Toluene is sold as a form of paint thinner. It should be about $5 a gallon if bought in 5 gallon drums. (Use all 5 gallons with one tank of gas. You'll about 99 octane if you do.) Make sure it's PURE Toluene as best you can. It's already in gasoline, so it shouldn't harm anything. Xylene works like Toluene as well if that's all you can find. However when using Xylene put it in BEFORE your fuel, then quickly pump fuel in to wash down the Xylene. If it's left in the fuel-tube it will corrode the rubber. It's not a problem once mixed with gasoline, but in high concentrations it's a problem. I found that out myself the hard way.
You could also buy that Torco stuff. It's only about $12 + $8 shipping or so. It's almost pure MMT (anti-detonant) and will take the octane with one can per tank from 93 to about 98. If this makes no difference, 100 octane probably won't either. I've used both.
Here are a couple other things to try:
1. If it's a mapping error you might be able to get around the error by moving the nozzle by the intercooler and then moving the temperature sensor up near the throttle body. That way the ECU "sees" the colder more dense air from the water injection.
2. I highly reccomend heat insulating your intake pipes. Especially with T5 as they are aluminum. I did my T7 plastic pipes and noticed an immense difference in hot weather:
http://www.saabscene.co.uk/ubb/ultim...ic/23/970.html
The insulating wrap can be bought at nearly any local hardware store for like $5 a roll, and it should take between two and three rolls if you also do the intake before the turbo as well.
3. If it never freezes in the winter where you live, you might consider bypassing the throttle coolant heater:
http://www.saabscene.co.uk/ubb/ultim...ic/23/974.html
T5 cars use a 1/2" tube to the throttle, T7 cars use a 1/4". Since that was my car (T7) you'll need a larger bypass tube. The coolant tubes are also located differently on T5, but you should be able to find them pretty easily.
Hopefully if all of the above techniques are implimented you will see much more power!
Adrian~