The R models will be MUCH faster than the Low Pressure Turbo GLT models, but the R and the T5 models are pretty close. Supposedly the engine programming is such that the R models stay on the boost a little longer than the T5's.
--
Nathan Valles, Black 855R, MBC, tint, strut brace, RE 730's

I think the enhancement that would make it faster is a chip
to allow it to build more boost. Thats the easiest way to
make horsepwoer with a turbo engine.

I have a 98 S70 T5M (236 HP / 241 lb/ft) with a manual tranny and
it is pretty fast stock. But, it does not seem all that much different
then other turbo 850s/70s I see driving around here (turbo are a sporty
bunch and there are a whole lot of Volvos in the Bay Area). (No, we
don't drag race from stops but at freeway speeds you see people
using the car's horsepower all the time to pass and merge.)

If you look at the numbers as published in the automotive press, the fastest of the entire 850-70 turbo series is the C70 HP coupe with the manual transmission, which is also the lightest.

The published numbers in general show that manuals are quicker than autmatics and that lighter versions are quicker than heavier versions. The Rs do have more HP but in the case of the V70R at least is's all -and more- lost to the torque converter and the AWD system.

A V70T5 manual is faster than a V70R, about a second to 60.....

-Punxsutawney Phil

stiffer suspension, 17" rims, more options added...should be close, but 222 vs 240...18 hp is 18 hp.

Check out the specs at the TME website (http://www.tme.com/eng_index1.htm), click on Questions, see # 4 or 5.
--
(98 S70 T5SE misc mods, mostly lighting) (92 940GLE)