Advice on vacuum pumps.
06-11-2016, 12:49 PM
#1
Advice on vacuum pumps.
Does anyone have any experience with vacuum pumps? I am in need to get one with pulling only 10 in.hg at idle. I'm looking for the smallest and quietest one available and after reading some reviews, I'm not sure as to what would be a decent one to look at. Some are big and bulky, some vibrate, some don't pull as high as vacuum as they claim. Also any suggestions as to where to mount it would be helpful also.
06-11-2016, 05:13 PM
#3
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Advice on vacuum pumps.
I use a GZ Motorsports sportsman pump on my race engine. It's based off the old Ford smog pump. My crankcase is sealed. I have to remove a valve cover to put oil into it. My dipstick has a sparkplug boot over it to seal the end.
I run a 5/8" hose from a port on one of the valve covers to the pump. I use a vacuum regulator tee'd into the inlet side of the pump. If vacuum goes below the setting of the regulator, it will open to allow a bleed. Too much vacuum in the crankcase can cause oiling problems in a wet sump system. I try to limit mine to around 12-13 in hg. At idle, it might pull 1-2 in hg but at idle it doesn't need to pull a lot of vacuum. I think my pulley size has the pump running at half the engine rpm.
Exactly what do you need a vacuum pump for? To pull crankcase vacuum, a belt driven pump works best. If you need it for the brake booster, an LT1 electric smog pump works very well but isn't big enough to pull a lot of vacuum for the crankcase.
The smallest of vacuum pumps can pull 28 in hg given enough time and demand is low.
I run a 5/8" hose from a port on one of the valve covers to the pump. I use a vacuum regulator tee'd into the inlet side of the pump. If vacuum goes below the setting of the regulator, it will open to allow a bleed. Too much vacuum in the crankcase can cause oiling problems in a wet sump system. I try to limit mine to around 12-13 in hg. At idle, it might pull 1-2 in hg but at idle it doesn't need to pull a lot of vacuum. I think my pulley size has the pump running at half the engine rpm.
Exactly what do you need a vacuum pump for? To pull crankcase vacuum, a belt driven pump works best. If you need it for the brake booster, an LT1 electric smog pump works very well but isn't big enough to pull a lot of vacuum for the crankcase.
The smallest of vacuum pumps can pull 28 in hg given enough time and demand is low.
06-11-2016, 06:58 PM
#4
Re: Advice on vacuum pumps.
Well, my bad. I should have given more details as to why. My brake booster works as if i have manual most of the time. If i hit the pedal more than once at idle, it will barely hold the brakes unless i stand on them. I don't think i have a crank case vacuum problem. My idle is set at 1000 rpm to get the vacuum to 10. I have been dealing with this for some time, and really should get them working better. With the cam I have, Comp thought I would be on the border for vacuum, and they were right. It's a custom grind cam they recommended for the motor we built. I have been looking at those electric vacuum pumps, but am not sure if i should go that direction or a pump as you guy's suggest. I think i just need it up to 15-18 in.hg.
06-11-2016, 07:03 PM
#5
Supreme Member
Re: Advice on vacuum pumps.
what size stall are you running? maybe a converter change would help with the brakes? just a thought.
06-11-2016, 07:33 PM
#7
Supreme Member
Re: Advice on vacuum pumps.
you think a vacuum resivoir might work? its quit a bit cheaper.
https://www.summitracing.com/parts/sum-g1464
https://www.summitracing.com/parts/sum-g1464
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06-11-2016, 08:09 PM
#8
Re: Advice on vacuum pumps.
you think a vacuum resivoir might work? its quit a bit cheaper.
https://www.summitracing.com/parts/sum-g1464
https://www.summitracing.com/parts/sum-g1464
06-12-2016, 09:59 AM
#9
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Car: 2002 ws6, 2011 sierra 6.2L 6 speed
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Re: Advice on vacuum pumps.
They make electric vacuum just for power brake applications
06-12-2016, 06:44 PM
#10
Re: Advice on vacuum pumps.
