what's the difference between twin screw, centrifugal, single turbo and twin turbo?

[Sonolin]

Originally Posted by circuithero

Always such a dangerous topic! Ill give my personal experience as I used to play the turbo game... But first, my own small rant:

//RANT//

...

Thank you for the post and good to hear from a first hand track experience.

I've calculated it out, and cost wise (just up front costs) it would cost me at least 10-15k for a proper track setup. That's a lot of money.

Personally I'm just being patient and trying to figure out if I really want to go down that road, but I'm definitely enjoying the car currently N/A.

Oh and if you haven't noticed there's some *really* fast lap times for these cars floating around (for N/A e85). @robispec was getting ~1:35 at WSIR which is a very good time for a light 4 cyl car, and @CSG Mike got a 2:00 at buttonwillow which is blazing fast. So definitely very high potential N/A as well

[AVOturboworld]

Originally Posted by Ammonia

On topic, basically our little 2.0 wouldn't produce enough exhaust to make a twin set-up viable is what you're saying @AVOturboworld ?

If you find small enough turbochargers, and also find space for them and two exhaust manifolds, and figure out the oiling and water cooling system, you could theoretically make it work. But turbochargers that small would run out of breath very quickly. If you used two larger turbo's to have top end, you'd likely end up with something laggier than a single mid-range turbo.

[Ammonia]

Originally Posted by AVOturboworld

If you find small enough turbochargers, and also find space for them and two exhaust manifolds, and figure out the oiling and water cooling system, you could theoretically make it work. But turbochargers that small would run out of breath very quickly. If you used two larger turbo's to have top end, you'd likely end up with something laggier than a single mid-range turbo.

And one small turbo + one larger turbo would be dumb considering you can just get a twin scroll, right?

[Hanni_0176]

Originally Posted by Ammonia

And one small turbo + one larger turbo would be dumb considering you can just get a twin scroll, right?

Except I'm not aware of any twin scrolls currently available for our cars yet. I know that JDL is almost finished designing one, but it's still not production ready AFAIK.

[Bonks86]

Originally Posted by Hanni_0176

Except I'm not aware of any twin scrolls currently available for our cars yet. I know that JDL is almost finished designing one, but it's still not production ready AFAIK.

They threw up a pic of the kit yesterday on their FB

[MikeW]

The BRZ is too slow no matter how you look at it. I have a WRX and BRZ of the same year and which I choose to take on a short road trip is a coin toss. I live in the south so windy mountain roads are not in the equation; and if that were an option than my guess is the N/A BRZ would win out most of the time.

I plan to go with an FI solution for the BRZ, but then again...

[AVOturboworld]

Originally Posted by Ammonia

And one small turbo + one larger turbo would be dumb considering you can just get a twin scroll, right?

Small + large is still two turbo's to spin up. Not to mention the plumbing is horribly complicated and usually only undertaken by the OEM manufacturers when they can design for it.

A twinscroll with EL headers is, in theory, a solution to that. The problem is that twinscrolls are mainly aimed at stretching out the range of the turbo performance. They don't make more power, per se, just extend the range of that power. In a real world example you have on one hand the JDM Legacy 2.0 liter twinscroll, and the JDM STI 2.0 twinscroll. The Legacy could get the turbo spooled up and going by 2000~2400rpm, but it really only held that power till 5800rpm or so before dying off. The STI would spool up well for a larger turbo, but it still didn't spool up till 3500-4000rpm. They ran the larger twinscroll so it would make power out to the 8250rpm limit.

Which all boils down to this point - you size a turbo not just for outright performance, but for where it will perform. If you are simply chasing a peak whp figure, well, just slap as large of a turbo on that will at least spool at 6000rpm. But if you are looking for drivability, you look at one that'll spool up as soon as possible without dying off too much before redline at 7400rpm. If you are looking for pure torque numbers, go even smaller, but it'll run out of breath long before redline.

[regal]

Originally Posted by jamesm

Centrifugal supercharger are a bastardization of the two, and IMHO, not worth consideration. They are mechanically driven turbos for all intents and purposes. So, you get boost that ramps up as RPM's rise. It's basically the worst of both worlds: limited efficiency, parasitic loss, etc. without the benefits down low of a PD blower. The upside is that they're generally easy to install and package.

Call me old school but this is how a perceive centri's. At low RPM's they almost have to have less torque than stock because of the energy spent spinning the "half turbo with a pulley." Granted these new cetris require much less work to spin. So maybe it is time to give the centri a fresh look.

