Run nitrous, or increase compression?

I'm trying to milk a little more speed out of my ride, and right now I'm debating between two options. First, install a 100ish HP shot of nitrous, but then I'd have to buy something like a msd 6al or something along those lines. My other option was to have my heads machined, ported and milled to increase my compression from 9.5 to aroun 10. Which one would you guys go with? The head work will probably cost less, but I'll have to run higher octane gas.

------------------
1986 Z28
383 ci Stroker, Dart Sportsmen 2 heads, roller rocker arms, Crower Hot Street Beast cam, edelbrock 750cfm carb and performer rpm intake, Corvette Servos, shift kit and 2600 rpm stall convertor, 3.73 gears and Eaton limited slip posi rearend.

Nitrous

Both routes can be expensive depending on what parts you buy and what you expect from it.

You'll see a better gain from the nitrous though. Bumping up the compression and porting the heads may give you about 60 HP's were the Nitrous will give you as much as you want. Provided the motor can handle it.

Another vote for nitrous!

------------------
Mario,
White 94 Z28 (http://www.z28roc.cz28.com/index.html)
Yeah I got a few mods
Video (http://www.z28roc.cz28.com/purge.mpg)
Black 87 IROC-Z (http://www.z28roc.cz28.com/iroc5.jpg)

both, but if only one, then def. nitrous. w/10:1 all youneed is premium gas.

<font face="Verdana, Arial" size="2">Originally posted by Alpine455:
Nitrous</font>


This guy is the man as you can tell by his vote.

I say a 100 shot and forget about it http://web.camaross.com/bb/biggrin.gif back the timing down 2-4 degrees and run 92-94 octane. yer all set to go. add headers for an extra punch and a cutout http://web.camaross.com/bb/biggrin.gif


------------------
Denny Villemure
1989 Camaro IROC-Z Convertible, 305 TPI, 2.73 Gear, Flowmaster 2 chamber. 15.60 on motor, 14.20 on a 75 shot from NX. Woo hoo!
www.denny.cz28.com (http://www.denny.cz28.com)

Nitrous.

Generally, a one point increase in compression equals about 3-5 percent increase in hp. So you are looking at about 1.5 to 2.5 percent increase in hp with just milling.

I am all for motor power but when you are on a budget, nothing beats dollar per hp like n2o.

if you have your heads decked you may run the risk of changing your angles and intake may not line up perfect, then you can start blowing out intake gaskets by the runners. not a fun problem to deal with.

N2O of course

Alright, it sounds like nitrous is the general consensus. I guess I'll have to start looking around for a kit http://web.camaross.com/bb/smile.gif

------------------
1986 Z28
383 ci Stroker, Dart Sportsmen 2 heads, roller rocker arms, Crower Hot Street Beast cam, edelbrock 750cfm carb and performer rpm intake, Corvette Servos, shift kit and 2600 rpm stall convertor, 3.73 gears and Eaton limited slip posi rearend.

IF the right guy does the heads- I say do the heads.

If not- get N20.

Steve

You would really do the heads instead? To be honest, I kinda want to keep my car bottle free, but I do want a noticeable increase in power.

you are in luck! i have a NX wet kit for sale for $450! let me know...

bkelley89z@cs.com

Brandon

------------------
red 89 IROC 5.7L A4
-K&N air filter, Flowmaster 3" exhaust, Hedman shorty headers and 3" Y-pipe, MAC offroad pipe, Vortec heads, B&M Transgo shift kit

"THINK OUTSIDE THE BOX"

Neither. The heads, I assume, are still the old steel ones. The NO2 system has to be filled every 6-7 runs give or take. Why not get a vortec supercharger. That way you will have something when your bottom end chokes. Sooner or later you are going to replace the intakes (very restrictive) and you might as well do it when rebuilding a new engine. Then you can set it anyway you want and turn up the boost.

How does the car run as it sits? IS it a pig or does it put down good numbers? I forgot to ask the first time...

As you can see here, some reccomend spending $450 on mods and others reccomend spending 5-10 grand http://web.camaross.com/bb/smile.gif

------------------
Denny Villemure
1989 Camaro IROC-Z Convertible, 305 TPI, 2.73 Gear, Flowmaster 2 chamber. 15.60 on motor, 14.20 on a 75 shot from NX. Woo hoo!
www.denny.cz28.com (http://www.denny.cz28.com)

Theres no real reson to debate this issue if on a budget and looking for the best gain. I dont know if those are aluminum or cast iron heads, but, Increasing compression on those heads if they are cast iron, you will be forced to run high(er) octane gas, if aluminum youd be fine. But the increase in horsepower will be minimal at best.
The nitrous on the other hand, reguardless of what people think, wont damage your motor. If your and idiot and jet it lean then ofcourse your going to have problems, but people dont see it like that.
My motor is a 1970 4 bolt 350, stock steel crank, stock rods and TRW pistons. Nothing major in the lower end. Aluminum heads also.
My nitrous system is jetted for 185hp. Usually I have only the 2nd stage on which is roughly 125 hp. I run that on 1 step colder plugs and 94 octane pump gas. I go through maybe 10 lbs a week and have been spraying the **** out of this motor for 2+ years now. Only thing thats happened is my rear main seal leaks, but that would happen reguardless. Done leakdown and compression tests and people cant believe its still together and shows that little of leakdown.
Car goes mid 12`s on motor and will go 10`s, but my daily setup, being my car is my only car and a daily driver, it "should" go 11.50 or better on nittos.
Nitrous rules

The car runs pretty decent as it sits now. I just want to milk some more power out for those "slightly behind" situations. The heads are cast iron. So if I went with nitrous, what all do I need to buy and do to make it safe as possible?

