Agent_D

iTrader: (2)

ok, at the shop the guy said he could make custom intake manifolds, what do you think about this setup.

cool air/ram air intake with 76mm piping, 76mm AFM or MAF, 76mm custom TB that is smooth, none of the warm up stuff on it, just a smooth TB with the primary throttle plates, a custom 6 port intake manifold that has 6 seperate runners, maybe 1" longer than stock, and the runners bigger than stock, at the end of the 5th/6th port runners have a set of smooth flow port sleeves integrated with the manifold set in the open position, or if you dont want integrated sleeves thats your choice.

what would you guys think of something like that?? im gonna restore the faith in n/a owners with this shop, and if we have enough support the sky is the limit on what parts we can get made.

what would you think of an n/a running on stock port making 200 or even 210rwhp?? would that peak anyone's interest?? i hope so

peace

FC3AZ

I am all for it, for my 87 SE!!!!!!

amemiya

you have to set the langth of the intake runners to match the port and rpm band you are shooting for. The longer you go the more low end you make and you will want a smaller port to match. If you are shooting for high rpm power go with a bigger port, shorter runner.


(lso if you are doing it for a 6 port moter than rather than make 6 runners up to 1 TB, try to make a seperet TB for the 5 and 6 port, with almost no runner langth.)IMO

good luck let use know how it turns out.

NZConvertible

Sounds like a lot of time and money spent unnecessarily. First off, you can't replace the AFM with a bigger one, the ECU won't know what to do with it. And with the porting required for 200+rwhp you'll probably need an aftermarket programmable computer, so the AFM is gone anyway. Second, why have someone build you a custom intake manifold ($$$) when you could buy (new or s/h) a 6-port Weber manifold and an aftermarket Weber-style throttle body, say twin 48 or 50mm, with four stock injectors (250fwhp @ 80%). You'll probably spend less money, it'll be a million times easier to do, and you know it'll work.
BTW, no offence but is this an actual project or a high-school pipe dream...?

Bambam7

The weber setup sounds very nice.
I'd love to have nice twin TB's.

blu_gxl

hey i've never heard of the weber set up where can i research or get it?

james

Agent_D

iTrader: (2)

this is an actual project.

ok how is there a conflict with the 76MM AFM (3") and the ECU, it will hook up to the stock wiring harness, it just lets a lot more air get through the intake.

i dont know how much power this will actually be worth, but i think it will be cheaper than the manifold for the carb's

this is going on my car when we get it done, i will post dyno results before and after

NZConvertible

Good to hear...You don't understand how these work. The ECU reads air volume and temp as voltages from the stock AFM. It looks up tables to calculate air mass flow from these voltages. If you just throw another AFM on, the relationship between the airflow and voltage will be completely different and the ECU will be thinking there is very different airflow than the engine is actually getting. In short, you'll be lucky to get the engine to run at all. If you're thinking of converting to a hot-wire type mass airflow meter, you're even further off track than I thought. You really need to learn a bit more about how EFI works.Not carb, EFI throttle body. Same flange pattern as a Weber IDA carb. A lot easier to do than a complete custome set-up that won't necessarily be any better. I just think you could spend your time and money a lot more wisely.

FPrep2ndGenRX7

NZ convertible is right(atleast I think he is). Get the Racing Beat upper manifold for the 6-port engine and add some TWM throttle bodies(expensive but nice). Use the stock injectors. I speculate you would get the same results if not better at half the price of a custom manifold.


www.twminduction.com
www.racingbeat.com

Agent_D

iTrader: (2)

ok i see NZvert. im not really that shabby on the EFI system, all i know is the guy told me he could make one that would work i guess we'll find out lol

let say the AFM door is 1/4 of the way open, it sends a certain voltage to the ECU and the ecu adjusts the injectors to inject the right amount of fuel to keep the air fuel mixture at an optimum, am i correct??

now if we had a bigger AFM that sends the same voltage as a stock one when the door is open at any certain point, the air fuel would be off therefore it would be running lean, correct??

NZConvertible

Basically, yes. The opening of the flap gives air volume flow, the in-built temp probe gives air temp and the computer uses those to calculate air mass flow.That's a bit confusing. A bigger AFM with the same amount of air flowing through it will open the door less (because of the larger cross-sectional area) and hence the computer will think less air is entering the engine than actually is and inject less fuel. So yes, it'll run lean. At cruise the ECU's closed-loop mode might be abe to compensate but as soon as you put your foot down, it'll lean out.
My main point is you would need to source an AFM that has airflow/voltage and temp voltage ratios exactly the same as the stock one. The chances of that are tiny. Trust me, if there was a simple way to replace the AFM with a better flowing one, someone would have done it long before now!