typhoone

Okay, i have searched the internet, talked to friends, talked to mechanics, and anyone else with an answer and I keep getting different answers. I am starting my build after i get my taxes, I am putting an LS1 into a 1986 Nissan 300zx. But people keep giving me contradictory answers on what i thought would have been a simple question. Carb or Fuel Injection? I was thinking about fuel injection and just getting an LS1 off ebay that is already fuel injected and going from there, but my buddy that is going to help me put everything in and fabricating everything said that it would be better for me to go carb. He said if i went FI i would have to get the ecu, and get the sensors and get them put in and all that fun stuff, and that even pro drag cars use carbs and all that fun stuff, but whatever i want he will help build and will put in. Please, i have searched through google, hybridz, ls1 tech, and all kinds of other things, which is the better route for power? Please don't say search, i have. i haven't found anything that helped. Thank you

baldwintpenguin

The next question you need to ask yourself is what kind of power are you going for(how much hp/tq would you like to see)? Is this going to be a drag car (1/4 mile) or a street car?

300bhp/ton

You can go either it's your choice and both will work.

But if your friend is comparing frigging top fuel dragsters he's just being a ****. I mean how do you see driving down the highway

If you go EFI you can either use a loom say from an Fbodyor go custom like Megasquirt. Both will work and both are fully tunable.

If using a GM PCM then EFi Live or HP tuners would be a good investment, don't waste your money on hand held tuners though. Failing that most good dyno shops will have the correct software, but it means paying for dyno time even for a small change.

A good EFI setup will allow much smoother and reliable running plus much better mpg. With EFI you have proper control and tuning ability plus datalogging.

If you want to go carb then GM Performance offer a converison kit and I thing a few others do also. It's not cheap. Now carb engines usually have fantastic throttle response and are capable of making similar PEAK power. However they generally lack the full tunability across the entire rpm range, this usually means a worse idle and more likelyhood of surging if you go for a big cam. Plus mpg will generally suck by comparsion. If you plan on FI carbs bring a whole new issue, sure there are plenty of proven carb FI setups but they are often for a singular purpose.

First off you need to ensure the carb and manifold can take high pressure (floats, seals, etc.) This can be a pain to start with. You then have the issues of suck thru or blow thru (BIG topic of debate). But tuning is often the worse, off boost you won't need much fuel but on boost you need loads. This means as carbs can't adapt the same as EFI you generally have to run the motor pig rich off boost so that it's safe when on.

For a 1/4 mile warrior it doesn't matter because they spend the majority of their time at WOT. But a street or circuit motor is a different ball game.

Now I know carbs and FI can work, but IMO it's just a lot more effort and will usually lead to a compromised setup.

My choice would be EFI. The only reason I'd go carb is if the motor was going into a period car or hot rod where a carb setup would be more in keeping (70's Fbody or '32 Coupe, etc.) You won't have as much wiring to worry about with a carb setup either.

If you maximum performance and driverbility look to EFI. Take a look at some of the cam profiles people daily drive (Trex from Thunder Racing or MS4 from Texas Speed & Performance). These are only really possible because of the EFI, on a carb setup such cams would be OTT for street use for most people.

Welcome to the 21st Cent!!!

typhoone

Thank you for your help, just wondering, i just realized that the car that i am putting the ls1 into is was fuel injected. Would i be able to use the sensors that it came with, or will i have to get new ones?

Asmodeus

talk to people in the engine conversion section.

WhiteKnightZ28

iTrader: (5)

I'm starting to think you may not have a clear grasp on the scope of your project...

typhoone

any insight as to why you said that would be helpful, otherwise i don't have clear grasp on what you just said. I have posted in the conversion section, and they have helped me out, so i know that i have to get the sensors for the ls1.

300bhp/ton

What sensors are you actually meaning?

If you get a Ls1 and PCM from an Fbody it will have all you need.

I mean you really don't need much in the way of sensors to get a car up and running using EFI. Sure if you want cruise control, ABS, TCS and all the other tricks a PCM controlled EFI unit can supply then you'll need everything. But apart from that fueling and timing are probably the only things you really need to worry about, espcially if you are going for a manual gearbox.

And I think the reason WhiteKnightz28 said what they said, was because it isn't a 5 min job to do a engine conversion. It needs to be well planned to the last nut and bolt and is quite a major undertaking.

And without wanting to sound nasty you still sound as though your at the "hay wouldn't it be great to have a LS1 engine in a......" phase. Rather than actually having sorted out the game plan of what you want to do.

The Ls1 is in essence a pretty simple powerplant, even with the factory EFI. So the decision to go EFI or Carb should bear no relation to the LS1 specifically as this decision would exist for pretty much any setup using any engine.

An old fashioned carb setup will be easier to put together but to get the most of it you'll still need to use a proper electronic controlled ignition system and fuel system. This means it will still run an ECU/PCM. And will still require tuning. If you go for the old fashioned points style setup you really are just compromising the potential and reliability of the engine.

Personally I love carb engines and espcially throttle response, but having owned multiple carb engines they are more fickle and require more constant attention.

If I where you this is what I'd do.

1. Write a simple mission statement of what you want to achieve, highlighting and major milestones, e.g.

"To fit a LS1 with a manual tranny into 'x' car and have it producing 400rwhp n/a and be suitable to run FI later on."

This should define what you want to do I would also include a realistc target budget of what you want to spend.

Now start and list all the major items you'll need using a spreadsheet or similar, you can then break this down and include smaller/specific items as sub categories.

From here you should be able to see the scope of the project and also run an initial cost estimation. From here you can see if it possible within budget or not. And either adjust the budget accordingly or your definition of what you want.

Unless you have excess money and time and probably ability to custom fab parts I would stick with what is tried, tested and proven. Take a look at how other people have done engine swaps and use what they have learnt.

typhoone

that is all a very valid pointand that is what I am doing. I won't even be staring on this build for another month or two. I would like the car to be running by around june or july, but I don't plan on this being done until I am a senior in college, and I am a sophmore now. me and a couple of buddies are doing this, and one of them owns two businesses around town and has agreed to sponsor me for 65% of all cost. plus my buddy Ed has built more than a few motors and can fabricate just about anything I need. so trust me, I am past the '' this sounds cool'' phase, now I am trying to plan the build before I do the build. the extra sensors I was talking about ere the MAF and all that fun stuff. but thank you for all of your help, I appreciate all criticism that isn't just snobbs being snobbs, so I didn't think you were being nasty. anything someone else knows about this that I done is always MORE than welcome. thank you once again

BrandonDrecksage

iTrader: (1)

your best bet is to buy a longblock with ecu and harness, plus get tranny off of ebay..or something similar. are you going with a m6 oir a a4? the longblock with ecu and harness should have 90% of what you need. the bitch is going to be installing evering thing, and by everything I mean the wiring. You stock gauge cluster, may or may not work. stuff liek your fuel level will still work, but the coolant, oil preassure, tach, speedo..ect won't There is probably a way to get it to work or just buy aftermarket gauges. Just realize what your doing is not gonna be easy and if you have an electrical problem, its going to be a bitch. How strong is the stock rear in that car? The carb option would be a waste becasue the engine sould come with all the senors you need, besides o2 senors that you would need to get welded into the exhaust that you have. jsut the conversion forum.

typhoone

I am goin with the a4 simply because this is mainly going to be for weekend riding plus some racing. the stock rearis pretty strong on the zx, but I will still wind up upgrading it eventually and adding an lsd. I am not too worried about the gauges because I wanted new electronic ones anyway. like I said, me and a budfy will put it in, while Macon Moore High Performance will be doing ALL the fun wiring. they can have that fun. lol