Turbo/Supercharging Your FRS
 

Tell us how you plan to or would like to do to the FRS when you decide to take the plunge and go boosted, whether it be turbocharger or supercharger, small single or moderately big single, custom tubular manifold or cast manifold, for track use or just a fun street car. Tell us, just for some fun.

If you are not here to post thoughts on a setup or comment about an idea, and are just trying to argue that this is dumb and there are other things that YOU think are more important, then GTFO, there are other threads for what your probably thinking and if there isn't, then start one, but please stay on topic

This thread is basically to hear the other side of the community, I think we've heard plenty from the ones that are satisfied with 200bhp in a 2600/2700 lb car

If TRD does end up releasing the supercharger, i will get it. That along with some nice exhaust and intake. I won't get to into the tuning of it, just simple power increase/bolt ons will be good enough for me. But first, some suspension goodies to help put the power to the ground

Basically, i'll be keeping it simple.. faster than stock, & turns even faster, but hopefully retains it's daily driver comfort.

my plans are to take my GTX3076R and some other parts like my tial MV-R, Q BoV, and my intercooler off scion tc and see if i can't build around those. assuming that it is a viable option and the the car doesnt blow like crazy when boosted. thats also one of the reasons i am going to wait a year or 2 before it comes out to get it. i would like to have a 500ish RWHP car but i could very well be dreaming and this car might not be able to make that kind of power without swapping the engine. and at that point i honestly don't know if i would be interested in it.

Greddy is still working on a FA20 turbo kit too so i would like to see what kind of power that puts down so i can see the ballpark we are working with for boost.

Ditto.

I like the idea of a supercharger or maybe a dual/twin setup to minimize lag. I have contemplated it many times for my miata. I don't want to have to worry about this car as it will be my DD so reliability is key. A low boost supercharger giving a similar power band to stock with just more push would be nice. Maybe getting it up to 250hp and 230ft/lbs. I will drive it stock for a long time though so this might be put on at around 60k when I would do an engine refresh and maybe swap out some internals.

I fully plan on learning by example and will let the big boys blow some engines up and take the path they have blazed.

NA Subaru engines have never liked boost. I'm not sure this one will be any different, but I know it will be way more complex. If I do get one of these this model year, it's not having any appreciable engine modifications until the warranty is up. Hopefully, by that time the aftermarket will have figured out what's going on or a factory turbo version will come out. Personally, I see those offset/asymmetrical con-rods being an issue unless this engine really sees some development from the aftermarket. I'm not sure how much of a tuner car this actually will be; I'm rather certain most of the tuner-friendly marketing is simply that: marketing.

In any case, for the average user, extensive engine modifications on a brand new ~$25K car are out of the question.

Unless you were going with a mid sized turbo towards the bigger end, a single turbo on it wouldn't have very much if any lag. I would think you'd have more lag on a twin setup being that only 2 cyclinders drive each turbo, unless they were pretty small like the 300zx turbos, those things look like they should be in a fish tank eating algae.

Judging by the amount of publicity this car has already gotten from diff informative sites/magazines and the fact that greddy has done one for formula D(yes I know it's not the same engine) I think that will help promote it in the aftermarket world and get some good parts/companies back it. Then again maybe not, who knows

I think If they are going to make a factory turbo version, it won't come out until 5 years later after the N/A release date.

I was thinking the same thing. Taking parts from my turbo scion tc and work around that or start from scratch. I wouldn't mind a supercharger also.

i'd only rock a S/C if it sounded like a kenne bell or whipple s/c i love that sound

Supercharger for simplicity. No exhaust work needed. No need for oil. Linear power band.

But going crazy is have the fun.... Lol

why do ppl think you can't get linear power out of a turbo? if it's properly sized you can get linear power. this is on a garrett t3/t4 .60 trim .82A/R.

for example here is my car on 8psi.

http://i93.photobucket.com/albums/l41/Syldrin/8psi.jpg

wtb a like button.

^^ I agree, it's all in the sizing and aspects of your build. There's a perfect turbo for every build IMO

Only if it actually sells, which entirely depends on market conditions.

Judging by previous Subaru experience and knowledge, the turbo I would go for for a 2L boxer would be a mid-frame twin-scroll snail. Something along the lines of a TD04 twinscroll, or IHI VF37 that the EJ207 STI had. Twin-scroll at least improves transient response, which is the downfall of any small displacement single-turbo car. Off-boost torque would likely be a problem for this platform, as it is with the 2L WRX. This engine seems to be a little...deficient on torque, but we'll see what power curves actually look like soon enough I guess. DI will be a factor, I just don't know how it changes the equation (until you get fueling issues and the HPFP and injectors become a problem; I hear that's expensive).

I hate to be a debbie downer, but I really don't anticipate too many good turbo setups on this engine without it being built up. It's not gonna be the next Supra, that's for certain IMO.

