you say that..... but when we did this on a TT racecar on gt30 frame turbo, we gained power and torque and spooled 1000+rpm sooner with much broader powerband.

in theory *potential* top end power could be effected, but also consider how hard you are running the turbo and the power band/delivery you are looking for... Its not all about peak figures on dyno plots but how its delivered, particularly in fwd application. 1.6bar in the TT as reference
 
From what i've seen in a friends ibiza 20vt with gt28rs and .86 ar he gained top end power compared to our usual .63 ars :).

also my setup with T3 .63ar 28RS and a friends identical setup-tune with T25 .63 ar, while tuning the unitronic file we noticed my setup drops .1 bar from over boost whereas his .2 bar

so it kinda helped me maintain bit more boost throughout the whole rev range.

havent dynoed -finished mine yet though so i dont know the figures as my clutchmasters fx300 broke down, but will do soon and let you know on the results :)
 
top end power wasnt what i was chasing, i wanted something that would spool earlier and more progressively so it was more 'manageable' power :) i used to have a mk3 ibiza 20vt with a GT28RS and that was a dream to drive with power delivery although a bit on/off (REVO) but retained traction most of the time... the GT2871R i had (.86) had no gradual power delivery and was just all out or nothing, so im hoping the new turbo will be much more friendly... and its always nice to have a new toy in the engine bay :D
re top end power, im limiting the revs to about 7400 anyway because of standard valve train so this was another reason to remove the .86
 
From what i've seen in a friends ibiza 20vt with gt28rs and .86 ar he gained top end power compared to our usual .63 ars :).

also my setup with T3 .63ar 28RS and a friends identical setup-tune with T25 .63 ar, while tuning the unitronic file we noticed my setup drops .1 bar from over boost whereas his .2 bar

so it kinda helped me maintain bit more boost throughout the whole rev range.

havent dynoed -finished mine yet though so i dont know the figures as my clutchmasters fx300 broke down, but will do soon and let you know on the results :)

is the sacrifice in response worth it though?
 
is the sacrifice in response worth it though?


Dont get me wrong.
I prefer response, quick spool (ok not to K03s standards :p) instead of that little bit extra in the high rev range.

Thats why i didnt go for the 2871 myself.

however i am pretty tempted to upgrade to the GTX2867R once they are out even though i havent finished yet with my RS setup :rofl: