What's the better of the L28s

[Guest XTCshri2222]

I plan to do a whole rebuild an converting the L28 into a 3.1 stroker.

 

Question is what system is superior the fuel injection or carborated systems?

 

Which would be the HP winner

[Guest bastaad525]

Programmable fuel injection, of course.

 

or, if you just want stock vs stock (SU carbs vs. stock ZX EFI) then still the EFI ASSUMING it is in perfect tune and running order (which every ZX I've known of definately was NOT)

 

performance carbs like tripples could probably outgun the stock EFI for top hp, but for the price, you would get even more power out of a lower cost programmable unit like SDS. Megasquirt is even cheaper though we are all waiting to see some hard numbers on what it can do.

 

I've only had SU's or stock EFI on any of my Z's. I liked the SU's because of their ease of tuning and maintenance, and, there's really not too many things that can go wrong with them, and if something does, it doesn't take a genius to figure out what's wrong. On the other hand, I like the better mileage of EFI, I like that it starts easier, and never diesels the way my SU's always did after shutting off. But... man do I go crazy when something goes wrong on the EFI... I'm STILL chasing bugs out of my turbo motor with stock efi setup.

 

if it were me, and I were building another N/A motor, a street motor, in a 240, not too concerned with all out speed, I would definately go with SU's.

[SleeperZ]

I plan to do a whole rebuild an converting the L28 into a 3.1 stroker.

 

Question is what system is superior the fuel injection or carborated systems?

 

Which would be the HP winner

 

Short answer - fuel injection. It might not be the most cost effective for your application, but it wins in driveability and power, especially with a turbo.

 

I'm using a factory EFI, consistent 12.5:1 a/f ratio at WOT, and 27 mpg cruising 80mph. And it's a pussycat around town, except for the 4 puck clutch.

[johnc]

Motec is probably the best current PGM FI available although DTA has a good reputation and seems to be gaining ground on Motec, especially in Europe. Traditionally the high horsepower normally aspirated L6 engines have used triple two barrel carbs like Webers, Mikunis, or Solexes but the tread now is away from carbs to something that provides individual cyliner mixture and ignition controls. With the flow problems inherent on the exhaust side of 3 & 4 some sort of tuning is needed to balance out the power delivery.

[rayaapp2]

No one mentioned why the carbs are no-good for high hp applications.

 

Basically the SU carbs cannot support high hp because of there size.

The EFI system can.

 

If you want a carb system look into a 4 barrel conversion from Jim Cook Racing.

 

I doubt that it would be good for a stroker though. I would go after-market like everyone has suggested.

 

check this site out for good stroker info

http://www.geocities.com/inlinestroker/

[johnc]

No one mentioned why the carbs are no-good for high hp applications.

 

Because carbs are fine for a high hp application and have been used successfully for decades.

[SleeperZ]

No one mentioned why the carbs are no-good for high hp applications.

 

Basically the SU carbs cannot support high hp because of there size.

The EFI system can.

 

If you want a carb system look into a 4 barrel conversion from Jim Cook Racing.

 

I doubt that it would be good for a stroker though. I would go after-market like everyone has suggested.

 

check this site out for good stroker info

http://www.geocities.com/inlinestroker/

 

Carbs are fine for high hp. But they have less tolerance for load variations; as a consequence they will not behave as nicely or efficiently at part-throttle. And don't do a 4 barrel - the L series intake manifold is notorious for poor fuel distribution, and that will hurt high hp applications.

[fl327]

id go with the carbs, keep it simple with the NA.

turbo boost is very nice though.

[technicalninja]

One of the nicest aspects of a stand alone F.I. system is that with software changes it can adapt to the Z owners whims. While the "big" engine is being built you can use a "mule" stocker motor and the injection will work fine. If you change your plans you do not have to purchase new fuel delivery equiptment.

I would use an early 280Z manifold, properly sized injectors (many good choices exist both new and used), and a 60mm throttle body (aftermarket or KA engine type).

Many choices exist for aftermarket F.I. systems. Whole threads exist on this site which debate the different brands. Good pieces are available used.

Carbs can and will continue to power high horsepower engines but they have to be matched closely to their application. Some carb designs allow the owner to change the basic flow capabilities of the carburator (Weber DCOE, Mikuni PHH, Solex) but require additional parts to make these changes Basic 3X2 Weber choke change= 6 chokes@$20, 6 mains@$4, 6 airs@$3=$162 per major flow change. The cost for the same change with the F.I. is some laptop time (both of these changes assume that labor costs are not a factor). The F.I. can be harder to understand but once learned it is easier to work with than carbs and has proven dependable.

F.I. can support a 500 HP L series turbo. I do not believe that carbs can.

[Guest bastaad525]

XTC - what are you up to dude? We've actually been thru this whole thing before, you started a thread and then disappeared from it, even though a few of us were still giving some good info for you, you apparently decided to ditch the idea and go with an RB motor or an SR20DET. Now you're back to wanting a stroked N/A motor? Then you will want a Turbo again? We all kinda agreed that either an L28ET or a V8 conversion would be best for the goals you were talking about, but you weren't interested. I remember you said the V8 was out because of the kind of shows you will be attending with your Z. So, again, for the goals you talked about earlier, and in answer to your broad question "which would be the HP winner?" the answer is simple: L28 Turbo motor, period. Seems to me you're still up in the air with the whole thing... you really gotta sit down and decide exactly what you want with your car, what your goals are, how much HP you want, how important is reliability, driveability, cost factor. The options you've expressed interest in so far vary VASTLY in each of these aspects.

 

Also... I notice that again, you have posted the question but dont seem to be following along with the replies... come on dude if you're gonna ask for help at least follow up, it's your topic, your question... last time we got 3 pages into your question and you never even replied. You had already moved on to a new thread that you started about some OTHER engine you were apparently then set on doing... only to come back and start another one yet again about another engine you are 'definately' going to do. Come on dude... foooooooocus... foooooooooooooocus.

[Guest XTCshri2222]

XTC - what are you up to dude? We've actually been thru this whole thing before' date=' you started a thread and then disappeared from it, even though a few of us were still giving some good info for you, you apparently decided to ditch the idea and go with an RB motor or an SR20DET. Now you're back to wanting a stroked N/A motor? Then you will want a Turbo again? We all kinda agreed that either an L28ET or a V8 conversion would be best for the goals you were talking about, but you weren't interested. I remember you said the V8 was out because of the kind of shows you will be attending with your Z. So, again, for the goals you talked about earlier, and in answer to your broad question "which would be the HP winner?" the answer is simple: L28 Turbo motor, period. Seems to me you're still up in the air with the whole thing... you really gotta sit down and decide exactly what you want with your car, what your goals are, how much HP you want, how important is reliability, driveability, cost factor. The options you've expressed interest in so far vary VASTLY in each of these aspects.

 

Also... I notice that again, you have posted the question but dont seem to be following along with the replies... come on dude if you're gonna ask for help at least follow up, it's your topic, your question... last time we got 3 pages into your question and you never even replied. You had already moved on to a new thread that you started about some OTHER engine you were apparently then set on doing... only to come back and start another one yet again about another engine you are 'definately' going to do. Come on dude... foooooooocus... foooooooooooooocus.[/quote']

 

hey sup, it'd not that i'm not following ppl's info it's just i'm tring to gain all the info i can b4 i do anything to it.. Cause once i do it iI don't wanna have to change it later. An since this is being built be my an my friend, i'm tring to avoid as many bugs as possible just tring to gauge everything. Originaly i was thinking on a definet motor swap, but then one member had posted a link to aftermarket L28 parts which i hadn't been able to find, an after realizing the L28 wasn't that hard to get parts for, i decided to keep it simple . The original reson i was leaning to a swap was for driveablity an repair parts.

[Guest bastaad525]

