riceball777

I'm looking for a upgrade turbo for my s2000 and I have decided between the garrett gtx3576r with a t3 .63 hotside or the borg warner efr 7670 with the t3 .83 hotside. Which one should I go with. I have always been a fan of garrett turbos but I have read that the boost response/ transit response and spool is amazing and superior because of the titanium turbine wheel from the EFR.

Here is a pic of my current setup. I'm currently using a garrett ball bearing 50trim turbo



Here is my current dyno. 395whp on 91 octane 11psi and 501whp on e85 17 psi

wantboost

iTrader: (2)

The efr is a great turbo but be warned they changed from investment casting to green sand casting for the turbine housings (unless they have old stock laying around which is highly doubtful) so it will look like a run of the mill turbine housing.

The Garrett is also a great choice...

Have you done any plotting of compressor maps?

We also need a detailed list of motor/drivetrain modifications as well as what the cars purpose is.

Maybe theshodan can chime in

riceball777

The engine is a bone stock f20c with about 110k miles with the past 30k miles being turboed it has all the basic supporting mods.

Tubular t3 sidewinder manifold , full 3" exhaust with all the standard supporting mods. Its tuned on aem series 2.
diff and transmission is stock with an act hdss clutch

The car is a street daily driver that sees 100+ miles a day in stop and go traffic with the ac on all day. I do auto cross the car a few times a year. I'm just looking for more power just to play around with with out being super laggy. The car is driver on 91 octane 95% of the time and is on e85 5% of the time/

boosted_D

iTrader: (1)

Very surprising making that kind of power on a stock motor for as long as you have. Just curious, what's the reason for an upgrade? You don't expect to make more than 500 whp on a stock motor do you?

riceball777

if you knew anything about s2000's you would know that almost no one builds s2000 engines because the stock engine had forged internals and can take 600-700+whp with no problem. there are count less 500whp + s2000 with the stock engine.

reason for upgrade is because I want a litter more power espically on straight 91 octane. I'm running a old out dated non billet wheel fariely small old school garrett ball bearing 50 trim turbo, so I'm leaving a lot of power on the table.

TheShodan

iTrader: (14)

I think we've covered this before when he was comparing the GTX3076R with the EFR7670, but to expect a bit more powerband and punch with the GTX3576R because of the fact that the GTX3076 Compressor wheel is now matched to a slightly larger 68mm turbine of the GT3582R.

The compressor map of the GT3576R and GTX3076R are the same because they use the same compressor wheel, so there's no need to post those up.

But for your current dilemna, I think its the GTX3576R as a ball-bearing turbo that's going to be the winner in this case for the 2.0 and 2.2 litre setup as the S2000. This is mainly because of the aerodynamics and efficiency of the turbine wheel of the 68mm (N111) 84 trim wheel. I think it is much more robust for the displacement than the 76mm turbine of the EFR.

I was a little disappointed with all the great things the EFR compressor wheels, housings and cartridges have to offer; only to put a generically designed low-speed turbine wheel on it.

Example.

The N111 Turbine wheel.



EFR 7670 turbine wheel



This is the 7670 wheel compared to the popular S366.. Notice, its smaller than the S366, but save for a slight contour in the mid-section of the turbine blade, has essentially the same aerodynamics from over 15 years ago. Even Garrett had the edge then.



What this tells me from the tests I've done with it on the S2000, is that even with the true twin scroll housing, its the compressor wheel doing all the work instead of the combination of both compressor and exhaust wheels sharing the responsibility as it supposed to.

With all the use of compressor maps, people still forget that its the turbine wheel that helps with responsiveness and efficiency, and that the dissection of that map is only the first step; we need to look at the turbine wheel just as much as the compressor.

Bottom line, I love the EFR. Its a fantastic compressor wheel/housing and turbine housing combination. On paper they would change the earth, but after using a few of them, I think that all the math and specifications got my expectations a bit higher than I should have let it. Here, this is where a simple change of using the GTX3576R would be more beneficial, provided you give it some serious pressure over 14-16psi, and go for 20+. If you're looking at pump gas 91 octane only, this is even more the better choice. The EFRs like good boost pressure in order to be effective. The same goes with the GTX, only, its a little more forgiving.

Hope this is helpful

riceball777

Thanks for all your help.

