Smallest Turbines?
 

:dancegay: Hello Everyone, I am new here. I own a 99 base and Im thinking of going turbo... but not just turbo... SEQUENTIAL Turbo... so I was wondering if anyone has heard or seen any miata going this route? I checked on someone who had his white 92 hooked up with Gt15 but those were not sequential anyways let me know what sup... also does anyonw know where I can find the samllest turbo for my set up?

The Chevy Sprint Turbo was about the smallest commonly available turbo I have seen, its a bad ass little turbo to boot.

Mark

Yeah, the guy that used the two GT15's had good success with them. He said they spooled up as fast as one GT28R .64 a/r. I normally am not a fan of using a twin turbo setup on an inline 4 cylinder, but his GT15 setup really is fucking sweet.

I totally dig the idea, I don't think it's been done before. But I have to ask, why? What research have you done that leads you to want to go that way? I'm truly curious.

Perhaps two of the K03 turbos off a VW/Audi 1.8... should start to spool just off idle and be at full whoosh by about 2500. Two of those running 10psi each would be fun.

Good call. The K03 is as fast sooling as you can get while still moving some air. Hell.....People have even made 250 whp at 300 wtq on just one although I wouldn't recommend it. I am going to use one of those when I turbo our Xb next year. Should be a great match to the 1.5 liter.

I've always loved the idea of two turbos with no lag... One small and one big. The way a sequential turbine system works in simple words is that one spool sup at lower rpms while the other spools up at the higher ones, therefore eliminating the lag. I know Iknow a T3 or Gt25 probably have almost no lag due to being ball bearing instead of journal bearning turbos but I want to be different. I know I could get a supercharger but then... you dont get that signature sound... I think it be cool to go to my car meets and be like yeah... I have two turbos... and one is bigger than the other... LOL!:ugh2:

GO to garretts website i think they have gt12 dont remember tho.

I was lookin a them earlier today... but wtf... does only up to 130 means? if i use it in a sequentila manner i mean the turbo will still keep spooling after liek 4k or so... I want around 180-200whp so maybe I need a GT1544 and a Gt20:confused:

Damn, those are small... probably for a motorcycle.

Gator, I like your style. I look forward to watching this thing happen. Are you going to fab all the stuff yourself? Do you have a budget? What about a power goal? Even 2xK03's would probably push enough air for the 300HP club. If you're thinking one that small, and one even bigger, I hope you're smart on engine management. Also, nothing about the stock motor will handle that power for long... like minutes. If the idea is just to be unique, but leave the power at respectable levels, a couple of those motorcycle turbos would be the trick.

They're small enough that, they'd fit, the Manifold and DP's would be easier to fit, and you could probably get away with just basic engine management... a Link would be the most you'd need.

Yeah Im not going for crazy 300HP... I want 220 FLYWHEEL HP at MOST! I have about 2k saved... I know is not much but probably enough to buy either both turbos or the engine management. I will probably used pre fab stuff from the guy with the twin set up... https://www.miataturbo.net/forums/showthread.php?t=3721
I would proabably use the t12 and the t1544, I have to call Garrett and ask about their flywheel estimates and how they would work in a sequential turbo matter.

Ahhhhh, there so cute.

So you've got two turbos each capable of flowing ~130hp worth of air, for a total of 260hp, or almost as much as one GT2554R.

Each one will be spun by 900cc of exhaust gases vs. 1800cc pointed at a single turbine. So, they might spool marginally faster than a single, T25-sized turbo, but not by much would be my guess.

For 180rwhp and looking for something with instant spool I'd just look into a GT2554. You're looking at a lot of work for an easy power goal.

Look at the comparison of the GT2554, my T3 S60, and a Greddy turbo at 8-9psi:

https://www.miataturbo.net/forums/at...5&d=1159381776

both the gt2554 and t3 had boost control problems, but you get the idea.

