Tripple Mikuni carbs & Turbo Engine

[superduner]

Hi guys i just got MAJORLY hooked up with two cars. HArd to believe but this is the list

 

1969 Z with n47 engine (l28) with tripple mikuni carbs. and other electronic ignition components MSD bla bla bla (some rust)

 

1972 z with L28ET stock motor straight body no rust.

 

for $800

 

my question is...

 

Can i, and is it recomendable if i build the l28et but run the tripple mikunis?

would i get more power?

what are the Pro's and Con's of running this setup?

 

 

any help would be greatly apreshiated thanks guys

[PanzerAce]

Jesus, the carbs alone are worth double what you paid for the cars.

 

 

Do you mean building a blow through turbo setup? It's been done, but Tony D will tell you to skip it and just build a screaming L28et for the same cost. the real issue from my reading with building a L28t engine with carbs is finding the intake side equipment. Either it's a bad design (like the cartech), or you can't find them (SK, HKS, etc).

 

If I got those two cars, I would pull the carbs, replace them with some cheaper carbs, then flip the '69 (or part it out to collectors).

 

 

edit: Actually, if either of those cars has AC, I know someone in SD that'll buy one of them for a good price if it runs well. PM me if you decide to get rid of one

[ARiskyCvt]

You know what most people will say.

Its dumb to do it because of the fact that we now have EFI!

It will be easier to tune.

Carb are unpredictable because of weather changes.

 

Well personally that's all dumb FACTS!

I love Old school tech. We live in the west coast so it the weather doesn't change that much and drastically. (Almost spring and summer all year long)

 

It is doable as long as you have money! of course.

I hope those carbs aren't 40's! too small for turbo. At least 44mm. check the butterfly if it says 175. If it is great start. Look for a surge tank plenum. Not that hard if you have money.

 

any other questions you can PM.

[superduner]

Great. Thank you. yeah i emails some peeps that seemed to know their stuff about Z's and surprizingly they all said to just go all turbo and slang the Mikunis or build a NA with them later. Im thinking of possibly if not MOST likely slanging the 69 once i get it in DECENT shape. "hopefully" yeah i know 800 was a steal for them. the first thing i saw when i poped the hood open on that 69 was $ rolling in my eyes when i saw the mikunis. haha But il make a new thread at the start of my project thanks alot for the replies. you guys are great.

[slo.s30z]

Post picts!

[Guest 280ZForce]

i believe I have a rare carb'd turbo intake manifold that bolts to triples that you may want.

[superduner]

thanks guys i decided i will be going fuel injected. might spend a little more for the whole set up but at least i can rest assured i whont need to worry as much about running lean. or adjusting the carbs and detonating my engine as much.

[essdeezee]

By the way, did I mention that I hate you? And next time you find a pair like that in SD, tell me first ok?

[superduner]

oh it was'nt anywhere near SD. i had to drive 4 hours to FILLMORE CALI to get um

[cockerstar]

That's still easily worth it!

 

I would say build a DD out of the '69 (with the triples, ~150-200hp, something fun and comfy) and build a weekend car out of the '72 with the l28et. The best of both worlds!

Although a bit more expensive to do

[essdeezee]

Well worth the drive. Didn't mean to bust your chops too hard, good find!

[superduner]

haha naw its alright me and a cousin MIGHT get teh 69 with the mikunis, rollcage, etc etc etc this friday if he's down. but il keep posted. and post up pics of the car once we get it IF we get it as well as other pics of cars he has incase anybody is interested and wants to save the drive there.

[Tony D]

You know what most people will say.

Its dumb to do it because of the fact that we now have EFI!

It will be easier to tune.

Carb are unpredictable because of weather changes.

 

Well personally that's all dumb FACTS!

I love Old school tech. We live in the west coast so it the weather doesn't change that much and drastically. (Almost spring and summer all year long)

 

It is doable as long as you have money! of course.

I hope those carbs aren't 40's! too small for turbo. At least 44mm. check the butterfly if it says 175. If it is great start. Look for a surge tank plenum. Not that hard if you have money.

 

any other questions you can PM.

