280 vs 272
Originally Posted by Tom Sawyer
I will be on a 3076R and well-tuned AEM EMS shortly. Is there any reason to go 272 as opposed to 280 given that setup? With the versatility of the AEM I can't see any downside to going bigger. Your thoughts?
Tom
Tom
l8r)
Last edited by Ludikraut; Dec 16, 2005 at 11:35 AM.
My 280s set at +2/0 (don't try this without expert tuning) spool as quickly as my 272s did at -3/-3, both configurations reaching full boost by 3500rpm with a TME 16G Ti/Al turbo.
- However -
With the 280s I made 30 ft/lbs greater torque than with the 272s, reached peak torque ~200rpm quicker, with no change in boost pressure. This is probably more reflective of the cam timing than the cams, but the point is I definitely didn't lose any torque by going to the 280s, so the notion that one loses torque with the 280s is baseless and is dependent upon tuning accuracy and other factors.
Despite the advanced cam timing with the 280s, I reached peak power at 6400 rpm, just as I did with the 272s set at -3/-3. The difference is I made 16whp more with the 280s, again with no change in boost pressure.
Note: This was all done with a Dyno Dynamics dyno, so tack on another 12-15% to those differences for Dynojet numbers.
I did however install a new IC at the same time as the HKS 280s, so maybe there is some difference there, but from what I've seen, most of the observed difference is due to the cams, the timing thereof, the capability of the tuning hardware, and the skill of the tuner.
- However -
With the 280s I made 30 ft/lbs greater torque than with the 272s, reached peak torque ~200rpm quicker, with no change in boost pressure. This is probably more reflective of the cam timing than the cams, but the point is I definitely didn't lose any torque by going to the 280s, so the notion that one loses torque with the 280s is baseless and is dependent upon tuning accuracy and other factors.
Despite the advanced cam timing with the 280s, I reached peak power at 6400 rpm, just as I did with the 272s set at -3/-3. The difference is I made 16whp more with the 280s, again with no change in boost pressure.
Note: This was all done with a Dyno Dynamics dyno, so tack on another 12-15% to those differences for Dynojet numbers.
I did however install a new IC at the same time as the HKS 280s, so maybe there is some difference there, but from what I've seen, most of the observed difference is due to the cams, the timing thereof, the capability of the tuning hardware, and the skill of the tuner.
For you that don't know the difference between a DD and DJ, this is the equivalent of 400+whp on a Dynojet. . . and I haven't turned the boost past 25psi.
Next dyno session will show the addition of the SMART upgrade for the Xede, Buschur's EVO-9 20G with Ti/Al wheel, and 30psi in the midrange.
Next dyno session will show the addition of the SMART upgrade for the Xede, Buschur's EVO-9 20G with Ti/Al wheel, and 30psi in the midrange.
Originally Posted by Ted B
For you that don't know the difference between a DD and DJ, this is the equivalent of 400+whp on a Dynojet. . . and I haven't turned the boost past 25psi.
Next dyno session will show the addition of the SMART upgrade for the Xede, Buschur's EVO-9 20G with Ti/Al wheel, and 30psi in the midrange.
Next dyno session will show the addition of the SMART upgrade for the Xede, Buschur's EVO-9 20G with Ti/Al wheel, and 30psi in the midrange.
Sweet power and awesome info for everyone
. I have read it before myself when you first posted the info.