Loving boost
 

Yes, Subaru NA engines do like boost (have done 50 or so) and Subaru engineers clearly stated 5 weeks ago that the engine in this vehicle has sufficient strength to take boost on top of the already stratospheric compression ratio

Boost and high compression don't play nice on pump. Detonation, detonation, detonation.

EDIT: I see you're from Aussie-land. All of you bastards are crazy and do amazing things :burnrubber:. On our side of the pond, I haven't seen N/A turbo builds do too well. Cheers mate! :happy0180:

ummm... thats not linear...

want linear?

http://www.boefabrication.com/Media/Images/vvt_tvs.jpg

now that's linear...

6 - 11psi boost
 

You are right about the N/A + turbo - it does mostly fall apart with time, goes very well for a while

We usually increase comp ratio if we select high strength parts, but totally happy working in the 10 -11:1 range as normal practice with 6 - 11psi boost. The 12 is right up there but the Subaru engineers said motor is strong enough for moderate boost pressures to be applied. A centrifugal charger is the soft choice - least stressful to motor so it should work well

All that said, this motor in 86 and BRZ looks difficult to strap something onto

I am not saying it can't be done right with a turbo setup, and i should have said sequential not twin in my original post for linear non lagging power, but I like the relative simplicity of a supercharger. However I do also like the fact that mpg saty approx the same with a turbo set up over a supercharger.

I guess I just like NA power I just dont like the crazy cost of ITB's, valves, springs, cams, ports, ect that come with each little increase in power. So a low boost supercharger skips a lot of those steps with about the same power increase and powerband.

Ahhhh ITBs. I love how they sound. Seen one or two attempts at it on Subarus; wonder what the Porsche side of that equation looks like. As for a sequential twin turbo setup, I think the piping would be at best difficult and the gains not worth the complexity over a properly sized twinscroll turbo.

I'd be interested in seeing what a positive displacement supercharger would do and what it would drive like.

Of the Subaru 4s I have supercharged we have seen cruise fuel economy increase over stock numbers - just a few % normally, however i am talking centrifugal which are low in parasitic drag

Superchargers all come with either a deactivation clutch or bypass valve, so the parasitic drag is actually very low. You shouldn't see mpg decrease driving at part load. Well, a twin screw compressor might see a bit, probably not much.

If anything, it's probably a turbo that decreases everyday fuel economy, because that thing is always sitting in the exhaust stream and intake.

True enough

The thing that probably goes against the turbos more than something sitting in airstream is the low compression ratio that accompany's them, efficiency goes out the window pretty fast with low comp

Well with a supercharger if you want to make similar power you have to decrease compression ratio as well. So if we're talking the same compression ratio, a supercharger than is deactivated uses almost no power, while a turbo sitting in the exhaust will create some backpressure under moderate load, which has to blow through the throttle/blowoff valve, wasting all the energy. Now of course part of that energy was "free" in the sense that in a supercharger it would be blown right out the exhaust, but part of it is not free because a turbo is designed to create more restriction to extract more power for the compressor, rather than be as efficient as possible in cleaning up the extra energy in the exhaust.

Well with a supercharger if you want to make similar power you have to decrease compression ratio as well[/QUOTE]

True enough, however we never decompress when we fit a system to a Subaru 4, we just make what power we can from the engine to maximise benefit against minimised costs. I think that will also represent what most 86 owners will want also

Right, I guess you could say turbo builders are looking for more power so they would want lower compression, but if you are looking to forced induction as the cheaper way to add a modest amount of power, swapping pistons out would kill the cost advantage unless you're looking for a huge increase in power, which isn't going to be cheap anyways.

its prett close to being linear. but you did indeed trump me on linear. what car is that on?

Looks like a stock ford f150 EcoBoost, sept it's not enough hp

And def no where near enough torque

i was thinking a honda with a some sort of FI on it. torque fits.

its a TVS supercharger upgrade for the elise/exige: http://www.boefabrication.com/Supercharger.html


This dyno graph represents just a taste of what can be done with a sturdied up 2ZZ with stock porting and stock cams and 9:1 compression vs a stock engine but with headers and decat running on the Rev400tvs with an EFI standalone EMS. The difference is amazing and more than twice the torque and horsepower to the wheels with silky smooth drivability…

http://www.boefabrication.com/images...e_vs_Stock.jpg

if somebody makes a SC kit for the FR-S, that can make this kind of power, with that kind of linearity, who needs a turbo? :burnrubber:

If scion or subaru will not have a turbo charge version my choice is swap the motor with a sti or wrx engine from an impreza, rumor say wrx is downgrading to 2.0liter but still have 270bhp so if this is true 270bhp is a good amount to me.

http://wot.motortrend.com/breaking-n...hp-143875.html

stock gas milage with a turbo while having a 340whp car? yea i will keep my turbos :thumbup:

If someone can come out with a reliable supercharger kit that will mostly likely meet my goals. Im not looking for a crazy amount of power.

+1

how to mount your Roots SC?

like this:
[u2b]uvg0EjU8W7I[/u2b]

additionally, you can incorporate the water-air intercooler into the manifold, perhaps using laminova heat exchangers...