 

I don't recall anybody saying it was 'dumb', but then again masochisim never is well undestood by those who aren't 'into it' as well.

 

It's not a matter of dumb, or anything like that. It's that it's cheaper, easier for people to get right quicker, is on most of the current generations 'learning curve' and the most important 'dumb' thing of them all: It's hands down reliable.

 

Far from it to be driveable and reliable.

 

Most people who rave about 'the good old days' weren't there to experience it firsthand.

 

If you want to actually DRIVE the car in varying conditions...go EFI and don't waste your time.

 

I'm not saying it's dumb, but I'll remind people that 'old school tech' encompasses HKS ITB Throttle Bodies, or SK ITB's and a generic, hidden EFI controller. Same Blowthrough Plenum, and about...ooooooh 27-30 years old? That old tech enough?

 

If you want 'old tech' for Turbo, look to a 'Turbo Toms' drawthrough, or a Crown Conversion using a Corvair E-Flow Turbocharger and no wastegate, with a single SU providing fueling.

 

I've got one of each, and can extoll the virtues and vices of each. Thank gawd I don't have to drive them every day!

 

And before anybody retorts about EFI being 'hi tech' or 'new tech' I'll remind you the Datsun has had EFI since 1975. The VW Type 3 since 1968.

 

And in aftermarket applications, the 240Z Rally Cars in 71 or 72 had a JECS ITB EFI Setup!

 

So before you slough off EFI as not being worthy of being classed as "Old School Technology" get those facts straight... You can have EFI hardware on that car from the early 80's and be TOTALLY 'period correct'!

 

I know I do, and I am.

 

That you have updated a hidden component to provide much better control is never seen (the EFI Computer). The look is still spot on period correct to those who know what they are looking at, and the thought of that old school EFI componentry always gets noticed.

 

 

Nice find on the pair. How low is the VIN on the 69?

[PanzerAce]

Tony, how much of the decision to use EFI on a rally car was because of reliability/power, and how much of it was to prevent fuel starvation/over rich?

[ARiskyCvt]

Hey Tony

 

It wasn't suppose to be an insult or anything in that nature. I always hear and see people say eh carbs are crap or unreliable and I personally don't think they gave it a chance.

 

I never said EFI is garbage or anything. Tuning with efi is the GREAT and alot more efficient.

 

Like I said Tony wasn't suppose to be an attack.

[Tony D]

Tony, how much of the decision to use EFI on a rally car was because of reliability/power, and how much of it was to prevent fuel starvation/over rich?

 

All of the above! During the extremely rough sections, and even to this day with many of the Baja cars, Carbs simply have to get a lot of modifications to keep fuel aeration and sloshing under control. Left or right hand turns can present different situations.

 

Power/Reliability in the EFI Off Road cars is a relative thing. They also used Mechanical FI (lucas slide valves) as well---mainly to combat the aeration and sloshing issues.

 

Being nostaligic is one thing, but truly knowing what was out there in the day is another thing altogether. I know the comment wasn't an attack, but it was totally dismissive of the systems that were out there at that time. It's just presenting a woefully limited scope of the picture, and mischaracterized what was really going on...

 

For some hobby streeters, carbs will be fine. But in most cases where class rules are restrictive (SCCA Mandated use of the 44PHH...) and a series popular, that 'look' may get overplayed and skew perception of the general tone. To the casual observer, it will look like that was the only option available at the time...and that is FAR from the truth!

 

Sure, in the USA many people slapped mikuinis on the car.

In Japan, it was deriguer...

In the UK slidevalve MFI was used, and even here in the USA Hilborn and Kinsler componentry was used on MFI systems (of which I posess an example as well...)

 

It most decidedly was not just all carbs carbs carbs carbs...

