CamaroStylin

hey hey everyone. i was just being educated on a new engine that GM is comming out with that has two LS2 engines put together basically to create a 16cyl engine putting out over 1000 hp. they are testing now, naturally aspirated and supercharged. anyway, the thing still gets like 20 something miles to the gallon because before you reach a certain throttle position the engine is just running on 4 cylinders, hardly consuming any fuel at all, but when you get into the petal all 16 cylinders are firing and launching that car like a nitro coupe. anyway, i'd like to build another engine for my 87 camaro. it came factory as a 305 IROC and right now has a SWEET 350 in it that was build from a 95 pickup truck block, but its got a carb on it and i really want a holley stealth ram. my question is, can you program the holley stealth ram to run on 4 cylinders below a certain throttle position just like some of the newer v-8s and such that are out? what would be needed to actually do this? any help would be appreciated. thanks guys

trwchevy

ummm i think a specially fabricated manifold...see the quadrajet has the large primarys and small secondarys....if you make a dual plane for the back four cylinders and the front four cylinders you could get a carb that would only open the secondarys when you get into it.....that would be pretty cool...good luck

CamaroStylin

the stealth ram is a multi port injection system-im not talkin about running 4 cyl on my intake now, i mean on a stealthram system it would be a matter of computer programming to control it.... or a set of 4 relays controlled by a throttle positioning sensor to open the circuit on 4 injectors before a certain position, but that would throw off the O2 sensor

TheGreatJ

It's not really feasible. The traditional SBC firing order isn't condusive to cylinder dropping.....if you try to run it on 4 it will vibrate like a ****. Plus, you'd have to either retro-fit a brand new ECM with cylinder dropping capability (read as: big bucks) or learn enough about GM's programming language to write your own code for an older computer and hope that it works.

trwchevy

ahhh yess...haha i think ive been inhaling a little to much carb fumes....lol

Lungz

I actually think I heard something about this 2 years ago. I think it was going to be used for a new Cadillac but it got dropped. It was part of the northstar program if i remember correctly. I think it was going to be a v10 or v12 tho. I found this link that has info on it, as far as I know, this program has been scrapped for awhile though. http://www.caddyinfo.com/xv12.htm

klumb15

yea this is old news already....they debuted this caddy with this engine in it almost a year ago....

Lungz

I thought they scrapped it in favor of an 8 cyl with similar properties. I could be totally wrong though, I only remember earing that the 12 cyl was scrapped.

CamaroStylin

hmmm.... ive never done any work on car's computer. i've taken computer programming classes though. what would be involved in messing around with the programming? hooking up a Holley Stealth Ram computer to my laptop and changing the basic coding? any info on the actual steps to computer mods would be awesome you guys.

the idea itself isnt scrapped at all. cars are comming out soon, maybe even now, that use that idea. i dont disagree with TheGreatJ on vibration and reliability issues with a regular chevy small block, but i know it's being used in newer designs, like the LS1 and such.

TheGreatJ

Caddy's are using a cyl. dropping system on some of the newer models, and Dodge is equipping the "Hemi" motors with a variable-displacement setup as of next year. Caddillac has tried it once before (back in the day) and it was pretty unreliable....they tended to get stuck in 4cyl mode which means NO power around town. Most people decided to lock the car in 8cyl mode instead of actually repairing the problem.

Dodge's new system is going to use a set of funky-designed lifters and solenoid valves....it will actually force the lifter to collapse when the cyl. is dropped so that the valves won't even open as well as shutting off the injectors and coils.

As far as code modifying goes, you'll just have to check out DIY-EFI.org and the DIY-PROM section over at TGO.....I'm learning a little about it but I'm not anywhere near advanced enough to give any kind of explanation.

85_305

Wow.. all this technology you guys speak of is amazing; auto coil shutoff's, solenoid valves, fuel-shut off
Neato!

92RS305#2

its called Displacement On Demand (DOD) and Diamer-Chrystler already uses it in their hemi motors. cars coming out with those huge 12 and 16 cylinder engines are also starting to incorporate this technology. its something like a 25% better fuel economy in those dodge cars. its sad how i learn all this no from my instructors but from being bored in class and just reading car magazines. i go through about a magazine a day and the average magazine cost me 4-5 dollars so thats like $20 bucks a week spent on just car magazines.

bmillington

Just a thought, If you could get the computer to control each injector, then only open 4 of them but change which 4 every 4 rpm's. So each cylinder would be firing every other time. That might fix the vibration problem, or make it worse I don't know.