best "stealth" turbo?

[avriette]

So, Colin has officially complained that I'm mistreating the car by not giving it more power. I guess it might be time to rectify that. As I look at all the turbo kits, turbos, and various setups, it seems like none of them are really designed with the intent to appear as though the car is stock. As I've gone over before, I have a cop magnet on my bumper. I'd like to be able to say, "no really, ossifer, look under the hood. it's all stock." Is this possible? It seems that some of them bolt into the same spaces, and are un-coated, but it seems that all of them are rotated, and I don't want or need a fmic. I'd like the stock, bolt-in position, no fancy coatings, and retain an internal wastegate.

What to do? I could probably put it together without Sandy even noticing. "Yeah, dear, the car does seem faster these days. Must be the new air filter Don Beyer put on the car." Between retaining the "stock" spt catback, stock turbo position, hopefully the stock tmic, I think it would be hard to see much of a difference in the engine bay. I'll just tell her Colin needs to work on the toaster. Yeah, that's it. Pin it on Colin.

Sure, the gains would be modest, but my guess is they'd also be cheap(ish) and it's not like the car isn't fun to drive anyways. As I've been cruising around on the webs tonight (downloading a gig of Apple developer cruft...) I think I'm more interested in the anti-lift kit, brake pads and lines, and various bushings to tighten up the way the car feels. Fast is fun, but if you can't get there because you're plowing into a corner (or lifting out of it), it's not worth much.

[Sabre]

Trust me, she's going to notice! Start her off with a DP/Intake/Tune. When she gets use to that, add a FP Green (IIRC, you can retain the stock TMIC.... but it's better to go a little bigger!) with injectors, fuel pump and tune. At that point, you're into the 300+WHP club.

[chicken n waffles]

at least get a stealthback and stage 2 flash, minimum.

[avriette]

Trust me, she's going to notice! Start her off with a DP/Intake/Tune. When she gets use to that, add a FP Green (IIRC, you can retain the stock TMIC.... but it's better to go a little bigger!) with injectors, fuel pump and tune. At that point, you're into the 300+WHP club.

What's to notice? I can't imagine it will be much different off-boost (except perhaps being a little laggy...?), and at WOT, it's still going to be the fastest thing she's ever driven. Are you referring to noise? Or what?

And I was actually looking at the SZ turbos. It looked yesterday like the Green was a little out of date compared to the newer ones.

[Sabre]

Trust me, she's going to notice! Start her off with a DP/Intake/Tune. When she gets use to that, add a FP Green (IIRC, you can retain the stock TMIC.... but it's better to go a little bigger!) with injectors, fuel pump and tune. At that point, you're into the 300+WHP club.

What's to notice? I can't imagine it will be much different off-boost (except perhaps being a little laggy...?), and at WOT, it's still going to be the fastest thing she's ever driven. Are you referring to noise? Or what?

And I was actually looking at the SZ turbos. It looked yesterday like the Green was a little out of date compared to the newer ones.

When I took her for a ride in my car with the stock turbo and my tune, she noticed, so there is no way you're going to fly under the radar with a new turbo. It will be louder (exhaust, intake and BOV(even with 100% recirc) and she'll definitely feel the power difference. That is why I'm strongly suggesting that you take it in stages. As Ben said above, get a DP, maybe an intake and load a Stg 2 map. That will give you plenty of power until you both learn to drive it to it's limits, then add the turbo (as well as intake, TMIC, injectors and pump).

BTW, the SZ49 is a great unit that you can probably still run with the stock TMIC, but it would be better to upgrade it to a larder TMIC if you plan on doing any racing/classes. Darrin is the resident turbo expert though, definitely talk to him!

[avriette]

As Ben said above, get a DP, maybe an intake and load a Stg 2 map. That will give you plenty of power until you both learn to drive it to it's limits, then add the turbo (as well as intake, TMIC, injectors and pump).