 

No matter where you were and you started getting into rarified atmospheres of top-tier tuners even as far back (that I personally know of) as 1984, there were analog standalone fuel computers (EFI) in Japan, Haltec was availabe at that time I believe, and ITBs were all over the industry. From Japan I've a catalog from Snagyo Kiki (SK) with their EFI system that was given to me in 84 or 85, and it was the new 82 or 83 eidtion catalog! I've catalogs from the USA in the 80's from Tull Fuel Injection... Kinsler's Catalog was on mimeographed sheets in Pica 12 point with halftone B&W Photographs! If that's not "Old School" I don't know WHAT is! Eggers and Vickers out of WISCONSIN was making L-Engine Hilborn and Kinsler compatible induction sets---and those are oin a CARBURETTED STUD PATTERN! That means pre 1975!!!

 

Even the "Wangan Midnight" movie using the SSS car shows blowthrough carbs on the car at the beginning of the show, but by the 3/4 point in the production if you are looking closely you will see the exact same set of HKS ITBs on that car as I have on mine! And that was a car with 600 HP in the early-mid 80s' on carbs and when the movie was filmed (87 perhaps) during the filming the car's setup changed.

 

EFI is "Old School", Mechanical FI is even "Older School"...

 

But make no mistake, sentimentality aside, this site and forum is about performance. If you want to make a period correct setup that's one thing, you realize the sacrifices and tradeoffs you will have to make.

 

But technology evolves, and gets better, and we shouldn't stand on sentimentality when performance is the goal.

 

To Lost Fairlady's comment about people saying 'eh, carbs are crap, they haven't given it a chance'---leave me out of that comment if you will. I tried, for over 10+ years. I successfully ran a 350 HP Blowthrough system from 85 to the late 90's. But there was a point when EFI technology (The actual ECU portion) came to a price point where it was simply foolish to remain sentimental or deny the obvious performance advantages inherent in the systems coming available, and tolerating the buggy nature of carburettors in that situation just became a 'why bother with this B.S. any more?' situation. I can say 'meh, carbs are crap' because in a blowthrough system they pretty much are compared to a similar setup using ITB's (of whatever vintage) and any number of different modern standalone EFI computers, up to and including the ubiquitious Megasquirt. It will make more reliable power, it will get STUPENDOUS fuel economy (my triple blowthrough 44s averaged 17mpg in daily driving, so I think I have 'proper tuning of carbs' down correctly...the EFI ITB setup effortlessly gets a minimum of 5-8mpg more in mixed driving...), and be dead-nuts reliable after a long high speed blast down the freeway at 110F, and then pulling off to sit in city gridlock trying to get to the Petersen Museum in Downtown L.A.

 

Been there, done that.

 

As for '40's being too small'---I've got milk crates full of em and tell ya what, taking the venturis out gives me a 40mm straight bore, FAR better than any 44 PHH setup flow-wise. Some epoxy or heliarc for injector bungs at the front of the barrels, or in the manifold itself, and there you have it: low cost, period correct looking EFI-ITB's with all the look of original Mikuinis. There's a reason I didn't chuck them, and there's a reason I harvested as many as I did while living in Japan (out side the fact they were dirt cheap at the time...)

 

The last reason to go EFI, is that unless you are committed to buying specially formulated racing gasoline made to run in Carburettors, the pump gas you get today is now ALL formulated to run in EFI systems. Many of the issues people are having with their SU's in the midwest are directly related to the reformulated gas cooking off like it did in the south and southwest years ago. Poor atomization, stumbling when cold, hard to start when hot, vapor locking...all from improperly formulated fuels being used in a carburetted car. Go down and buy some real carburettor formulated gas from ERC or VP and WATCH how much better your old-school car will run! It's a startling change. Last year for MSA I bought a 55 gallon drum to run the weekend and didn't skip a beat all the weekend long. I'm stretching the response to other realms a bit, but fact of the matter is if you want to DRIVe your car, it's best to have a fuel system that is compatible with your fuel that is available. And that's EFI or possibly even MFI, but if you're willing to buy the right gas for it (and I'd HIGHLY recommend you do) then carbs can be made to run O.K., just don't delude yourself into thinking you are getting a performance advantage. It's pure sentimentality that will have to drive the decision, not logic or practicality. Call a spade a spade and we'll all get along fine! ;^)

 

EFI was there since 71 or so on a Datsun. So don't count it out just because you didn't know about it, it's as Old School as Mikuinis and Datsun Competition Stickers.