Weber Tuning!!
#1
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Weber Tuning!!
Hello everybody.
Last week I started my project of rebuilding my 45mm DCOE Weber carb so I bought from a well known shop the parts that I needed.
I got a new rebuild kit, .300 neddle and seat.
Well, now it is finished and installed in my car but the carb is giving me a lot of trouble, it has a nice idle between 900-1000 RPM and it works great on idle but when you push hard the accel pedal it will reach fast to 4800 RPM and when the secondaries open the carb sounds like he is not getting the right amount of fuel...
I know I need to change my fuel pump but the gas filter is always full and under hard acceleration in only gets down a little bit, he gets to 3/4 of the total amount of fuel inside it.
My car has a 12A with streetporting and bridgeport only in the intake secondaries of the engine, MSD Blaster 2 Ignition coils, Accel High Performance Plug wires.
My jetting right now is:
38mm Venturies
160 Air correction jets
200 Main Jets
f16 e Tubes
f9 65 idle jets
0 Bypass.
I was trying to use the carb with 190 Main Jets but he did not work well and with the 200 is the same problem. I am thinking to put in my car a DLIDFIS upgrade as a side project, to have a better ignition system but I don´t know if it will work well I will need help with the wiring too.
If anybody has a an idea about what i have to do with my carb please post it here because is horrible to have a nice great look 7 without the real power he needs to move...
Last week I started my project of rebuilding my 45mm DCOE Weber carb so I bought from a well known shop the parts that I needed.
I got a new rebuild kit, .300 neddle and seat.
Well, now it is finished and installed in my car but the carb is giving me a lot of trouble, it has a nice idle between 900-1000 RPM and it works great on idle but when you push hard the accel pedal it will reach fast to 4800 RPM and when the secondaries open the carb sounds like he is not getting the right amount of fuel...
I know I need to change my fuel pump but the gas filter is always full and under hard acceleration in only gets down a little bit, he gets to 3/4 of the total amount of fuel inside it.
My car has a 12A with streetporting and bridgeport only in the intake secondaries of the engine, MSD Blaster 2 Ignition coils, Accel High Performance Plug wires.
My jetting right now is:
38mm Venturies
160 Air correction jets
200 Main Jets
f16 e Tubes
f9 65 idle jets
0 Bypass.
I was trying to use the carb with 190 Main Jets but he did not work well and with the 200 is the same problem. I am thinking to put in my car a DLIDFIS upgrade as a side project, to have a better ignition system but I don´t know if it will work well I will need help with the wiring too.
If anybody has a an idea about what i have to do with my carb please post it here because is horrible to have a nice great look 7 without the real power he needs to move...
#4
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
I tried two times with 40mm venturies but he gave the same trouble...
I don´t know what else to do since here in Guatemala City we do not have a real expert in weber carbs...
20 days ago somebody killed one of my friends and he was a great carb tuner...
I don´t know what else to do since here in Guatemala City we do not have a real expert in weber carbs...
20 days ago somebody killed one of my friends and he was a great carb tuner...
Originally Posted by d0 Luck
38 venturies seem small to me; hence you not getting enough fuel towards higher RPM range. try upping it to 40 or 42 and see if that works
#5
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
A more larger idle jet will not affect my idle when I start the car??
I´m surprised about that you are telling me to take off the venturies of the carb and run it like that, ok I will try this weekend to know what happens with it...
When you tell me to give a bump to the main, you are trying to tell me to hit the main as somthing can be jamed or blockage???
I´m surprised about that you are telling me to take off the venturies of the carb and run it like that, ok I will try this weekend to know what happens with it...
When you tell me to give a bump to the main, you are trying to tell me to hit the main as somthing can be jamed or blockage???
Originally Posted by wackyracer
Use larger idle jet for much more aggressive take off.
38 venturies are too small for that application. Run the carb without it venturies. Give it a shot, you will be surprised.
Air/Main set up will make it lean out on how RPM. Use smaller air jet or bump the main.
