Fellow brickboarders,

I have been looking at the brickboard for quite a while, and I would like to share some simple and cheap performance upgrades that anyone can do. I have done all these things, and driving my volvo now is much more enjoyable. I have a 1991 940 Turbo, and on the local dyno I have improved the rear wheel HP 38 Ponys. There is also a in your seat acceleration improvement.

First check and change spark plugs and wires my car has 133K and it had the original wires.

Then look over the turbo plumbing and make sure that noting has rotted out.

Buy a calibrated turbo gauge I selected VDO because it matches the other gauges.

Buy a bunch of 3/8 fuel line and replace all of the vac. line that come off of the intake manifold. I used small hose clamps at the ends. You must make sure that no vac. lines come off or the engine will overboost or run rough.

Buy a dawes device and adjust turbo to 10 psi. the dawes device goes between the turbo and wastegate located under the turbo. I put hose extentions on the outlet of the turbo and the inlet of the wastegate and installed the dawes device between them. (I talked to a local mechanic who used to live and work in sweden, the turbo volvos are de-tuned prior to comming to the USA, emmisions, gas mileage, tires breaking loose on wet pavement etc.(many people who buy volvos new would probably not appreciate laying a patch of rubber going around a wet corner) .Boosting up turbo pressure to a max of 10 psi is relatively safe on the entire drivetrain. some people go 12 psi, but honestly the improvement is minimal. Sidenote, if you boost up the pressure too high, the fuel pump will automatically turn off - (built in safety measurement from volvo, imagine that). From my experiance, with the boost set at 12 psi when passing someone and downshifting the boost pressure spikes slightly over 14 psi only for a moment and trips the overboost safeguard. Its not fun to have your car shut down when trying to pass someone. Also, your MPG will drop to about 18 to 19, but in my opinoin its worth it.

Change your air filter, remove all of the foam insulation that is stuck to the lid of the air box as well as the block of foam in the box itself - I believe that the foam was installed as an afterthought by volvo becuase of turbo noise comming back thru the air cleaner. at the bottom of the box there are two tubes that feed the box. one comes from the fender, the other from the engine compartment. There is a plastic flap held down with a hex screw that covers the tube from the engine compartment, - remove this, at higher boost levels the engine needs more air, even though its warmer than the fender air, the volume is needed. You will notice a wheezing sound come from the turbo once all the foam is removed from the box, this is normal.

lastly, put a turbo muffler on in place of the stock, a turbo muffler is cheap, almost as quitet, and flows better. By doing the above cheap modifications, the turbo spools up faster, it pulls harder and smoooother to 5000 rpm and is more enjoyable to drive. Keep in mind that before you do the above check to make sure you dont have any existing problems under the hood.

And very lastly, the rear differential on the turbos has a locking type that engages both rear wheels once the difference in wheel spin between the two rear tires reaches a certian point... If you start to notice vibration from the rear of the car when you turn or put a heavy load in the back or tow something, the clutches in the diffetential are not slipping as they should. I noticed this when I increased the power, I would guess that the locking differential really never engauged because prior to the mods mentioned above the rear wheels never broke loose thus never having to lock. Anyways, change the differential oil with some synthetic like 'Redline' and put some differential treatment in to encourage slippage. All the problems all went away.

If anyone has any thoughts or concerns please reply.

ps I just put 17" rims with 45 series tires on, it rides a little rougher, but it shure handles nicely.