Hmmm well I would say, just from looking at the goals you originally said you were aiming for, as far as the amount of power you are trying to achieve, I dont think you're gonna be happy with an N/A L28. Even with a stroker, you're looking at a lot of work, to get relatively little amounts of power. Don't get me wrong, there are guys on here with very strong running strokers, but most of them have a LOT of money tied up into them to get them there. Or are like Norm and have done all or almost all of the work themselves by hand. Norm is always a good example of what can be done... but he is also the exception, rather than the rule. Again, I would say that if a V8 is out of the question, an L28 turbo would be most likely the easiest and cheapest way to get a motor that's putting down more than 200hp at the wheels. With a bone stock turbo motor, with just a few simple mods like boost controller, intercooler, exhaust... you can easily get up to 250hp at the wheels. And there is still plenty of room for more power after that with programmable EFI and such. Whereas an N/A motor is pretty much getting to it's limits at or before those power levels unless you are REALLY putting a LOT of cash into it. I can't say I've ever heard of a street L28, stroked or not, getting more than or even as much as 300hp at the wheels. And even if there is one, it is getting that way high in the power band, and compared to a turbo motor with the same hp numbers, the N/A will have MUCH less torque. Torque is what you feel that makes the car feel fast, hence the turbo car will usually feel faster. Sorry if I seem like I'm trying too hard to deter you, but again, i've been down this road. I built up an L28, actually to a 2.9, with cam and headers and free flow exhaust and high compression and a light flywheel and ACT clutch, and after over $5k spent, had a car that was still pretty mediocre by todays standards. Now with my turbo motor for roughly the same amount spent I have a car that is as fast as some of the faster cars on the road and I still have barely scratched the surface... I haven't even installed an I/C yet, and I'm running crappy exhaust... everything is bone stock except for the boost controller, and I'm ALREADY at 200hp at the wheels. My built N/A motor put down 170. I'm just trying to save you from going down that same road I went, which was, as far as I am concerned, a waste of LOTS of time and money.

[Phantom]

XTC,

You gunned it all down with the last sentence of your post. You're looking at a highly modified motor and you want reliability and easily available parts? That's an oxymoron. If you want reliability and easily obtainable parts keep the stock L28 and just improve its breathing a bit (intake, exhaust, cam). That won't cost a lot and the engine will run forever. If 150 rwhp isn't enough for you then you need to give ground on the reliability issue or swap in a higher HP stock configured motor. That is exactly why I put a stock LS1 in my car. Lots of HP and excellent reliability. It has started first time and run great since the day I brought it home.

[Guest bastaad525]

Agreed, if you want reliability and ease finding parts, the more stock you make things, the better, and the best solution is just to swap in a stock motor that or near stock motor that already has more power. He's not going to do a V8 though, we already suggested that to him. So, again, next best option would be a stock L28et. Reliable as the day is long, and still easy to find parts for. And way easier than building a stroker motor and cheaper as well.

[Guest battg8r]

What aftermarket fuel injection systems work? I have an '83 L28 non-turbo I'm going to swap into a '72 240. I like the fuel injection but I don't know how well the one on the works, and I have dual webbers on the L24. I was thinking about using those on the L28 and cut out some of fuel line problems. But if there is an affordable aftermarket FI system I would go with that.

 

Thanks,

[mobythevan]

The List:

 

You got the Z31 ECU upgrade that is probably easiest and cheapest but lacks some of the programmability. ~$100

 

MegaSquirtnSpark the next most expsensive and has good programmability but is do-it-yourself kit. ~$300

 

SDS next most exspensive and good programmability, first of the actual aftermarket systems. ~$500

 

After that all the usual aftermarket systems that are around $1000 and above.

 

These all work good. Not sure what problems you have with the stock non-turbo EFI, but my stock turbo EFI system worked good.

[Mudge]

Basically the SU carbs cannot support high hp because of there size.

 

They can be built for it, or you can get other carbs - but the FI stuff is likely going to be expensive and a tad time consuming. I love FI, but carbs would be "simpler" generically speaking.

 

Carbs do quite well but I have a hard time picturing AF dispersion as better than injected, even injector type differs.

 

Carbs are often jokingly described as "a metered fuel leak," or "the only device known to man to provide an incorrect AF ratio at all RPMs." Without custom EFI though, the stock stuff isn't going to cut it I think.

[Guest battg8r]

Thanks for the list. I'll do some checking. My problem with the stock FI is that I don't have all the parts, and the ones I do have are not in the best shape. Replacement may be easier and better than repair. I might end up using my carbs to start and swap to FI in the future.

[zredbaron]

XTCshri2222, I just bumped a thread I started about two months ago "NA 3.1L=>head & camshaft questions"

 

A lot of the same stuff is talked about there, but the thread is all out performance, no stock parts considered. There's a lot to learn in that post. Also, you can read an article of FI vs. carbs (article discusses TWMs 3x2 bodies). The article was written by DRAG Sport magazine. Here it is:

 

http://www.twminduction.com/ThrottleBody/carb_vs_fi.pdf

 

Good luck with your decision, I've been deliberating for a long, long time! I do think that when I can afford to drop $5k on it, I will do the TWM and TEC-III setup. I really don't think that can be topped...