77 280 FI swap for carbie??

[gator]

I am looking for input as to the pros and cons of removing my FI system (it is working ok) for SU carbies. I really dont like the FI system and am wondering what carbie I can put on here. I am guessing almost any SU from any Z? What would be the best carbie? Would and early (70's) z carbie work well and would it produce the same HP and would it improve/reduce my MPG?

Thanks ..Bruce

[sblake01]

Okay, I'll bite since you didn't get any responses on your other version of this yesterday. Why would you want to do this? Are you having trouble with your FI system? You'll get other opinions I'm sure but putting carbs on an FI car is a downgrade based on my experience. And there is a lot more to this than just swapping intake manifolds. Properly operating fuel injection is much easier to deal with than carbs. I had to learn quite a bit about these systems because I was clueless when I bought my 280 in 1997. I picked up a lot of knowlege on this site. I can basically troubleshoot any problem on either of my EFI L6's now, and this knowlege even helps me with my wifes J30 which is a bit more complicated but has some of the same stuff. I can't really offer any insight on making the changeover since I've never personally done it but I have seen strong running cars with either. I don't think that a carbed car can equal the MPG of a FI car but I haven't done a side by side comparison. I have, however owned both, and my 78 280 and my 79 810 both get better mileage than either my 70 or 72 240 did. Stronger runner stock vs. stock? I have to give the nod to the early cars although it's a mental comparison that spans over 30 years. But my later cars are definately better highway cruisers. I don't know if any of that helps you but if it were me, I would stick with the FI.

[gator]

Well .. the thing is that the FI system in the car has been pieced together alittle so there are pieces of hose fitted here and there and it looks pretty crappy. I intend to restore this car completely and I dont like doing things half way. The cost to rebuild the FI system could be quite high I would guess. Please correct me if I am wrong .. I am really looking for others input here .. So my thoughts were that the SU's make for a much cleaner and neater engine compartment and I have experience with them. It also seems like a pretty easy change over.

I am also considering tripple webbers now that read more into the forum. That could be a kewl project and would have great results. Cost is not really a big consern here .. but would these tripples make a no-daily driver or do they produce a nice smooth ride? My plan also includes a mild cam with high perf timeing gears.

Thanks for the input. B

[beandip]

I just installed '82ZX engine in my 240 and gave away the injection. I am running SUs and a cam , and headers. the compression has been raised to 9.5 to 1 and I have a '79zx ignition. the change over is no problem . Unless you are going all out and want top end performance , stay with the SUs they are simple and work well. I know a guy that turns in the 12s at the draggs in his 240 running Sus and street tires and it is his driver. Another friend of mine has a built Z with a set of tripple Mikunis and it goes like a mashd cat . But the tripples are more complicated and they are most effective at the hi RPMs . For a street driver the SUs is a good way to go. In my openion. Changing from injection will be a learning experience if you havent driven a Carbed car in winter . The computer working the injection for you will make adjustments in fuel richness when the engine is cold . You must do this with the use of the choke to richen the mixture. You will need a couple of tools to be able to adjust the SUs . A UNI-SN is a must , it is used to ballance the air intake of the carbs so that they are the same . this is the same thing for any multi carbed engine . Go to the tec page and look up adjusting SUs , it's all covered there . SUs are so less complicated and there are zero sencers to go bad. If you have further questions that I may be able to help with send me a PM Good luck , Gary

[viparz]

I am about to do the same changeover. The guy who owned the car before me made the swap and it has given me nothing but trouble. This car is not to be a daily driver so efficiency is not a concern I am no mechanical genius and even less so an electrical genius. Am I right in believing that swapping to SU's would make everything much simpler? As I am teaching myself as I go an advantage of this would be being able to use stock wiring diagrams.

Other than the manifold and carbs, what else would I need to change to make this conversion?

Any help would be great