STi Conversion Questions

[jpfillion]

This is my first post, so I hope I've hit the appropriate site and area. Sorry for the length but I wanted to make sure I painted a full picture

I'm looking to perform an engine swap / conversion and have some choices to make.

My current vehicle:
* 2001 Subaru Legacy GT Limited
* 4 speed auto
* 16" alloy rims

The option I was provided by Planet Motorsport in Guelph, ON
* 98 WRX STi 2.0L JDM Engine @ 285 hp - "low mileage"
* Intake, engine, exhaust, drivetrain, DCCD, brembo brakes
* 5 or 6 Speed manual swap

Reason:
* Headgasket failure in 2001 N/A engine - 200,000+ km

Goal:
* $12,000 - $15,000 price range
* Daily Driver, including winter
* Somewhat of a sleeper, it should be all go not so much show
* Med-Quiet on the highway, don't care if it's a little loud when I step on it though

I'm going to be hard on this car, plain and simple. On my way to work daily there are some gravel roads that I take (shorter distance, fewer cars, more fun). I live in an area where there can be lots of snow.

5 vs 6 speed:
* From what I've heard, I should avoid 5 speed and go with 6 speed as it will die the way I will use it. Research has lead me to believe this will be the first thing to go even with all other stock WRX parts (including clutch). I'm prepared to spend more if this is a sure-fire breaking point.

Engine:
* Are there any concerns with 98 2.0L STi JDM Engines? I have been searching for awhile and not found anything concrete one way or the other for this specific engine. I'm most concerned if it is one with a known head gasket issue (98' DOHC appears to be the affected). I've heard the 2.0 L blocks are bullet proof.

* Can the Engine be mapped? I'm interested in launch control and stage upgrades via mapping changes. I've seen on Cobb tuning launch control is available for 2.5 L (CobbTuning.com - 06/26/07 - Launch Control (Subaru 2.5L)). They also only seem to have WRX 2002+.

* I have heard that light-weight (not under driven) pulley's make it harder to drive in the snow. I was hoping to use Group A light-weight pullys to increase low end torque (Group A Subaru Performance Products - Pulleys). Does it really cause that much extra difficulty?

Other things I have considered:
* Anti-sway bars - too stiff of ride when on gravel or rough roads?
* Cold Air / K&N intakes - will this kill low end torque, or be balanced by light-weight pullys?
* Will 16" rims fit brembo breaks or will I need to upsize to 18"?
* Is there a mechanism for the parking break to disengage rear wheel drive? I know WRC cars do this but can't find info for STi's
* Front mount vs top mount intercooler - major advantages / disadvantages?
* Skid Plates? - will this offer protection from gravel, or am I just being overly cautious?
* End links? Group A Subaru Performance Products - End Links
* Stroker kits? - this may become expensive

Anything I haven't considered? Any recommendations for changes to this plan?

All input is welcome, this site seems like it holds many knowledgeable members. I grew up loving to drive but never having influences on working on cars. I've only started to learn in the last few years on my own... and I know I've got a lot left to learn

Thanks for your input!

[thack03]

Millennium Auto -Specializing in Subaru WRX STI
they have a full 04-07 STi swap for 12k, everything you'd need and you could use cobb ap and their LC
to clear the brembos you would need at least 17s and you would have to check the offset on them to be sure they clear the brembos or any 18in rim would clear. Sways wouldnt be too stiff on those roads and
a skid plate would probably be a good idea if you frequent gravel roads.
for street STi's they have the dccd where you can push more power to the rear wheels but they are always awd, there isn't a unlocking mechanism
stroker kits would probably take you out of that price range, and you always want to have extra money for maintenance anyway
for the intercooler it depends on how much power you want and how big of a turbo you run. if you are staying with a stock sti block and turbo stay with a tmic

[Chase]

Wow, that's a great price. They do the dash and suspension too. Plus they do the work, I think that's the ticket. Is it worth the drive for you?

[jpfillion]

Thanks, that's really good info and inspires some more research to do on my part. I appreciate all of the info.

One thing I should have mentioned was that the car cannot drive very far without over heating, so it will have to be towed to location. Unfortunately this makes anything far very costly quick. Planet Motorsport in Guelph (30min away) will do all the work, unless I can find someone just as close for less $.

