slow hardbody why?

[450r]

I have a 1992 nissan d21 hardbody it is a 4 cylinder 5 speed 4wd and has 180xxx km, it is lifted and has 31 inch allterrains. When i am on the highway doing 110km/h and come to a gradual hill it starts to slow, i have to put it right to the floor and drop it down to 4th sometimes half way up just to keep above 80. Would this be because of the bigger tires, i don't think they would make it that bad would they? Anyone have any ideas as to what could cause this? Or are all these trucks like that?

[PEZi]

i'm pretty sure it has to do with the placement of the fuel pump and pickups lines and such... you're losing pressure as the fuel sloshes backwards

i've heard of this before but i'm not sure if its the entire problem

[seang]

Your truck weighs more than 3,500 pounds, it has the aerodynamics of a mobile home, and it has 134 horsepower. 80 uphill sounds about right. People intuitively think the nissan hardbody is a light weight vehicle. Its a juggernaut.

[450r]

Haha ok, one of my friends said his dad had one a while back and it was the same way. I guess i'll just have to deal with it. Whats the best way to get performance out of these motors?

[seang]

You've come to the right place for that! The naturally aspirated ka24e/de topic has alot for your setup, as does this forum. Personally, I have advanced my distributor all the way on my truck, its the same motor you got. I run 91-93 octane now. I ran a 2 inch straightpipe from the catalytic converter all the way back. Some people run 3 inchers on theirs, but the objective here is to get some more TORQUE at highway rpm, a 2 inch is better for high exhaust gas velocity. It does improve the feel a bit, and its not that expensive. Make sure to run the pipe all the way out from under the truck or else you will get terrible boomy resonance. Also, I bought a big square of bulk 2 stage filter foam and zip tied some around the nozzle of my airbox. I previously had a K&N, but that even felt more restrictive than this, and this was way cheaper. My truck sounds pretty good, and power is better. Its not gonna take your breath away, but its a little better. I can't seem to post pics or else I would show you my air filter setup.

[blacksrjdm]

Swap a V8 titan motor into it. U'll have no problems with power.

Or even easier, an ls1.

[PEZi]

Your truck weighs more than 3,500 pounds, it has the aerodynamics of a mobile home, and it has 134 horsepower. 80 uphill sounds about right. People intuitively think the nissan hardbody is a light weight vehicle. Its a juggernaut.

why is the hardbody so much heavier?

my truck weighs next to nothing

[seang]

I don't know, but my 1987 2wd was a little more than 3000 lbs. and my 1997 4wd is a little more than 3500. I drove them both over a scale just so I could know for sure because people were telling me different. How much does your 720 weigh in at, PEZ?

[PEZi]

I don't know, but my 1987 2wd was a little more than 3000 lbs. and my 1997 4wd is a little more than 3500. I drove them both over a scale just so I could know for sure because people were telling me different. How much does your 720 weigh in at, PEZ?

well my 720 is fully gutted... but it sits right in around 2,000