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Precision 6870 CEA GEN2 Release

Test Results by Sound Performance

The time has finally come! We are officially able to announce the highly anticipated 6870 CEA GEN2 from Precision Turbo & Engine and release our test data. I will tell you upfront, it's exactly what we were promised and everything that we hoped for. I had the privilege of enjoying the 6870 CEA over a weekend's time and can personally attest to how much fun it is having a turbo this size making this much power!

I apologize for the dirty turbo pictures. We were so excited to start doing the testing that I didn't get a chance to snap and pictures of it out-of-the-box.

Test Mule:
SP Built 3.0L Motor w/ SP-spec Wiseco 10:1 pistons, Manley Turbo Tuff 625+ rods, Titan Billet Mains, ACL-X Bearings
SP Built Head (stock ports, performance radius valve job, standard size valves)
GSC S2 cams w/ Supertech valvetrain
SP Racing F1 Manifold (OG single-wastegate prototype design)
No QSV used during testing
4" Trucker Flapper Exhaust (no Cheetah pipe this time :))
GReddy 3-Row FMIC
SP 3" Cold-Side & 4" Hot-Side Intercooler Piping
ProEFI 4" Throttle Body
ProEFI Pro128 Standalone EMS
Test Fuel: Ethanol

We have 4 different setups to present data for. They are as follows:

#1 - PTE 6870 CEA GEN2 .81 A/R (undivided)
#2 - PTE 6870 CEA GEN2 .96 A/R (undivided)
#3 - PTE GT42-7275R CEA .98 A/R (divided)
#4 - PTE 6766 CEA GEN1 .81 A/R (undivided)

As you can see, this collection of turbos will allow us to present a very diverse "best case" scenario for power output of three different turbo sizes, two of which being the 6870 CEA with two different turbine housing sizes. It should also be noted that the PT6870 is the only CEA GEN2 turbo in the bunch. There will be a few additional variables to discuss but for now, let's get to the pictures, videos, and dyno graphs.


























 

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Discussion Starter #3 (Edited)
RESULTS

#1 - PTE 6870 CEA GEN2 .81 A/R (undivided) | Fuel: 77% Ethanol

810whp 645wtq @ 24psi (base boost) - 36.08psi EBP
865whp 726wtq @ 25psi (peaks at 28psi drops to 25psi) - 50.56psi EBP
976whp 843wtq @ 34psi (peaks at 36psi drops to 30psi) - 55.25psi EBP
1059whp 922wtq @ 37psi (peaks at 40psi drops to 31psi) - 56.85psi EBP




#2 - PTE 6870 CEA GEN2 .96 A/R (undivided) | Fuel 69% Ethanol

955whp @ 33psi - 49.7psi EBP
1028whp 855wtq @ 33psi (peaks at 37psi drops to 29psi) - 50.84psi EBP




#3 - PTE GT42-7275R CEA .98 A/R (divided) | Fuel: 75% Ethanol

731whp 498wtq @ ~17psi (creeps to 20psi) - 21.94psi EBP
865whp 668wtq @ 26psi
956whp 749wtq @ 29psi (peaks at 31psi drops to 29psi)
993whp 799wtq @ 31psi (peaks at 35psi drops to 30psi)
1010whp 837wtq @ 32psi spinning tires (peaks at 34psi drops to 31psi) - 51.46psi EBP




#4 - PTE 6766 CEA GEN1 .81 A/R (undivided) | Fuel: 69% Ethanol

836whp 662wtq @ 25psi (base boost) - 35.78psi EBP
905whp 785wtq @ 30psi (peaks at 31psi drops to 27psi) - 50.56psi EBP
949whp 822wtq @ 33psi (peaks at 36psi drops to 29psi) - 56.43psi EBP




COMPARISON/ANALYSIS

6870 .81 A/R 1059whp vs 6870 .96 A/R 1028whp

As you can see here, the .81 A/R was the optimal choice for my 3.0L 2JZ motor. The .96 A/R only added lag and if you reference the boost spool comparison below, we also weren't able to see as much boost with the duty cycle all-in. This tells us that we were at a limitation of the compressor wheel flow itself and not because of back pressure. We were monitoring back pressure but I didn't include the data here since it wasn't a factor. Based on this information, there's no need for the bigger hot side unless being used on a larger displacement motor.