38 venturies are too small for that application. Run the carb without it venturies. Give it a shot, you will be surprised.
Air/Main set up will make it lean out on how RPM. Use smaller air jet or bump the main.
#6
Always waiting for parts!
iTrader: (2)
Originally Posted by Killer Bee Fan
Hello everybody.
Well, now it is finished and installed in my car but the carb is giving me a lot of trouble, it has a nice idle between 900-1000 RPM and it works great on idle but when you push hard the accel pedal it will reach fast to 4800 RPM and when the secondaries open the carb sounds like he is not getting the right amount of fuel...
My car has a 12A with streetporting and bridgeport only in the intake secondaries of the engine, MSD Blaster 2 Ignition coils, Accel High Performance Plug wires.
If anybody has a an idea about what i have to do with my carb please post it here because is horrible to have a nice great look 7 without the real power he needs to move...
Well, now it is finished and installed in my car but the carb is giving me a lot of trouble, it has a nice idle between 900-1000 RPM and it works great on idle but when you push hard the accel pedal it will reach fast to 4800 RPM and when the secondaries open the carb sounds like he is not getting the right amount of fuel...
My car has a 12A with streetporting and bridgeport only in the intake secondaries of the engine, MSD Blaster 2 Ignition coils, Accel High Performance Plug wires.
If anybody has a an idea about what i have to do with my carb please post it here because is horrible to have a nice great look 7 without the real power he needs to move...
also are you running a fuel pressure regulater, is it still the stock fuel pump. if it is the stock pump you probably dont have enough fuel pressure to feed the carb over 4800 rpm and its drying out.
Was it on the car before the rebuild?, if so time to take it apart and see what got changed.
Last edited by seanrot; 02-03-05 at 01:45 PM.
Trending Topics
#8
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by seanrot
4800 RPMs describe what the car is doing, your description of a (1)sound doesnt do much. Is the engine bucking and popping or running sluggish with the little venturies you have its going to have more pull down low. bigger venturies will give you more up top. So descride the actions sounds the engine is making and see if that make it a little easier. (2) BTW i'm sure its a 2 barrel carb, sorry no secondaries.
(3) also are you running a fuel pressure regulater, is it still the stock fuel pump. if it is the stock pump you probably dont have enough fuel pressure to feed the carb over 4800 rpm and its drying out.
(4) Was it on the car before the rebuild?, if so time to take it apart and see what got changed.
(3) also are you running a fuel pressure regulater, is it still the stock fuel pump. if it is the stock pump you probably dont have enough fuel pressure to feed the carb over 4800 rpm and its drying out.
(4) Was it on the car before the rebuild?, if so time to take it apart and see what got changed.
1.- The sound that I mentioned is like bucking and popping like he is getting having to much fuel in it, he continues accelerating but he accelerates very hard until 6, 7 or 8000 RPM.
2.- You are correct; I made a mistake in what I said; there are no secondaries, is when the carb uses the mains when trouble comes.
3.- I´m not running a fuel pressure regulator; I have right now in the car a Horrible Facet Pump (Round One) that worked well before with the little Nikky. I don´t think the carb is getting dryed out, because the fuel filter is always full of gas...
4.- No, the carb I got it from a friend (Not a Good Friend); he was using it in a 13B Bridgeport Engine, the carb had the Venturis really bad bored to 40 mm and the neddle and seat did not matched the carb... Thats why I buyed the .300 neddle and seat for the carb...
#9
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by wackyracer
here's a link to a good reading material. this will give you a better idea on how they interact
http://www.aircooled.net/gnrlsite/re...es/jetting.htm
http://www.aircooled.net/gnrlsite/re...es/jetting.htm
Thanks for the help, going on reading...
#10
Always waiting for parts!
iTrader: (2)
bucking and poping is going lean and incorrect timing, too much fuel is sluggish. change your pump get a regulater. Drive like bat out hell.
the carb is running outa fuel in the float bowl not the filter. You will always see fuel in the fillter engine doesnt suck gas from the filter. your engine is sucking your carb dry and you pump cant keep up.