This is one i have been eyeing up, but not sure where I can mount it. http://cvrproducts.com/2014/product/...c-vacuum-pump/
06-23-2016, 08:33 AM
#11
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Car: 87 Iroc 5.7,67 SS Camaro,90 Formula
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Re: Advice on vacuum pumps.
Buy a vacuum can.. $50 bucks and done. Will usually solve the problem for good. Jegs, Ebay
06-23-2016, 08:46 AM
#13
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
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Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Advice on vacuum pumps.
Mount it under the battery if you have to.
06-25-2016, 10:47 PM
#15
Supreme Member
Re: Advice on vacuum pumps.
What are the specs on the cam? Have you tried adding some idle advance(idle spark) to the timing to increase vacuum? Higher stall converter would allow you to bump idle up another 100rpm or so to help vacuum.
How about better brakes? If you are running stock brakes on the 87, they were barely up to the task of stopping the vehicle when it was stock. Adding power and decreasing vacuum, which the wimpy stock brakes rely heavily on, just makes them almost useless. I remember really jamming on the pedal to stop my car and the fear of not being able to stop. My motor made 14inches at idle last time I checked. It idles at 22 degrees. 3,500 stall speed Edge converter.
I went to Fly N Bye for their 13" front kit with Wilwood 4 piston calipers, 02 Camaro SS brakes on the back(12" rotors with large piston aluminum calipers and internal band parking brakes). Fly N Bye calls the rears their LS brake kit.
No more braking problems.
How about better brakes? If you are running stock brakes on the 87, they were barely up to the task of stopping the vehicle when it was stock. Adding power and decreasing vacuum, which the wimpy stock brakes rely heavily on, just makes them almost useless. I remember really jamming on the pedal to stop my car and the fear of not being able to stop. My motor made 14inches at idle last time I checked. It idles at 22 degrees. 3,500 stall speed Edge converter.
I went to Fly N Bye for their 13" front kit with Wilwood 4 piston calipers, 02 Camaro SS brakes on the back(12" rotors with large piston aluminum calipers and internal band parking brakes). Fly N Bye calls the rears their LS brake kit.
No more braking problems.
06-25-2016, 11:00 PM
#16
Re: Advice on vacuum pumps.
What are the specs on the cam? Have you tried adding some idle advance(idle spark) to the timing to increase vacuum? Higher stall converter would allow you to bump idle up another 100rpm or so to help vacuum.
How about better brakes? If you are running stock brakes on the 87, they were barely up to the task of stopping the vehicle when it was stock. Adding power and decreasing vacuum, which the wimpy stock brakes rely heavily on, just makes them almost useless. I remember really jamming on the pedal to stop my car and the fear of not being able to stop. My motor made 14inches at idle last time I checked. It idles at 22 degrees. 3,500 stall speed Edge converter.
I went to Fly N Bye for their 13" front kit with Wilwood 4 piston calipers, 02 Camaro SS brakes on the back(12" rotors with large piston aluminum calipers and internal band parking brakes). Fly N Bye calls the rears their LS brake kit.
No more braking problems.
How about better brakes? If you are running stock brakes on the 87, they were barely up to the task of stopping the vehicle when it was stock. Adding power and decreasing vacuum, which the wimpy stock brakes rely heavily on, just makes them almost useless. I remember really jamming on the pedal to stop my car and the fear of not being able to stop. My motor made 14inches at idle last time I checked. It idles at 22 degrees. 3,500 stall speed Edge converter.
I went to Fly N Bye for their 13" front kit with Wilwood 4 piston calipers, 02 Camaro SS brakes on the back(12" rotors with large piston aluminum calipers and internal band parking brakes). Fly N Bye calls the rears their LS brake kit.
No more braking problems.
06-26-2016, 06:55 AM
#17
Re: Advice on vacuum pumps.
I'm not arguing anyone's suggestions, but I think some clarification might help you know what you need depending on what your goal is. If you want better brake assist on first apply, I don't see how a vacuum reservoir is going to help. Your concern at that point isn't the volume of vacuum, but the level of vacuum assist you don't have. If your first-apply pedal assist is ok and you just need the same assist on more than one pedal apply, a reservoir will help you. If you want better first apply pedal assist, you will need to increase vacuum.
