requires race fuel, you probably will see little to no gain and all that extra $ will just be going out the tail pipe.
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Old 11-12-2003, 06:17 PM   #14
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Thanks A418t81. My engine and pretty much everything else is stock, and I think it's tuned just to 91. I know that a *little* extra octane - as long as it's unleaded - will not cause any harm, and will give a small performance increase. I agree entirely with not using leaded juice, but am still wondering if 100 unleaded (the mildest of the race fuel bunch) would lead to any noticeable improvement without damaging anything...
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Old 11-12-2003, 06:47 PM   #15
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If the xt ecu reacts the same as the stis ecu then you should get a noticable gain when using higher octane unleaded. The sti ecu will take advantage of higher octane thats why they ping sometimes the ecu is just seeing how far it can go on whatever octane you put in.
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Old 11-12-2003, 07:21 PM   #16
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Thanks Afpdl. It seems that I'll be giving the 100 unleaded a try one of these days... I'll make sure to report on any measurable performance improvements.
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Old 11-13-2003, 10:04 AM   #17
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IMHO, go with a handling mod first. If you looking for something inexpensive and less likely to cause warranty issues, get a bigger swaybar.

For oil, I would recommend Mobil1. It's an easily accessible Group 4 oil (out of 5). You can see some used oil analysis' at bobistheoilguy.com forums

Also, check out the Forester Forum if you haven't already.

-Dennis
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Old 11-13-2003, 05:28 PM   #18
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Thanks for the tips, Bluesubie. I did check the Forester Forum, but it seems to be much less active (and inherently with less technical/useful info) than the Factory 2.5L Turbo. I'll keep checking both in the future.

Just a last question concerning the Mobil 1 - what grade? I presume 10W-30 would be viscous enough for a typically hot climate and many short drives, which is my case here in Los Angeles. Any words of wisdom?
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Old 12-16-2003, 08:47 PM   #19
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is short shifter available for the new XT?
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Old 12-17-2003, 01:06 AM   #20
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Kart boy makes a short shifter! And Mobile 1 is the only way to go. As far as mods go on my xt I'm going w/ bolt ons. Avoid the dealer unless something serious comes up including oil changes wich are overpriced anywayz. Now what I'm running so far is a Perrin MBC(manual boost controller$90),a Perrin short ram intake$170), and a Forge BOV(blow off valve$180) that is actually made for the forester XT. This can all be easily removed even by the blind in an hour -2hrs maximum w/ bad weather and a hang-over. Future plans are catback exhaust(wich will not void the warrenty, I asked the local service rep), down pipe(maybe void but is bolt on), Brake upgrade (who wants stock brakes anyway?)
The ever so controversial ground wires $100,etc.etc. Hopefully this helps w/your descision.(sorry for the Novel)
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Old 12-17-2003, 11:25 AM   #21
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A really simple and cheap mod is to use a drop-in panel filter like the KN. I like it alot on my STi and it doesn't freak out your ECU like a short ram...advanced ignition timing is good for power-making. I know it's only gonna add like 5-7 whp or so which honestly isn't on the butt-dyno lvl, but you do get to hear alot more out of the turbo (why have one otherwise?) and BOV. Not to mention no warranty issues at all.
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Old 12-17-2003, 03:41 PM   #22
BBrown
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Thanks, guys. I'll keep learning about warranty- and wallet-friendly mods, and might make some in the not-too-distant future. I am an absolute novice in the aftermarket mod scene, and need to learn a *lot* more before I can make an informed decision.

One of the things I am seriously considering is the 20mm STi rear swaybar, which can actually be installed at my dealership without any warranty issues whatsoever. People that have installed 18mm or 20mm swaybars in the XT seem to get considerable handling improvements. This is a cheap "mod" (about $100, as I am told), and the gains are allegedly very noticeable.

Another thing I will probably do, is change the tires/wheels, once the stock Geolanders give up.
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Old 12-17-2003, 03:54 PM   #23
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Can't wait till the hollidays are over, she should be rollin' 18's. They seem to look best on Foresters w/out too much loss in performance.
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Old 12-17-2003, 05:26 PM   #24
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The 2.0 forum has a lot of oil threads. The hardcore guys run Amsoil because thats what SWRT run, but its not as cheap or easy to find like Mobil1. Either way, oil brand is not going to make a difference. Frequent oil changes, using a magnetic band on the oil filter, allowing proper warm ups and cool downs will.

If you are interested in a $400 dollar or less mod for HP, an uppipe and downpipe is a good combination. You can "gut" the downpipe (drilling out the catalytic converter instead of buying a new one without a cat), but you're best bet is to buy a new one and new gaskets to avoid fit issues and that nasty carcinogen effect.


Full_Clip uses Crisco and some hamsters for more HP in his Honduh.
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Old 12-17-2003, 05:59 PM   #25
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VSB - any pics?
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