Super vs Turbocharging the car

[uspspro]

Originally Posted by eikond

Even at 5 or 6 PSI, I'm still a little concerned that the compression is too high and it may not be safe.. Are the knock sensors good enough to prevent problems?

What impact does the direct injection have on all of this?

A bump from 200 at the crank to 250 or 275 at the crank sure would be nice! It doesn't have to cost $5k to do it either. I bet a decent kit could be put together for $2k or less.

I doubt that an intercooler would be required either.. sure it would help, but you wouldn't need a massive front mount like people run on their Supra's and other aftermarket kits.

Does the BRZ/FRS use a MAF sensor or MAP? If MAF, you'd have to recirc the blowoff valve.. .though at only 5 or 6 psi it might not be a huge deal anyway.

How about tuning? Would you use something simple like SAFC to fool the system or actually get a full tuned ECU chip or something.. that would expensive!!

$2k is too damn cheap to be a full on kit (including tuned ECU or piggyback)

The intercooler will help make this safe with the high c/r. We definitely want an intercooler.

[SUB-FT86]

Originally Posted by brillo

It would seem to me that the FR-S / BRZ could really benefit from a small efficient low boost s/c that wouldn't require an intercooler. I bet you could create a sub $4k kit that doesn't add much weight, gets you like 50whp/50ftlb on 5-6lb of boost.

What do folks think of a non intercooled low boost s/c? What type would you go with?

Adding something like this would make the BRZ limited my favorite car under 100k.

[JohnnyR]

Originally Posted by eikond

How about tuning? Would you use something simple like SAFC to fool the system or actually get a full tuned ECU chip or something.. that would expensive!!

I wouldn't JYP a kit onto this car, and would shy away from any kit trying to just use a Apex'i SAFC solution. You'd have to expect a full-on stand alone for engine management to feel "safer". High comp is a concern, and who knows the grade of internals in this thing, is there wiggle room? We know this engine is being used in the next WRX, but I'm sure it'll be significantly built up out of the box.

Even at lower boost levels, with high comps, you'd still want a small IC to at least cool the charge a bit I'd wager. Even a good flowing/exchanging side mount would do the trick, but wouldn't doubt for a second to see a full on FMIC in proper kits for this.

That said, I'd still be leery of aftermarket solutions for this. TRD kits (usually SC) would be ok obviously, as it'd work with your warranty most likely, unless it's considered an "off-road part" and blows up your warranty, then I'd stay away.

But, all in all, at this point it's all a guessing game. Not many know the strength of the internals right now, and those who do, haven't spoken on that yet.

[AVOturboworld]

Boosting a n/a Subaru motor gets a lot of negative feedback primarily because people try to bolt on WRX parts without tuning and call it a day. One of the big issues is the stock wastegate on a WRX turbocharger is set for a minimum of 8psi, the other big issue is, of course, the complete lack of any tuning.

OTOH, I've got a AVO kit on the shop Outback 2.5i that went on at 180,000 miles and is now sitting at 198,000 miles. That sort of reliability comes from having everything done properly and understanding that oil changes and other regular maintenance are more frequent with a turbo model. It went from 110ish whp to 204whp.

Things to keep in mind with high compression motors is boosting has much more effect per psi than with a low compression motor built for turbo's. That's why the 2.5i n/a at 5psi is making roughly the same whp as a 2.5GT at 12-14psi.

I do wager we will see some blown engines once turbocharger kits and supercharger kits become available. It'll be for the same reason as other n/a FI kits, though - people get curious and will turn up the boost past safe levels to see what will happen...

Regards,

Paul Hansen
www.avoturboworld.com
www.facebook.com/BRZSportsCarClub

[Dimman]

Anyone know of a boosted IS350? Could give some insight into sorting the fueling and high compression.

[Kwaziekeller]

First, I love forced induction and have been around a lot of different cars/setups. There are lots of differences between the different supercharging setups (positive displacement vs centrifugal) and turbocharging. There are pros and cons of each setup and ultimately once they are available, then it will be your choice. I haven't gotten my FR-S yet, so I can't say which option I'd chose, but being that I like drag racing, it will probably be a turbo or centrifugal s/c. It all comes down to what you want. Low-end and mid range torque, or high horsepower, or something in the middle? I won't say any way is better than the other but generally, turbos are regarded as more efficient because they do not use power to make power (a belt driving a s/c pulley uses engine power to make power). Turbo setups are generally more complicated than s/c setups and require more detail when installing and tuning, and usually cost more because of this fact. This debate can go on and on, and there will always be people who feel that one setup is superior to the other. Personally, I've driven Kenne Bell (twin screw, positive displacement s/c) Cobras, my ProCharged SRT8 (centrifugal s/c) and plenty of turbo cars (my old '04 Neon SRT4 for starters). It will come down to what you want and what personality or power delivery you like most.