This is going to be a big purchase and I just want to know if both turbo are of equal size and equal power potential which turbo will be better. A garrett GTX or a borg warrner EFR? Does the titanium turbine wheel of the EFR really make it respool and respond that much better??

So you feel the gtx3576r will be better than the efr 7670 for me?

TheShodan

iTrader: (14)

Again, read my comments, Yes, the GTX3576R would be a better option.

Please note that the titanium structure was for durability, not response.

riceball777

You are actually one of the rare people that have recommended a garrett GTX over the EFR.

I have asked in a lot of other forumes and i'm getting a lot of mixed opinions. Some people sware by the new erf turbos saying nothing will come close to the spool and transit response and the EFR technology is revolutionary and other people say the garrett's GTX lie is the best money can buy.

TheShodan

iTrader: (14)

I look at it on a case-by-case basis, and not just overall specifications. Most that have that opinion don't even have one yet, or speculate that because they are using certain materials and flange designs that it takes over everything outside of the purpose and use of the wheels themselves. Every turbo company has its benefits and drawbacks when it comes to design and use.. EVERY COMPANY. So I look at all of them the best way I can with the turbos I've personally worked with and experienced.

Again, I like the EFR too, but you asked specifically about your S2000, and that's the basis on where I made my analysis. This seems to be a similar consensus with the Evolution 2.2 and 2.3 litre upgrades as well.

TheShodan

iTrader: (14)

I'm currently working on some experiments with these in a journal bearing package by using a GTX3582R Compressor wheel in the GTX3076R Compressor cover (smaller housing, more compact volute) with a 71mm turbine wheel in a .63A/R, to see if there is such a thing as a journal bearing alternative for bigger punch. The next one I'll try is a GTX3076R compressor wheel with the 71mm journal bearing turbine wheel.

Here's the original GTX3076R in its matching compressor cover



Here is the GTX35R compressor wheel in the GTX3076R compressor cover. Considering the GTX35R compressor wheel is 62.5mm, (a full millimeter larger than the GT35R wheel at 61.4mm) its a tight fit.

redflaredcrx90

TheShodan

iTrader: (14)

I've made 2 so far for hondas. One mild build, one fully sleeved

wantboost

iTrader: (2)

I would love to see a comparison of an identical gtx series turbo... journal vs. Bb just to see how the wheel performs.

boosted_D

iTrader: (1)

I'll admit I'm no s2000 or F20C expert, I know very little about them.

I do realize they have forged internals OEM. I just remember reading that stock sleeves and ring lands were not reliable much after 450-500 whp on a sustained basis.

TheShodan

iTrader: (14)

They're fine. trust me. we do 500-550whp on stock engine all day. If its not tuned or maintained well, all it takes is one person on a forum to say that "ringlands are bad" or some other nonsense.

riceball777

Weak stock sleeves and ring lands are a trait of the d series and b series engine not of the s2000. The f20c and f22c is extremely strong and virtually no one builds the engines even When going for big hp turbo setups.

TheShodan

iTrader: (14)

More like the D-series than anything else. Not even the B-series.

Tony the Tiger

The F20/F22C's are stronger, but many people overlook the fact that these motors push big power because they are efficient. An efficient motor often times is a reliable one. A poor tune on these motors still blows pistons and crack sleeves.

The EFR turbos have a lot of hype, but after they have toned down a bit with info being refined down to actual users, it's not as spectacular as I thought.

Garrett is too popular, and I commonly see mismatched turbos all the time because they are so readily available with so many housing and wheel options. For the EFR, the choices were very limited, so users ended up having really well matched turbos for their particular engine along with guidance from pros who help market the EFR turbos.

Unfortunately, there is very limited data that can be shared online regarding turbos. Dyno results is only half the story on how the turbo responds under hundreds of different situations. Track and racing results do not show much in regards to street characteristics or street cars limited by pump fuel and other restrictions.

I wouldn't have gathered so much info if I hadn't purchased like a million turbos in the past decade...lol The amount of cars I own, and ones I've tuned and driven also gave me the opportunity to swap each turbo into different platforms, and mix them all around to get a grasp on these concepts.

Just by dividing certain turbo characteristics into a few typical categories, I can almost conclude that you can never have one turbo that is "perfect" for all purposes. For example...

Fast spool from a stand still, rolling start off idle RPM's:
- Small A/R housing, low speed compressor/turbine wheel that can deliver the hit at low turbine speeds. Turbo sizing can be seen from the BMW N54 in an extreme case, and how their turbos are very low speed units.

