You don't want backpressure on your exhaust. The idea is to eliminate it as much as possible. Test pipes and HF cats do that. Test pipes save the most weight. The stock cats not only restrict exhaust flow, they are HEAVY!!

plenum spacer would help add power...

pulleys are good for shedding a few pounds and freeing up some hp...

same goes for lightweight flywheel/clutch

the open end differential probably isn't much fun so you might think about upgrading that too.....

there's a lot you can do without going FI, in fact, I would recommend it.

 

In your situation, I'd get the coilovers first
Replace your tires is they are nearly warn with something better
Otherwise move on to Plenum Spacer, A front lip if they have one available, and a piggy back and good tune. Then wait to get FI and get brakes and all other mods necessary

 

ok, i thought you wanted a lil back pressure on the exhaust. i should have as little as possible? ok, i can deal with that, what kind of a piggyback is good and easy to work? and what do you guys recomend for a plenum spacer?

 

All plenum spacers are the same. Just find the cheapest one. Motordyne and Skunk2 are the more popular ones on this site. I wouldn't mess with a piggyback ecu. So many are coming out that by the time you go FI, you may want something totally different or you'll have to try to find a tuner kit to accomodate what you bought. A piggy back with harness and sensors will cost no less than $1000 and you won't se much gain in NA.

 

Yes, I do.

 

You want an appropriate amount of back pressure for a N/A engine. This has to be matched to the rest of the systems in the engine, like cams, intake manifold, etc. Only time you want as little back pressure as possible is when you are using forced induction.

I think (hope) the point being made by roast is that on the 350Z, the stock cats are a large restriction, and by eliminating that restriction, you can tune the rest of the exhaust better by correct header choice, pipe diameters, etc.

 

I heard the Crawford Cast Plenum?????

 

I don't know. Did you? What did it say?