I am curious of how much HP is parasitically lost with the Vortech at 2-4krpm? I know the WOT dyno pulls don't show much but what about light/mid throttle?

Originally Posted by circuithero

Always such a dangerous topic! Ill give my personal experience as I used to play the turbo game... But first, my own small rant:

//RANT//

There is a lot of bias coming from the guys trying to sell you boost. I have nothing against them but take everything with a grain of salt and do your research!

1. First and foremost: F1 is not going turbo because that is what the teams and manufacturers want to improve performance. It's a silly regulation change to develop a better perception from the outside and make the sport seem more green. On the one hand with F1 developing technology this could trickle down to the OEMs, with more and more cars going OEM FI. Aside from that, I do not see it as an advantage at all and is another bonehead move by the regulators combined with a lot of politics in the background.

2. The McLaren is faster than a 458 for maybe two laps, before it starts pulling timing because of heat saturation and to protect the car. I believe Motortrend ran into this in a 3 car comparo. Ultimately, in a time trial the McLaren is a superstar, need to go the distance? Nada.
I assure you the Italia v8 cost a lot more to R&D and build. I suspect McLaren went with boost because that is all they could afford as they are not a giant like Ferrari. But that is just that, speculation.

3. Im sorry but an NA engine making the same power with the same cooling will no way in hell generate as much heat. With a blower you are compressing air which is what generates the heat and how much heat is a function of efficiency and how much air you are compressing. The NA engine will cost 3X more to build and will never have the torque but it will certainly run cooler.

//RANT//

My personal experience is with turbo miatas. I had the chance to purchase a well sorted, NA bolt on 1999 Miata or a boosted 1990 track monster. I went the fast and furious route and lost 1-1.5 years of possible and proper race experience and coaching. Mind you this is from the perspective and POV of a guy who likes the racing more than the wrenching and tuning. I sure as hell don't spend my time on highways doing "pulls".

Turbos do have a lot going for them and have come a long way in the last 3 decades. Way better compressor ranges and efficiency, easy map switching (Piggy Backs are the worst, ask me how I know), launch control, flat shifting...etc, etc. They will make you the most hp/$, without a doubt.

Example: Only with a turbo can you make 200whp/200lbft out of a 1.6l miata motor. For the same money, NA you would be lucky to get 140/100. BUT! And this is a HUUUUGE BUT: its not all fairy land and pure numbers, there is a lot more especially depending on what you want to do. Common scenario from miata world, might sound familiar: "Hey guys, love the car, so much fun to drive but could use a bit more power - so I have 4k and Im looking for 200whp". Universal answer will be boost and you will hit your power level. Done. Easy.

But then, you need a clutch. Car is also running a bit hot in traffic, so need a bigger radiator, maybe patch up some ducting. Tuning is a bit rough could use some dyno time. Boom, your 4k proposition is now 6k if you are lucky. If I was to boost my car and I didn't love trackdays and autox so much, I would definitely be going turbo. You get the great Jeckyl and Hyde where offboost you can be sipping gas and getting stock mileage with no extra attention and one downshift and you leave all traffic 2 blocks behind in a couple seconds. Plus, that torque hit is what boostheads love and nothing hits as hard as a well sized turbo. On the other hand, torque brakes stuff.

God forbid you try to track your 6k (if your lucky) proposition. Get ready to: overheat, blow oil, exhaust manifold is loosening (I melted a dipstick, with a heatshield in place), intercooler piping coming off...etc, etc, etc. You are in for another 3-4k just to get her to survive a 20 minute session in moderate heat. Most of the miata guys quickly learned to save the boost only for the street cars, some spent megacubic dollars making their cars reliable on track and most that like the racing invest in a low power, miata race car that costs them much less to run. You eventually get used to any power and quickly learn that it is all relative. I would rather drive my car 10/10ths the entire time and progress as a driver than get faster with parts and be driving the car between 8-10/10ths because its too damn hard to drive consistently at the limit. You would see these boosted miata guys, with more than double the power, better suspension components getting walked on by caveman spec miatas with 100whp and cheap suspension components.

And that is the crux of the matter. I have nothing against boost as long as you are aware it is always a larger financial commitment then you expect unless you have been down the road a couple times and know to take your estimated cost and double it when all is said and done. You want to be top dog, the fastest and chasing big dogs down? You will need boost and you will certainly pay to play. Remember you are adding more points of failure, more heat, more weight and more torque. That all requires higher maintenance and parts will wear out faster = $$$. If I had a dedicated race car and 8k laying around my street FRS would be running a nice <insert vendor> turbo. Would I try to track a boosted FRS? Hell no, been there done that. Better buy a racecar and it will be just as fast, more reliable and I won't ruin my daily and go through months of headaches.