The stg 2 goodies are the plan. It seems to me that turbo work is cheaper than I thought, and nowhere near as hard as it used to be. As far as the limits, I think you forget my background. I'm already at the limits of the suspension. I think that will actually be a more drastic change. Power-wise, it can't be any more difficult than tail-sliding a 2200lb RWD car. I always ease Sandy into these sorts of things, so I wouldn't worry too much about that. That, and she always asks questions when she's unsure of something. Except snow.

(besides which, it's not a malevolent deceitful thing; mostly it's just that she'd object to fiddling with the car on principled grounds rather than a safety concern. I look at it as a joke.)

BTW, the SZ49 is a great unit that you can probably still run with the stock TMIC, but it would be better to upgrade it to a larder TMIC if you plan on doing any racing/classes. Darrin is the resident turbo expert though, definitely talk to him!

The Perrin top-mount is a bit bigger and has better flow from what I understand. What's the actual difference to the engine? Is the heat drop that pronounced? What about the actual volume of the IC? A smaller intercooler, smaller turbo (compared to eg SZ55-60), and a modest tune seems like a better way to go until we decide what to do with the cars. I suspect she'll have a lot less interest in the Subaru when she realizes it's nowhere near as fast as the Ninja.

[Sabre]

The stg 2 goodies are the plan. It seems to me that turbo work is cheaper than I thought, and nowhere near as hard as it used to be. As far as the limits, I think you forget my background. I'm already at the limits of the suspension. I think that will actually be a more drastic change. Power-wise, it can't be any more difficult than tail-sliding a 2200lb RWD car. I always ease Sandy into these sorts of things, so I wouldn't worry too much about that. That, and she always asks questions when she's unsure of something. Except snow.

Oh, I had no doubts you could drive it. I remember some of the machines that you have told me owned! I was more worried about how Sandy would handle the sudden increase in trq/hp.

The Perrin top-mount is a bit bigger and has better flow from what I understand. What's the actual difference to the engine? Is the heat drop that pronounced? What about the actual volume of the IC? A smaller intercooler, smaller turbo (compared to eg SZ55-60), and a modest tune seems like a better way to go until we decide what to do with the cars. I suspect she'll have a lot less interest in the Subaru when she realizes it's nowhere near as fast as the Ninja.

With the larger turbo (even modestly larger), if you constantly go on boost (such as during a race/school), you will definitely heat soak the stock TMIC. Once the ECU starts to see warmer air coming in, it will yank timing in a jiffy. Take a look at the SSAutocrome one as well. Very large, not much pressure drop and cheap

[drwrx]

I've noticed my name being batted about so I'll chime in:

A stage 2 Sti w/ tune will run around 300 whp / 330 lb-ft on a dynojet. (peak torque @ around 3,500 rpms peak whp around 5,500 rpms)

A TD06-20G (injectors, pump & tune) will run around 350 whp / 360 lb-ft on a dynojet. (peak torque @ around 4,250 rpms peak whp around 6,250 rpms)

A FP Green / SZ49 / Frank 50 will run around 375 whp / 380 lb-ft on a dynojet. (peak torque @ around 4,750 rpms peak whp around 6,750 rpms)

The SZ55 and "new HTA Green" will run around 400 whp / 400 lb-ft on a dynojet (peak torque @ around 5,200 rpms peak whp around 7,000 rpms)

The FP Red / SZ65 / Frank 60 will run around 440+ whp / 420+ lb-ft on a dynojet (peak torque @ around 5,500 rpms peak whp around 7,500 rpms)

The "non-rotated" GT3076 will perform very similar to the FP Green / SZ49 / Frank 50

The "non-rotated" GT3582 will perform very similar to the FP Red / SZ65 / Frank 60

I mention these because you mentioned "stealth" turbos

Your numbers will vary.

You might want to take a ride in Julian's car and decide wether or not that's "too much" for you. He's somewhere in the neighborhood of 440+whp (SZ55, FMIC, water injection, built engine, etc.)

If the choice were mine, I'd probably go FP Green. It's only $1,400 has a good service record, and there are lots of folks running them with very consistent results.

