Supercharger or Turbo ?

[Jordo!]

Originally Posted by MatadorRacing_F1

I'll ask again, Ever driven a modern Turbo car?

Roots blowers obviously get on boost sooner, but really, if you look at the trade offs it really does not make sense in a non V engine config.

Speaking of which, how do you really plan to put a roots blower on a flat 4?

OEM no, aftermarket yes. But again, I think were debating the perception of lag rather than the actual lag...

What's wrong with a roots blower on a flat 4? In fact, I'd say for a small displacement engine that will tend to have limited low speed grunt, for a daily driver or autox car a roots blower is probably a better choice.

The major lament about roots blowers on a small motor is the limited top end, not the low speed torque.

I'm not knocking turbos, but they simply have different flow characteristics than roots blowers, and what will best suit an individual depends on their personal preferences and style of driving.

EDIT: Oh, wait... flat 4... good point. I thought there were a few production set ups like that tho -- no?

[ichitaka05]

Originally Posted by NESW20

want to know a secret fix for "lag"? DOWNSHIFT.

Ha, I have better idea. Just do Anti-Lag System. No lag period... at the same time, shorten the life of the engine. lol

[bpv417]

I'd have to say turbo is the way to go for a 2.0 motor = )

[Matador]

Originally Posted by NESW20

want to know a secret fix for "lag"? DOWNSHIFT.

throttle response has nothing to do with turbo lag. there is a difference between throttle response and boost response. a good driver will be in the proper gear for conditions, and thus, this whole lag argument is moot.

-Mike

What this man said.

Originally Posted by ichitaka05

Ha, I have better idea. Just do Anti-Lag System. No lag period... at the same time, shorten the life of the engine. lol

Originally Posted by Jordo!

OEM no, aftermarket yes. But again, I think were debating the perception of lag rather than the actual lag...

What's wrong with a roots blower on a flat 4? In fact, I'd say for a small displacement engine that will tend to have limited low speed grunt, for a daily driver or autox car a roots blower is probably a better choice.

I didn't say anything was wrong with it per say, I just wonder how you PHYSICALLY plan to do it.

Srsly, the sheer physics of it are mind boggling [/powers]

.........Lest you plan to put one on either head or a massive blower?

[ichitaka05]

Originally Posted by MatadorRacing_F1

Hell yeah!

Originally Posted by MatadorRacing_F1

I didn't say anything was wrong with it per say, I just wonder how you PHYSICALLY plan to do it.

Srsly, the sheer physics of it are mind boggling [/powers]

.........Lest you plan to put one on either head or a massive blower?

Some ppl are doin' SC on their Impreza. IIRC Raptor made NA Impreza SC kit for it too. Raptor SC kit

As for Root blower, are you talkin' bout this?

.

[Siriusly.Andrew]

why Roots?

isn't Centrifugal more efficient? its smaller and lighter, does the same boost as say a Roots or Twin-Screw?

I suppose if your looking for down right low end power and torque then yeah, Roots and Twin-Screw but considering the engine is a HIGH REVVER, low RPMs is considered 5000, which is plenty of exhaust for a turbo.

[WingsofWar]

this thread suddenly fails

[Matador]

Originally Posted by ichitaka05

Some ppl are doin' SC on their Impreza. IIRC Raptor made NA Impreza SC kit for it too. Raptor SC kit

As for Root blower, are you talkin' bout this?

.

Look at the complexity of those setups. The amount of plumbing and fabrication needed. Is all that worth it just to be different? I honestly can't support a case for a roots blower on a boxer engine, cause I can't see how any of those setups would be better than a proper snail.

The build by Skidd is actually pretty cool, but...seriously, cost/performance/time ratio, do you see yourself bothering to do all that?

[ichitaka05]

Originally Posted by MatadorRacing_F1

Look at the complexity of those setups. The amount of plumbing and fabrication needed. Is all that worth it just to be different? I honestly can't support a case for a roots blower on a boxer engine, cause I can't see how any of those setups would be better than a proper snail.

The build by Skidd is actually pretty cool, but...seriously, cost/performance/time ratio, do you see yourself bothering to do all that?

I agree w ya. Once upon the time, I thought bout making my RS SC, but it was too complex so I gave up... but if you look at Raptor's SC, it's fairly easy to set up & give you helova good hp/tq for low psi. As for the cost, just bit cheaper than doin' the swap... so in the end, I was saving up to do H6 & 6sp tran swap til FT-86c came up. lol

[NESW20]

Originally Posted by Siriusly.Andrew

why Roots?

isn't Centrifugal more efficient? its smaller and lighter, does the same boost as say a Roots or Twin-Screw?

I suppose if your looking for down right low end power and torque then yeah, Roots and Twin-Screw but considering the engine is a HIGH REVVER, low RPMs is considered 5000, which is plenty of exhaust for a turbo.

hell, 3000 rpms is enough for a turbo out of a 2.0L. it took me a second to understand what you were getting at (just woke up, ha), but it's a pretty good point.

the engine is likely going to rev fairly high, so who here really needs to drive around at 2000 rpms?

-Mike

[Jordo!]

Originally Posted by MatadorRacing_F1

Look at the complexity of those setups. The amount of plumbing and fabrication needed. Is all that worth it just to be different? I honestly can't support a case for a roots blower on a boxer engine, cause I can't see how any of those setups would be better than a proper snail.

The build by Skidd is actually pretty cool, but...seriously, cost/performance/time ratio, do you see yourself bothering to do all that?

Argh -- I hadn't thought of that. Not used to thinking about boxer motors at all... good point.

[cbishop11]

Having driven and built both, I'll turbocharge, especially since its easily been done before on this configuration. The only thing that may turn out to be more expensive than your typical conversion is upgrading the direct injection fuel system. It may only be a matter of finding compatible upgrade parts, or we may have to wait for aftermarket support. Who knows until we see the actual car. A supercharged setup would appear quite complex, and would rob too much torque, in my opinion.

As others have said, these days turbo lag is really not an issue anymore. As long as you pick the right turbo and build your motor accordingly, you wont notice much lag. A good tune is also essential.

To be honest, a 2.5 turbo swap from an STI would probably be simpler than trying to convert this 2.0 N/A DI to forced induction, but that is another thread...

[ichitaka05]

Originally Posted by cbishop11

To be honest, a 2.5 turbo swap from an STI would probably be simpler than trying to convert this 2.0 N/A DI to forced induction, but that is another thread...

That's not true. Japan have been using 2L Boxer engine since 90's til just recently. It has more Turbo upgrade parts for 2L than 2.5L parts.

[WingsofWar]

i think what most people are forgetting in this thread is that, this Toyota variant engine is completely built from scratch. While this may seem like nothing new on paper, a 2L flat-4, it is not a flat-4 that anyone would be familiar with from any aspect. The engine is not built by subaru and then just planted into the FT, so what you may know about previous designs by subaru that are similar may not completely comply to this D4S.

So when cBishop11 says a swap would be easier than a F/I conversion for this Toyota D4S he would probably be right, seeing as how there are ZERO aftermarket options for this 2.0L boxer.