For the engine, intake, exhaust, brakes I was looking at was <7k for the parts in Canadian dollars, and the rest of the 12-15k budget would be spent on the 6 speed and any extras (such as 17/18" rims apparently - thanks for that too; skid plates, etc). I would like to spend the money smartly such that the drive-train / transmission could withhold potential future engine swaps (should I happen upon more money once this engine sees it's eventual death) - Dream is a Cosworth 2.65L; 3.6L H6 Turbo would be awesome, but I doubt very cost efficient since Perrin only appears to have made a 1 off (Perrin Performance H6Turbo (2006) - YouTube - perrin H6). I kinda like my dash the way it is too... maybe I'm weird that way lol.

Defiantly leaning towards the skid plates... just gotta get the cost for around here but I'm sure it wouldn't be a budget budget breaker.

If sways wouldn't make the ride too stiff then I'm sure my very aggressive cornering would welcome the addition - looking forward to this

My hope for the unlocking / clutching mechanism was for turns / maneuvers that require ebrake, but I'm sure I can do almost as well with getting used to the clutch if there isn't something readily available.

For power goals, I want as much power that I can reliably attain (not killing the motor or other parts) while maintaining daily driver and decent mid-range torque. So far it seems like 285hp is my starting goal (although I wouldn't complain about attaining 300+).

Some remaining Q's:
* Launch control / mapping - I'm assuming the 04-07 STi swap recommendation was because mapping isn't available for the 98' 2.0L JDM STi.
* Problems with 98 2.0 L JDM STi engine? Headers, etc?
* 5 vs 6 speed
* Light weight pullys?
* End Links

[RcrsWetDream]

I've noticed very little increase in NVH since I put Perrin 25mm front and 22mm rear sway bars on my 09 WRX. The only time I really notice any stiffness over stock is going over speedbumps, other than that it's pretty smooth. On the lateral though- whole new animal!! Example: My favorite freeway exit ramp merges into a 55mph road with no stops, so you can fly off the ramp and onto the road. Before the sways I had some pretty good understeer at about 50-55mph and would push through the corner a bit (no traffic don't worry). After the sways I can hold 70 with a bit of turn-in. Understeer was gone.

Almost forgot, get the end links while you're doing the sways. Saves basically doing the work twice if you decide to do them later- which you will because the stiffer sways will break your endlinks before long with some spirited driving. If you upgrade your bars and not the links, you're really hurting upgrade potential of the bars.

[thack03]

the 04 07 sti package was recommended because yes theres mapping as well as parts are easier to get ahold of and you get the extra .5L for more power, with that motor all you'd need is stage 2 for your power area and the 12k price tag includes the 6 speed and ever part needed for install, so on top of that it would be 1200 for sti bbs's with tires from same site, then take out around 600ish for sways and endlinks (make a huge difference when pushing the car/a must do for you)
-not sure about light weight pulleys because i dont have one, but for a dd I doubt it would do much for you
-I would go with the 6speed unless you really want a 5 and will pay for something like a PPGs for strength or weaker mfactorys but its personal choice of gear ratios and if you want the dccd
if you bought the package with 2.5 sti block and 6speed w/ brembos as well as the bbs's, sways, and stage 2 stuff it would be around your 15k budget but you would have everything you wanted.
Im also sure you could find better deals just saying

[turmic]

Originally Posted by jpfillion

Some remaining Q's:
* Launch control / mapping - I'm assuming the 04-07 STi swap recommendation was because mapping isn't available for the 98' 2.0L JDM STi.
* Problems with 98 2.0 L JDM STi engine? Headers, etc?
* 5 vs 6 speed
* Light weight pullys?
* End Links

Btw, you're looking at crank hp numbers. Not wheel.

Launch control will undoubtly break any trans if ran hard enough. (Some guy broke his GT-Rs trans after about 1200 trips down the dragstrip with the moddified version of LC that GT-Rs can use. Granted its not true launch control though. Haha, the end of the story is nissian denied his trans repair. Because it was logged in the HUD that he did that.)

We as a forum community don't have a great knowledge base on anything pre-02 wrx/sti. North American Subaru Impreza Owners Club will have a better JDM knowledge base. Unfortunately it can get pretty flamey over there.

6 speed is normally better. This holds true for USDMs, though PPG 5 speeds can probably be even stronger than 6 speeds.

Light weight pullys are not that bad. I wouldn't do it, but YMMV. Just avoid under drive pulleys, I think those are the ones that are bad.

Most people will say to do the endlinks while doing the sways. It completes the package and takes full advantages of the set-up. Just find the right parts. Not all endlinks and sways are created equal.

