on any n2o systems you up the HP by changing the orfice size of the jets. Most direct port systems start with a #18 jet which relates to approx 12.5 HP per cylinder. The #21 jet will give you 18 HP per cylinder. You must also run a jet for the gas. On the 450SL we ran a separate fuel pump @ 5 psi because the car was CIS.

Nitrous is a sudden boost of power which affects mostly low end and mid-range performance. Try to avoid its use for above 6000 rpm. (What I mean is hitting the switch above 6000 rpm) I have found that to be useless. 50-60 HP of NOS on most cars will not hurt the engine except for Honda Civics SOHC 1.6L and Nissan Sentras 1.6L engines those are the ones I see throwing rods all with 50 hp.

I have never seen a german car break from a "safe" stage of n2o. I installed a 100 HP of n2o on a customers 92 M3 back in 92 and the car is still running n2o today and still posts 1/4 mile times of 12.77! Whats a better way to spend less than a $1000 and get that kind of HP? I have even n2o'd a VW beetle with a 40 hp engine! using a Sneaky Pete kit. Back then the kit was $125 and easy to hook up!

I have also used n2o in my road racing 77 VW Rabbit 1.6L. My driver posted the fastest practice time of all the sedan cars by 1 second. Which was also faster than all the qualifying times! The engine was BONE stock as how it left the factory. Suspension was modified. Just added 80HP of n2o. We could make 3 hard charging laps per bottle. It was fun blasting past the Porsches coming off the turns!