[Tony@vargasturbotech]

Ok, so as many of you know there is another vendor who is building an N55 upgrade and he is touting his version as the best and that a hybrid turbo is as he said recently is a "piece of junk" keep in mind this vendor produces hybrid turbochargers for a living and was going to do a hybrid N55 but after he ran into some serious problems, we had quite a head start at that point, and he switched gears. Now that he has switched gears the hybrid idea is a "piece of junk". I decided to take a look at both upgrades and compare them from as factual a stand point as possible before either of them are officially released or running on a vehicle. Of course I am going to slightly biased towards mine, but we make a similar style upgrade for the N54 as he is for the N55 its our Stage 3 and we know quite well what is involved and who it appeals to. I would appreciate that vendor and other vendors who just want to argue staying out of this thread as per the rules, but I encourage everyone to speak their mind on where I might be right or wrong on this comparison. If the other vendor wants to do his own comparison he can make a thread for that purpose and I will stay out of it. Ok, so lets take a look.

Vargas Hybrid Garrett GTX N55 upgrade:

PROS:
- Stock fitment: Uses the stock turbine and compressor housings, meaning your current aftermarket down pipe, charge pipe to the Intercooler, intake, etc will all bolt right up

- Stock appearing: Warranty will remain intact, we are inserting a new BB CHRA into the existing N55 turbo and will be adapting the stock lines to work with it. What this means for people with cars under warranty is. You do NOT lose your warranty. It will be like bolting up hybrids on an N54 from the outside you will be hard pressed to notice anything out of the ordinary

- Packaging: BMW went with a reverse rotation turbo in the first place because they can package it very very efficiently and tuck it against the block and leave plenty or room for everything else, keeping it in this package makes it very clean and very easy to install

- Price: Our upgrade is $3999, the other vendor has let it be known their upgrade is going to be $5000-$5500 or higher, yes he is telling everyone they are getting a much better turbo but we will look at those facts in a minute

- Availability: We are literally a week away from installing and testing, the other vendor has been working for over a year and has a flange, and a turbo, some lines, and line adapters, expect 3-4 more months before it is testing, would be my guess. Again a guess based on building a similar style kit.

- Performance / Spool: Using the stock housing but a much bigger GTX Dual Ball Bearing CHRA means we will still get lightening spool and a car that feels and drives much like it did stock, just with much higher WHP ceiling. This means minimal turbo lag, and awesome top end

- Tuning: Our hybrid will be keeping the stock vacuum actuated wastegate actuator and other stock features the DME expects to see. This assures that tuning the hybrid will be as straight forward as possible.

CONS:
- WHP CAP: Using the stock housings we are capped at 500-550WHP, for most this is more then enough and if you are worried about any of the issues above, then this HP level is more then worth the trade off. The other vendor would also have you believe the stock housing is a poorly designed unit. Keep in mind it was designed by the same company who designed the turbo he is selling, and it is a VERY nice housing and manifold with a LOT of potential. We have not a single worry about it performing how we want it to.

- Do not see any other cons if you can think of any please post them


Other Vendor EFR stage 3 style upgrade:

PROS:
-WHP flexibility: Since the upgrade completely gets rid of all your stock components, (downpipes, charge pipes, lines, intake, manfold, turbo, etc) You have a few choices of turbochargers with max BHP ranges from 560-800 BHP (EFR 7064 350-560 MAX BHP, 7670 400-650 MAX BHP, 8374, 500-800 MAX BHP). For people looking to really push the envelope past 500-550 WHP this is the most likely the upgrade for you with the flexibility of the bigger turbos

CONS:
- Fitment: If you take a look at the pictures below you will see the size difference between a Garrett GTX (how big the GTX is, is honestly moot as we only use the CHRA in the stock turbo which remains exactly the same size and bolts directly up like factory) and a BW EFR turbo. I used the pictures just so you can see how big these turbos really are. The EFR's are huge turbos and are very very hard to fit in many engine bays. This means it will take up all available room and most likely be a very complicated install, much like a Stage 3 set up

- Non stock appearing: You can kiss any warranty goodbye as soon you install this upgrade in your car, every last thing on that side of the motor will be different. It will not take a skilled tech to spot everything that is out of place and your warranty goes out the window. Keep in mind this isn't a tune you can just uninstall when you need to go to dealer for a problem. On the other hand with our upgrade, if you need service, flash your car back stock and the turbo will perform just like the stock turbo and will remain hidden.

- Packaging: This goes back to the size difference and the fact that this upgrade is going to be normal rotation, meaning unless he wants the exhaust side facing forward the turbo is going to be pushed well away from the block and could very well have fitment problems on different platforms the N55 comes in.

