4bbl 280zx
03-09-2008, 06:21 PM
#1
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Location: Concord, NC
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4bbl 280zx
Hey guys...been a while since I posted. Anyway I wanted to put to rest some stuff about the 4bbl conversion on the 280zx's. I made friends with a guy that owns a used car lot a while back and he has 5 280zx's one of which is a 1979 coupe just like mine that has been converted to a 4 barrel carb. As it sits it has the stock L28 block and head and has the Arizona 4bbl intake with the Holley 390cfm carb. The exhaust manifold is stock but it has a full 2 1/4 aluminum exhaust pipe from the manifold to the rear and ends with a canister muffler, no cat. 5-speed tranny and stock rear end.
He took me for a ride in it and I was amazed...AMAZED. It pulled hard all the way to the redline with no flat spots at all and the sound from the vacuum secondaries was awesome, deep and cool sounding over the somewhat quiet exhaust. The car started right up and we let it warm up for a bit until the electric choke did it's thing. He has the choke set at 1,500rpm and the warmed up idle at 750 or so. Worked perfectly. He has an electric fuel pump running at 7psi and it is very near the stock fuel pump and new metal and rubber fuel lines with a glass filter just before the carb. Other than a few other minor mods thats all that was done to it.
The fun part is when he let me take it for about half a day to play with it. The gas needle barely and I mean barely moved and I romped on it alot...I had permission to do so lol. He told me it has been set up like this for about two years and has never had an issue with it running rough, not starting, or any problems with the carb. He said that on the highway he is around 30+mpg and says it pulls better than the FI did. The only thing he said he had to do was tune the carb a little over the course of a week or so which he said was easy and straight forward if you follow Holley's instructions.
So it is a pretty good option for those who don't want to keep messing with the old FI and the 4bbl conversion really does work and works well. I am glad I finally had the chance to play with it first hand and see for myself if it was worth spending that much money on and it is if you want to keep it non turbo and not want to mess with wires and the computer or injectors and blah blah blah. So you change a fuel filter every so often, big deal...at least it's not 6 injectors or O2 sensors or EGR's...you get where I am going.
He took me for a ride in it and I was amazed...AMAZED. It pulled hard all the way to the redline with no flat spots at all and the sound from the vacuum secondaries was awesome, deep and cool sounding over the somewhat quiet exhaust. The car started right up and we let it warm up for a bit until the electric choke did it's thing. He has the choke set at 1,500rpm and the warmed up idle at 750 or so. Worked perfectly. He has an electric fuel pump running at 7psi and it is very near the stock fuel pump and new metal and rubber fuel lines with a glass filter just before the carb. Other than a few other minor mods thats all that was done to it.
The fun part is when he let me take it for about half a day to play with it. The gas needle barely and I mean barely moved and I romped on it alot...I had permission to do so lol. He told me it has been set up like this for about two years and has never had an issue with it running rough, not starting, or any problems with the carb. He said that on the highway he is around 30+mpg and says it pulls better than the FI did. The only thing he said he had to do was tune the carb a little over the course of a week or so which he said was easy and straight forward if you follow Holley's instructions.
So it is a pretty good option for those who don't want to keep messing with the old FI and the 4bbl conversion really does work and works well. I am glad I finally had the chance to play with it first hand and see for myself if it was worth spending that much money on and it is if you want to keep it non turbo and not want to mess with wires and the computer or injectors and blah blah blah. So you change a fuel filter every so often, big deal...at least it's not 6 injectors or O2 sensors or EGR's...you get where I am going.
03-09-2008, 08:09 PM
#3
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Join Date: Apr 2006
Location: Concord, NC
Posts: 2,826
Originally Posted by NismoPick
Meh.... I've given my opinion on 4bbl L28's. 
On a side note, turbot5 is about to pee his pants because your PM inbox is full.
On a side note, turbot5 is about to pee his pants because your PM inbox is full.
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