4-barrel intake: THE FACTS

[brokebolt]

I've been thinking all day about this. We Z guys should pressure not each other for facts but others with the resources to get things done. We should have an independent organization do a "Induction Challenge" and post the result for all to see. It would have to be someone impartial and knowledgable about Z cars and the different inducitons. We would need to use the same car and have a team organize it all. I'm no promotor just a Z guy looking for fact, what ever the facts are. Get "Sport Z" magizine to set up camp in Arizona (or someother location) and do some dyno pulls using a stock L-28 and the different inducitons. Sport Z can post the results over several issues keeping the sales up and getting the information out that we Z guys would like to see. It is Sport Z after all and we are discussing Z sport cars. I could see that many parties would like to see this, AZCar, Ztherapy, Sport Z, Clifford Research, Weber, Cannon, and TWM. All of who have a stake in the market for aftermarket Z enthusiests.

 

Dave, I see what your specific addressing about throttle response. I would not agree that the 4bbl is the only induciton with good pep on the throttle. Any hesitation, backfire, or other induciton related problem would need to be sorted out and would suggest a problem. The 4bbl may give the driver the perception of more power due to the different power bands of the induction, but the Dyno would varify beyond arguement. I'm not pro SU or 4bbl or trippple or even EFI but lets see some raw data on all of them, that is my only point. I agree tuning trippples for ANY purpose is a ball of wax. Cost goes up (everthing is in sixes, jets, etubes, etc.) and so does the skill level. Much more involved than a single downdraft or dual SU's.

Let's get Sport Z involved.

Mike

[arizonazcar]

My toes aren't stepped on at all.........I sincerely think it would be very usefull to have an independant 3rd party post their first hand observations,

especially someone who's both literate and has an interest in the subject.

Dave

[arizonazcar]

The only reason I started this thread was in response to an absurd statement

posted that the 1st an last cylinder would run lean and that the 4-barrel can not be made to run properly. I NEVER sold these as a drag racing specific part. I'm sure that tripple webbers will make more power (at least they should) as will ANY turbocharged car with EFI, again you miss the point.

[Guest plainswolf]

Wow this sure turned into an interesting thread!

 

But I must admit Dave does make a very valid point.. there are alot of guys out there just like me who have a Z and either just want to keep the thing up an running as well as possible, or want to see exactly what they can change on it to make it even better.

 

For less than 600.00 total(shipping included), I was able to get not just a rebuilt intake system, but a brand new one.

 

I compared the costs of a rebuilt S.U. system to Dave's Holley setup. But that was not my only reason.

It was the simplicity of his system (the engine compartment is SO much less cluttered up now)

the reliability of it(based on 2 years experience now),

combined with parts availability(I can get the parts quickly at almost any autoparts outlet in the country).

and it's potential for further power upgrades. (this intake can take alot more cam and head flow than stock).

And lastly, he's not kidding when he says driveability.(When it's a -20 degree winter morning this thing starts without fiddling with anything)

To be honest, I kinda though he was full of crap when he told me about the 'as good or better gas mileage' with this sytem, but I have to admit, he was quite correct.

 

But this is just my opinion based on my 2 years experience running this sytem.

[brokebolt]

Dave, I under stand you point and you reasons for the post. I have been preaching for years about the options available. As I've stated there is a stigma that follows the 4bbl. Most folks make claims about hood cleanances and such not ever running one or seen one upclose. I've run them all, I've tried to be impartial not bash or back up anyone or claim unless I can prove it. Like I've said before in other posts I've bought stuff from you in the past and have recommend you for parts to select personel. Go here and read the first sentence and then scoll down and read the last sentence.

 

http://www.cardomain.com/memberpage/496289/6

 

I think that eveyone who reads these recent threads about 4bbls will see that the most important thing here is information about the facts. I feel we have made some positive ground in the discussion about the 4bbl and perhaps posted some arguments both for and against the 4bbl. After all this site is dedicated to the HybridZ.

 

Plainswolf, what kind of MPG numbers have you experienced? Cold weather starts are a true testiment to any induction. I grew up in Idaho and anyone who has tried to start an engine (any engine; tractor, car truck, etc) at 30 below zero knows that those are the hardest conditons possible...especially for a street machine/daily driver. My Z has issues at 40 degrees above zero.

Mike...as Adam Corolla says, "Good times."

[JMortensen]

4-barrel intake manifold $259

holly 390 CFM elect. choke around $300

cable linkage $25-$39

Chrome aircleaner $25-35

Low pressure fuel pump $29

Total cost should be around $650

 

http://www.ztherapy.com

 

Simplest carbs I've ever seen outside of a lawn mower or weedwhacker

Refurbished better than new carbs with roller shafts and grose jets $595

Instructional video $15 (if you're not an expert, you WILL be)

Unisyn $35

Total cost is $645 and they bolt right up.

