saab 9-3 turbo aerodynamic mods-help and suggestions needed!

[Drive Stick]

320, if your engine bay is anything like that on my 1998 saab 900 turbo with the 2.0t .. you should be able to quite simply install a filter in place of the stock air filter box, and it will suck in HOT air. In fact the shiny turbo heat shield you see there, I had made to lower intake temps since the stock one was missing. If I remove it, intake temps rise like crazy.



Fabricating under-body flat panels will be a great addition. Lowering the vehicle helps a lot, though most people on here aren't interested in that sort of modification it seems. Lower you are to the ground, less air travels under the vehicle / simple / cheap.

Blocking the intercooler would be a no good idea unless you fabricate an under-car airdam which directs airflow over the intercooler - the engine will run too hot under boost and high loads without sufficient air passing through it. (especially with a hot air intake installed.)

Fashion some wheel well covers for a cheap removable way to increase gas mileage.

[320touring]

drive stick- my engine bay is exactly the same except i have a t7 lump

I like the info on the air intake-looks a simple mod-i may just extend the air intake route rather than fit a cone filter.

Tomorrow i should be able to find locating points for aero mods

[aerohead]

Pushing the mpg from 32.2,to 42 mpg is a 30.43% increase.
To do that all with aerodynamic drag reduction would require cutting the Cd by 60.86%,down to Cd 0.117.
It's not impossible,but not 'practical' unless you finished my trailer for me and pulled it around behind all the time on the open road.
You'd most likely need to remove the entire roof and greenhouse and begin fresh,a daunting task.
If you will go to GOOGLE IMAGES and search for the MG EX 181and GM Sunraycer,these will give you an idea of what Cd 0.117 would look like.

[320touring]

Originally Posted by aerohead

Pushing the mpg from 32.2,to 42 mpg is a 30.43% increase.
To do that all with aerodynamic drag reduction would require cutting the Cd by 60.86%,down to Cd 0.117.
It's not impossible,but not 'practical' unless you finished my trailer for me and pulled it around behind all the time on the open road.
You'd most likely need to remove the entire roof and greenhouse and begin fresh,a daunting task.
If you will go to GOOGLE IMAGES and search for the MG EX 181and GM Sunraycer,these will give you an idea of what Cd 0.117 would look like.

hi, thanks for the calcs!
the mpg figures i'd like are in UK gallons so not that bad.

I'm doing 40.2mpg uk according to the onboard just now

I'll not be aiming for such a drastic Cd reduction, but looking for practical options that will enhance the car's aero performance and help to increase mpg

[lunarhighway]

next time you fit new tires prehaps you can fit tires that are within the cars specs but narrower... this will of course alter the cars ride a little, so perhaps it might not feel like an upgrade (although narrower tires are better in the wet where you're most likely to get in trouble so it's not really a downgrade in all respects), it will reduce frontal area and rolling resistance. alternatively you could go with a set of low rolling resistance tires... i hear the new ones are about just as good when it comes to grip as standard ones. that's not gonna work miracles, but it'll add to the rest

[320touring]

Originally Posted by lunarhighway

next time you fit new tires prehaps you can fit tires that are within the cars specs but narrower... this will of course alter the cars ride a little, so perhaps it might not feel like an upgrade (although narrower tires are better in the wet where you're most likely to get in trouble so it's not really a downgrade in all respects), it will reduce frontal area and rolling resistance. alternatively you could go with a set of low rolling resistance tires... i hear the new ones are about just as good when it comes to grip as standard ones. that's not gonna work miracles, but it'll add to the rest

i inspected the tyres on the car yesterday-they are virtually new-probably 8mm on them all, so not swapping them soon..

However, i'm thinking that tyre spats will offer similar gains, so at least i'm thinking in the right area