Instant spool recovery during a drag racing situation:
- High speed turbine wheel, but must carry some inertia. A heavier turbine wheel for example, actually responds well in a drag racing situation. A lighter ceramic wheel for example, actually performs worse in this aspect (e.g. response difference commonly witness between JDM vs USDM twin turbos on a Supra 2JZ-GTE).
- 2-step ALS solves all problems regarding getting the turbo spooled up properly, of course, depending how severely oversized the turbo is in relation to engine size/VE

Instant spool based on engine RPM -- road racing situation, like popping off the corner after a hairpin:
- Small turbine wheel, and very efficient compressor. The turbo must flash quickly into powerband, but not necessarily a full torque/full boost hit. Commonly witnessed why many Evo 8/9 owners chose turbos within these specs (e.g. Forced Performance Turbos)

Linear spool/ high resolution of power and being able to control it -- Hill climb racing, canyon carving, etc..
- Turbos with much larger compressors than turbine
- Many turbos were sized and matched for the JDM market due to their driving patterns.. HKS twin kits for Skylines, HKS turbos in general for the Nissan market.
- Examples. GT2871R aka GTRS (HKS), HKS T51R SPL w/ 76mm compressor wheel, HKS GT3037 twins for Supras, etc..

So at the beginning of every answer I give to all those turbo questions, I always ask "what do you intend to do with the car", and "what is the purpose of the build".

Big power on pump gas street car, but with a good spool balance?

Circuit racing to compete, and to win? Is ultimate HP very important in winning? Any octane limitations?

Traction limited? (if ultimate power is easy to obtain due to engine platform)

Novice driver? Or just a cruising car for enjoyment? Smoothness and linearity will be very important.

I can almost choose any turbo within the whole Garrett turbo line up on the same engine platform, just because of those differences

TheShodan

iTrader: (14)

^^^ Which is why I ask that with EVERY turbo request. Remind me to keep this explanation as a sticky so I can use this for others.. hehe.

wantboost

iTrader: (2)

I've seen people make 800hp on stock k24 bottom ends.... don't ask me how

riceball777

So, Tony what turbo should I upgrade to for my needs. gtx 3076r, gtx3576r, efr 7670, efr 7064? I want the best turbo for my need and I would think it should be one of the above turbos. We all know precision turbos are junk so they are out of the equation.

The car is a street daily driver that sees 100+ miles, 15,000+ miles a year a day in stop and go traffic with the ac on all day. I do auto cross the car a few times a year. I'm just looking for more power just to play around with with out being super laggy. The car is driver on 91 octane 95% of the time and is on e85 5% of the time.

out of all the things you listed it would be

Big power on pump gas street car, but with a good spool balance

LightningTeg

Good thread. I love when you 2 (Shodan and Tony) post haha

spectacle

Tony the Tiger

If you intend to get as much power out of 91 oct, I assume this will be in the high 450WHP range... Remember, there is always a trade off if you are limited by octane.

If it was my car, I would actually get a GTX3582R... You'll be making this type of power at about 15-16 PSI, and on the X-35R wheel, it is right at PEAK efficiency of 78%. With this efficiency range, the turbine will also work less hard to push that airflow, and you can keep the T3 0.63 A/R. It will also allow more timing due to this peak efficiency, which is the biggest obstacle because you are octane limited.

For spool, the smaller GTX3576R will come in faster, but at 450 WHP+ puts you at < 72% compressor efficiency. The S2000 engine like to pull in a lot of air, and compressor efficiency drops if whatever reason your engine decides to flow even better due to difference in manifold, exhaust, etc... The X-76R only reaches 75% if you run beyond 18-19 PSI of boost, but then this extra boost will now make the engine work harder because you are still on the same turbine. Again, being octane limited, you are forced to run a 0.82 A/R housing if you want to keep it safe with this turbo.

So the beef of this post, is whether the larger X-82R wheel + 0.63 A/R turbine is better, OR the smaller X-76R wheel + 0.82 A/R? I would actually recommend you the GTX3582R + 0.63 A/R because the range in which the compressor is efficient is much wider than the smaller X-76R, so there is actually more room for error, but the smaller turbine housing makes it respond well for low RPM spool. It will spool quicker and flash into power quicker than the smaller X-67R + larger 0.82 A/R.