I've looked in the archives, no dice. Is the T5 the evolutionary name of the Turbo? Or is (was) it an upgraded, concurrent model ?

Thanks!

In '97 Volvo introduced the 850 GLT as a low pressure turbo designation causing the need for diffrenetiation between the two turbo modles. Thus the T5 designation was born.

'94-96 850 turbo's and '97-'00 850/S70 T5's have the same high pressure turbo.

How does "T-5" differentiate from GLT any more than "Turbo"?

The GLT turbo models (turbos introduced on GLTs in 97) use

a smaller turbo. It builds less boost but does build boost

faster. This is called a Low Pressure Turbo. The High

Pressure Turbos (T5s) obvously build more boost and flow more

air. Note, the torque curves I have seen for LPT and HPT show

the HPT has more torque at all engine speeds (many think the

LPT has more -- it probably just has less turbo lag).

The HPT engine has thicker cylinder walls (and thus displaces 2.3

liters vs. 2.4 for the LPT). The thicker cylinder walls can handle

more heat stress. Along the same lines of handling heat are

changes to the pistons and other engine internals (including

sodium filled valves) on the HPT engine. The HPT also uses oil

cooling for the crank (a stream of oil is sprayed on the crank).

Sometime around the 2000 model oil cooling was introduced on the LPT

(and maybe the base engine, not sure). So, the HPT is basically

beefed-up to produce lots of power while the LPT does not use all

of the same expensive parts; but, the LPT is not as stressed so

it does not need all of the expensive parts.

The 2001 LPT produces 210 lb/ft torque wich compares quite well

to the 222 lb/ft of the 850 high pressure turbo models.

I was commenting only on the name. To change the name from turbo to T-5, (which means turbo, 5 cylinder) wouldn't seem to go very far in alleviating confusion with the GLT. (also a turbo, 5 cylinder.) If the goal of rebadging was to eliminate confusion between the models, why not 850-HPT and 850-LPT?

Good point. In 97 the only way to know the GLT had a

turbo was to look under the hood. Volvo never mentioned it

in the badging (like they do now) and they seemed to have

wanted to keep the fact the the GLT now had a turbo a

secret (I don't recall any adds or much publicity). Maybe

they were afraid it would eat into T5 sales?

Don't forget that on the turbo models, whether it be LT or HT, the exhaust was rectangular..... a way to distinguish w'out looking under the hood between turbo and non-turbo models. Both T-5 & GLT had this trademark.

For marketing purposes, the turbo was re-badged as a T-5. The turbo was always a T-5 in some markets.

Difference? About 50hp. LPT is around 200, T5 is about 250.

The 850-Turbo has a high pressure turbocharger, same as the T-5. First U.S. year was 1994 with 222 BHP.

In 98 the T5 went to 236 bhp and the 01s are at 247.

They keep squeezing more and more out of that little 2.3

liter engine.

How? If it is hardware, I want to put it on my 94 854 Turbo. I know the fuel injectors are different, anyhting else?

Prospero

The downpipe is a bit different on the 70 series. Also,

the engine management system is probbaly more precise allowing

the engine to run longer at higher boost (the R models allowed

max boost for about 10 seconds, the 70 series will just hold it

as long as no pinging or overheating occures) . Variable valve

timing introduced in 99 (or was it 00) also must help.

The LPT engine has really improved. The 01 Low Pressure Turbo

produces 210 lb/ft torque -- very close to the 850 turbo models.

in the torque area.

I thought the variable valve timing was only for emission purpose ONLY.

What a waste of technology that would be...

Emissions is only one of the compromises a dumb/std/fixed cam profile must

worry about.

Also, at WOT, emissions "don't count"...