51 IDA on 12a, not PP...

sen2two · 10-18-2010, 11:24 AM

I just bought a 85 gs with a 12a and it already has a RB manifold and Holley. Not sure if its a RB 465 or a 600cfm holley. The guy I got the car from bought it as is and didnt know, and from what i'm told... i can bet it's a 600.

So, I have these 51 IDA webers with a IDA 12a manifold... I know a holley 600 is far to large for a stock or street ported 12a. But I have had them run fine with the over sized holley before. So is that to say, I can use my 51 IDA, even know they are to large, and get them to run good until i get get a nice 45 or 48 IDA?

Or is a 51 just so over sized it will never even come close to running right?

t_g_farrell · 10-19-2010, 07:30 AM

It will depend on the chokes you have in the 51. If its a stock port 12a you will
need to have a choke down in the 37-38mm (or whatever increment Weber
chokes come in thats close to that) for decent idle at a reasonable rpm.
Otherwise it will have to idle up high to keep running to get the velocity it
needs due to the size of the weber.

730RWHP12A · 10-19-2010, 01:50 PM

the 51 will work fine, like tj said simply install smaller chokes and it will drive great

Buggy · 10-19-2010, 03:50 PM

Agreed. That's one nice thing about the weber carbs, you can change the venturi/chokes to configure the carb to work with pretty much anything.

sen2two · 10-19-2010, 05:27 PM

Now i am pretty new to webers. I have owned a few, but never took them apart. How would I go about swapping out the chokes?

Where would I get the smaller chokes also?

730RWHP12A · 10-20-2010, 10:26 AM

ill check and see if i have some. to remove them, remove the carb top,remove acc pump nozzels, then slide out the aux venturies, then slide out the venturies/chokes. its real easy

.

sen2two · 12-06-2010, 07:35 PM

Did you ever check to see if you had any?

730RWHP12A · 12-15-2010, 10:51 PM

i found some 37mm

they are in a 48 IDA i recently acquired. it came off a 12A

sen2two · 12-16-2010, 09:15 AM

Sorry, found another set already. Wasnt sure if you were going to reply. Thanks though.

10-18-2010, 11:24 AM	#1
sen2two KTEC Join Date: Jan 2009 Posts: 642 Rep Power: 0	51 IDA on 12a, not PP... I just bought a 85 gs with a 12a and it already has a RB manifold and Holley. Not sure if its a RB 465 or a 600cfm holley. The guy I got the car from bought it as is and didnt know, and from what i'm told... i can bet it's a 600. So, I have these 51 IDA webers with a IDA 12a manifold... I know a holley 600 is far to large for a stock or street ported 12a. But I have had them run fine with the over sized holley before. So is that to say, I can use my 51 IDA, even know they are to large, and get them to run good until i get get a nice 45 or 48 IDA? Or is a 51 just so over sized it will never even come close to running right? __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

10-19-2010, 07:30 AM	#2
t_g_farrell Waffles - hmmm good Join Date: Aug 2008 Location: Huntersville, NC Posts: 757 Rep Power: 0	It will depend on the chokes you have in the 51. If its a stock port 12a you will need to have a choke down in the 37-38mm (or whatever increment Weber chokes come in thats close to that) for decent idle at a reasonable rpm. Otherwise it will have to idle up high to keep running to get the velocity it needs due to the size of the weber. __________________ 1980 GS stockport, Fat Nikki, RB Dual Facetfuel pumps, Holley regulator, RB Street port exhaust, 2GDFIS, MR2 MK I electric fans, 2G strut bar, relayed fans, lights and fuel pump, LEDs Project Fat Nikki Budget 12A rebuild Video setup < $30.00

10-19-2010, 01:50 PM	#3
730RWHP12A Rotary Fanatic Join Date: Mar 2008 Location: chatsworth, california Posts: 349 Rep Power: 18	the 51 will work fine, like tj said simply install smaller chokes and it will drive great __________________ rotaryshack.com

10-19-2010, 03:50 PM	#4
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	Agreed. That's one nice thing about the weber carbs, you can change the venturi/chokes to configure the carb to work with pretty much anything. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place

10-19-2010, 05:27 PM	#5
sen2two KTEC Join Date: Jan 2009 Posts: 642 Rep Power: 0	Now i am pretty new to webers. I have owned a few, but never took them apart. How would I go about swapping out the chokes? Where would I get the smaller chokes also? __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

10-20-2010, 10:26 AM	#6
730RWHP12A Rotary Fanatic Join Date: Mar 2008 Location: chatsworth, california Posts: 349 Rep Power: 18	ill check and see if i have some. to remove them, remove the carb top,remove acc pump nozzels, then slide out the aux venturies, then slide out the venturies/chokes. its real easy . __________________ rotaryshack.com

12-06-2010, 07:35 PM	#7
sen2two KTEC Join Date: Jan 2009 Posts: 642 Rep Power: 0	Did you ever check to see if you had any? __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

12-15-2010, 10:51 PM	#8
730RWHP12A Rotary Fanatic Join Date: Mar 2008 Location: chatsworth, california Posts: 349 Rep Power: 18	i found some 37mm they are in a 48 IDA i recently acquired. it came off a 12A __________________ rotaryshack.com

12-16-2010, 09:15 AM	#9
sen2two KTEC Join Date: Jan 2009 Posts: 642 Rep Power: 0	Sorry, found another set already. Wasnt sure if you were going to reply. Thanks though. __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2