If your thinking of going for a bigger TMIC, I would get an SSautochrome TMIC over a name-brand. Their cooling capacity has proven again and again, fitment is perfect, and they are very inexpensive ($200).

A set of headers and a bigger up-pipe wouldn't hurt either since your taking out the turbo anyway. I thought Andrew's ebay set for $120 were decent. They had some fitment issues, but nothing that wasn't manageable.

Remember, I'm the cheap guy. That's how I roll.

[avriette]

A FP Green / SZ49 / Frank 50 will run around 375 whp / 380 lb-ft on a dynojet. (peak torque @ around 4,750 rpms peak whp around 6,750 rpms)

Can you comment on the physical differences between the SZ and the green?

The SZ55 and "new HTA Green" will run around 400 whp / 400 lb-ft on a dynojet (peak torque @ around 5,200 rpms peak whp around 7,000 rpms)

Are you saying here that for the additional money between the 49 and the 55 (including the parts independent of the turbocharger) is only going to net 25hp?

The FP Red / SZ65 / Frank 60 will run around 440+ whp / 420+ lb-ft on a dynojet (peak torque @ around 5,500 rpms peak whp around 7,500 rpms)

And what level of boost is this? And how much of it is "under the curve"? I've seen videos of the kilo-hp Supras, and they're actually kind of mild until about 5000 rpm, when they absolutely explode. That's useless to me. I'm more interested in a linear progression of power than I am in peak numbers.

The "non-rotated" GT3582 will perform very similar to the FP Red / SZ65 / Frank 60

The GT3582 is actually the one I thought had the most promise.

You might want to take a ride in Julian's car and decide wether or not that's "too much" for you.

Yeah, it is too much. The way I drive, if I had peaky performance, or a crushing onset of power, I'd lose the car pretty easily. I want to be able to pull out of turns, on the gas, and not have to worry about the car sliding off the road. And this is not mentioning the cost, of course.

If the choice were mine, I'd probably go FP Green. It's only $1,400 has a good service record, and there are lots of folks running them with very consistent results.

Buddy of mine at work has a Green. It is pretty fast, but I haven't driven it, and unfortunately for me, I suspect that just looking at numbers isn't going to tell me which one I prefer.

If your thinking of going for a bigger TMIC, I would get an SSautochrome TMIC over a name-brand. Their cooling capacity has proven again and again, fitment is perfect, and they are very inexpensive ($200).

Julian seems to be saying that the bigger tmic is mandatory.

[Phibs]

If I had to do my car all over again I'd stick with Stage2 or go all out and do a 30 or 35R with Meth, a built motor, all supporting
mods, and the Hydra EMS. But that's just my opinion. Stage2 @ 300Whp is definitely fast, add meth to that w/ a good EMS and...
jeeaaaauh!

[zaxrex]

If you are skittish about going for an AM intercooler and will not be concearned about track restrictions, you could implement a more robust TMIC water sprayer. That would allow you to have increased efficiency, look stock, and get more power.

As far as stock LOOKING goes, if you hack a factory turbo heat shield, nobody will see the turbo. Unless they really know what to look for.

[avriette]

If you are skittish about going for an AM intercooler and will not be concearned about track restrictions, you could implement a more robust TMIC water sprayer. That would allow you to have increased efficiency, look stock, and get more power.

That was my thinking. Pull out the timing a bit, reduce the boost, and you still get a reasonable gain compared to the stock turbo, and still be using the stock parts.

As far as stock LOOKING goes, if you hack a factory turbo heat shield, nobody will see the turbo. Unless they really know what to look for.

Hadn't thought about this.

[complacent]

The SPT turbo heatshield works well to this extent as well.

I'd say stage II then coilovers.

[drwrx]

Can you comment on the physical differences between the SZ and the green?

Not really, they are basically the same TD-06H turbine with a 49lb wheel

Are you saying here that for the additional money between the 49 and the 55 (including the parts independent of the turbocharger) is only going to net 25hp?

