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Arazona Zcar intake vs. Fuel Injection-Long-pix


280zex

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1st- I did this on my own and am in no way connected to Arizona Zcar

2nd- I am no expurt either ;-0

Car-81976 280z

Engine-F54 block-N47 head-all stock internals

Exhaust-6 to 1 ceramic coated headder. 2 58 aluminized stainless 1 piece mandrel bent pipe with a flowmaster xxl muffler.

Trans- 1982 280zx 5 speed. stock clutchflywheel.

Rearend- R200 with a quafe 3.90:1

 

Intake Manafolds- 1 stock 1982 fuel injected intake. 1 Arizona Zcar 4bbl intake.

 

Fuel Delivery- 1 Mega squirt v1.1 pcb 3.0. Flow tested new stock injectors-185 ccmin @ 37 psi. Pallnet 60 mm tb. Pallnet fuel rail with pressure guage. AEM adjustable pressure regulator. all Russell AN fittings, fuel filter, and fuel lines. All new wiring, fuel hoses, pump, fuel filter, clamps, relays, eveyrthing I forgot is new except the droping resistors. These are the stock DatsunNissan resistors that were in the car. These were checked again and again and again and found to be good.

 

1 Holley 390 cfm 4 bbl vaccuume secondarys-all stock. I got this from Allstate carb-Central Islip- Long Island, NY. It is Zinc coated and very shiny!

 

At the time of the swap from a runningtuneddynoed Megasquirt to the Arizona intake and 4bbl carb it was 22 degrees F in my garage(this is important).

Turn around time 3.5 hours from running F.I. to running carb. I did this all by myself. First here's a pic of the M.S. fuel injection system installed on my car....

P1090017.jpg

 

The Arizona Zcar intake arived when promissed. I spoke with Dave on the phone when orderd. Nice guy-got some laughs :wink: The IM gasket surfaces were perfect. The casting and lettering-Arizona Z Car- was nice and clean. The IM came with 4 sae allen bolts for the carb. Here's the IM mounted.....

Pictures012.jpg

 

Here's the mounted carb-I'm not done with the hose routings yet. This pic is today running..

Pictures016-1.jpg

 

I do have the 2x9 air cleaner and throttle cable suggested by AZC. Yes the air cleaner fits under the stock z hood no touchy either. Cost of the IM shipping and all was 281.00$ US. The Carb was 322.00$ US.

Cost of the M.S. fuel injection setup was expensive as I replacedrewired everything. However Megasquirt itself is not expensive. I got it assembled and with the wire harness from DIY for 499.00 I think.

 

So here it is. MSFI vs. Arizona Zcar intake with a 4bbl carb. Starting the engine - MS requires no touching of the gas peddal hot or cold. Carburation requires the choke to be set when the engine is cold i.e. pressing the gas peddal atleast 1x. Driving the car - Fuel injection is snappier than carburation on the bottom end or taking off from a dead stop. Cruzing down the freeway at 60 mph in fifth gear 3k rpm then stomping on the gas peddal(not suggested as this might get you a ticket or worse) there was no difference in either acceleration. I do have an accelaromitor(sp?). There is a noticeable suction sound from the carb as it almost sits under the louver vent in the hood. Fuel consumption - I get 22 mph with either setup-cruzing @ 60 mph in 5th=3k rpm. Looks - I had way more positive responce with the carb setup than the msfi. I drove around to different autoshops with the hood off and showed off. The local tunner shop was disapointed I went to carb. They were trying VERY hard to get me into going turbo for quite some time now.

Tuning the different setups - MSFI requires a laptop. The Holley requires a screwdriver and a small socket. I am using an Innovative LM1 wbo2. I had to rejet my Holley. Stock main jets are .512 I went up to .54 only on the 2 primary jets. I will need to get a smaller pump shooter for the accellarator pump. I don't know yet what size is stock but I do know its too much for my particular setup. from a 13.6 afr @ idle to 10.0 afr is too much gas!! No big deal there. My local auto store carries a bunch on Holley stuf right on the wall.

 

Dyno is already done for the MSFI. This Sat I will be going to the same dyno for the Arizona Zcar intake and Holley 4bbl. What does a dyno run prove?? I dunno for shure. What truly needs to be tested is the flow rate between a AZC intake and a stock FI intake.

