more power

[cat tech]

hi, just signed in,i have a 98 z71-it was equipt with a 5.0(i got a little hard on it) i bought a 5.7 and installed it and it runs good.i have also bought smog legal headers,dual cat/y pipes,and the flowmaster cat back kit,also a k&n cold air intake.my question is this,before i invest in a power programer, would buying an ecm from a 99 2500 series truck be a better way to go? the 99 2500 series is rated at 290 hp and 330 ftlbs torque.im planning on buying a camshaft from jeggs that will require a programmer, but if i can get an ecm them a programer i should be able to get all the legal power that can be had.any help with my problem would be greatly appreciated.

[jdfenske]

by the looks of your nick you've had your way around diesel stuff?

unfortanlly for all the time and money you spend trying to get the best bang for you buck, it won't be worth it. it'll burn more gas but won't perform better for what extra it burns. i called jegs once to do the same with my 350 and it ends up being alot of money to have them program a ecm for the cam your installing, and even then you can't go too erratic because the computer can't compensate to meet emissions. old school stuff you could go so far you'd be lucky to get it to start and/or idle. but with smog laws and very tight parameters for the ecm to try and meet, your very limited

i redid mine and i know it was doing at least 300. but with everyone going with oversized tires, overdrive trans, i went with high flow heads, oversized valves, and a cam that moves the powerband lower.

i've rebuilt my share of engines, nothing beats tight rings and crisp valves.

[98k1500]

would love to do something like that to my truck, but i have no alternate vehicle if'n i were to need one...i.e. to get to work...not sure if i could get a head job done in a weekend,more power would be nice, i say screw emissions, kansas doesnt inspect the vehicles every year for tags anyway... it is possible to build a healthy,and efficient engine with out cats and all the other ****... it just takes planning, but im no expert nor a veteran, i love to read articles and try to experiment a little on my own though... no better way to learn...

[jdfenske]

totally, anyone can build anything hardcore but he wants to use a computer, and the whole point of computer controlled combustion is to meet emissions specifications.


only way around it is to hack the PCM and write your own code. and you'll need a PC with a serial cable, some type of terminal software, either HyperTerminal for winblows, or if running unix/linux or the BSD's , one of their telnets and attach via one of the /dev/com#

THEN fire it commands and start changing stuff, assuming you know what to tell what.

now of these days the engine computer and trans computer are on the same bus, so, both will listen, giving the command to make them reply is going to be the long painstaking trial and error.

or pay hundreds and have someone write your own chip, but i love to program, so i do some of this myself.

then your going to have to do ALOT of math.

TPS x MAP / temp - this * that take square root of this blah blah blah = injector pulse width.
not in that order, but in the end and on the opposite side of the = is the pulse width of the injector. but somewhere in there you have to include the o2 sensors.

in my opinion, just stick with carb if you want to get raw power. the rule still applies since the first engine was made.
more gas burning = more power.

i laughed when chrysler tried to remake the 'hemi'. it was designed to burn gas, and burn alot of it.. i think it was a mistake to make a 'fuel efficient" version. why take an application that's designed to guzzle gas and try and have it run 'high horsepower' in a such tight emissions situation???

nothing was as good as the old 426 with twin 4 barrels.

my uncle had a 426hemi with a 4 speed, he'd burn thru 1st, 2nd and 3rd, and 1/2 thru 4th. i have yet to see a fuel injected 'performance' hemi roll off the show lot.

but anyways

have fun making things work with the computer swap and stuff. If you make something work, post some results, i'm sure lots here would like to see, me one of them.

[stumpuller454]

i`ve got a local guy that represents WESTERS,we will soon be doing a test on my truck, i have a superchips max micro-tuner, we are going to test and see which gives more HP and tourque, wil post results when completed, hopefull sometime this week, If emmisions is of no concern they can program/delete anything related. just ordered a **** load of extra go fast goodies and will install and report back after we go re-tune for those items(:

[cat tech]

unfortunatly for me i live in a state that emmision tests yearly,i've thought on this subject for awhile.going on the therory that an ecm wont reconize the difference between a 5.0 and a 5.7 (it will run the 5.7 like the 5.0) even if the engine specs are different like cam,injectors,and sensors. my new question is, If an ecm from a 2500 or 3500 series truck equipt with a 5.7 is programed with higher specs (290 hp 330 torque)why would the ecm reconize what truck it is in? my idea is to have two ecm's one that is maxed out,the other for inspection.after all the check engine light only bothers me when it's time for inspection,besides its faster and easier to swap an ecm than strip all emmisions and put them back on.

[keithr0005005]

first off if your putting a vortec 350 (96-2000) in your truck youll only be making 255hp and 335lb of torque. there is no power difference from 1/2 to 1 ton as far as the motor. as for the computer you need to find an ecm from a 350 because of the different specs. junkyard special. all vortec 350s make the same power

[stumpuller454]

my truck is 1.2 seconds quicker in 0-60 times with superchip performance tune, just installed headers larger custom air intake with high flow air sensor and throttle body, may have to get high flow cats now, but i`m not quite done everything at the moment, will be maybe somewhat finished tommorow, hopefully.

[436'd skylark]

Originally Posted by jdfenske

nothing was as good as the old 426 with twin 4 barrels.

my uncle had a 426hemi with a 4 speed, he'd burn thru 1st, 2nd and 3rd, and 1/2 thru 4th. i have yet to see a fuel injected 'performance' hemi roll off the show lot.

but anyways

.

hehe. if your gonna beat a hemi, ya better have a BUICK!
Had to throw it out there. if your ever bored google PLymouth GTX vs. Stage one Buick. It was a great article by MCR. two essentially stock muscle cars running head to head. the big ole buick mopped the hemi GTX. both were slightly more than stock, but its a good read. sparked a huge buick vs. mopar rivalry.

gotta love it being a buick guy. plane jane 455 with 10.25:1, a hydraulic flat tappet cam, and a Q-jet to boot smoked the twin carbed, high compression, solid cammed hemi car..