The only difference between the FP green / SZ49 and the SZ55 is that the SZ55 has a 55lb wheel and the Green has a 49 lb wheel.
And yes, it's really only worth around 25 whp.
The new HTA green uses a different cartridge than the standard FP Green (it also requires a 3" intake)
There is a write-up on the performance differences between the old FP Green and the new HTA Green here:
http://forums.nasioc.com/forums/showthr ... =HTA+green

And what level of boost is this? And how much of it is "under the curve"? I've seen videos of the kilo-hp Supras, and they're actually kind of mild until about 5000 rpm, when they absolutely explode. That's useless to me. I'm more interested in a linear progression of power than I am in peak numbers.

Most of the larger (FP Red, GT3582) will be very late spoolers. As I indicated they do not reach peak torque until past 5,000 RPMs, and all require lots of boost (26+ psi) and ideally meth injection or race gas to take full advantage of them. These will be similar to the Supras you are referring to above. If you want great throttle response at lower RPMs than a GT35R is NOT for you.

The GT3582 is actually the one I thought had the most promise.

If your going to go GT35R I'm not certain I would bother with a stock location set-up. To take full advantage of the GT35R you will want a 3" intake which means intake, and turbo inlet (and a difficult install in stock location), a Big MAF, TGV deletes, custom up-pipe, down-pipe and FMIC tubing. There are several kits out there. Ultimate racing's sells for $3,600 which includes turbo, intake, up-pipe, down-pipe, wastegate and dump tube. The FMIC kit with tubing is another $1,650. The tubing sells for $350 and you can get your own core.

Honestly, if your thinking of this path, I would find a tuner you trust and find which set-up he likes and follow his recommendation.

Yeah, it is too much. The way I drive, if I had peaky performance, or a crushing onset of power, I'd lose the car pretty easily. I want to be able to pull out of turns, on the gas, and not have to worry about the car sliding off the road. And this is not mentioning the cost, of course.

Honestly, if Julian's is too much, than the (non-HTA) FP Green sounds like the right choice:
1. It's stock location and bolt's up w/o issue
2. You can keep your current intake and turbo inlet
3. You can keep your TGVs

Try to get a drive out of your buddy with the Green and see if it's the right amount of power for you.

Julian seems to be saying that the bigger tmic is mandatory.

I would agree with Julian, a bigger TMIC or FMIC would be a wise choice.

It should be pointed out that a GT30R (depending on the trim) is not much of an improvement over an FP Green.
Most plots I have seen of the GT3071 are very similar to the FP Green on pump gas @ 21-23 psi. They spool about the same with the GT30 getting a bit better top-end power in most cases, 10-15 whp on average.

However, a stock placement GT3071 is $1,895 from ATP and the FP Green is $1,399.
That $500 could pay for your down-pipe, headers and TMIC!

[Phibs]

With stock placement larger turbos, afaik you have to do TGV deletes too. And it's a bitch to work on them.
Stock placement large turbos FOR THE LOSS. Go rotated or don't do it.

[Sabre]

You only have to do TGV delete's if you are going to a 3" inlet with a stock location turbo. You get a little better spool up with a 3" inlet, but it's a PITA.

[avriette]

So, it's just the DP? Do I need gaskets or bushings or anything like that? Is there much functional difference between the Oakos and the others?

edit: and there seem to be a bunch of < $200 headers for the 2.5 on ebay. they look mostly similar, although the weld quality on some is better than others. are they all roughly the same? is there something to look for/look out for?

[drwrx]

There are primarily 3 shorty down-pipes that will work w/o any issues:
1. Stromung: $200 divorced wastegate design. I have installed a number of these and they are very nice.
2. bosal: $230 divorced wastegate design. I had one my WRX and it is now on a buddy's WRX (comes with gaskets)
3. Oakos: $144 It does not have a divorced waste gate like the others here. I'm using it on my Forester.