 

Summation - I will be keeping the Arizona Zcar intake and Holley 4bbl setup. I like the looks and the sound. As for the over all driving MSFI is very crisp where the carb is not off the line and NOT dragracing. Stomping on the gas from a stop there is a .o5 g's difference in favor of the MSFI. Same fuel milages in cruz and city-Seattle has lotsa hills.

I will be selling off the MSFI system probibly e-bay. I hope to regain my funds from the AZC intake and carb purchase. I still need to finish my fuelvac hose routing for the carb. I'm shure I left something out...

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  • 9 months later...

I would be very interested in seeing the dyno test numbers when you do that. im doing the 4bbl swap right now, just need to order my carb. im also waiting on my electronic ignition and multi spark to show up. so you say to use the 9x2 filter, i ordered a bigger one, but that is good to know, i was not quite sure about what to use.

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  • 11 months later...

ok here is the dyno info. sorry no vids I had no friends available ;-(

msfi on f54 block/n47 head with 240sx throttle body, stock injectors. 147.1 hp and 171torq @ 5500 rpm.

Holley 390cfm 4bbl with vac secondarys(sp?) with the AZ car intake.

146.9 hp and 167torq @ 5500 rpm...

The first dyno run with the holley was no good as my secondarys were stuck closed. I think I bumped the linkage during the install.. oops.

All was not lost the dyno run for the holley on only the 2 main barrels was 130 hp and 145 torq.

What I did notice was that the 4bbl setup developed close to peak power sooner and then slowly rose to the final #'s. I ran 135 hp and 160 torq starting at 2200 rpm. The msfi setup had a nice rate of power developement through the rpm's and peaking at 5500 rpm.

The fuel map for bolth setups was very close. I had installed the 4.5 powervalve in the holley but leaned out too much befoer it started to function.

My current Holley setup is 6.5 powervalve, the white secondary spring, # 55 main jets and the stock secondary jet plate. Holley calls this a 134-34. what this is in actual jet size?? I have no clue but my afr's are ok. 12.5 afr at wot. I cruze at 15.2'ish.

The afr's wonder a bit on the 4bbl vs msfi (any fi system). the fuel map for the msfi is almost perfect vs the carb. Why you ask?? Well the 4bbl works on vacuume and is also effected by the weight and rear gearing of the vehicle. It should lean out a bit before the power valve starts to work, it also leans out a bit before the secondarys start to work.

I like the carb and have other plans for this setup (blow through).

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I think they call that real world data!

 

280zex thanks for the follow up post on your results. Nice work buddy!

 

Stomping on the gas from a stop there is a .o5 g's difference in favor of the MSFI.

 

Are you using a G-Tech meter to achieve this particular G-force result?

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I have an Autometer DPIC( Driver performance information center) guage. Kinda like g-tech but no gps..on bolth dyno tests my DPIC predicted hp was only off by 1 hp(less than) so even without gps tracking it does seem to perform. I did have to get a weight on the car with me in it. 2750lb me+car+1/2 tank gas. Yup itsa pig!!

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what do you weigh?? 2750 minus 180 for you and say, 40 pounds for about 7-8 gallons of fuel, is only 2530 pounds.. Not TOO bad, and 180 was a guess. If you are bigger than 210#, well, then.... your car is under 2500! It takes some doing to shed weight, and 2500 is right where a seater 280Z normally sits.

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I can't prove it with the data you collected. But...I'd bet that a properly tuned STOCK EFI system with the SAME exhaust would be within 2-3% horsepower/torque/milage of both the systems you tested.

 

The carburetor WILL be easier to tune! At least for me. But I like the stock EFI.

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  • 3 weeks later...
ok here is the dyno info. sorry no vids I had no friends available ;-(

msfi on f54 block/n47 head with 240sx throttle body, stock injectors. 147.1 hp and 171torq @ 5500 rpm.

Holley 390cfm 4bbl with vac secondarys(sp?) with the AZ car intake.

146.9 hp and 167torq @ 5500 rpm...

The first dyno run with the holley was no good as my secondarys were stuck closed. I think I bumped the linkage during the install.. oops.

All was not lost the dyno run for the holley on only the 2 main barrels was 130 hp and 145 torq.