 

Throw in a $5 screwdriver from the hardware store and you're good to go.

 

Ported carbs are $650 and flow 340cfm IN THE RIGHT DIRECTION. Does a 390 cfm Holley flow 390 cfm when there is a wall of aluminum right underneath it? I've never tested it, but I have my doubts...

 

Bottom line for me is I know which induction I like best... MIKUNIS!

[Guest plainswolf]

My costs were abit less..

I shopped around.. got the brand new carb from either Jegs or summit, cant quite remember, but I do remember it was 259.00

 

dont you also have to provide a rebuildable core for the S.U.'s?

[johnc]

We should have an independent organization do a "Induction Challenge" and post the result for all to see.

 

And who's going to pay to get this done?

[Mikelly]

Well I for one must say that I'm pretty darned impressed... You guys have a vendor willing to pony up a carb and intake for someone to use in comparison, for independant testing, and no one is taking him up on it?

 

Dave, I'm glad you are here at HybridZ. I'm also glad to see you stepping up and doing EXACTLY what I was hoping you would do, which is provide technical data while you try to offer your products...

 

Good to have you here!

Mike 8)

[BillZ260]

Maybe SportZ could help out and have the mag run the tests and publish them. I am pretty sure everyone would be satisfied by the data they publish This is an interesting thread adn I want to see the test! Even if I am runnin too many cyls

[arizonazcar]

UBELIEVEABLE , Someone has posted their opinion based on first hand knowledge and experience with the product!

To Plainswolf: Please post your honest opinion as to whether mixture distribution issues exist and have you examined the sparkplugs for any tell-tale signs of mixture problems.

Also please let us know if your air cleaner clears the hood.

why not post a picture while you're at it?

Thanks,

Dave

[Mikelly]

Dave, Over the years I've spoken to you no less than 40 times on the phone, and I visited your shop once while in Phoenix.

 

I raced a 4 Barrel intake carb setup on a 260Z for a year in Solo2 and I think it boils down to the loose nut behind the wrench. I had all kinds of issues with the worn out pieces of junk that I scavaged from junk yards and used as my 390 carbs... Many times it was often the fact that the units were worn beyond belief. I could put a 600CFM carter carb on the car and it would run much better than the 390 Holley. But hey, such is life... I think a comparo on a dyno would answer a lot of questions, especially IF an independant shop was involved.

 

Mike

[brokebolt]

Someone should contact Ken Jones at Sport Z magazine. He has access to a Dyno and has done several articles about perfromance related issues and he has posted his dyno results in Sport Z mag. The summer issue 2004 he states he is going to be doing some projects on this 280 Z, one of which is a supercharger mounted on a Clifford manifold. The other upcomming project is a Weber Trippple 40 set up on his 3.1L. Before he pulls the 3.1L out and does his supercharger have HIM do some testing with a Bob Sharp (AZCar) manifold and his Clifford Research manifold and his Trippple set up; which he says he is already going to published. I know he has already tested the SU set up on his 3.1L in back issues of the publication he writes for and was addressing using a larger carb from a Jag. Would be nice to see him package the results on all the testing he has done for a ongoing issue to issue "Induction Challenge". This would be nice to see.

 

Dave, I posted my results of the 4bbl, "the 4bbl may give the driver the perception of more power due to the different power bands of the induction", and " the 4bbl doesn't take up that much space it is very compact. Ease of maintanence, yes parts are more readibly available at autoparts stores and such; ask your local parts guy for SU needles and nozzles or even needle valves." Just no MPG numbers to state.

Mike

[Guest plainswolf]

Well the funny thing is, I took notice of this thread mostly because I am runnning Dave's intake system (and tuned header as well) and I had JUST changed my plugs a few days ago!.

 

Car was running abit rough and spuddering all of a sudden, as if it was missing on a cyclinder. So after checking the plug wires, distributor cap...etc.. I got new plugs , new air cleaner after work.. well the problem seemed to work itself out before i even got home to take a more thorough look and put the new stuff on..bad gas probably

 

The plugs when pulled all seemed alot better than I thought after a couple year's use on such an old, tired engine. They didnt show any signs of excesisve oil use or any rich/lean conditions as they were all the same color exactly....But now having new plugs I installed them anyways.

 

My air breather just happens to be the 9inch chrome style with a 2 inch element in it. When I bought it I did have to cut off a abit of the top cap bolt to close the hood but only about an inch or so..

