While the above graphs show the EFR7670 runs off the map at redline, and still makes great power. Check this out!
The EFR being quite a bit smaller than the GT3582R (in the compressor map department) it easily holds it own with the GTX3582. The faster spooling nature the fact it easily keeps up until 6000, I say the EFR7670 is worth a measly loss of 15WHP. Also during these tuning sessions, I had pulled some timing from the map because I was getting some increased engine noise as I was during the 1.7bar runs. I suspect that had the runs been done with race fuel, I would guess that the spread in HP would have been almost nothing. But as I said before, these tests were done to represent what most customers do with their cars.
And I bet that if I did a drag race with both the faster respooling nature of the EFR is going to make it a faster car. If you are running to 8000rpm or a lot more boost, then the GTX3582 comes into play, or the EFR8374. But in this case the EFR7670 is versus the GTX3582R w/.82 I would still pick the EFR7670 as on the road, this turbo feels significantly faster off boost and also between shifts.
On the Dyno Conclusions
The EFR7670 is a turbo that I personally feel compares more like A GT3582R, but spools faster on the dyno (like a GT or GTX3582R w/.63Ar). Comparing the EFR7670 to a GTX3076, its slightly laggier, but that lag is a trade off for more power. Since the GTX3076R and EFR7670 have very similar compressor maps, the HP gained is do to the higher flowing turbine housing/wheel. Since the dyno is very controlled, and a high loaded run, in all these tests the super light Titanium Aluminide turbine wheel doesn't come into play at all. What this does show is the turbine wheel and compressor wheel design is a notch up over the Garrett GTX stuff. From what I have seen Borg Warner has designed a turbo that does what they say it should. It makes more power and spools faster than the GT3582R.
On the Road Conclusions
My conclusions are this. The dyno conclusions do not match what I "feel" on the road. On the road, I feel like this is much more lively than the GT or GTX3076R. Its interesting as in some road tests the EFR7670 shows the same spool up RPM as the GTX3076 w.82ar, but it feels so much snappier between shifts light load low RPM shifts. Meaning the normal day to day 2000-4000RPM shifting is about 50% better than it was before. In some logs I notice that the GTX would show say 2-3psi of boost at these really low RPM's, where the EFR is showing about 5psi. Its only a couple PSI but that makes huge difference in how it feels. You can see this on the dyno graphs where the EFR is making more TQ at 2000-2500.
Under full throttle high RPM acceleration, again the car feels a bit faster. It feels like Its right back on the power. When comparing this to the GTX3582R graphs I have, it blows it out of the water. When comparing it to the GTX3076, its very close in respool time, but there is this thing that just "feels" better.
I am compiling some road going plots of the GTX3076R and EFR and I think this will show what I am feeling.
I used to think that there are lots of turbos out there, depending on the size of the turbine, its going to spool at a particular RPM, depending on the compressor wheel used, your redline and boost, its going to make a given HP. So then it was a matter of what size wheels Garrett and others used to create a given turbo and it was a balancing act of spool and HP. But Borg Warner has proven that there is some magic left in its turbos in that it actually spools faster than its comparable GTX/GT3582R turbo and makes almost the same power, if not more on the GT3582R.
PERRIN Performance will hold off on making conclusions about the entire EFR line when we are able to test an EFR7064 and the 8374. After seeing when these spool up, and the HP they make, I think we and other customers can decide if the EFR is here to stay. What I suspect is that the other EFR turbos are going perform better in one way or another to the Garrett product but will fall in between Garret part numbers in some way. That is not bad as it will make for a big balancing act of price, spool, HP, durability, features and feel.
What is next? I am going to beg and beg to get a test EFR 7064 turbo and in the mean time, I should have the test 8374 turbo from Full-Race any day and that will be bolted on and dynoed. I think this turbo will make more power, but I hate to say, I am not going to be running it high enough boost or high enough redline to really see where it kicks butt. For these tests I will be dynoing it purely to see when it builds boost. I will do the 1.7bar and 1.9 bar runs just for fun, but its not going to be making that much more power.....right???
Over the last couple of weeks I have been asked: Are we giving up on Garrett? No way! These turbos are very well proven and while they sometimes have a bad name in the quality department, I can say over the last 2 years we have had 3 warranty issues come up. Relative to how many we have sold, that % is very very low. I see that they will always have their place and customers will always want a Garrett turbo with an external wastegate.
Lots of fun stuff to come over the next few months!