Dustinx22

Hi im pretty new to the 1993 camaro i just bought a 1993 z28 with a comp cam in it and an msd distributor, and what i believe to be a zex dry shot nitrous kit otherwise everything else is bone stock. I was wondering what i can do to up my horsepower and torque without needing to upgrade internals. The zex dry shot nitrous kit hooked up but the guy i bought it from said that after the cam was put in the car it fell flat on its face in the quarter mile when he used it. So if any one has sugestions on what upgrades to start with that would be much appreciated. Or if you know how i can fix the issue it has while using nitrous.

Injuneer

How does the ZEX kit supply the added fuel when you spray? Does it increase fuel pressure like the NOS 5176 dry kit? I know it adjusts the nitrous flow rate based on bottle pressure, but that's just tweeking the A/F ratio. Confirm it is part #82018.

How much are you spraying? What cam are you using? LSA is important with nitrous. Who tuned the base case (normally aspirated) ECM chip for the cam? Do you have a fuel pressure safety switch? The added HP of the cam + the added HP from the spray may be exceeding the capacity of the fuel pump.

6SpdLT1Z

Need more info about the car. Do you have headers? Auto or 6 speed? Stall? Rear Gear?

Dustinx22

6SpdLT1Z the car has stock exhaust manifolds on it, it has the t56 transmission and it has 4:10 gears

Injuneer The fuel pressure is changed at the fuel pressure regulator. Ill have to check when i get home from work if its the 82018.Ill also post a pic of the spec sheet that came with the camshaft. I believe the shot is either a 75 or 100 shot and from what ive seen under the car it has an upgraded fuel pump. And im unsure of if the car has ever been tuned after the cam was put in. Where do you recommend I get an upgraded ECU chip.

Injuneer

If you can see the fuel pump under the car, it's an in-line booster pump, not the stock in-tank pump. I ran the NOS 5176 dry kit, and it worked the same way - came with an inline booster pump. Used a slipstream of nitrous through a low pressure regulator, and applied the reduced nitrous pressure to the vacuum compensation connection on the fuel pressure ragulator. With the 125-shot, it bumped the fuel pressure to 85-90psi when spraying. The in-line booseter pump was required to allow the fuel system to flow the required amount at that high psi.

As a result, it was mandatory to swap the factory ball & seat injectors out for pintle style, that could handle the high pressure. Also required a colder plug with much less electrode projection. The stock plugs would turn into glow-plugs with the nitrous, at least until the ground straps burned off. Also required a multiple spark box like the MSD to insure the plugs would fire with the increased cylinder pressures.

I think pcmforless.com has a guy named Alvin that specializes in the removable ECU chip speed-density tunes.

Dustinx22

So I couldn't post a pic of my camshaft sheet so I'll just have to post the specs the intake gross lift is .500 the exhaust gross lift is .510 the I take centerline is 110.0

Injuneer

You need to add duration of intake and exhaust at 0.050" lift, the lobe separation angle, what ratio rockers the gross lift is figured at, and what ratio rocker arms you are using.

Dustinx22

This is the cam that is in the car. I believe the rocker arms are stock. Which ratio do you recomend i go with?

07-304-8 - Xtreme Energy

Dustinx22

Yes the nitrous kit i have is the ZEX 82018

Injuneer

The 0.501/0.513 lift is calculated with stock 1.5X rockers. You would get 0.534/0.547 with 1.6X. Would probably require spring change and possibly push rods. That is a relatively small cam. With 4.10 gears you should be looking at a cam that has a higher RPM peak than the 5,000 RPM quoted on the Comp Cams card.

The ZEX kit can spray 70-125HP. How much more power do you want? Or are you simply looking for more power without the nitrous? Of course you need to find out what is wrong with the kit install. Make sure both pumps re working. Check to see if you have stock injectors, and if so, change them to a pintle style injector. You should also be using a different spark plug like the NGK TR6 non-platinum.

Consider cold air intake, throttle body coolant bypass, long tube headers. You should be OK with the inline booster pump for the ZEX kit.

Dustinx22

Looking closer at the car ive noticed the that it has the tb coolant bypass and looks like 2.5 or 3 inch exhaust from the cross over tube back, im planning on getting a cold air intake, bigger throttle body(52 or 58mm) getting a custom pcm chip for my setup, msd blaster coil and a msd ignition box and i just picked up a bbk under drive pulley for cheap, been looking into 1.6 ratio full roller rockers. I cant check the injectors till spring cause the car is stored for winter. Any other bolt-ons besides headers you can think of im missing that are a must? And are egr, pcv and secondary air deletes worth it

Injuneer

Don't worry about the throttle body for now, definitely NOT a 58mm with those mods.

You will gain no HP by deleting AIR or EGR. They don't operate at WOT. AIR only operates at startup for 2 or 3 minutes, then never runs again. EGR will only operate off-idle to 3,500RPM part throttle, and only when operating the engine under conditions that are likely to cause high combustion chamber temperatures. An example would be lugging the engine below 2,000RPM in 6th gear. In effect, it will actually prevent spark knock under those conditions.

Removing PCV can destroy your engine. PCV removes piston ring blowby from the crankcase, by using engine vacuum to pull fresh air through the crankcase. Since combustion gasses contain a large amount of water, that water can condense in the crankcase, and form acids in the oil. A breather in place of the full PCV system would allow pressure relief, but would not effectively ventilate the blowby.

Dustinx22

I knew how each of those work allready I was just seeing mostly about the air and egr if it was even worth my time and it's not so I'm just going to leave them and for the pcv I meant just take the tube running to the intake off and putting the little valve cover filter on

Dustinx22

When should I start looking into throttle body's than? After what kind of mods?

Injuneer

With a bigger cam and the full long tube exhaust, you could consider a 52mm TB.

Why do you want to delete the air supply line from the throttle body to the drivers side valve cover? Have you found evidence of oil blowing back into the throttle body? A breather/filter would eliminate the oil blowback, but at that point you might want to check and see why you would be getting the oil blowback. Since you 93 runs speed-density, and not MAF, removing the line from the TB will not affect long term fuel trims like it would in an MAF setup.

But there's no performance gain, unless you have excessive blowby pushing oil into the throttle body. Oil reduces the effective octane of the fuel.