I think the average around here is 4 to 6 psi of fuel pressure around here on webers. I have a Jay Cee Ent glass ball needle seat and run 7-8 psi in mine. Jay Cee seats are good to 9 psi before I get flamed.
the carb is running outa fuel in the float bowl not the filter. You will always see fuel in the fillter engine doesnt suck gas from the filter. your engine is sucking your carb dry and you pump cant keep up.
I think the average around here is 4 to 6 psi of fuel pressure around here on webers. I have a Jay Cee Ent glass ball needle seat and run 7-8 psi in mine. Jay Cee seats are good to 9 psi before I get flamed.
#11
RX for fun
iTrader: (13)
Originally Posted by seanrot
I think the average around here is 4 to 6 psi of fuel pressure around here on webers. I have a Jay Cee Ent glass ball needle seat and run 7-8 psi in mine. Jay Cee seats are good to 9 psi before I get flamed.
on the side note, Jack was the first in the VW group to knock out the wall on a 48 IDA.
#12
RX for fun
iTrader: (13)
killer bee
before doing anything else, if a holley pump is not available in Guatemala, you can run two pumps. Hook them in parallel set-up meaning, there is "WYE" from the main fuel line to the inlets of the pumps. And this apply to the outlet also.
Ditch the fuel filter in the carb. Im referrring to the one in the inlet fitting below the banjo bolt. enlarge them as well - see my mod on a IDA below. this mod will ensure that there is no restriction.
Work in your idle jet first, then the main.
before doing anything else, if a holley pump is not available in Guatemala, you can run two pumps. Hook them in parallel set-up meaning, there is "WYE" from the main fuel line to the inlets of the pumps. And this apply to the outlet also.
Ditch the fuel filter in the carb. Im referrring to the one in the inlet fitting below the banjo bolt. enlarge them as well - see my mod on a IDA below. this mod will ensure that there is no restriction.
Work in your idle jet first, then the main.
#13
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by seanrot
bucking and poping is going lean and incorrect timing, too much fuel is sluggish. change your pump get a regulater. Drive like bat out hell.
the carb is running outa fuel in the float bowl not the filter. You will always see fuel in the fillter engine doesnt suck gas from the filter. your engine is sucking your carb dry and you pump cant keep up.
I think the average around here is 4 to 6 psi of fuel pressure around here on webers. I have a Jay Cee Ent glass ball needle seat and run 7-8 psi in mine. Jay Cee seats are good to 9 psi before I get flamed.
the carb is running outa fuel in the float bowl not the filter. You will always see fuel in the fillter engine doesnt suck gas from the filter. your engine is sucking your carb dry and you pump cant keep up.
I think the average around here is 4 to 6 psi of fuel pressure around here on webers. I have a Jay Cee Ent glass ball needle seat and run 7-8 psi in mine. Jay Cee seats are good to 9 psi before I get flamed.
I was going to buy a Holley blue pump with regulator from summit racing or maybe a Carter; I have read that for rotarys is better if you use a fuel regulator from 1 - 4 psi; is this good or bad?? or maybe get one from 4 - up psi ??? And the fuel filters wich ones do you recommend me??
#14
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by wackyracer
killer bee
before doing anything else, if a holley pump is not available in Guatemala, you can run two pumps. Hook them in parallel set-up meaning, there is "WYE" from the main fuel line to the inlets of the pumps. And this apply to the outlet also.
Ditch the fuel filter in the carb. Im referrring to the one in the inlet fitting below the banjo bolt. enlarge them as well - see my mod on a IDA below. this mod will ensure that there is no restriction.
Work in your idle jet first, then the main.
before doing anything else, if a holley pump is not available in Guatemala, you can run two pumps. Hook them in parallel set-up meaning, there is "WYE" from the main fuel line to the inlets of the pumps. And this apply to the outlet also.
