Thread: Petrol 2wd TURBO tech

VNT's don't seem to like petrol engines. Chrysler did it 25 years ago and then no-one else touchd them.
Porsche finally did it only a few years ago.

A more modern BB turbo would be a good upgrade. But most petrol's are turbocharged for top-end power rather than low-mid range. A better BB turbo will wake up sooner but beyond that anything you do to get more low end will reduce the topend.

Are you okay with that?

Ben,

Saab have put a long time into research and Development, and depending on whether your 900 is an early model with KJET or later model 16V with L jetronic injection,(What year is it?) depends on the possibilty of modifying for more output. Saab have attached a lot of in built engine protection to their later EFI engines, the B204 (2litre) and B234 (2.3litre) are easily capable of 400 to 500,000kms, in turbocharged form. They do this with knock sensing and boost / ignition control, and it is very good at conserving engines. I would say that adding a VNT will upset the factory management to the point that the ECU will take over and bleed off early 'detonation causing' boost and advance as this is what it is designed to do. I would look into the addition of a megasquirt, Haltech, Motec or Wolf system to overcome this. Then yes it is a very good idea fitting a VNT as long as careful mapping is employed. Water injection will work well, as will a larger intercooler and you'll obviously have to use a high octane fuel.

Good engines, pretty well unbreakable actually

JC

Dougal - for overall driveability around town, I would be happy to lose a bit of top end.

It seems some of the saab guys have been playing with VNTs...


JC - it is the 2.0 16V. As you say the APC system is highly advanced, however the turbo boost control is fairly simple, and should be able to work with a different turbo.

It seems though, from reading on the saab forums, that either the (unumbered) boost guage on mine is reading incorrectly, or my turbo is not working 100%. I will make sure the turbo and APC system are working as they should first.

They are very good cars but need a lot of maintenance, done on time, and preferably by someone who knows them well.

Eff all resale value once a few years old like most of the complex and maintenance heavy Euros.

Originally Posted by isuzurover

Dougal - for overall driveability around town, I would be happy to lose a bit of top end.

It seems some of the saab guys have been playing with VNTs...

Got any more info on that turbo? Looks like a wastegate and VNT actuator on the same unit?

BTW if you want to experience the opposite turbo petrol experience (small turbo that's always working) go for a drive in a VW 1.8T. Sadly the one I got to drive was auto, manual would have been waaay more fun.

Originally Posted by Dougal

Got any more info on that turbo? Looks like a wastegate and VNT actuator on the same unit?

Not much:
[ame=http://www.saabcentral.com/forums/showthread.php?p=1764244#post1764244]Possible newb questions? - SaabCentral Forums[/ame]

Originally Posted by Brian Hjelm

They are very good cars but need a lot of maintenance, done on time, and preferably by someone who knows them well.

Eff all resale value once a few years old like most of the complex and maintenance heavy Euros.

Fortunately this one has been regularly serviced by a saab specialist. It has been very reliable so far (for me and the PO, who is a mate). And the price I paid can't sink much lower!

When new they were comparable to a 911. They are a very nice car to drive, and apparently had more output than the claimed 185bhp.

Originally Posted by Brian Hjelm

They are very good cars but need a lot of maintenance, done on time, and preferably by someone who knows them well.

Eff all resale value once a few years old like most of the complex and maintenance heavy Euros.

Didn't know landrover owned Saab.

Originally Posted by Dougal

Didn't know landrover owned Saab.

lol..


Btw - the guy had the turbo "made specially", and doesn't know which model VNT it is based on. It seems an interesting idea though, the Saab APC system still has full control...