Any road racers or autox-ers with carbed setup here?
11-28-2009, 10:45 AM
#1
Drifting
Thread Starter
Any road racers or autox-ers with carbed setup here?
I still haven't decided if my new engine combo will be EFI or carb
so I'm gathering as many infos and opinions as possible.
So, as title says it, does any of you race with carbed engine
and if you do, what carb do you use?
Are you satisfied with it? What are pros and cons?
so I'm gathering as many infos and opinions as possible.
So, as title says it, does any of you race with carbed engine
and if you do, what carb do you use?
Are you satisfied with it? What are pros and cons?
11-28-2009, 12:01 PM
#2
Race Director
I have a carbed 383ci LT-4 ~480 crank hp
It has a Quick Fuel- Wedge Float road race carburator #Q-750-CT
The only problem I have is a little bit of break-up at the point at part throttle right where the primary jets are maxed but before the secondaries come on. It is a little hard to describe, but it isn't a big deal. I love not having to worry about computers etc. Also, without a choke it takes it a few minutes before it warms up and wants to idle. Would be annoying on a daily driver, but no biggie on the track car. I'm sure there are some, but I can't think of any cons other than it costing you modification points depending on what series you are wanting to race with.
It has a Quick Fuel- Wedge Float road race carburator #Q-750-CT
The only problem I have is a little bit of break-up at the point at part throttle right where the primary jets are maxed but before the secondaries come on. It is a little hard to describe, but it isn't a big deal. I love not having to worry about computers etc. Also, without a choke it takes it a few minutes before it warms up and wants to idle. Would be annoying on a daily driver, but no biggie on the track car. I'm sure there are some, but I can't think of any cons other than it costing you modification points depending on what series you are wanting to race with.
Last edited by RedLS1GTO; 11-28-2009 at 02:35 PM.
11-28-2009, 12:39 PM
#3
Racer
Member Since: Dec 2004
Location: Gold Canyon, Arizona
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11-28-2009, 02:22 PM
#4
Melting Slicks
I'm using a Berrry Grant 650 mech. secondary for HPDE's. The only issue I have ran into is (I think) using a carb without the wedge shaped road racing floats. Last time out, I started to have a fuel starvation issue coming out of the corners. I'm now in the process of switching over to the road racing style of floats that should eliminate this.
11-29-2009, 05:55 AM
#6
Drifting
Thread Starter
Thanks guys. It looks that I'll go with RR setup carb. My car is also street driven,
but not much. Maybe 3tkm/year. Doy ou think that road race preped carb could
cause problems for street driving?
but not much. Maybe 3tkm/year. Doy ou think that road race preped carb could
cause problems for street driving?
11-29-2009, 09:00 AM
#7
Melting Slicks
Some race carbs come with a 1:1 linkage so all 4 barrels open simutaniously instead of progressional like street carbs. If this causes a problem you probably could switch the linkage though, since it is externally mounted.
Other than that, some race carbs don't use a "power valve" or at least ones with reduced flow orifices in the metering block. This results in using larger main jets and could result in lower MPG if you care about that due to the car running richer at non-WOT conditions.
Hopefully some carb experts will jump in here, but I think its all just tuning issues that could be worked around for the street.
Other than that, some race carbs don't use a "power valve" or at least ones with reduced flow orifices in the metering block. This results in using larger main jets and could result in lower MPG if you care about that due to the car running richer at non-WOT conditions.
Hopefully some carb experts will jump in here, but I think its all just tuning issues that could be worked around for the street.
11-29-2009, 09:54 AM
#8
Race Director
Some race carbs come with a 1:1 linkage so all 4 barrels open simutaniously instead of progressional like street carbs. If this causes a problem you probably could switch the linkage though, since it is externally mounted.
Other than that, some race carbs don't use a "power valve" or at least ones with reduced flow orifices in the metering block. This results in using larger main jets and could result in lower MPG if you care about that due to the car running richer at non-WOT conditions.
Hopefully some carb experts will jump in here, but I think its all just tuning issues that could be worked around for the street.