------------------
1986 Z28
383 ci Stroker, Dart Sportsmen 2 heads, roller rocker arms, Crower Hot Street Beast cam, edelbrock 750cfm carb and performer rpm intake, Corvette Servos, shift kit and 2600 rpm stall convertor, 3.73 gears and Eaton limited slip posi rearend.

Well, I see your running a carb, so a cheater (up to 250 hp) or super powershot (up to 175 hp) kit is what you would want.
I dont know what you have for a fuel pump, so MAYBE you might need a second one, highly unlikely. Basically, a hobbs switch(fuel pressure safety switch) is the best investment you would make as it would kill power to the nitrous solenoid should the fuel supply come up short due to something like a pinched or smashed fuel line, low on fuel and it moving away from the pickup on acceleration, or even the fuel solenoid failing to open at all. That would be definately be something I would buy at the same time I bought the nitrous kit.
Other than that, nothing really. If you buy an NOS brand kit, or any brand for that matter, the recommended jet sizes are already on the rich side and you would have to go from there. Just get yourself 1 or 2 steps colder plugs, so race gas and take it for a ride. If it pops out the intake its too rich, if it pops out the exhaust its too lean. If it dont pop, and you feel it didnt make that much of a difference try changing 1 of the jets 1 or 2 numbers at a time at the most. And id go up on the fuel before I went up on the nitrous just to be on the safe side, if it gets slower, put the original jet back in and try going up on the nitrous side and see what happens.

NO2 IMO is expensive because it needs to be refilled every so many runs. Sure it is cheap today but "You can pay me now or pay me later".

My only bias against NO2 is that it is a sudden shock to the system. HOWEVER, if you do it right and don't get carried away, you should be fine. Make sure your injectors and pump are capable of carrying the additional load when the gas is on.

People will argue that Nitrous doesn't hurt a motor if setup right.. i agree 100% but it does put more strain on the moving parts obviously! Unless your running a Jacobs mastermind that will slowly increase your shot.. your still SHOCKING the motor with all that fuel, air and nitrous. Cutting the heads is something you can't undo once they're cut thats it... at least a bottle you can take off. They say every point of compression is ROUGHLY 15hp. Personally I'd go with the heads not only have them machined but ported and polished!... and if your not happy.. then spray it!

------------------
(I know.. it's not an F-Body) 85 S-10 Millenium Yellow pickup, 12.21 @ 111MPH soon to be in the 11's (once we hook up off the line!.)

Personally, if I wanted to go faster I'd get the N20. Milling the heads and porting them would only yield perhaps 30-40hp considering that everything was set up right and you weren't getting any knock. Knock is bad because its anti-performance basically. These stock heads we have are only good to about 250-260 cfm with massive porting. Thats not very good considering that the LS1 heads flow 270 cfm stock. I'd rather pay for a set of AFR's that flow awesome from the box than spend money on the factory heads.

Nitrous is the way to go. AutoRoc got 1.4 seconds faster with a 75 shot of the NX kit.

Head work is something you are going to want to do sooner or later. You can do it yourself and save a bundle on aftermarket heads by getting the Standard Abrasives Deluxe porting kit. Most of the time a decent (though not perfect) job will gain you in the 10 to 15% range in hp. It is just sitting there waiting to be taken. But I wouldn't increase the compression. The cost of high octane gas over the years you own the car is a killer.

Nitrous is definitely an option, too. But I would prefer to get my engine as well sorted out as possible before doing that.

[This message has been edited by Sitting Bull (edited August 02, 2002).]

You really think you could get 10-15% increase in power? My heads aren't stock, they're dart sportsmen II's, and they're iron. They're supposed to flow pretty well already, but I've heard they respond great to porting.

<font face="Verdana, Arial" size="2">Originally posted by newby:
You really think you could get 10-15% increase in power? My heads aren't stock, they're dart sportsmen II's, and they're iron. They're supposed to flow pretty well already, but I've heard they respond great to porting.</font>


Oh yeah, on a 300 hp motor, adding a good set of heads will add 30 hp or so. I think your current Sportsman IIs are maybe even more than your engine can use. They are very optimised heads, meant for a really well built 350, 383 or 400.

At your level, you are probably ready for a snort of nitrous.


[This message has been edited by Sitting Bull (edited August 02, 2002).]