[scott70]

Was thinking about upgrading my old carter pump (many years old) to a Robb pump. My motor made 490hp/570 tq. @ 5200 rpm. Instead of monkeying around with the 550 I was going to straight to the 1100. Looks like physically its the same pump. My fuel system is all stock 1970. (3/8"). It says it needs a pressure reg. but it looks like theres one built in? I run a Qjet so if I got this one it should be able to adjust low enough (6.5ish} ? Back in the 90's that same carter pump did 11.7 at 115 mph and seemed ok. Not sure of the part number. I do take the car to the track now and then but just to play with street tires,4 speed and 3.31 gears. I have not put a pressure gauge on the carter pump. Guess I was figuring if the carter is lacking at all that the Robb 1100 should eliminate any of that.

[TCSGTO]

These are my thoughts after running the 1100 for around 10 years and deep into the 10’s on the drag strip.

If you are staying with the 3/8” feed line the 1100 won’t buy you anything over the 550. In the troubleshooting guide for these pumps it recommends 3/8” line up to 450HP for both the 550 and 1100. The key to success with any mech pump is a large, unrestricted feed line from the tank. The bigger the line the better the pump will work.

On my car I run a -10 from a sump at the tank to the pump and crank up the pressure if I go to the track. The flow advantage of the 1100 comes into play with a large feed line and increased pressure. It works for me but others haven’t been as successful. I also turn the pressure down to 8-9psi for everyday driving to take some load off of the pump eccentric.

Keep in mind the 550 can be upgraded to an 1100 at any time if you decide to install larger fuel lines later on. If you go with the RobbMc pump a vapor return line back to the tank will really help hot restarts.

[70GS455]

Mine made 586 hp/603 ft lb with the 550 pump and 800?Qjet. Had about 7.5 psi (dropped to 6 at WOT) and .149 N/S. A 850 thermoquad with the same pump made 590/611

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[scott70]

So it sounds like with my current fuel system set up the 1100 would be no advantage at all over the 550. But it wouldnt hurt anything going to the 1100? Its only another 100.00 which wouldnt break me.Of coursed the dyno numbers I gave was with the dyno fuel system which Im sure is better than whats on my car. So is the regulator built into the pump? Thats what it sounds like.

[BB70]

No regulator in the pump, that adj screw is to set your pressure.

[TCSGTO]

Originally Posted by scott70

So it sounds like with my current fuel system set up the 1100 would be no advantage at all over the 550. But it wouldnt hurt anything going to the 1100? Its only another 100.00 which wouldnt break me.Of coursed the dyno numbers I gave was with the dyno fuel system which Im sure is better than whats on my car. So is the regulator built into the pump? Thats what it sounds like.

Dynos don’t accelerate so there is no g force pushing the column of fuel in the line away from a mechanical pump. Fuel delivery issues show up when you have good traction and a car that launches hard. Try to keep the tank to pump line as large and unrestricted as possible with a mechanical if you plan on running slicks at the track.

You adjust the output on the 1100 with a threaded rod on top of the pump. There is a port in the pump body you can put a gauge in to check your adjustment. To get the advantage of the extra output of the 1100 you have to turn up the pump pressure and regulate it down near the carb.

[78w72]

good info above. dynos dont move so the #'s any given pump does on a dyno changes when you get to the track or even somewhat on the street with good traction. i have the 1100 pump on a low 11 sec firebird with robbmc 1/2" pickup & run 1/2" hard line & -8 braided line to the pump & -8 to the carb with a q-jet. i first had an edelbrock pump, similar to the carter that claims it supports "up to " 600hp, it did 520 on the dyno but would stumble on the street at full throttle & fell on its face at 12.2 & 116mph at the track. switched to the robbmc combo & no other changes & went 11.2 & best of 123mph.

to answer the regulator question, the 1100 can be dialed down to ~7psi but it also kills the gph output, most mid 70's q-jets can handle that psi, i turn it all the way down for street use & turn it up to about 8.5-9 for the track & dont notice any issues with flooding etc.

for the $100 its worth it to get the 1100 & be future proof, or you can have the 550 upgraded to the 1100 for the same $100 down the road. yes it wants a bigger line to support more power but even with the smaller 3/8 line it will do better than the 550 or carter, higher psi & gph is better regardless of line size, but its a losing battle to use these pumps with small lines.