[jpfillion]

Thanks everyone for your feedback so far, it has given me lots to consider and research.

thack03 - The more I look at that 04-07 STI Complete Drive Train Kit the more I like it. Does $12,000 include only parts or install as well? It's about 270km from where I am, so a tow will be expensive but could be worth it. The only complication is cross border stuff which scares me - they could tax the entire $12,000 at whatever they felt like on the way back. If there is anything similar in Canada I would defiantly be very interested to hear about it. The alternative is that I could order the parts to Canada and have someone install them here (I do not have the tools, workshop, knowledge, etc to install this myself).

turmic - you raise a good point regarding crank vs wheel hp. Is the hp figure for a 2.5L STi Engine 300hp at the wheels or crank? How much should I expect in drive train losses (25%?)? Does anyone know if the 165 hp figure for the 2001 Subaru Legacy GT Limited is wheel or crank? This will help me make comparisons. I will also keep in mind launch control and breakage, and will check out NASIOC should I decide to go with the 2.0L JDM engine.

RcrsWetDream - thanks for your account of sway bars, I defiantly have some favourite highway ramps so this helps with the speed comparison. Also I will take the advise on end links.

In the debate of 5 vs 6 speed, assuming I went with the stronger PPG 5 speed, I am interested which would provide faster acceleration? I understand gear ratios theoretically allow faster acceleration and better gear selection with the 6 speed, but does the extra shifting decrease acceleration between 0-160km/hr? I feel the type of driving I do will usually accelerate hard from a roll which I believe is where I would benefit more from a 6 speed.

Thanks again for all of your thoughts.

[newtothegame]

Just about all base numbers you hear from a stock engine are measured/given from the crank. And 25% loss is being way to generous/nice for these cars. Its more close to the 30% or more range unfortunately.

[basco]

The PPG's would probably be quicker acceleration just because you don't have so many shits...I know in an STi you need to shift 2 times to get to 60...but in a five speed you only need to shift once...which is also why the 09 WRX can post similar acceleration times to the 09 STi with less power

[turmic]

Eh, its all in the driver. In the 5MT vs 6MT debate. Yes, a good run in a 5MT 09 wrx will be close to a bad run in 09 sti. But, compare good run to good run. The STI even with a extra shift will always be faster. Some to the power, but close ratio trans are made for acceleration. Otherwise a lotus elise and exige would be a slow pos with 180 hp. Granted that car is light as all heck too. But, the commentary from the reviews....they'll give the close ratio the nod as to why the thing accelerates so damn fast.

So, take it in as a grain of salt. The STI ratios are thought to be better for auto-x'n too. Because you want to get the quickest accel out of your gears. Maybe I stand alone on this debate. But, its my opinion.

[mosc]

In japan, the STi had a 5-speed for a very long time and it's similar in durability to the current 6-speed. The number of gears has nothing to do with their strength. It's just in the USDM world, we've really only had two transmissions in turbo impreza's: A weak 5-speed and a strong 6-speed.

The 98 STi you're getting your engine from probably came with a very nice 5-speed for example.

[jpfillion]

turmic - I think that I would agree with you on this. I know it's an "extra shift", but I'm not drag racing it, I'm driving it on a road. One of the things I disliked about my Subaru transmission was going around a corner quickly then trying to accelerate out of it in 2nd gear. In my Auto 4 speed 1st went to 50, then 2nd went to 100. Trying to accelerate hard from 40-50km/hr up was not very possible since it would not shift down to first. I know in a manual 5 speed I could shift down to first, but it just wouldn't be as smooth as a 6 speed in all conditions. I would defiantly appreciate the shorter 2nd gear for coming out of tight corners.

I'm still on the lookout for a package in Canada comparable to Millennium Auto's - 04-07 Subaru WRX STI $12,000 package.

[jpfillion]

mosc - Good point about the JDM 5 speeds, any insight on the 98' engine? I'm afraid it's old and hard / expensive to get parts for. Also worried it suffers from head gasket issues and trying to find a 2.5L 04-07 STi kit in Canada (around Toronto - Guelph - Orangeville - Waterloo - London area).

[turmic]

jpfillion: I was making USDM statements. Mosc wrapped up the JDM section pretty nicely. Either 5 MT or 6 MT in the 98 package will not make a difference. In the new package it will. Plus, "power is always a downshift away." Thats a shoaf quote. Basically meaning if your cornering and you have to downshift to 1st in the 5MT or 2nd in the 6MT. Either one shouldn't be that noticeable of a difference in power delivery once the power kicks in. Unless of course...your using the new stock trans and not the 98 stuff.