Welcome to the board.
Nothing wrong with wanting to keep it N/A (IMHO). How far are you willing to go? (i.e do you have a goal in mind as it relates to desired HP?)
How many miles on your Z and what year is it?

I'm not sure where you are at right now w/ RWHP...maybe 190ish (???). Getting the #'s up on an N/A won't be cheap.

Before going internal, you can...

S-AFC II
Ground kit
Unorthodox Pullies (PS, Alt, WP)
1 Piece driveshaft (lightened...steel, aluminum, carbon fibre)
Electric fan

Internal...
Ported and honed plenum
Heads
Valves
Cam shaft
Tweak the timing

You could look to lighten the car by getting rid of the spare and jack, pulling the stock seats and installing aftermarket.

More importantly...suspension and braking upgrades. Don't forget them.

 

190ish??? I thought N/A Z's were 222hp stock!?!?

 

222 to the crank...my guesstimate refered to HP to the rear wheels.

 

he has that stuff done to his car tho
so hes probably got like 230-240 rwhp

 

The biggest h.p. increase comes from increasing the compression ratio on any given displacement motor. But that does no good unless you can get more fuel and air into the combustion chambers, and then out the exhaust pipes. Dan's right with the ported heads, larger valves and longer duration cams. Most of the external items only get you incremental gains. On top of that, you want to maximize displacement with as large of cylinder bore as is feasible. Then you can also get a stroker kit.

I myself will be aiming for around 15:1 c/r on my stock crank and rods. I can do this without pulling the engine, (I believe).

The 358 cu/in small block nascar engines that put out roughly 750 h.p. run around 22:1 c/r. Except for the custom cnc machined cylinder heads, they're mostly built from parts that you can buy from a store yourself. Except for the toyota i'm sure.

 

Yeah b...I may be low on my guess, but 230-240? I dunno about that.

 

Nah, actually, the number u guesstimated is about right. I have the following done to my '92 'Slick top' N/A and I am only making 184.6 BHP on Z1's dyno.
UR pulley set (CR, W/P, ALT, PWS)
JWT intake
AshSPEC ECU upgrade
HKS Hyper Exhaust
RVM intake Hard pipes
*I am running 18x8" in the front and 18x9" so that may be throwin the dyno off. Plus I was runnin a cheap grade of 93 octane gas.
My car is also pushing 156,000 miles. What really gets me is that a '94 BONE STOCK 'slick top' N/A laid down a 181 BHP the same day I dyno'ed my car. Thats why i just bought a doner TT car which is about to get an engine swap into my 'Slick top'. The N/a was fun, and a good learning experience. But for the dollar, the mods just do not show enough RWHP in return.

 

Yah, lol I know of a 91 Z with 75k on the odometer that ran 191 rwhp with full cat-back and intake..hmm

 

It's not uncommon for people who abritrarily modify components on their cars to lose horsepower.

 

A couple of things real quick...
raymond, depending on your motor's current compression, i'd have to venture a guess of 195-200 rwhp. You're going to want to look into JWT, GMS Racing, or an ASHSpec Eeprom to upgrade the ecu. Lose the iridiums, they're dragging you down, go back to the stock NGK's and there's possibility of making back some power. For the low cost of it, you need to start looking into a grounding wire kit. Our cars have a tendency of having bad grounds and causing sensors to not read quite right. Personally, my car smoothed out incredibly with the addition of one of these kits. Also, why're you aparantly against the use of nitrous oxide?

DanZ32, the UR pulley set (for all of the accesories) is truly a waste of money, that $200 is better spent elsewhere, they don't underdrive the pulleys, they just make them look pretty. The electric fan is not recommended due to the hp/reliability factor. They don't increase the HP to anything more noticeable, it's hard to find one that will meet, or exceed the CFM's of the stock fan, and I've seen too many end up with either shorts, or burnt wires, resulting in an inoperative fan.

CanyonCarver, are you planning on running your car for DD use? 15:1 is too high for street use, unless you plan on spending for racegas to fill every tank.

WhtFairLadyZ, If the profile of your wheels is what it should be, it won't throw off your dyno, but you have to remember, you're trying to spin a LOT more unsprung weight. Also, higher octane gas won't give you more power, you would have made the same power with 91 as w/ 93, or even your cheap grade 93.

Any questions?

 

A couple things... Dan's right about the underdrive pullies. The accessory pullies do underdrive the accessories and they are much lighter than the stock pullies. It may not be as significant as the underdrive crank pulley, but there is some horsepower to be freed up with them. The 1-piece driveshaft will definitely help. The grounding net is a great idea. As far as the electric fan goes, unless you have an oversized radiator, then the electric fan isn't a good idea. It doesn't push enough air. If you have the larger radiator, then go with the electric fan because it will free-up a couple ponies under the hood. Nothing you will really feel, but it is something. It will really clean up the engine compartment also. AS jk said, go back to the NGK's.

You said you have an EPROM upgade....who did it?

 

Isnt it bad or dangerous to use nitrous with an upgraded ecu? I mean with the ecu being upgraded I assume it is advancing timing and adjusting air/fuel ratio, which from what I understand is a bad thing when using nitrous. Maybe I am wrong. Anyone care to elaborate?

 

Nitrous isn'y my specialty at all. I believe that it turns the engine into a ticking time bomb. I think that no matter what you do with the ECU, you're still killing a perfectly good motor.

 

I do believe the whole point of nitrous is to use it in moderation.
Being constantly on the bottle, I agree, is signing the death certificate for your motor.