- Price: As discussed earlier the price on this upgrade will be at least $1500-$2000 and most likely more then the hybrid upgrade. This upgrade is basically a full stage 3 style set up. It is going to be priced like one. Think $5500-$6500

-Availability: As discussed earlier, most likely 3-4 months out from testing ( a guess), then it has to go into production. Though this might now be much of a con really because you are going to want to wait for your car to fall out of warranty before you purchase anyways so its prob a good thing its not going to be ready for a while

- Performance / Spool: As you will be able to see from the graphs below. Even with the same size A/R turbine housings, no matter what the vendor whats to tell you, independent testing has shown the GTX turbo of similar size spools very similar and in these tests FASTER than the EFR, and holds power nearly the same. Even the smaller 7064 will most likely not spool as quickly and is not capable of as much flow as our garrett set up, our wheels flow 8 lbs/ min more than a 7064, and 3-4 lbs/min than a 7670. Now take into account the fact that we are using the stock housing which will spool lightening quick and this upgrade will be using a very large A/R divided housing and an after market manifold. Expect big single style spool, IE full boost by 4000-4500 RPM depending on the turbo you choose. If you are going the full 800 BHP option (we have no idea how much the N55 can even handle then spool is something you will live with) if you are going the 550 WHP option, why would you want to deal with turbo lag when you can get near factory spool up using the stock manifold and housing? If these turbos were that much more efficient or that much better I would say so, but the facts and independent testing prove this is just not the case. A comparable size GTX matches them in almost every category and are close to half the size. Now this is not all the testing that has been done, there is a lot more out there, the EFR's are very efficient and awesome turbos, but the claims that they are head and shoulders above the GTX's turbos is just not the case. Feel free to do research and post in this thread what you find. I just ask lets keep the discussion constructive. This article here is very very informative and gives pluses and minuses to the EFR and GTX.

http://blog.perrinperformance.com/bo...sed-and-tuned/
http://blog.perrinperformance.com/bo...-tuned-part-2/


- Tuning: The stage 3 style upgrade not only changes all the hard parts it also gets rid of the factory vacuum actuated wastegate, and other parts on the factory turbo, what this means is, you now have serious hoops to jump through to control boost as the DME was never meant to control a boost operated wastegate. Think back to when the tuning first began on the bigger singles, boost control was one of the main issues and switching from vacuum to boost actuated gates were the reason. Not only is the N55 tuning no where near where the N54 is, this vendor now wants to start throwing things at DME that have been known to cause serious issues. All a recipe for a very hard time even once you get it installed

Ok with all that said: Here are some pictures of the GTX and EFR side by side so you can see the size difference, then you will see independent testing of the EFR 7670 and the GTX 3076. I tried to remain as factual as I could, but obviously I am biased towards our upgrade, but I truly believe the hybrid is the much better, and much smarter choice for 90% of the N55 owners out there.

Some comparison flow numbers as well:

If you correct all to the same inlet conditions and go by the maximum airflow on the charts:
GTX3076R - 65 lb/min
EFR7670 - 62 lb/min
GTX3071R - 57 lb/min
EFR 7064 - 56 lb/min

If you correct to the same inlet conditions and look at max flow while maintaining 60% efficiency:
GTX3076R - 64 lb/min
EFR 7670 - 60 lb/min
GTX3071R - 57 lb/min
EFR 7064 - 54 lb/min

On the turbine side:
GT30 T3 0.82 A/R - 23 lb/min
EFR 7670 - 24 lb/min
GT35 T3 0.82 A/R - 27 lb/min

Thanks for taking the time to read this.

[CombatNinja]

[fasteddie222]

+1

[Tony@vargasturbotech]

If you guys are expecting any sort of back and forth drama, its not going to happen. This is a factual comparison and if it gets derailed I will delete it. Pretty sad instead of having an opinion or something constructive to say, you pick up popcorn hoping for drama to start.

[CombatNinja]

Nice reply. Your post was intended to stir the pot. Period. I guess suggesting that I am in to watch this unfold is not kosher with you. You tuners are such bitches sometimes.

[Shogun1122]

I'm just going to take a wait and see approach. To me all that really matters is results. Both options are appealing.

For me, if the Vargas approach works as is claimed it is more appealing as I don't really want anything more than 500 hp and it retains as much oem as possible.

This car is my dd so it has to be reliable. Not that the rb approach won't be.

I think that all the guys looking to go deep into the 10's are most likely going to go with rb. I just don't thing that the Vargas option will get them where they want to be.

It's almost like the rb option picks up where the Vargas option leaves off.

[Tony@vargasturbotech]

Originally Posted by CombatNinja

Nice reply. Your post was intended to stir the pot. Period. I guess suggesting that I am in to watch this unfold is not kosher with you. You tuners are such bitches sometimes.

Well, me nor Rob are tuners. So slightly confused, on that. If making an actual comparison thread so people can understand the differences is stirring the pot then hmmmmmmm. You annoyed Rob by putting a premature price on his upgrade and now you just sit and wait for drama between the two. You sound like a fun customer to work with. Rob, you can have this one. Cheers

[turugara]

I think the test for me would be how reliable either kit makes power on a road course over a really hot track day, without meth.

[CombatNinja]

Excuse me for referring to some guy who makes go-fast bits for cars as a "tuner". Why don't you let us know what your title is so that nobody insults your royal highness in the future? You took my whole post wrong and now you are just acting like a douche. I like how you refer to your competition as "another vendor" in your original post and now you are using the guy's first name. You got your panties all in a bunch and your professionalism went right out the window. Nice.

[Tony@vargasturbotech]

Originally Posted by turugara

I think the test for me would be how reliable either kit makes power on a road course over a really hot track day, without meth.

A big single is going to provide a much less road course friendly power curve, the lag coming out of the corners is going to very prominent. Both will be very reliable, it's gonna come down to other upgrades, oil coolers, good fmic, etc