[blur]

Turbo's work well if you have more displacement. For instance, the 3.2 v6 J32a2 engine found in the CL-S, paired with a 6262 makes nearly instantaneous boost, since the engine has plenty of torque to begin with, and the displacement contributes to the larger volume of exhaust gasses spinning up the turbo.

With a little 2 liter, you'll definitely feel the lag. I drive my friend's WRX often and it feels nothing like my V6 does in terms of response.

[MANDALAY]

I do find interesting the comments on this thread.

With all the posts how many of you have actually taken a N/A engine and FI it ?

The relms of the real world will tell you one thing.

What can the engine hold ? I mean the whole package , engine , driveshaft , clutch etc.

Regardless having said that the C/R is starting at 12.5:1 that is high. Even a small boost is going to be really high. Imagine a runaway Turbo , im sure it will pop very fast.

A SC like the Rotrex will be very controlable but heck i wouldnt add much boost to an unopened engine.

To the comment Rotrex , SC not linear well thats a stupid comment because they are.

To the comment no low torque again have you done an installation ever ? Again just get a bigger unit.

To the comment < $2,000 which world do you come from.

The BMW 335i is engineered properly i have yet been able to see an aftermarket as refined and with poise as it or the Porsche turbo for that matter. As far as power well i have more with just 2 liters

If you like your 86 for what it has enjoy here. If you want more get ready to spend some serious $.

As an example of what i have accomplished so far on my SW20 , is a doubling of power with 15 psi from a Rotrex. BUT there is no way i would of with the stock 11:1 C/R. With the fear of destroying my N/A gear box im currently changing the gear box and the driving gear to the Turbo gear and at the same time a bigger Rotrex and upping the boost.

Want the N/A response driving experience get a centrifugal SC like the Rotrex.

FYI the 86 is virtually the same power as my N/A Toyota Red Top Beams engine and this is where its at now



For your conversion around 340 RWHP or about 400 Hp at the flywheel double the power.

Pretty linear i reckon dont you think. No massive jump in power like a turbo

$2,000 and you are dreaming

[uspspro]

Originally Posted by Dimman

Anyone know of a boosted IS350? Could give some insight into sorting the fueling and high compression.

Toms SC for IS350

Supposedly a guy in the Uk is at 385 hp

http://www.carsontuned.com/product/?id=2387

http://my.is/forums/f156/toms-superc...6/index10.html

There is an article posted here:
Remapped ECU, stock fuel system, positive displacement blower, intercooled, 0.4 bar boost pressure

[uspspro]

I'm thinking that the stock fuel system has a plenty of capacity for any amount of boost that would be okay on stock internals, it's just a matter of controlling it. I'm hoping one of these ECU-flashing solutions will have enough flexibility for boosted applications. I'm guessing 0.5 bar is probably the most we could run, and IIRC that's what the HKS kit is said to run.

[Dimman]

Originally Posted by uspspro

Toms SC for IS350

Supposedly a guy in the Uk is at 385 hp

http://www.carsontuned.com/product/?id=2387

Hmmm... kit is expensive and gain is only ~17% even intercooled (base kit claims 358 hp). Given the IS350 is 11.8:1 CR, this doesn't look good for this car bolt-on wise.

But if we could get ~17% more hp and torque (235hp/175 lb-ft and flat) at a sensible price it could be worth investigating.

[xwd]

Right now I believe Subaru will end making a turbo version probably using technology from the new JDM 2.0 DIT engine. It will make ample torque even if it is not tuned as aggressively for the US. I don't see Subaru doing a supercharger even if the packaging might be easier.

So I'm just going to wait for now.

Turbo or SC on this car is going to be a 5K+ endeavor IMHO to be properly done.

[uspspro]

Originally Posted by Dimman

Hmmm... kit is expensive and gain is only ~17% even intercooled (base kit claims 358 hp). Given the IS350 is 11.8:1 CR, this doesn't look good for this car bolt-on wise.

But if we could get ~17% more hp and torque (235hp/175 lb-ft and flat) at a sensible price it could be worth investigating.

The IS350 is nearly impossible to modify with bolt on type stuff.

Also there is little to no market for IS350 mods, since they would just bump up the cost to IS-F territory.

One article rumored that the HKS kit was 0.5 bar and raised power from 170whp to 250whp.

These kind of gains would be worth it, I think, and good enough for many. Need a full blown custom build for anything more.

[fatoni]

on one hand i think you could go more boost than people are used to simply because the direct injection is going to cool the intake volume significantly. on the other, there is that compression ratio. just be lazy, wait and see.