For track and autocross I personally do not like turbos. Aside from being financially inefficient - non-linear torque makes it difficult to drive at the limit, consistently and all the time. I have never driven a turbo car in anger that I was comfortable pushing to the limit off the bat. You need to know the car and the course like the back of your hand, otherwise you are not extracting the maximum from either or you are lying to yourself. First time I raced a beast of an SM E36 BMW (twin screw), with slicks, in the rain - I was pushing that car. Despite what everyone from turbo camp will tell you, properly sized turbo or not, as the boost develops (lag) you will have non linear torque coming on. Sometimes in autocross all I need is 0.5-1 seconds of throttle and I want the power to be consistent and predictable which is not what you will get with a turbo car. For that application I prefer the positive displacement motor, the boosted all aluminum I6 just felt like a race V8.

If you look up comparo reviews of these Porsches, you will see similar thoughts: GT3 (NA) vs GT2 (FI). Ultimately the GT2 is always faster but it is less approachable, consistent and the GT3 always wins overall.

I will leave you with one last thought: Good tires and Coilovers should be worth roughly 3-6 seconds on a 60 second course and cost you <5k. What do you think is cheaper/easier to replace, shocks or motors?

PS. I am taking the Porsche RS philosophy with this car. Take out 100-150lb without making it uncomfortable, get it to 200-220whp with minor bolt-ons and enjoy my giant killer on track. Its such a great platform, I would just prefer an ITR instead of a GSR

This is the best RANT on this sub forum IMHO. Such good points, I take it a step further and say if it isn't good enough for light track duty it isn't good enough for the long term on the street (200k mi DD.)

The thing a like about the innovate is it doesn't go overboard with torque/HP. When you look at the capital investment of the kits out there obviously the Innovate with custom castings for the intake replacement has to be up there. I know that the kit gets a lot of bad press on here but on paper it could have been a real sensible upgrade for the price, its a shame they want so many $'s to add fins under the blower ("intercooler") but I am afraid that a good tune and header may be the better option for me considering the cost.

What are your opinions on the modest twin screw upgrade vs I/H/E + Tune ? No E85 around here.

[circuithero]

@regal

Yea just want to make sure no one goes in with honeymoon expectations and is met with downtime and expenses they did not expect.

I was actually looking forward to the Innovative kit (no e85 here either) with the most interest as well but I think I will hold off for a year or two either way as I think my patience will be rewarded eventually, especially with the rate of development this car is seeing. I like the questions Dezoris is asking and I have yet to see answers with respect to that kit.

I came from a new Si that I got in 08. That car had been out for 2 years at that point and even then there was no off the shelf tuning solution and the NA 200whp club was small and inconsistent. By the time I sold the car 4 years later we had:

• Many tuning solutions and options
• Easy formula for 220-230whp with bolt-ons & tune
• Add cams to above and you have daily reliable, stock idle 250whp
• Boosted options had gotten much better and refined. Ie. Complete supercharging packages for an easy 400whp under 5k

The other thing to consider is the full package - Power to weight and weight distribution will also impact the car quite a bit. With most/all of the boosted solutions adding 40lb+ exactly where I don't want it: the front of the car and skewing the weight distribution in the wrong direction. I suspect the FA20 is not quite as great of an engine as the K20 (it sure sounds worse) but with development time an easy bolt package with 200+ whp will be developed. With that respect, for what I prefer I would take a 2600lb 200/160 NA car over the 2650lb 240/200 FI car. Lighter, simpler, more reliable, cheaper, better sounding (IMO), better balanced and running cooler at the expense of a bit of speed and torque.

Again personal, but not going FI would also still allow me to compete with the car a bit. AutoX in STX until its not legal and possibly throw in a rollbar and fire extinguisher and TT in a class where the car wont get eaten alive by Vipers.

[MikeW]

//RANT//

I have done quite a bit of fishing. Stripers on the Chesapeake, Yellowfin out of OC, redfish in So. LA, and specks everywhere. Now I just fish what's biting out my front door on lake Pontchartrain.

When I talk to young guys that have that spark in their eye and have or are about to buy their first offshore rig with all the toys and vodoo that goes into that sport it just makes me feel young again. I encourage them and swap some stories about when such things were new to me, and as I talk I know exactly why I did it.

I've never put FI in a car before. I've never tracked a car. I'm going to do both and am pretty damn excited. This is not about cost and smart investing, this is about fun dammit!!! I"m not getting younger, but this project makes me feel like I am.