Any of these above will work fine and will fit without issue. Whether you want the divorced wastegate is up to you. I've now had divorced, bellmouth and flat flanged versions and I'm not certain there is any difference in my experience. Granted, I'm only only running around 300+ whp on mine. Those running big power set-ups may not agree.

As for ebay headers I'll comment on my experience:
The ebay / megan racing one-piece headers are very nice. The welds are good and the quality is as good as any out there. However, they are one of the most difficult installs you will ever undertake. To get them to fit properly, you have to unbolt the engine mounts and jack-up the passenger side of the engine to get them in place. The up-pipe studs provided are also too long so you can NOT use them! You will need to either buy some or use the ones off your stock up-pipe.

The ultra cheap $100 two-piece that are currently out there do have some fitment issues. We installed a set on Andrew's WRX a few months back and they were a bit difficult. We needed 3 people, a lot of muscle and a rubber mallet to get them in place. They require a particular technique to install properly. Some would be put-off by this, but the first gen borla headers also had similar fitment issues and mine are still on my WRX and have remained leak free for 5 years. Andrew's appear to be holding-up just fine.

The rest is up to you. I do have to say, if you are thinking larger turbo as well as down-pipe and headers, you might as well swap out the up-pipe as well. the lager diameter aftermarket up-pipes have proven to make mor power up top where bigger turbos live. And if your going to pull the turbo, headers and down-pipe any way you might as well pull the up-pipe as well. And if you get the ebay header / up-pipe combo it's only another $20. So I would say go for it.

This is the header-up-pipe combo I'm refering to:
http://cgi.ebay.com/ebaymotors/Header-F ... QQtcZphoto

Have you made a turbo choice?

[avriette]

Any of these above will work fine and will fit without issue. Whether you want the divorced wastegate is up to you. I've now had divorced, bellmouth and flat flanged versions and I'm not certain there is any difference in my experience. Granted, I'm only only running around 300+ whp on mine. Those running big power set-ups may not agree.

Probably the Oakos then. Seems to me that a divorced pipe is an eventual certainty, but at that low a cost of admission, it's no big deal to buy "the right pipe" down the road.

To get them to fit properly, you have to unbolt the engine mounts and jack-up the passenger side of the engine to get them in place. The up-pipe studs provided are also too long so you can NOT use them! You will need to either buy some or use the ones off your stock up-pipe.

I gather from this description that there's at least a couple people who have done this that I could mooch off of.

The rest is up to you. I do have to say, if you are thinking larger turbo as well as down-pipe and headers, you might as well swap out the up-pipe as well.

Yeah. Again, it's a cheap part to put on the car. I waited this long because when I first started modifying turbo cars, it was insanely expensive. These ball-bearing turbos were up to $3k, and with all the extra stuff you could easily spend $5-6k to get even modest gains on the cars of the era. It's pleasing to know I can get a hundred or so more hp without spending too much.

Have you made a turbo choice?

I think I have. The more I think about it, the more it seems like there are really two kinds of power to be made from these cars. The first is up to about 400 at the wheels. After that, it seems like you have diminishing returns. The difference, as you noted, between the Green/SZ49 and the Red/SZ55-57 is at least a thousand dollars, substantially more work, custom tuning, and not worth even a hundred more horsepower. So, it seems to me for the meantime, there's no point in going any further than a Green or SZ49. The only reason I haven't just decided on the Green is Deadbolt's "rebuilds for life" policy. On the other hand, you've got to be doing something wrong if you need your turbo rebuilt, right?

[drwrx]

Probably the Oakos then. Seems to me that a divorced pipe is an eventual certainty, but at that low a cost of admission, it's no big deal to buy "the right pipe" down the road.

Honestly, if your thinking you'll do a divorced down-pipe at some point, you might as well pay the extra $55 and get the Stromung downpipe. Is the $144 vs. $199 really a big deal? Again, I don't think the Srtomung will make more power, but if you think you want a divorced pipe, you might want to get it now. No sense in redoing an install in six months if the cost difference is only $50 up front. Daddy's even sells them ceramic coated for $265. I spray coated my oakos dp with VHT 2000 and it's holding-up very well.