Ditch the fuel filter in the carb. Im referrring to the one in the inlet fitting below the banjo bolt. enlarge them as well - see my mod on a IDA below. this mod will ensure that there is no restriction.
Work in your idle jet first, then the main.
#16
Always waiting for parts!
iTrader: (2)
Originally Posted by Killer Bee Fan
Whta kind of pump and regulator do you recommend??
I was going to buy a Holley blue pump with regulator from summit racing or maybe a Carter; I have read that for rotarys is better if you use a fuel regulator from 1 - 4 psi; is this good or bad?? or maybe get one from 4 - up psi ??? And the fuel filters wich ones do you recommend me??
I was going to buy a Holley blue pump with regulator from summit racing or maybe a Carter; I have read that for rotarys is better if you use a fuel regulator from 1 - 4 psi; is this good or bad?? or maybe get one from 4 - up psi ??? And the fuel filters wich ones do you recommend me??
Fuel filter i would run a stock one and a clear one before the regulator.
#17
RicanRider
According to the weber manual. All weber side draft require a fuel presure of no higher than 2.5 and no lower than 1.5 psi
I run the following on my 45DCOE 12A Street Port 1982.
Idle Jets 60F9
Main Jets 200
Emulsion Tube F11
Air Corrector 180
Pump Jet 50
Chokes 40
Auxilliary Venturies 4.5
Needle & Seat 200
Carter Fuel Pump, fuel pressure at 2.5, headers, RB Muffler system. Jacobs Electronic Ignition with Direct Fire setup.... 2nd Gen spark plugs
With this setup I'm pushing 136hp at the wheel at 3300rpms Haven't try any higher due to engine being new (less than 1500 miles)
Then again, every engine is a slightly different...
I run the following on my 45DCOE 12A Street Port 1982.
Idle Jets 60F9
Main Jets 200
Emulsion Tube F11
Air Corrector 180
Pump Jet 50
Chokes 40
Auxilliary Venturies 4.5
Needle & Seat 200
Carter Fuel Pump, fuel pressure at 2.5, headers, RB Muffler system. Jacobs Electronic Ignition with Direct Fire setup.... 2nd Gen spark plugs
With this setup I'm pushing 136hp at the wheel at 3300rpms Haven't try any higher due to engine being new (less than 1500 miles)
Then again, every engine is a slightly different...
Last edited by JoseReyes; 02-04-05 at 01:37 AM.
#18
Originally Posted by wackyracer
holley red and use a thick rubber insulation to reduce the noise.
what u can do is insulate it yourself
but for the buck and performance u can't beat it
#19
RX for fun
iTrader: (13)
Originally Posted by JoseReyes
According to the weber manual. All weber side draft require a fuel presure of no higher than 2.5 and no lower than 1.5 psi
I run the following on my 45DCOE 12A Street Port 1982.
Idle Jets 60F9
Main Jets 200
Emulsion Tube F11
Air Corrector 180
Pump Jet 50
Chokes 40
Auxilliary Venturies 4.5
Needle & Seat 200
Carter Fuel Pump, fuel pressure at 2.5, headers, RB Muffler system. Jacobs Electronic Ignition with Direct Fire setup.... 2nd Gen spark plugs
With this setup I'm pushing 136hp at the wheel at 3300rpms Haven't try any higher due to engine being new (less than 1500 miles)
Then again, every engine is a slightly different...
I run the following on my 45DCOE 12A Street Port 1982.
Idle Jets 60F9
Main Jets 200
Emulsion Tube F11
Air Corrector 180
Pump Jet 50
Chokes 40
Auxilliary Venturies 4.5
Needle & Seat 200
Carter Fuel Pump, fuel pressure at 2.5, headers, RB Muffler system. Jacobs Electronic Ignition with Direct Fire setup.... 2nd Gen spark plugs
With this setup I'm pushing 136hp at the wheel at 3300rpms Haven't try any higher due to engine being new (less than 1500 miles)
Then again, every engine is a slightly different...
Try it with a IDA. Its like night and day.