I pity the people that bring rational thinking and fiscal consciousness to this board. All of the FI solutions on this board make our cars breath better, and a breath of fresh air is priceless in this world.

[regal]

Originally Posted by MikeW

//RANT//

I have done quite a bit of fishing. Stripers on the Chesapeake, Yellowfin out of OC, redfish in So. LA, and specks everywhere. Now I just fish what's biting out my front door on lake Pontchartrain.

When I talk to young guys that have that spark in their eye and have or are about to buy their first offshore rig with all the toys and vodoo that goes into that sport it just makes me feel young again. I encourage them and swap some stories about when such things were new to me, and as I talk I know exactly why I did it.

I've never put FI in a car before. I've never tracked a car. I'm going to do both and am pretty damn excited. This is not about cost and smart investing, this is about fun dammit!!! I"m not getting younger, but this project makes me feel like I am.

I pity the people that bring rational thinking and fiscal consciousness to this board. All of the FI solutions on this board make our cars breath better, and a breath of fresh air is priceless in this world.

Small world, I grew up fishing, moved to Louisiana and was a fishaholic in my 20's. Moved to the Midatlantic in my 30's, bought a big expensive offshore inboard for the Chesapeak and Atlantic. Within a year I was burnt out with the expense and driving. Sold all that and I just fish less than a mile from my house (from the bank.)


For now any header just to get rid of the too close to the engine manifold cat and a solid tune will hold me over till a real 200 rwhp formula is invented.

My personal opinion is the factory smogging in both the tune and manifold isn't just holding back power its harmful to the engines long term durability, so not waiting on that upgrade much longer. FI can wait, something like the 210hp greddy or 210p innovate would be ideal but in a couple years driveability will be better as tuners really figure out the DI.

[MikeW]

I lived in Lansdale, PA until the 6th grade, miss those summers.

[CSG Mike]

Originally Posted by circuithero

Always such a dangerous topic! Ill give my personal experience as I used to play the turbo game... But first, my own small rant:

//RANT//

There is a lot of bias coming from the guys trying to sell you boost. I have nothing against them but take everything with a grain of salt and do your research!

1. First and foremost: F1 is not going turbo because that is what the teams and manufacturers want to improve performance. It's a silly regulation change to develop a better perception from the outside and make the sport seem more green. On the one hand with F1 developing technology this could trickle down to the OEMs, with more and more cars going OEM FI. Aside from that, I do not see it as an advantage at all and is another bonehead move by the regulators combined with a lot of politics in the background.

2. The McLaren is faster than a 458 for maybe two laps, before it starts pulling timing because of heat saturation and to protect the car. I believe Motortrend ran into this in a 3 car comparo. Ultimately, in a time trial the McLaren is a superstar, need to go the distance? Nada.
I assure you the Italia v8 cost a lot more to R&D and build. I suspect McLaren went with boost because that is all they could afford as they are not a giant like Ferrari. But that is just that, speculation.

3. Im sorry but an NA engine making the same power with the same cooling will no way in hell generate as much heat. With a blower you are compressing air which is what generates the heat and how much heat is a function of efficiency and how much air you are compressing. The NA engine will cost 3X more to build and will never have the torque but it will certainly run cooler.

//RANT//

My personal experience is with turbo miatas. I had the chance to purchase a well sorted, NA bolt on 1999 Miata or a boosted 1990 track monster. I went the fast and furious route and lost 1-1.5 years of possible and proper race experience and coaching. Mind you this is from the perspective and POV of a guy who likes the racing more than the wrenching and tuning. I sure as hell don't spend my time on highways doing "pulls".

Turbos do have a lot going for them and have come a long way in the last 3 decades. Way better compressor ranges and efficiency, easy map switching (Piggy Backs are the worst, ask me how I know), launch control, flat shifting...etc, etc. They will make you the most hp/$, without a doubt.

Example: Only with a turbo can you make 200whp/200lbft out of a 1.6l miata motor. For the same money, NA you would be lucky to get 140/100. BUT! And this is a HUUUUGE BUT: its not all fairy land and pure numbers, there is a lot more especially depending on what you want to do. Common scenario from miata world, might sound familiar: "Hey guys, love the car, so much fun to drive but could use a bit more power - so I have 4k and Im looking for 200whp". Universal answer will be boost and you will hit your power level. Done. Easy.

