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KA with sidedrafts


alexg89

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4 hours ago, alexg89 said:

I see.. i may have to play with it.. as for tubes ive gone from f16 to f2 to f8s

 

Im getting pretty spent on tuning out of pocket lol a man only has so much left after bills and a Gf haha

That usually why the emulsion tubes are last.... the cost....

By the time you need them you already spend enough on jets......

 

Was the f8 tube what I had suggested?

 

I forget now.... I may have to grab my weber book and refresh my thoughts....

 

But I still think ..

Lean out the air screw for the idle.... 

Go bigger on the main to richen the transition and then you'll want to to lean out the top with bigger air correctors.. 

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11 hours ago, Crashtd420 said:

That usually why the emulsion tubes are last.... the cost....

By the time you need them you already spend enough on jets......

 

Was the f8 tube what I had suggested?

 

I forget now.... I may have to grab my weber book and refresh my thoughts....

 

But I still think ..

Lean out the air screw for the idle.... 

Go bigger on the main to richen the transition and then you'll want to to lean out the top with bigger air correctors.. 

I went back and read through and it the last Tube i ordered was the F8 and thats whats in it now 

this weekend ill have to go bigger on mains and airs and stick the the other idle jets in 

Theres a car show tomorrow so ill do it after that lol 

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I would definitely do the bigger air correctors regardless but choose 1 or the other between the main and the idle jet....

Doing both could give you confusing results..... and both can have an effect on the other.... 

 

Right now the idea is to get more fuel into the middle where you say it goes lean....  I'd rather see it a bit rich and try to lean it out after than the other way around....

 

Another thing to keep in mind is rpm vs throttle position.....   

 

I was keeping a log book with me and documenting the changes..... I would drive around doing errands or coming home from work making jet changes.... 

Then as you change things you should notice things getting better or worse....

 

 

 

 

 

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???? Got a pic of the ports and where they go?

Didnt know you could add a port the side drafts.....

 

But no it may help with some things but I thought the vacuum advance was more about emissions or something....

I honestly really dont know....

 

I dont know any one with side drafts running vacuum advance.... I know I am not....

 

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You know what I didn't even think about those.... I used them myself to balance my carburator....

 

I dont know if they can be used for what you thinking... and I wouldn't know if 1 or all 4 are needed....

 

I know they usually talk about ported vacuum vs manifold vacuum.... so there is a difference.....

 

I almost want to go do an experiment....

I have a manifold vacuum source hooked to my distributor right now only because I was curious what readings it would give me....

 

Side now I have a bluetooth digital distributor.... I have the vacuum map zeroed out and i am only running mechanical advance.....

 

But this setup has built in vacuum/boost gauge built in so I can see what the vacuum is doing in real time....

 

I could technically do what your saying to see and understand the differences... 

 

Unfortunately I'm in the middle of removing my intake doing some winter maintenance and upgrades so I cant do that right now.. but it's an interesting thought....

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Most of the time we only consider full throttle performance where the throttle is open and the cylinder completely filled with gas and air mixture. When compressed and lit, it burns very fast because the molecules are packed very close and tightly together. For this, a static advance of about 12 degrees BTDC is ideal to produce maximum cylinder pressures at about 15 degrees after TDC where the piston is still high in the cylinder and can efficiently receive it's push. Too early and the crank throw rod and piston are too close to a vertical line and can't move, too late and the expanding hot gasses are chasing a rapidly accelerating away piston in an ever increasing space above it.

 

Part throttle means maybe only a half cup of actual air and fuel gets by the closed throttle plate and into the cylinder, so when compressed, the widely spaced molecules burn much slower. In order to reach maximum pressure at the 15 degree 'sweet spot,' a means to advance the ignition to give it more time to burn is used. Intake vacuum varies with load, with high vacuum at light throttle and low vacuum at heavy throttle. By using a vacuum advance the distributor timing is varied with the load on the engine to keep the peak cylinder pressure always close to the 'sweet spot' extracting the most power out of your engine at all throttle positions. 

 

This is how static and vacuum advance works. Haven't even got to mechanical advance yet....

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  • 2 weeks later...

Just a little update, i ran the advance to one throat and it seems to have improved a little with a power curve which is nice. Not sure how it works or if its just in my head.

I believe i may run all 4 vacuum supplys to 1 vacuum canister and hook my power brakes back up and maybe run a small vacuum off to the distributor 

 

Also scored a Fidanza light weight fly wheel last night for 100 bucks so im pretty excited about that 

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5 minutes ago, datzenmike said:

Vacuum advance improves part throttle response and economy.