Other than that, some race carbs don't use a "power valve" or at least ones with reduced flow orifices in the metering block. This results in using larger main jets and could result in lower MPG if you care about that due to the car running richer at non-WOT conditions.
Hopefully some carb experts will jump in here, but I think its all just tuning issues that could be worked around for the street.
11-29-2009, 03:12 PM
#9
Melting Slicks
1) Bore and stroke.
2) Cam specs.
3) Dual or single plane intake.
4) Flow #'s for the heads.
5) Octane.
6) % full vs. part throttle. (It's set up to perform well at full throttle
)
11-29-2009, 05:06 PM
#10
Race Director
Bryan, that carb was built for that specific motor build. Here are 6 questions the carb builder asked when we had the carb built.
1) Bore and stroke.
2) Cam specs.
3) Dual or single plane intake.
4) Flow #'s for the heads.
5) Octane.
6) % full vs. part throttle. (It's set up to perform well at full throttle)
1) Bore and stroke.
2) Cam specs.
3) Dual or single plane intake.
4) Flow #'s for the heads.
5) Octane.
6) % full vs. part throttle. (It's set up to perform well at full throttle
)As for question 5, what did you usually run in it? What I put in at the track so far has been dependent on how my wallet was feeling that day.
Who did the carb? Was it done by Abacus as well? I learn something new about that car about every time I look at it.
Did you see the video I put up on here? Do you miss being behind the wheel yet??
Last edited by RedLS1GTO; 11-29-2009 at 05:13 PM.
11-29-2009, 05:52 PM
#11
Melting Slicks
Was hoping you were paying attention! Whoever built it did a pretty fantastic job as far as I'm concerned. I've gotten to the point that I hit that break-up spot about once or twice at most in a 30 minute session. Even then it's no big deal.
As for question 5, what did you usually run in it? 104 unleaded What I put in at the track so far has been dependent on how my wallet was feeling that day. We ran 93-UN, 104-UN, and 110-L through it on the engine dyno with very little change in HP.
Who did the carb? Check the receipt Was it done by Abacus as well? They ordered it I learn something new about that car about every time I look at it.
Did you see the video I put up on here?
COOL Do you miss being behind the wheel yet?? The wife does, and has just recently started talking about another low budget racer like the 89 we started with.
As for question 5, what did you usually run in it? 104 unleaded What I put in at the track so far has been dependent on how my wallet was feeling that day. We ran 93-UN, 104-UN, and 110-L through it on the engine dyno with very little change in HP.
Who did the carb? Check the receipt Was it done by Abacus as well? They ordered it I learn something new about that car about every time I look at it.
Did you see the video I put up on here?
COOL Do you miss being behind the wheel yet?? The wife does, and has just recently started talking about another low budget racer like the 89 we started with.
11-30-2009, 02:11 PM
#12
Racer
Member Since: Jan 2005
Location: Somewhere in the Finger Lakes of NY
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Fuel injection is a wonderful thing.
Current race fleet =
carbed Red Sled (Holley double pumper by Baker Carbs in NC)
carbed 240Z ("Italian fuel injection"...aka Webers)
FI Spec Miata
FI Le Plastique Pig
Carbs are "almost right, most of the time", the rest of the time it's "screwed up".
FI is "always right, all of the time".
My friend Mad Mike once put it this way, as we were dragging a carbed ice race car around a frozen lake, trying to get it to start on a cold (-5 deg. F, IIRC) morning:
"Carbs ? Who needs ANOTHER hobby ?".
Current race fleet =
carbed Red Sled (Holley double pumper by Baker Carbs in NC)
carbed 240Z ("Italian fuel injection"...aka Webers)
FI Spec Miata
FI Le Plastique Pig
Carbs are "almost right, most of the time", the rest of the time it's "screwed up".
FI is "always right, all of the time".
My friend Mad Mike once put it this way, as we were dragging a carbed ice race car around a frozen lake, trying to get it to start on a cold (-5 deg. F, IIRC) morning:
"Carbs ? Who needs ANOTHER hobby ?".