I've been saying this for years... yet noone at miata.net would take me seriously . Actually, I take that back... markp said it would probably work, iirc. However hopefully I'll have two of them tommorow, then the fun begins.

Twin turbos on a 180k mile engine? Should be a blast. :eek:


The major reason for the k03 for me is that my 1.8T VW takes them also, that way I don't have to have a pile of different turbos laying around for when I blow them up. I can buy one spare, rebuild it and its good for both cars.

Well, one K03 turbo might spool off idle (or thereabouts...actually, probably wouldn't start spoolling appreciably until ~2000 RPM, considering the K03 on my Jetta starts spooling ~1400 RPM, has 2000cc worth of air and 10.3:1 compression spinning it), but certainly not two of them.

I'm pretty sure one K03 (at least those in the current-gen VWs/Audis/Seats/etc.) flow enough air for ~220whp, so having two of them is probably way overkill and won't spool that quickly. If you're serious about twin-turbo'ing the Miata, you'd be best to stick with a smaller turbo.

The FD RX7 tried this type of setup and it proved to be problematic at best. There is a reason people switched to a single turbo.

But don't let that stop you, it would be a cool setup indeed.

Well, the FD RX-7 used a sequential setup: one small turbo and one large turbo. The new BMW 335i uses twin parallel turbos that're the same size...300hp/300lb-ft...10.5:1 static compression...peak torque by 1400 RPM....max boost of 8.5psi. I guess that means that each turbo is only being asked to produce ~150hp of airflow @ 4.25psi

The k03 falls flat on its face around 200hp (~12psi in a 1.8l Jetta/Audi). In the grand scheme of things it is a small turbo. Its more just an exercise in fun for me, as my Miata is no-longer my daily driver and I've wanted to do this for years.... just never really had the time to get around to it.

So maybe it doesnt spool til 2600 or so, ok. There are plenty of Miatas running around that are just thinking of coming out of vaccuum at 2600rpm. If I wanted instant boost I'd get a Coldside PD blower.... Instead I want something that is neat and different (I'd be what, number three?) and that has turbo whine like no other. Which K03's whine pretty loud... especially with only an aircleaner on them.

How will it spool? IIRC the compressor maps for a stock k03 show two of them coming into boost around 2300-2500rpm. I'll have to check when I get home, but it wasnt any number that was absurd like some of the really large turbo miatas that don't come into boost til around 4000rpm.

How will it actually spool? Noone has done it yet, so that is yet to be seen.

I was always told if you are below 3krpm in a Miata except when stopping you are driving it wrong ;)

And I'm talking a parallel setup, not sequential.

just make sure you do lots of research and math and match your small and larger turbos properly... it would suck if your little turbo ran out of breath before the big one was ready to take over the show. You might also look into the sequential system used on the BMW 535D, it's a selective system that doesn't pass all of the air flow in the top end through the small turbo (read restriction). Impressive setup and has a seemless power band... most fun diesel I've ever played with.

On the 2.0T FSI engines, they're topping out around 220-230whp at ~20psi of boost.

I'm not trying to dissuade you.

I'm not trying to dissuade you.

So what're you waiting for!? :bigtu:

And I've always told those people you must not live in the real world with stoplights and traffic...or you only drive your Miata on weekends, on the highway or on the track. Mine's a daily driver, and I like having some boost below 3000 RPM. It's not every day I get to wind it out to redline.

I know. I tried to point that out to Jay, and it looks like Arkmage still doesn't get it:gay:

The 2.0T runs a different K03 than the ones I'm getting from what I can gather. Noone has said for sure, but the general impression I have found from reading everything people have said is that it is a K03 Sport or a K03/K04 Hybrid.

Mine are the Pre-'02 K03's which are the smaller ones... but again, we shall see.

I'll map it out while I'm at work and see how the numbers work out.

Aha...see there, I knew those K03s were different, but was not aware they were markedly so.

I'm sure you can get those K03s a heckuva lot cheaper and easier than those small Garretts, too, huh?

