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-   -   dcoe jet sizes (read thi its really cool) (https://www.rx7club.com/1st-generation-specific-1979-1985-18/dcoe-jet-sizes-read-thi-its-really-cool-164875/)

Hyper4mance2k 03-09-03 01:39 AM

dcoe jet sizes (read thi its really cool)
 
Good now that i've got you in here those of you with Dcoe's tell me:
what engine, 12a or 13b
what size dcoe
emulsion tube sizes
and jet sizes

I've searched and read for about 2 hours now and the question comes up alot and never gets answered... so lets get something going.
ive got a 13b S4, 45 dcoe, f8 65 idle, and i think f11 125 main jets... i think i'm still too small on the idle jets and thats comming from 55's which were way to small the screws were almost falling out just to keep it ideling so i went up 2 sizes and i still don't think its enough. what do you think??

680RWHP12A 03-09-03 03:56 PM

if you think 65 f8 is too small try 65 f9 ,its a little richer...70 f8 is way too rich usally
on your main jet you should be using a 160 main jet at least for a 13b, good e-tube!

Hyper4mance2k 03-10-03 07:47 PM

wow i just went out and checked and its 180 f11 on the mains and 65 f8's on the idle so I guess i'll try and find some 65 f9's. and wow its nice to know that only 2 people on this entire forum have side draft webers...

TheTwinTurboRX-7 03-10-03 08:09 PM

Mine is not tuned right yet so its kind of hard for me to offer good advice just yet.

RotorMotorDriver 03-11-03 02:03 PM

I dont know shit about whats in mine. Id like to though. I took some jets out and looked around, and the only ones Im sure about are 170 main jets. I think it has F7 emulsion tubes, and 55 F8 idle jets, but then again, Im not really sure as to what Im looking at. This is a stock port 12A by the way.

~T.J.

Hyper4mance2k 03-11-03 04:39 PM

wow f7 on the main e-tube i think that might be a little small... but if we knew what everyone else was running we'd at leat have something to compair it to..

RotorMotorDriver 03-11-03 06:40 PM

Yeah, it is. I need some serious jettage, haha. Mine are pretty far off from what I would like to hit.

I was told to run (by Fast Freddies):

40mm Venturies
180 Main Jet
F-11 Emulsion Tube
160-175 Air Corrector
F-9 65 Idle Jet
65 Pump Jet
0 Inlet Valve

~T.J.

EDIT: For stock port 12A

680RWHP12A 03-11-03 08:28 PM


Originally posted by RotorMotorDriver
Yeah, it is. I need some serious jettage, haha. Mine are pretty far off from what I would like to hit.

I was told to run (by Fast Freddies):

40mm Venturies
180 Main Jet
F-11 Emulsion Tube
160-175 Air Corrector
F-9 65 Idle Jet
65 Pump Jet
0 Inlet Valve

~T.J.

EDIT: For stock port 12A

if you put 40mm venturies in you can kiss all you low end power good bye!!! and lots ob boging due to inefficianpt acc. pump squirt!
an F11 will wrk good but stock port motors seem to like f7 better

Hyper4mance2k 03-12-03 04:27 AM

jeese yea i was like whaaa? cause thats basicly my setup. i don't know what venturi i have though. i'm gonna have to find this all out soon.

Hyper4mance2k 03-12-03 04:56 PM

what would longer velocity stacks do on a car as opposed to shorter ones???

DriveFast7 03-12-03 10:39 PM

longer stacks legenthen the intake system and will shift the powerband *slightly* lower and give *slightly* more torque.

On a related note I just replaced the factory Dellorto 50mm stacks with TWM Full Radius 100mm stacks (girlfriend bought them for my b-day. GOOOOD girlfriend). In my 74 REPU with factory tall ports slightly enlarged [basically a streetport]. With the 50mms I was shifting at 4500rpm in normal driving. Truck weighs 2750lbs remember. I will post here if that shift rpm has come down with the 100s once I drive it this weekend.

Thanks,

RotorMotorDriver 03-13-03 01:34 AM

Ok, tonight I noticed that I have a "stumble" around 3K at a cruise. I dont know what this means.

Basically, Ill be driving down the highway at 60 in 5th (~3K) and if I just hold it steady, it kinda jump and lurches slightly. Anyone know what this means? It happens in any gear at any speed as long as Im at a cruise at 3K.

~T.J.

Hyper4mance2k 03-13-03 03:34 AM

too lean. from what? i do not know.. i think it might still be too small of idle jets at that speed.....

RotorMotorDriver 03-13-03 04:06 AM

Thats what I thought too. Too lean. In my experiance, too rich is a "bog", and too lean is a "stumble".

I know I need bigger idle jets, and I wanna try the bigger emulsion tubes and bigger main jets too. Hell, just bigger everything :D. Actually, Im waiting on jets to get here, and Im ordering my fuel pump and stuff in the next day or so, so when I get that on, I can eliminate some variables (in theroy anyway).

~T.J.

pillage6 03-13-03 08:07 AM

Could be your emulsion tube also I think.

Hyper4mance2k 03-14-03 04:46 PM

yea i wonder what everyone else is running to stop
That stumble
The bigget e-tube should help out the
Transition eliminating the stumble

RotorMotorDriver 03-14-03 06:15 PM

Haha, nice and low profile bump there man :).

Well, from my reading the emulsion tubes are really picky about the fuel leven in the float bowls to make them work right, and without a pump or regualtor, I know Im draining my bowls. I need to get that stuff so I can start the "real" tuning and eliminate some more variables :).

~T.J.

Hyper4mance2k 03-15-03 04:19 PM

yea thats what i need right now i've got a stock pump and a puralator fuel pressure regulator and only god knows how accurate it is..

RotorMotorDriver 03-15-03 06:48 PM

So seriously though, are we the only people that are using the 45 DCOEs? Where are all you other people with your jetting?

~T.J.

mperformance 03-16-03 10:18 PM

I don't remember mine...it's just perfect.

I run 36 venturis though...40s is way too much.

Hyper4mance2k 03-16-03 10:33 PM

well go look at what you got hommie

RotorMotorDriver 03-17-03 02:36 AM

Seriously man, let us know your jet sizes, and what kinda porting it is also :).

~T.J.

Hyper4mance2k 03-19-03 06:23 PM

went out looking for shorter velocity stacks yeaterday to no avail. damn i want some shorties.. more power

680RWHP12A 03-19-03 09:12 PM


Originally posted by Hyper4mance2k
went out looking for shorter velocity stacks yeaterday to no avail. damn i want some shorties.. more power
if you want some shorter ones , i can get you some!!;)

jutny 03-19-03 10:24 PM

how does the jetting for a DCOE compare to that of a DHLA?

anyone have some tried and true combos for a 48dhla on a stockport 12a?


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