7275 Div .98 A/R 1010whp vs. 6870 .81 A/R 1059whp

This comparison made me want to cry! It's worth noting that this is a GT42 frame 7275 CEA and is a class-legal turbo. Spool-wise it's identical to a 7175. The 1010whp graph shown here is not a best-case scenario. There was no one sitting in the hatch and the tires spun hard. It also should have been revved out higher. Since I was preparing for FL2K14 at the time, I called it quits on the dyno and loaded up the trailer. Unfortunately this is the only dyno graph I have to fairly compare my GT42-7275 to the 6870. After driving both setups, I can tell you that the GT42 holds power up top stronger. In the end though, the 6870 makes the same power as the 7275 at all boost levels!!




6766 .81 A/R 949whp vs. 6870 .81 A/R 1059whp

Before we talk about the 6870 here, let's talk about the 6766 making 948whp! I was blown away at this. Next, we have to address the spool difference (or lack thereof!). I questioned the dyno graphs since tire spin was an ongoing issue and that can start to skew the dyno graph itself. After pulling the logs and generating the spool comparison you see below, I can confirm this minute 70rpm difference in spool between these two turbos. Based on my experience, I feel that my setup is slightly holding the overall spool results back a bit. My setup is definitely not optimized for spool with the long-runner F1 manifold, 4" cold-side pipe, 4" throttle body, large plenum intake manifold, and GSC S2 cams. I personally feel that a setup with a little less aggressive flow components would see a larger difference in spool between the 6766 and 6870 (nothing overly dramatic though). I was going to do a little more digging through logs to see if I could draw a more solid conclusion of this theory but haven't had the chance yet.




6766 .81 A/R 949whp vs. 6870 .81 A/R 1059whp vs. 7275 Div .98 A/R 1010whp
NOTE: Different color coding to help differentiate data from 3 separate turbos

I have the colors different for this one so don't confuse the HP and TQ curves with the 3 separate turbos being listed. This one pretty much speaks for itself and sums everything listed above.




Spool Comparison

This data is compiled directly from the logs pulled from the ProEFI. I went every 500rpm in the log, interpolated where required, and created the graph you see below to confirm what types of spool times we were seeing with all four setups tested. This also shows the capabilities of peak boost as I derived this information from the all-in dyno pulls.




http://www.youtube.com/watch?v=iG53McBNJ88

http://www.youtube.com/watch?v=9zvSj3bg14s


Thanks for looking. I hope this data has been presented in an easy-to-understand manner (as easy as possible with this overwhelming amount of data) and has been useful to you!

As I imagine you've hoped, we have the PT6870 CEA GEN2 officially available for purchase!

Precision PT6870 CEA GEN2 Waterless DBB
SP (4" inlet, 2.5" outlet) or HP (4" inlet, 3" outlet) Anti-Surge Ported Compressor Housings
T4 V-Band .68 A/R, .81 A/R, .96 A/R Turbine Housings
List: $2399.99
CLICK HERE to view/purchase PTE 6870 CEA GEN2 on SPR e-store

www.spracingonline.com
www.precisionturbo.net
 

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Kappa Check 1 2
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damn you steve! ^^

On topic:
 

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GE with boltons ;)
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damn you steve! ^^
I literally thought this to myself also!

In for divided housing.

FS:6766 1.00 a/r divided.... lol
 

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I haven't even installed my 6466 and I don't to anymore... but I don't have a built rear end so I guess this will be my turbo when that time comes. I have virtually the same motor setup but I have some bowl work in addition.

Beautiful setup. Can't wait to do some business with you guys!
 

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Damn!!!!! I'm so happy I held out lol. my setup is changing!
 

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Great info and the turbo looks amazing. Not that familiar with the 2j, why does it not hold boost to redline? Surprising that you would be able to get more boost and power out of the .81 than the .96 AR.
 

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Great info and the turbo looks amazing. Not that familiar with the 2j, why does it not hold boost to redline? Surprising that you would be able to get more boost and power out of the .81 than the .96 AR.
The back pressure of the .81 wasn't limiting the power, it's out of compressor wheel.
 

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Seems like an amazing turbo. Outperforms both the size smaller and the size larger! With gains everywhere!

do you guys tap the turbine housing for the back pressure sensors?
 
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