So ive read.. but the part throttle issue still stands.. i went up on the idle jet 1 size and the air corrector one size.. so it has 140 mains and 190 ac.. 60f8 idles

 

I really just need to buy the stuff ive been talking about and start with new combos.. i need to get 34mm chokes and 45 and 50 pumpjets to see if i can make this any better.

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Too rich. 9 is as low as the gauge can read!!!! it could be 7!  Super lean on deceleration is ok. It won't over heat anything because it's only running on idle mix and tons of air. Mine will go just over 20 briefly on deceleration. Drives around between 14 and 15.5 or 16. The mix is a bell curve. Running 14.7 is ideal but between 14 and 15.5 surprisingly has little effect on power and running rich just throws gas away. Full throttle is another thing entirely and below 14.7 is good and 13s better when really hooning it. I've managed to get mine up into the 10s when flat out . Was 9.6 which with my gauge was as low as it would read. Closing in on what I would like, somewhere in the 13s.

 

Bought 20 jets from China for $10 that are all under .115mm? The original bike carbs were 146 but I drilled them to 180 following (bad) instructions. Drilled them to 120 then 130 and looks like just under 146 might be the answer. Can't work on them right now.

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Yah this has been my problem from the get go .. its always on 9 .  BUTTTTT the other problem i have is that its in the stock o2 bung on the header for cylinder 2 so im guessing all of them off cylinder 2 

 

I need to get a bung welded in past the collector so i can see what is really going on but i assume its not gonna be much better 

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3 hours ago, alexg89 said:

 

 

Also scored a Fidanza light weight fly wheel last night for 100 bucks so im pretty excited about that 

 

Off topic a bit... but interested to hear you experience with this once you get it installed....

 

I'm running one on my DE with the 240sx 5 speed and an aluminum driveshaft on my 510 and my trans sounds like tin can full of gravel on decel... sounds like some others have had similar experiences with the light weight flywheel... and that a heavier one quiets the noise--- I'm wondering if there isn't enough inertia to keep things from "bouncing" off each other in the trans.... revs real quick though...

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6 minutes ago, demo243 said:

 

Off topic a bit... but interested to hear you experience with this once you get it installed....

 

I'm running one on my DE with the 240sx 5 speed and an aluminum driveshaft on my 510 and my trans sounds like tin can full of gravel on decel... sounds like some others have had similar experiences with the light weight flywheel... and that a heavier one quiets the noise--- I'm wondering if there isn't enough inertia to keep things from "bouncing" off each other in the trans.... revs real quick though...

Fun fact, the guy just sent me pictures of it after i bought it.. Its a cheaper version .. some 160$ brand .. but i got it for 92 bucks with shipping.. im gonna have the run out checked on it and make sure its true and balanced before i actually put it on.
As for noise, yah that happens.. the heavier flywheels hold more inertia and make things quieter .. Just like the dual mass flywheels in corvettes, when they are changed to a solid flywheel you hear alot more chatter and noise. 

Bearings and what not take a little bit more of a beating but im not to worried about it to be honest, im just trying to get rid of rotational mass from the motor to the wheels.. Next thing will be a one piece aluminum driveshaft from a frontier but the drive-ability will probably go down the drain after that lol 

 

by chance do you have a video of it free reving? id like to hear what kind of response it has 

Edited by alexg89
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it sounds pretty good. you need to pull your wideband out and recalibrate it cause it sounds too good to be that rich. and yes it needs to be in the collector or even a little further back. if they see too much heat then they die. 

 

also wideband sensors die really easily so if you have another one to try I would. it runs too good to be pegged at 9 all the time.

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On 2/8/2020 at 3:38 PM, scooter said:

it sounds pretty good. you need to pull your wideband out and recalibrate it cause it sounds too good to be that rich. and yes it needs to be in the collector or even a little further back. if they see too much heat then they die. 

 

also wideband sensors die really easily so if you have another one to try I would. it runs too good to be pegged at 9 all the time.

 

I may have to recalibrate it and see what happens. it does run pretty good but it needs more to it. so with that being said

im on the way to building another motor and ill get to do this all over 🤪

Gonna go with some Aries 10.7:1 and deck the head a little so should put me over 11 a hair bit

 

B1Sy8z7.jpg

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23 hours ago, alexg89 said:

 

I may have to recalibrate it and see what happens. it does run pretty good but it needs more to it. so with that being said

im on the way to building another motor and ill get to do this all over 🤪

Gonna go with some Aries 10.7:1 and deck the head a little so should put me over 11 a hair bit

 

B1Sy8z7.jpg

 

 

 

i like your poster

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