Car's a 87 S4 with 1300 miles on a rebuild, i have ported heavy the UIM & LIM ,and the ACV and smog pump are gone ,also im running premix, with a 3in single exshaust.and my timing is advanced a couple degree's.no aux port sleeves,no EGR valve.

Now my question is i just got a NOS nitrous oxide setup it was a wet system but im planning on using it as a dry setup. i will be only shooting a 50 shot. I have a remote bottle opener too. If i upgrade my secondaries to a 88 t2 550's injector's will that be all i need to make sure i dont run lean up high? or should i upgrade the fuel pump too? I already know i have to back my timing off a couple of degree's retard. and i dont really want to have to install a fuel pressure regulator for the t2 fuel pump i have but what do you guy's think? I also have a afr guage too should i use it?

PS: ive read 1300cc article about it but i want to be SURE! ya know.

 

You don't need to install an fpr for the TII fuel pump. The Walbro 255 lph is cheaper than the oem TII pump if you do upgrade. I don't know why, after spending the money on a fresh rebuild, people get cheap on the rest of the mods that have the potential to put the engine at risk.

NAs tend to run a bit rich to begin with, you might get away with just the 550 cc secondary injectors. If you want to do it right, or go more than a 50 shot, go wet.

If you want better overall and total performance, i.e., the area under the curve, re-install the aux sleeves and get them working. Removing them yields a net total loss.

 

The way im going about it is the car is setup too make power between 3.5k and 7.5k rpm's.I was looking on nitrousdirect and they have 20,25,30,35,40, shot nozzles soo im going to go with a 35 or 40 shot now,becuase i dont want to much wheelspin its bad enough now. And i dont want alot of sudden shock on the engine mounts and drivetrain, Does anyone know if the stock pump can handle 550's in the secondary position?