But then, you need a clutch. Car is also running a bit hot in traffic, so need a bigger radiator, maybe patch up some ducting. Tuning is a bit rough could use some dyno time. Boom, your 4k proposition is now 6k if you are lucky. If I was to boost my car and I didn't love trackdays and autox so much, I would definitely be going turbo. You get the great Jeckyl and Hyde where offboost you can be sipping gas and getting stock mileage with no extra attention and one downshift and you leave all traffic 2 blocks behind in a couple seconds. Plus, that torque hit is what boostheads love and nothing hits as hard as a well sized turbo. On the other hand, torque brakes stuff.

God forbid you try to track your 6k (if your lucky) proposition. Get ready to: overheat, blow oil, exhaust manifold is loosening (I melted a dipstick, with a heatshield in place), intercooler piping coming off...etc, etc, etc. You are in for another 3-4k just to get her to survive a 20 minute session in moderate heat. Most of the miata guys quickly learned to save the boost only for the street cars, some spent megacubic dollars making their cars reliable on track and most that like the racing invest in a low power, miata race car that costs them much less to run. You eventually get used to any power and quickly learn that it is all relative. I would rather drive my car 10/10ths the entire time and progress as a driver than get faster with parts and be driving the car between 8-10/10ths because its too damn hard to drive consistently at the limit. You would see these boosted miata guys, with more than double the power, better suspension components getting walked on by caveman spec miatas with 100whp and cheap suspension components.

And that is the crux of the matter. I have nothing against boost as long as you are aware it is always a larger financial commitment then you expect unless you have been down the road a couple times and know to take your estimated cost and double it when all is said and done. You want to be top dog, the fastest and chasing big dogs down? You will need boost and you will certainly pay to play. Remember you are adding more points of failure, more heat, more weight and more torque. That all requires higher maintenance and parts will wear out faster = $$$. If I had a dedicated race car and 8k laying around my street FRS would be running a nice <insert vendor> turbo. Would I try to track a boosted FRS? Hell no, been there done that. Better buy a racecar and it will be just as fast, more reliable and I won't ruin my daily and go through months of headaches.

For track and autocross I personally do not like turbos. Aside from being financially inefficient - non-linear torque makes it difficult to drive at the limit, consistently and all the time. I have never driven a turbo car in anger that I was comfortable pushing to the limit off the bat. You need to know the car and the course like the back of your hand, otherwise you are not extracting the maximum from either or you are lying to yourself. First time I raced a beast of an SM E36 BMW (twin screw), with slicks, in the rain - I was pushing that car. Despite what everyone from turbo camp will tell you, properly sized turbo or not, as the boost develops (lag) you will have non linear torque coming on. Sometimes in autocross all I need is 0.5-1 seconds of throttle and I want the power to be consistent and predictable which is not what you will get with a turbo car. For that application I prefer the positive displacement motor, the boosted all aluminum I6 just felt like a race V8.

If you look up comparo reviews of these Porsches, you will see similar thoughts: GT3 (NA) vs GT2 (FI). Ultimately the GT2 is always faster but it is less approachable, consistent and the GT3 always wins overall.

I will leave you with one last thought: Good tires and Coilovers should be worth roughly 3-6 seconds on a 60 second course and cost you <5k. What do you think is cheaper/easier to replace, shocks or motors?

PS. I am taking the Porsche RS philosophy with this car. Take out 100-150lb without making it uncomfortable, get it to 200-220whp with minor bolt-ons and enjoy my giant killer on track. Its such a great platform, I would just prefer an ITR instead of a GSR

We've been doing just fine testing a turbocharged BRZ. Granted, the car also has proper cooling upgrades done, but adding a small turbo isn't an issue at all.

[CSG Mike]

Originally Posted by Sonolin

Thank you for the post and good to hear from a first hand track experience.

I've calculated it out, and cost wise (just up front costs) it would cost me at least 10-15k for a proper track setup. That's a lot of money.

Personally I'm just being patient and trying to figure out if I really want to go down that road, but I'm definitely enjoying the car currently N/A.

Oh and if you haven't noticed there's some *really* fast lap times for these cars floating around (for N/A e85). @robispec was getting ~1:35 at WSIR which is a very good time for a light 4 cyl car, and @CSG Mike got a 2:00 at buttonwillow which is blazing fast. So definitely very high potential N/A as well

I don't think it would cost THAT much for a track-worthy FI setup. PM me if you want to go over some figures and what we recommend. We've played with more than a few FI cars already, and know what works.

Also, some clarification. Our 2:00 at Buttonwillow is on a 100% stock engine with California 91 octane. All OEM cats were in place, no aftermarket intake, or midpipes. All we had was an axleback (and we make zero claims that it has power gains).