Good observation.

 

It is still spooling significantly slower than one would expect a 2.5 to be. My JB Red, which should spool about like a standard EF3, hits 20# by 3700-3800 RPM. The whole point of the 2.5 is that it should spool markedly quicker than a standard EF3.

Your 4-5 half turns translates to merely 2 complete 360* rotations. You have to try preloading it more to see if you can get it to wake up earlier.

 

Here's another boost graph... still working out some issues. The boost curve is fantastic though... hits 25 psi at 4000~ RPM, 28-29 by 4400, and holds 27+ PSI out to redline.



Would you suggest 7-9 half-turns of preload then? Where do I hit the limit of diminishing turns with preload on the arm? I can go preload it more right now.

I am going to say this: do not bother with the 18 psi spring in the WGA for this turbo. Go straight to 22 psi. I have no clue why MAP thinks it's OK to include the 18 psi spring in the WGA. This turbo REQUIRES the 22 psi spring.

 

check my thread last page: https://www.evolutionm.net/forums/ev...f2-5-a-10.html

 

Spools pretty well. You have any tentative numbers for 27-29 psi?

 

Honestly it spooled right where I thought it would. It does spool a few hundred RPM quicker than an EF3 on average... Remember this is a non-mivec Evo 8 you are looking at. The turbine does appear to make significantly better torque numbers according to evotuner's dyno. So the spool numbers don't quite seem to show it all. The only question for me now is... at what power level (airflow) does that EF2 turbine become a bottleneck and the EF3 turbine becomes more beneficial in the trade off?

 

Where are his torque numbers in comparison to mine?

Also when I made 456 on the dyno that translates to over 500 on a dynojet which seems to be the norm for dyno results nowadays. I cant say that it really ever becomes a "bottleneck" what more do you want from a middle of the road (sized) stock frame turbo? My graph never fell flat on its face in the higher rpms, the turbo kept pulling. If you want 600 get an EF3 or EF4

We'll see here in about a week once mines rebuilt with a new turbine side if we can gain a couple hundred rpms and say 20ft lbs of tq

 

Hi, Buddy No, i'm fine with my Ef2 now. Looking forward to see some new results from your rebuilt soon...

 

Are u referring to my last post? if so, I did mention "according to evotuner's dyno". If my info is correct the Ef2/2.5 turbine is a 65MM TD06. If that's the case it has displayed good torque numbers on yours, and a multitude of FP Green's out there (even though FP uses a slightly different aero). So it's reasonable to assume it will produce better torque numbers compared to an EF3 on average as yours has shown.

Well considering you are only around the 50 lb/min range of compressor that flows 60 lb/min, you really aren't pushing that compressor or turbine. Remember a hybrid is only a good match if the turbine wheel will support the compressor flow. So it remains to be seen if that compressor is a good match for that turbine on the higher pressure ratio and flow numbers. The larger 67MM turbine will flow more. Period. So there will be a point of diminishing returns where the EF3 will be much more beneficial in overall performance. Where that exact point is, is hard to say. Only time will tell, but it's reasonable to assume that this little hybrid is good for a small window of power, pressure ratio, and needs a more focused setup for it to be beneficial. Remember this isn't the first time a turbo manufacturer has built a hybrid out of existing turbos. For instance the GT3076, GT3082, and BW262. All of these hybrids were failures at least a certain extent. For reasons of mismatching compressors with a turbine that won't support it. So like I said, time will tell.

well good luck to you. Look forward to the results.

 

sticking with my stock IX turbo, dont see the point. If i want >500whp ill consider an ef3 or red. Other than that not worth the hastle in my opinion.


BBK Full(Non BB) still seems like the best mid 400's turbo while retaining similar to stock spool.

 

any news on this sir?

 

I got mine tuned but my fuel pump needs to be replaced so I wasnt able to finish the tune. We ended at 393hp @ 24psi on 93. No e85 tune for now. My tuner said it has some more in it but he cant up the boost until I replace my fuel pump. I'm still on the stock cams so I know thats holding me back quite a bit. Im very happy with how the car sits now though. It pulls smooth all the way through redline. I love that it does not run out of breath up top like the stock turbo did.

 

Was this on a dyno ?

 

graph?

 

Yes it was on a dyno. I think it was a dynojet but cant be 100% as it was the first time I have been to that shop. Unfortunately, I dont have any graphs because his printer was not working. I have done a few pulls on the street using virtual dyno to compare and it was very close to the "real" dyno #.Those are the only graphs I have but they are on my laptop so I cannot post them up at the moment. Overall, im very pleased with the turbo and its a great daily driver upgrade for sure!