#21
Always waiting for parts!
iTrader: (2)
Originally Posted by wackyracer
Try it with a IDA. Its like night and day.
the main reason for raising the fuel pressure is to keep the float from dropping very far. the higher the fuel pressure the more stable the level of fuel will be in the float bowl. The fuel will flow in faster and keep the fuel level in the carb from dropping. granted this is as long as you have a needle and seat that can handle the higher pressure. with a new 300 seat you shouldnt have a problem with 4-6 psi.
#22
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by seanrot
no joke there.
the main reason for raising the fuel pressure is to keep the float from dropping very far. the higher the fuel pressure the more stable the level of fuel will be in the float bowl. The fuel will flow in faster and keep the fuel level in the carb from dropping. granted this is as long as you have a needle and seat that can handle the higher pressure. with a new 300 seat you shouldnt have a problem with 4-6 psi.
the main reason for raising the fuel pressure is to keep the float from dropping very far. the higher the fuel pressure the more stable the level of fuel will be in the float bowl. The fuel will flow in faster and keep the fuel level in the carb from dropping. granted this is as long as you have a needle and seat that can handle the higher pressure. with a new 300 seat you shouldnt have a problem with 4-6 psi.
All of my friends only have IDA on their cars and they use 4psi as well for them.
Robert from Rotary Shack told me to get the Holley street pump that delivers 5psi without using a fuel press regulator???
#23
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by wackyracer
holley red and use a thick rubber insulation to reduce the noise.
Thans man... Another question: Can you tell me the difference between the Holley Blue and the Red one Fuel pumps??? Which one is better for a rotary?? (ONE DAY I AM GOING TO CHANGE THE 45 DCOE FOR A 48 - 51 IDA)
And what about the Carter Fuel Pump?? I was going to buy weeks a go this one:
Vendor Carter
Product Line Carter Universal Rotary Vane Electric Fuel Pumps
Free Flow Rate 72 gph
Maximum Pressure (psi) 8
Inlet Size 1/4 in. NPT
Inlet Quantity Single
Inlet Attachment Female threads
Outlet Size 1/4 in. NPT
Outlet Quantity Single
Outlet Attachment Female threads
Quantity Sold individually.
Notes (Not Specified)
Vendor Holley
Product Line Holley Blue Electric Fuel Pumps
Free Flow Rate 110 gph
Maximum Pressure (psi) 14
Inlet Size 3/8 in. NPT
Inlet Quantity Single
Inlet Attachment Female threads
Outlet Size 3/8 in. NPT
Outlet Quantity Single
Outlet Attachment Female threads
Quantity Sold individually.
Notes Includes regulator.
Vendor Holley
Product Line Holley Red Electric Fuel Pumps
Free Flow Rate 97 gph
Maximum Pressure (psi) 7
Inlet Size 3/8 in. NPT
Inlet Quantity Single
Inlet Attachment Female threads
Outlet Size 3/8 in. NPT
Outlet Quantity Single
Outlet Attachment Female threads
Quantity Sold individually.
Notes (Not Specified)
#24
RX for fun
iTrader: (13)
the red is 7 psi max. blue is 14-18 IIRC. With the carter, I, including my friends, have similar experience of inaccurate fuel pressure despite running new power line and such. I personally dont have (or heard) any bad experience with the holley red. also, the holley F/P/R comes in two settings: 0-4.5 and 4.5-9 (I prefer the 4.5-9)
#25
No Pistons
Thread Starter
Join Date: Sep 2004
Location: Guatemala City
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by wackyracer
the red is 7 psi max. blue is 14-18 IIRC. With the carter, I, including my friends, have similar experience of inaccurate fuel pressure despite running new power line and such. I personally dont have (or heard) any bad experience with the holley red. also, the holley F/P/R comes in two settings: 0-4.5 and 4.5-9 (I prefer the 4.5-9)
Ok, so you recommend me the Red Holley Fuel Pump. What do you mean for Holley F/P/R ??