I'll bet the VAG 1.8 head flows a lot better than the Miata head to spool the K03. My opinion, two turbos, a custum funky manifold, lots more piping = more stuff to go wrong. It certainly isn't a budget solution. Would be cool though.

I certainly hope anyone going the TT route has good welding skills or a good friend who does as the manifold itself will be pricey.

Frank

I'll let you know tommorow. :cool: But it looks that way. Many VW guys dump their stock K03's for larger turbos, so they are a dime a dozen. I've seen them go for as low as $30 a pop for one in decent shape that needs new bearings, and about $200 for one that has minumal shaft play and is really good shape.

Plus they have round turbine inlets and outlets, so making a flange is not complicated at all, as there is no custom shaping of tubing to make it fit. Add in the fact that it is a water and oil cooled turbo.. more piping, but hopefully longer life. About the only downside is that it is a journal bearing.

I have access to a TIG the size of a VW Bug. So that is not an issue. I also have a drill press, arbor press, bandsaw, etc. Oh, and a plasma cutter. Sound be fun. :)

The original poster was talking about sequential. What the hell are you guys going on about? ;)

We are a bit more realistic in our desires ;)

Sequentials require all sorts of mechanicals to make them work well. You have to have an exhaust diverter so that you can spool the small turbo up quickly, then you have to have some sort of pre-spool control to get the large turbo to start spooling. You also have to be able to keep the air from the small turbo from flowing into the larger turbo and pushing it backwards or just plain flowing out. The list keeps going. It is doable, but takes a lot of work.

Honestly I dont like boost too soon on the miata. If I was making 10psi @ 3000rpm I would be blowing my tyres off . I get 7psi by 3400rpm and 10psi by 3700rpm on my car and it still spins 1st and 2nd ( with 225 wide hancook rs2's in the rear ). I would expect the K03's to hit full boost around 3500rpm in the miata...maybe sooner since they have a very small light turbine in them. My friends Jetta could make 15psi @ 2100rpm with a 3" exhaust so I know they will spool sooner than 4000rpm.

Yeah, but then the VW has a crappy exhaust manifold and restrictive downpipe and its still making full boost around 2000rpm.

damn
 

DAmn guys!! FREE FOR ALL???:td:

Not really, we just jumped from sequential to parallel. Same arena, much easier to do. If you really want to do your sequential setup, go for it. I'd love to see one, but go find someone with a RX7-TT with the sequential setup and look at how many vaccuum lines (I think it is like 27-37) it takes to get it to work, then look at how many actuators have to function for it to work. It is not easy to do, nor is it easy to keep working.

A turbo-compounding setup might be easier to do.... just a thought though.

Very true. When I put the numbers on the compressor map tonight for a 1.8 with one k03 it is kinda scary, anywhere beyond about 3.5k you are down around 50% efficency. Granted 3k rpm is right around 68%-73% depending on the boost, which is right around cruise RPM, so that works. You just reach the choke point (12-14psi) pretty quick if you start upping the boost and run to redline. Kinda explains the lacking top-end in my VW. :rolleyes:

And for those that want to know... by the chart, two k03 turbos on a 1.8 miata should have boost onset around 2200-2400rpm, and you can run up to around 20-22psi before choke point (at higher than 2400rpm, obviously). At 4000rpm anything from 8psi - 18psi is right in the most efficent part of the map (73%), and 20psi is only down to 71%.

This of course is assuming no pressure drop, standard day, sea level, etc, etc. Which we all know is bullshit. So take it as you will. I'll post the graph when I dig my laptop out.

You'll run into many of the same issues be it sequential or parallel so the info is still pertinent.

Frank

As before, standard day, no pressure drop, ideal manifold, etc. It wont perform this well in the car. This is for two k03 turbos, not one. The colored lines are RPM, the points on the lines are 6,8,10,12,14,16,18,20psi of boost.

Enjoy, and please if you see an error point it out.