What I did notice was that the 4bbl setup developed close to peak power sooner and then slowly rose to the final #'s. I ran 135 hp and 160 torq starting at 2200 rpm. The msfi setup had a nice rate of power developement through the rpm's and peaking at 5500 rpm.

The fuel map for bolth setups was very close. I had installed the 4.5 powervalve in the holley but leaned out too much befoer it started to function.

My current Holley setup is 6.5 powervalve, the white secondary spring, # 55 main jets and the stock secondary jet plate. Holley calls this a 134-34. what this is in actual jet size?? I have no clue but my afr's are ok. 12.5 afr at wot. I cruze at 15.2'ish.

The afr's wonder a bit on the 4bbl vs msfi (any fi system). the fuel map for the msfi is almost perfect vs the carb. Why you ask?? Well the 4bbl works on vacuume and is also effected by the weight and rear gearing of the vehicle. It should lean out a bit before the power valve starts to work, it also leans out a bit before the secondarys start to work.

I like the carb and have other plans for this setup (blow through).

 

Your response off the line with the carb is governed by your accelerator pump and its calibration. Once you're over the initial hump of takeoff, your torque is clearly superior to FI because of your comment on how much power is made at 2K rpm!.

 

Some tune time will improve your 'off the mark' acceleration. The Arizona manifold is designed as a 'dual plane' manifold and is responsible for your low down grunt. The stock EFI manifold isn't a dual plane, it acts like a single plane, which is why it doesn't have the low end of the Arizona. The interesting point is that even as a single plane manifold arrangement, it produces only a fraction more power than the Arizona combo. It would suggest to me that the EFI manifold is a compromise manifold, built to be reliable but not particularly spectacular in any one area except for providing the engine with a stable A/F mix and that is the responsibility of the ECU, not the manifold! The Arizona was built primarily with torque at low rpm's in mind and to nearly match the EFI at the top end is clear evidence of the ordinary nature of the EFI casting. I feel its those long and skinny runners on the EFI that hurt the top end IMO.

 

Unfortunately, the Z chassis doesn't easily allow for goodies that I have added to my car. A 1 inch phenolic 4 hole spacer keeps the carb cooler and allows the mixture to mix better before the turn into the manifold. It's also a progressive diameter/volume change from venturi to spacer to manifold, hence not upsetting the air velocity greatly and keep the fuel in suspension better. The other point of interest is the height above the carb choke horn the top of the air filter top sits. I run a K&N 3 inch 14 inch diameter filter on top of my Holley. There is reasonable height above the horn as to not upset the flow of air into the carb mouth.

 

If you don't need/want to rev your engine too high, keep the revs below 5.5K and enjoy the torque of the Arizona/carb combo. That's what I have on my engine because, like you, I enjoy the simplicity and responsiveness of that combination. :)

 

BTW, that #34 secondary plate reads the same as a 52/53 Holley main jet.

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Soo... I have a 72 240z with a arizona manifold and 4bbl and i love it, but my z is being stripped, painted and waiting on an LS1.

 

sooo . I just bought an 81 280zx for 400 hundred bucks, and it runs really rough and lumpy.

 

Do you think it would be as easy to bring over my 4bbl of my 240 and put it on the s130? I noticed your 280 had megasquirt efi and I wonder if it would be as easy to take off the stock efi and swap on the carb?

 

ps. your pictures dont work and I would love to see the pics of you swapping the two out.

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  • 3 years later...

Hello, Now that you have had your Arizona Zcar manifold and carb set up for 4-5 years, what is your impression? I have a 1976 280z, and a 1983 280ZX. I am tearing apart the 76 engine currently, replacing seals, timing belt, etc... I am planning on getting the Arizona Zcar manifold. Would love to hear your opinion.

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  • 1 month later...

Hello, Now that you have had your Arizona Zcar manifold and carb set up for 4-5 years, what is your impression? I have a 1976 280z, and a 1983 280ZX. I am tearing apart the 76 engine currently, replacing seals, timing belt, etc... I am planning on getting the Arizona Zcar manifold. Would love to hear your opinion.

Well I like the carb in every way as apposed to the FI setups I had, however I have converted to a turbo blow thru holley setup now. I will always suggest the AZC intake and holley carb setup, its easy to install and easy to tune, AND gets almost the same fuel milage!!

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