 

As for exact gas mileage I couldn't say and it took me awhile to find out because having a new intake and exhaust system, well, as much as it REALLY woke up my engine, I was putting my foot into it on a regular basis. That combined with the fact that My old S.U.'s were quite worn out. But I am very pleased with the gas mileage and especially around town believe it or not. My Z is my primary driver now especially since gas prices are so high as my only other vehicle has a Ford 400 in it which guzzles gas like a drunken sailor.

 

the best thing I CAN say about the system is that it starts faithfully every single morning to take me to work and run errands after work..etc.. and it gets mighty hot here in western NE in the summer where we have at least 10+ days every year of over 100 degree heat, and Brutally cold in the winter time!

 

There was one morning just this winter that I awoke to -27 degrees and I have to admit, though sluggish as hell the dam old Z started right up! I was very impressed! Now how the hell this hot, windy old desert area could get that dam cold amazes me, but needless to say we get QUITE the extremes in weather here.

 

Dave's system DOES exactly what he says it will do, it plain works, and works extremely well! All the other like manifolds I looked at for the same conversion were considerably more expensive(and had hood clearance issues I believe) and at least one of them was a single plane manifold. I wanted a dual plane manifold for my everyday driving. He was also extremely nice over the phone as I called him twice and both times he thoroughly explained exactly what needed to be done..etc..If it wasnt for his system, my Z would just be sitting here unused waiting for a V8 I hope to have in by the end of next summer.

 

I am not so much biased either way as far as intake system, which either boils down to economics, expertize, or personal preference, but at the same time I am very impressed and pleased with Dave's intake system.

[arizonazcar]

NOW THAT'S THE POINT!

Dave

[JMortensen]

EXACTLY!

[datsunlover]

Well, I'd be curious as to how this comparisan turns out (if it ever happens) as I am going to be running su's, bu they are.. uh... tired.

I Was thinking of a 4bbl intake, but was woried about the 'suposed' problems with them. I have a friend with a Jeep YJ, and he swears up and down that a single carb on an inline 6 is no good, because of the differing lengths of intake runners/, causing lean/rich problems. Not to compare a Jeep and a Z too closely (here comes a flame.. I can feel it.. ) BUT the general layout of a carbed I6 remains the same, regardless of manufacturer. With this in mind, combined with the negative things I heard about the Z 4bbl intakes, I admit that I was not too keen on shelling out big $$$ for an intake/carb/accs, and in the end STILL have a poor running car. (this whole thing came to be, because my FI was shot, and I didnt want to spend $1000+ HOPING it would fix it) FWIW, I paid $100 CAN for my intake and twin SU's, and they DO work, albeit a bit rough/rich. I'm gona keep an eye on this thread now. Hope something works out and this 'issue' gets resolved.

[Guest plainswolf]

Ask him to prove it to you! I run this intake setup on my Z and I HAVE verified that NO such condtion exists with this setup on my Z. If it did, I wouldnt even run this sytem!

 

Remember all of the inline six cylinders that came from the factory with a single intake manifold and carb?...

 

Ford, Gm, Chrysler ALL had inline 6cylinder engines that came from the factory this way. I doubt they would have done this and continued to do this for decades if it was an inherently flawed system.

 

It really boils down to personal or economical preference. It appears both systems have their merits.

[Kazuya1274]

Speaking of 12 second runs with a 4 barrel carb, has anyone ever used a 4 barrel with a turbo? Just how much clearance do you have between the carb and the hood on a Z? I think the aluminum housings I have seen for turbo'd carbs would sit too high to allow you to close the hood. This would be worth considering for me, since I blame my smoked engine on the fuel system (either #6 injector wasn't always firing, or the injector harness coming loose under torque) and would be cheaper than buying an SDS or something. As for the air/fuel distribution issues, pretty much all inline 6's suffer from this. From looking at my stock FI intake, its quite obvious that number 6 cylinder gets the least amount of air anyways. It should be the richest running cylinder. As for putting a turbo with a 4 bbl carb, that distribution issue might calm down with the force of a turbo going through it.

[JMortensen]

Yes, there was a turboed 4 barrel that was bought recently by one of the guys here, I think it was Bob Hanvey(?) Extremely fast, widebody kit, really really incredible car. Was set up for road racing. I think Bob was going to put an RB26DETT in it IIRC.

 

I've seen others too, but that one...

 

Here's some pics: http://www.geocities.com/row4navy/rb26swap/72Datsun.html

As to this:

Ford, Gm, Chrysler ALL had inline 6cylinder engines that came from the factory this way. I doubt they would have done this and continued to do this for decades if it was an inherently flawed system.

 

I guess that's the reason those same vehicles came with that AWESOME log style exhaust manifold, right? Because they wouldn't put it on there for decades if it wasn't flawed... [/url]