[scott70]

So,,,,,,my gto in its current combo will probably not see sub 2.0 60 ft times ever again...I put the original 4 speed muncie back in with the original 3.31 rear and hard launches are not going to happen unless I really push it which I don't want to break anything. So 8" wide bfgs t/a is it. Just figured it's time to replace the fuel pump and want the best one to get and perform without redoing the whole fuel system. My exact setup back(carter and 3/8" line) in the late 90's would 1.65 60ft and 7.4@ 92mph with no issues. So the 1100 turned down to say 7.5 -8 psi would still outperform the 550?

[OCMDGTO]

If you went 11.7s with that pump I wouldn't change a thing. Put a pressure guage on it that you can see inside the car, it will tell it all. I personally had no luck with the 1100(8an from tank to pump, 6an from pump to carb). Pressure dropped to 3psi(did not fall on its face) and it left me stranded on a road trip. TC definitely has it figured out!

[78w72]

Originally Posted by scott70

So,,,,,,my gto in its current combo will probably not see sub 2.0 60 ft times ever again...I put the original 4 speed muncie back in with the original 3.31 rear and hard launches are not going to happen unless I really push it which I don't want to break anything. So 8" wide bfgs t/a is it. Just figured it's time to replace the fuel pump and want the best one to get and perform without redoing the whole fuel system. My exact setup back(carter and 3/8" line) in the late 90's would 1.65 60ft and 7.4@ 92mph with no issues. So the 1100 turned down to say 7.5 -8 psi would still outperform the 550?

it will provide more gph at 7.5-8psi vs the 550, but how much of a benefit that little increase will make on smaller lines is probably very minimal & may not be worth it if you dont plan to go any faster than you are now. & if the carter isnt showing any signs of starvation with your current combo & it went 11.7 previously, doesnt sound like it needs to be upgraded.

[ponjohn]

Originally Posted by 70GS455

Mine made 586 hp/603 ft lb with the 550 pump and 800?Qjet. Had about 7.5 psi (dropped to 6 at WOT) and .149 N/S. A 850 thermoquad with the same pump made 590/611

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What is this combo?

[mchell]

Originally Posted by OCMDGTO

If you went 11.7s with that pump I wouldn't change a thing. Put a pressure guage on it that you can see inside the car, it will tell it all. I personally had no luck with the 1100(8an from tank to pump, 6an from pump to carb). Pressure dropped to 3psi(did not fall on its face) and it left me stranded on a road trip. TC definitely has it figured out!

^^^^^^^

Same experience with me.....went back to an electric

If your carter is working....keep it

Note that some mention they are using them with sumped tanks.... I would guess this may improve success. If you are pulling from a stock tank you may not improve at all by “upgrading”

[70GS455]

Originally Posted by ponjohn

What is this combo?

It's a stroker BBB, 482 ci, 6.8 rods, ported AL heads that flow 325/210 cfm, 10.7 CR, 236/244 on 113 hydro roller, Johnson lifters, 1.6 roller rockers, 2" headers, port matched dual plane B4B, 1" semi-open spacer, HEI with DUI module, 800 cfm Qjet prepped by Everyday Performance, 850 cfm Tquad prepped by Ken Manley, 950 Holley Ultra HP, Robbmc 550 pump, no regulator. Haven't put it on the street yet, so results are from the dyno only. Have a 1/2" hard line from tank to pump, 1/2" Robbmc pickup. Hopefully won't have fuel delivery issues on the street.


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[Skip Fix]

My Buick buddies always liked the B4Bs. Even with ported iron head they would get in the 10.90s easy.