During the press days at the Geneva Auto show I had a long talk with Manfred from Hirsch, we talked about engines and engine tuning, and after that I had a better picture on what they do and why they do it.
Saab changed the 2L engine in the 9-5 between MY ’10 and MY ’11. The engine from MY’10 has the GM internal code of LDK and the engine of MY’11 is called LHU. The differences between both engines are not big, but enough for Hirsch to have to redo all the work done with the LDK engine.
Those engines have a different engine control units. While the older one uses a Bosch Motronic ECU, the newer engine uses the GM-Global ECU, although I’ve sometimes heard the name Saab system 3.
This (I will call it System 3) ECU was developed by the guys of GM Powertrain Sweden in Södertälje, nearby Stockholm.
Many of you may remember that GM sold the Saab engine production facilities in Södertälje in 2008 to the Austrian company AVL. Well the engineering department that developed System 3 was also sold to AVL.
Here are some important passages from the press release in 2008.
The sale of the Södertälje Powertrain organization also announced today includes the site, buildings and the transfer of the employees to AVL, as well as an Engineering Service Agreement for the first two years of AVL’s ownership, said Kjell ac Bergstrom, Executive Director GM Powertrain Sweden.
The service agreement secures GM Powertrain Sweden uninterrupted access to the expertise and services at Södertälje Powertrain Engineering AB (SPEAB).
SPEAB currently has 117 employees and an annual turnover of 150 MSEK. It will continue to deliver services such as Trionic Engine Management System development and calibration to the GM Group.
Putting all together, for me System 3 is the latest, and sadly last, incarnation of the Trionic engine management.
Going back to Hirsch, Hirsch created last year an engine upgrade for the LDK, but only for the automatic transmission. From last summer they had to redo the whole work, as the System 3 and the Bosch Motronic do the same things in a completely different way.
But for those interested, the engine upgrade for the LHU and LHU\BP, manual and automatic, FWD and XWD, is ready and the homologation is being done at this moment in Sweden. The upgrade should be available at the beginning of April.
They are planing to get this upgrade also for the 9-3 Griffin, but the power amount available on the 9-3 could vary from the value of the 9-5.
Hirsch has released two engine upgrades for the three TTiD4 engine variants that the 9-3 offers. The TTiD4(160) and the TTiD4(180) can be upgraded to 200 hp, the TTiD4(130) on the other side only to 170 hp. The reason is quite simple, Saab uses smaller brake discs on the TTiD4 and with those brake disks the amount of legally allowed power of the car is limited to 170hp.
In other words, the smaller engine could be upgraded to 200hp but then you would have to change the brakes otherwise the car loses the homologation and can not be driven on public roads.
The same will happen with the new 9-3Griffin petrol with 163hp, it mounts smaller brakes, and thus the maximum allowed power will be less than its 220hp counterpart.