The more I think about it, the more it seems like there are really two kinds of power to be made from these cars. The first is up to about 400 at the wheels. After that, it seems like you have diminishing returns. The difference, as you noted, between the Green/SZ49 and the Red/SZ55-57 is at least a thousand dollars, substantially more work, custom tuning, and not worth even a hundred more horsepower. So, it seems to me for the meantime, there's no point in going any further than a Green or SZ49. The only reason I haven't just decided on the Green is Deadbolt's "rebuilds for life" policy. On the other hand, you've got to be doing something wrong if you need your turbo rebuilt, right?

You and I are very much on the same page. If you want daily driveability with some serious punch a 350-400whp low 12 high 11 second car should be more than enough. That is enough to take on 99.9% of all cars on the road. If you really want to chase after Vipers, Vettes and 911 turbos than yes, you may have to step-up to a race gas, alky injected, 500+whp that can run mid-low11s. But the price for admission to that show can get costly; intake, inlet, FMIC, TGV deletes, injection kit, perhaps even engine rebuild costly.

As for the difference between the options. The SZ49 at $1595 is $200 more than the FP Green $1,399 / Frank 50 $1,399 / Dominator 1 $1,375.

Basically, what your paying for is insurance. It might be worthwhile to do some searches and see how many of these kinds have failed, see what it costs to have them rebuilt. And how good is deadbolt to deal with on rebuilds.
I think Julian can chime in here.

Most turbos fail for one of two reasons: 1. oil starvation (oil pump failed or oil line clogged). 2. object impact (something got sucked into the compressor). I'm betting that neither of these will be covered under Deadbolt's free rebuilds for life.

[Sabre]

I think Julian can chime in here.

Most turbos fail for one of two reasons: 1. oil starvation (oil pump failed or oil line clogged). 2. object impact (something got sucked into the compressor). I'm betting that neither of these will be covered under Deadbolt's free rebuilds for life.

Yep, my turbo failed because of a failed oil pump, which lead to all kinds of nice scrap metal getting into the floating bearing... not fun!

Deadbolt has been very good about rebuilding my turbo. They of course charged me when the oil pump failed and the turbo locked up, causing all kinds of problems, but that was understandable. I've had it rebuilt by them 3 other times and have been happy. There is still a small oil leak on the inlet side, but I've given up trying to solve it.

People have had GREAT success with the Green, esp. the newer version of it. I would really give that a look since IIRC, it's based on a Garrett wheel.

[avriette]

Deadbolt has been very good about rebuilding my turbo. They of course charged me when the oil pump failed and the turbo locked up, causing all kinds of problems, but that was understandable. I've had it rebuilt by them 3 other times and have been happy. There is still a small oil leak on the inlet side, but I've given up trying to solve it.

Errr. What happened the other times?

[complacent]

Deadbolt has been very good about rebuilding my turbo. They of course charged me when the oil pump failed and the turbo locked up, causing all kinds of problems, but that was understandable. I've had it rebuilt by them 3 other times and have been happy. There is still a small oil leak on the inlet side, but I've given up trying to solve it.

Errr. What happened the other times?

I think that can be politely read as: Yes, free rebuilds for life. But we screw up just like everyone else and let a sloppy turbo leave our shop. We just happened to do that to Julian three times.

Take from that what you will.

[Sabre]

Well, that's the odd thing... I need over sized bearings in my turbo (because of the terrible things that happened when my motor blew). Every time the turbo came back, it was always good and tight (no shaft play etc. etc.), but I still get a small oil leak on the inlet side. I really don't want to take the turbo off again, so I just make sure I blow out the oil every once in awhile Basically, the first time I go on boost (if it's been awhile), I get a little oil smoke, after that I'm fine since it's all blown out. I'm running a little bit higher flowing oil pump now, since the SZ series is based on a floating bearing, I have to wonder if the additional pressure is causing some of the problem. Anyway, it's a minor inconvenience to me, but maybe not to others.