LPT Vs "Normal" turbo on a 900 classic
Ash
I'm a bit of a Saab novice, I just need to know what the difference is
between a LPT and a normal turbo on a classic 900,
TIA,
Ash
Dave Hinz
I don't think LPT was offered for the classic 900. What part of
the world, and do you have a specific car (which year) in mind, or
is this more of a general background question?
Dave Hinz
Paul Halliday
12/05/2004 20:53:
> I'm a bit of a Saab novice, I just need to know what the difference is
> between a LPT and a normal turbo on a classic 900,
Hi Ash,
Simply put, the LPT boosts up to around half a bar of boost - hence, Light
Pressure Turbo. The LPT is only an option with the 16V models - the full
turbo models could be 8V or 16V, usually referred to at the T8 and T16
models around these parts.
The "normal" turbo will boost higher (typically 0.6? bar for the T16, 0.75
bar for the T16S/SPG or 0.85 bar for the Carlsson/Ruby models) and has the
benefit of the APC system, which can be regarded as an electronic boost
controller. The theory is, APC will provide the optimum performance for the
car given the vast number of variables - ambient temperature, air pressure,
fuel grade, etc. It is an excellent knock protection system. LPT cars do not
have this.
APC is well worth it, but I've not heard anyone grumble about their LPTs.
They're different cars and each have their merits - both are very
customisable. Take a look at http://www.900aero.com/ for wads of information
about the APC system ... And tuning it :)
Paul
1989 900 Turbo S
http://saab.go.dyndns.org/
Paul Halliday
http://www.saabmuseum.com/900/my.html - look at MY1990 :)
They're the Mitsi turbo without APC - the turbo is controlled traditionally
by the wastegate actuator that simply takes a pressure from the turbo, or
manifold.
Paul
Dave Hinz
Hm, I'll be darned. Never run across one of those, maybe not for the
USA'n market?
Dave
Paul Halliday
Yeah! I doubt a "balance between performance and fuel economy" would've gone
down well over your side of the pond :)
Over here, they're very popular among Saab tuners. They can be upped from
145 BHP to around 185-200 BHP pretty easily. Just wind up the wastegate
actuator and add an intercooler. As you can imagine, the engine bay is
pretty sparse, so there's loads of room in there for intercoolers, water
injection systems, etc. I know of some that have had APC (or parts of it)
grafted in to monitor knock via a dash mounted LED (pin 19 on the 25 pin box
IIRC). Knock is thus controlled by the foot! I would regard full APC as the
better option for uprated models, but ...
Paul
MH
Then read this first;
http://en.wikipedia.org/wiki/Saab
> I just need to know what the difference is
> > between a LPT and a normal turbo on a classic 900,
> I don't think LPT was offered for the classic 900.
> ...
Yes it was!
A friend has a 16v 900S (LPT - Low Pressure Turbo) there is no intercooler
or boost guage
I have an 8v 900T (FPT- Full Pressure Turbo), is has an intercooler, a
boost guage and APC (Automatic Pressure Control).
------
MH
'72 97 '77 96 '78 95 '79 96
'87 900T8
Ash
"Ash" <ash...@hotmail.com> wrote in message
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Ash
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Richard Sutherland-Smith
Dave Hinz <DaveM...@duck-creek.net> wrote:
1990 Light Pressure Turbo 145bhp
1991 Light Pressure Turbo AERO 145bhp
source "SAAB 99 and 900 The Complete Story"
--
Richard Sutherland-Smith
19 Webb Road, Wanganui
New Zealand
75 99
87 900T
96 9000 Aero
76 Lotus Elite
chicchomu
900S.
At the time, in Japan, the 900 line-up was as below.
"900I(normal aspiration)":125hp
"900S(LPT), 900S cabriolet":145hp
"900turbo(HPT),900turbo cabriolet":165hp
"900turbo16S(HPT), 900turbo16S cabriolet":165hp with special suspension
900turbo16S seems almost correspond to SPG in the States.
All models are controlled by not BOSCH ECU but LUCAS ECU, and this line-up
is basically the same as Europe one.
The boost of LPT is limited to 0.45bar without APC or intercooler but the
other parts including ECU are common to the "normal" turbo except the
"over pressure switch" that cuts the fuel at 0.6-0.7bar in 900S but
0.9-1.0bar in 900turbo.
At first, you must be able to install easily the intercooler and piping
into your 900S without any special adjustment.
The problem is the APC. The APC seems to be also installed but it is not
so easy.
The easy alternative is EVC (a kind of boost controller) by HKS or any
other manufacturers, though I am not sure you can get this device out of
Japan.
The EVC has the almost same machanism as the APC (in other words, the APC
is the original and primitive model of the EVC) except the knowking
sensor, but can control the boost more quick and linear than the APC and
you can set the boost level up as you like.
The boost of 900turbo without any tuning is limited to 0.9-1.0bar as I
mentioned above, but in actuality it boosts up to about 0.7bar at most
under the good condition.
So you might be able to feel more power than 900turbo by the EVC's quick
response even if you set the 0.6bar boost considering a little
overshooting.
If you want over 0.7bar boost, you must adjust or replace the overpressure
swith for 900turbo (you can make an access to the part by removing the
under panel from driver's side at left handled car).
If you want over 0.9-1.0bar boost, though I do not recommend considering
the total and sure balance, you must resolve the problem of knocking (EVC
does not have knocking sensor) and need total tuning including the fuel
system etc.
chicchomu
I recommend you introduce a turbo gauge for monitering the boost exactly.
MH
Looks really nice, and has an Aero kit as well.
It is very similar to the one my friend has - a 1992 or 1993. He paid around
10000 euro for it, Italian import into NL. Looks like UKP1700 is a bargain
but there are 5 more days to go.
--------
Henrik B.
"MH" <nom...@nowhere.no> skrev i en meddelelse
news:c7u2dc$31l$1...@news2.tilbu1.nb.home.nl...
> boost guage and APC (Automatic Pressure Control).
APC = Automatic Performance Control
Just to clearify. ;o)
M.v.h.
MH
> APC = Automatic Performance Control
> Just to clearify. ;o)
OK, my owners manual (in Dutch language) is not clear on that.
In the APC section it only mentions 'turbodruk regeling'.
mvh Martin H.
Paul Halliday
12/05/2004 22:13:
> What are your thoughts on this...
>
>
> http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=18263&item=2477996013
> &rd=1
To be fair, it seems a little high for an LPT without body kit and no
leather. That said, it's in great condition - black is a bad colour for
keeping shiny. If it's pristine otherwise, it might well be worth it - you
can source leather interior and the Aero bodykit for scappers.
My 0.02 UKP :)