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A little too much for the L16?


slowmomiata

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would a cannon intake manifold and a weber 32/36 electric choke be

a little too much air and fuel for a stock L16? i am in the process of doing

an ei dizzy swap, and i want to order a header just for looks and weld

up my own header back exhaust with some 2inch, but i dont want to

flood the stock little L with a bunch of air and fuel...

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i figured as much, without doing internal mods the engine is

only gonna suck what it wants to, but with the manifold i figure

i will have it for future builds like an l20b, which is what i want,

the one i bought for 50 dollars was kinda a bust, i brought it

home, popped off the valve cover and lost faith due to the

rust on the cam, it was more than surface, i still have to pull

the head off but that was disheartening.

 

i really want to try to do a blow through setup with the little

l16, but that will take some serious work and welding, but

if i accomplished that setup i am sure the cannon would help

with the flow :)

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The stock manifold is fine with a 32/36 weber and adapter plate. Save your money.

 

Stock L16 exhaust is more than enough... Save yourself the time bother and money.

hearervsstockL16-18-1.jpg

 

A 2" pipe is on the large side. Go only 1/4" bigger than what you have.

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i have an auto without a tach so i dont know when it shifts,

and i know datzenmike, i read numerous posts on your

experience and wisdom of the stock manifold, but i literally

just want the header for looks, i am trying to restore the

car enough and clean it up enough for the local car shows

here that are infested with muscle cars, last year there

was only 3 imports, a riced out super gay civic, and 2 porsches

and on of the porsches won the import class and they both were

bone stock, no variety.

 

i plan on installing just a little vato-zone tach to see where the

tranny is shifting, just have to find the signal wire, i havent

ratsun searched that yet but thats soon to come, then maybe

i will drag the auto tranny gears out to 7000 if i feel like passing

a prius ;)

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i have a 280z 4spd and a zx 5spd, thats further down the road when

i have all the parts, butits almost nice just being able to leisurely

cruise without shifting haha, i have a miata and try daily driving

that, shift shift shift down shift shift shift down shift rev match

punch it shift hahaha

 

i will manual swap eventually but the auto thats in it shifts so

perfect and smooth still i wanna get my miles out of her

before i gut it

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went to ed hanson's muffler shop yesterday n got a complete exhaust from y pipe back. 2"

i feel like 2" is indeed too large for the 1.6 but my case is different in that im bout to swap in

the l20

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free flowing exhaust is free flowing, i am sure i wont gain any

actual hp from it but i want it to sound a little better but not

too ricey, i am gonna weld in a resonated mid pipe and do

a nice high quality muffler out the back, when i actually get

the time to do it i will take pictures and a video of it afterwards

 

i know the auto is killing the speed more than anything but

its what i have for now until i convert it...

 

i just want to update and make everything more efficient,

hotter spark, more air etc, right now i lug around getting

32mpg, i wonder how that will be affected after all the mods,

ill post that result as well

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Back in the 50s? Hot rodders found that dual exhaust on V8 cars made them faster. Police cars used to be simply a family four door with paint, siren and flashing light. Ford started putting duals on police interceptors to give them an advantage.

 

You want maximum exhaust gas speed through your pipe. The exhaust is traveling so fast and the momentum so high that it 'sucks' much of the left over exhaust out of the cylinder. This means the the engine has less work to do pushing it out and when the intake opens during valve overlap it can 'suck' fuel and air in, again reducing the work needed by the motor to pull it in. Too big a diameter pipe and this free 'savaging' is lost and power drops. Car manufacturers have to pick a size that best fits a wide RPM range. A smaller pipe 'fits' a low mid range RPM but not the cars potential top speed because no one expects to drive there normally. Now if you could design a pipe that changes diameter to keep exhaust speed high at all RPMs you would have something then!!! Somewhat like variable valve timing (V V T)

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what i didnt understand is they were saying the hot fresh burnt gases move to

cold air in the exhaust, it kind of sucks it out, so wouldnt a large header that

had a molded or bolted on heat sink be ideal since it would be significantly

colded than the gases in the cylinder??? but then the argument would be that

once those gases hit the cold air they would slow down tremendously cause

the molecules arent as excited so you would hurt more than help, so there is a

happy medium but who has found it and can prove it? i figure no one has taken

the time to do a dyno test with stock exhaust, then a header with stock exhaust, then

a header back exhaust system that varies in exhaust diameter with each header back.

 

so who knows haha, i do know its been shown that a header sacrifices low end torque

for more top end, but i am not racing my 4dr 510, i dont expect to beat sohc civics haha,

i just want it to look good, have a nice appeal to it under hood, and sound a little bit

aggressive with a nice growly tone, just not ridiculously loud cause i hate that haha

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You really need to research exhaust theory before getting in a discussion like this.Exhaust science is just that -a science.And Mike is correct.The gases don't "hit cold air" until they have left the tailpipe.

 

 

Exhaust gas leave the cylinder in the neighborhood of 1400 degrees.Guess what it's temp is by the time it hits the muffler?

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idk what the temp is so i will guess.... 1 dollar bob?

 

what your science behind it all ztrain? honestly i dont care

if it helps or not, it would look cleaner under the hood, and the

exhaust i will weld up and hope it sounds good, if not i will keep

changing it until i like it haha

 

that is a pretty cool manifold, but what carbs does it take?

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that is a pretty cool manifold, but what carbs does it take?

 

It had 46mm SUs on it.....38 SUs would be much more fitting for an L16

It's from Australia....and seeing that is has 4 bolt flanges compared to the typical 2 bolt 38s.....I'm thinking other carbs were or could be mounted..(?)

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Look at it this way. At 7K RPMs there is lots of exhaust gasses and a stock manifold and pipes might be considered too small possibly even restrictive. In this case a header and slightly larger diameter pipe is in order and does not drop the gas speed overly.... but at low and mid range speeds where everyone drives 99.999985% it does and there is a slight loss.

 

 

You know the ricer kids that run around town with a spoiler? Or drilled rotors? Well a header and 3" exhaust is just one more thing borrowed from real race cars that do not translate well for street use. If fact they are pretty much useless and for show.

 

What's the 510 exhaust pipe size anyway? 1 5/8? maybe? Going to only a 1 3/4" or 0.125" will increase the cross sectional area by 16%!!!!! A 2" pipe is 50% larger. Enough for 1 1/2 L16s .... ok if planning a turbo later.

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idk what the temp is so i will guess.... 1 dollar bob?

 

what your science behind it all ztrain? honestly i dont care

if it helps or not, it would look cleaner under the hood, and the

exhaust i will weld up and hope it sounds good, if not i will keep

changing it until i like it haha

 

that is a pretty cool manifold, but what carbs does it take?

 

400 degrees.Now if this means nothing to you and you still want a bigger pipe thinking you'll go faster,sell the Datsun and buy a VW bug.

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slowmomiata

Dude you got a L16 and a auto why worry about all this

Just leave the stock exhaust manifold. open up the pipe at the Y pipe fpr 1.75 or 2inch all way out the back to a turbo muffler. call it good.

 

since you got a auto I wouldnt even worry about the carb swap untill you have a manual in there and then swap over to better carb set up. Cause AIm thinking dual carbs on a auto might even be slower

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i never thought it would make me faster, i said i want it

to sound a little better, i hate bugs fyi, and datzenmike

i would really like to try to make a blow thru setup later

down the road but i have way more things i need to

learn about carbeurators before i try that, but thats way

further down the road, like i said the header will be for show

and exhaust for sound, no performance gain is really

expected at the moment

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