ICEmanZ

under the hood of my 1983 Z28 sits a 305 LG4 V-8 engine, backed by a T-5 5 speed tranny.

now i looked up the specs and i found that my LG4 is only putting out 150HP at 4000RPMs.

as you can see the car doesn't produce much power to begin with, but for some reason my engine just seems to lose it's life at higher RPMs.

i understand that peak horsepower comes at 4K, so obviously there should be some sort of power loss above that, for example: between 4K and my redline of 5K. however, it seems as though the power curve is falling off sooner, like it feels my engine just dies ubove 3500RPMs(engine gets louder, RPMs go up, but my Z doesn't seem to go anywhere!).

so what i'm looking for is to add some high-end power, or maybe even just power in general! haha

any advice for adding some ponies up in the RPM band?

94z'sson

ditch the 305 and T5

and get you a nice 355 or 383 and get a T56 (6spd) or auto

cuz there isnt really any way to add power other than making your car bottle fed

my car is and my dads is so spray it

ICEmanZ

i rather not do any major work that's gonna require a nice sum of money, money which i do not have to spend right now at this point. so dumping the 305 and the T-5 is pretty much out of the picture.

i'm pretty content with my 305/T-5 setup, except for the loss of power high up. for the most part i stay below 3K anyway, where my car actually moves pretty nicely! i'm just looking for that extra boost up high, ya know?

as for nitrous... eh, i don't know, i rather keep it naturally aspirated, but maybe as a last resort i'll look into nitrous a little more seriously.

thanks 94z'sson for your advice...
i'm still open for other opinions!
all comments are welcomed and appreciated! thanks!

jd13

Many thirdgens die up top. My 350 does too. It just runs out of breath at 4000 rpms.

You might want to look into a supperram setup. You might lose a little unf down low, but it will pull a lot harder on the top end. Sorry I don't have a link for you offhand, but you could check out www.thirdgen.org for a ton info.

doug791

wow i would stay away from the nos. From the sounds of it your cars a daily driver. I am also assuming that you want the higher end power for things like high speed passing on the highway? and really who runs a shot of nos during normal driving conditions? i dont know a ton about the 305's but id bet its the same sort of mods for my car. Headers make a big difference and i forget the proper info but different types of headers give you power in different places. other then that id say an exhaust as well maybe some hi flow cats that sort of deal

91Z28-350

he doesn't have TPI.

I wouldn't spend money on an LG4, but if you have to...

Powerband is controlled by the cam. You'd need heads, intake, exhaust, and a new carb to match it. The usual spew.

ICEmanZ

ok well thanks guys!

i think i'm just gonna deal with it for now. i mean how often am i above 3500 anyway? i can tell you it's not very often at all.

i was just wondering if there was anything that could be done to increase high-end power... now i know what needs to be done. so maybe once i get some money together i may follow 91Z28-350's advice as far as getting a nice cam.

Nitromethane

now THAT sounds like burnt valves or valve float. get a valve job, its due anyway.

BamaZ28

I had an LG4 COmputer Controlled Q-jet for a while. They have no outstanding power or torque. I hate to say this, but you'll have to deal with it, or maybe switch to holley, and a new intake. Bypassing the computer. Maybe some exhaust would help. They are weak

BamaZ28

ICEmanZ

valve job? yikes, sounds like that's gonna cost me some money!

what exactly is a vavle job?
where would i go?
how much is it gonna cost?

do you really think i need it?

Nitromethane

You can wait till the car does 0-60 in 20 seconds, but after 75k a valve job is always a good idea, usually around $250 + gaskets. A local machine shop will be able to do it for you. It may not be your only problem tho, so instead of pumping money into the car, just wait till it doesnt run anymore n decide where to go from there.