To give a different comparison... If you have/use air tools, think of it this way; you try to use an impact wrench to remove lug nuts, do you want a small 2 gallon nailer compressor at 40psi or a 30 gallon compressor at 110psi? It's two different variables that afford two different things. If you take that same 40psi on a 30 gallon compressor(bigger reservoir), you still take forever to get the lug nut to break loose @40psi, but you'll be able to use it many times before the compressor kicks on to build pressure again.
Though my comparison is a difference of positive vs negative pressure, a larger reservoir(or adding one when one doesn't already exist) doesn't make it easier to push the pedal, it just means you can push the pedal more times before it gets even harder to push.
Many newer GM cars now have a supplemental vacuum assist pump on them because of variable valve timing and other reasons, take a look at how those are setup, or even take one off a car in a salvage yard and mirror the setup in your car. Under the battery tray is a great location, if you look on the other side, you'll see another vacuum reservoir there already for accessory operation (HVAC, Cruise, etc.) though I wouldn't use it for the brakes because the ports are rather small, I'm just mentioning it so you can gather mounting ideas.
To give a different comparison... If you have/use air tools, think of it this way; you try to use an impact wrench to remove lug nuts, do you want a small 2 gallon nailer compressor at 40psi or a 30 gallon compressor at 110psi? It's two different variables that afford two different things. If you take that same 40psi on a 30 gallon compressor(bigger reservoir), you still take forever to get the lug nut to break loose @40psi, but you'll be able to use it many times before the compressor kicks on to build pressure again.
Though my comparison is a difference of positive vs negative pressure, a larger reservoir(or adding one when one doesn't already exist) doesn't make it easier to push the pedal, it just means you can push the pedal more times before it gets even harder to push.
Many newer GM cars now have a supplemental vacuum assist pump on them because of variable valve timing and other reasons, take a look at how those are setup, or even take one off a car in a salvage yard and mirror the setup in your car. Under the battery tray is a great location, if you look on the other side, you'll see another vacuum reservoir there already for accessory operation (HVAC, Cruise, etc.) though I wouldn't use it for the brakes because the ports are rather small, I'm just mentioning it so you can gather mounting ideas.
06-26-2016, 08:56 AM
#18
Re: Advice on vacuum pumps.
I'm not arguing anyone's suggestions, but I think some clarification might help you know what you need depending on what your goal is. If you want better brake assist on first apply, I don't see how a vacuum reservoir is going to help. Your concern at that point isn't the volume of vacuum, but the level of vacuum assist you don't have. If your first-apply pedal assist is ok and you just need the same assist on more than one pedal apply, a reservoir will help you. If you want better first apply pedal assist, you will need to increase vacuum.
To give a different comparison... If you have/use air tools, think of it this way; you try to use an impact wrench to remove lug nuts, do you want a small 2 gallon nailer compressor at 40psi or a 30 gallon compressor at 110psi? It's two different variables that afford two different things. If you take that same 40psi on a 30 gallon compressor(bigger reservoir), you still take forever to get the lug nut to break loose @40psi, but you'll be able to use it many times before the compressor kicks on to build pressure again.
Though my comparison is a difference of positive vs negative pressure, a larger reservoir(or adding one when one doesn't already exist) doesn't make it easier to push the pedal, it just means you can push the pedal more times before it gets even harder to push.
Many newer GM cars now have a supplemental vacuum assist pump on them because of variable valve timing and other reasons, take a look at how those are setup, or even take one off a car in a salvage yard and mirror the setup in your car. Under the battery tray is a great location, if you look on the other side, you'll see another vacuum reservoir there already for accessory operation (HVAC, Cruise, etc.) though I wouldn't use it for the brakes because the ports are rather small, I'm just mentioning it so you can gather mounting ideas.
To give a different comparison... If you have/use air tools, think of it this way; you try to use an impact wrench to remove lug nuts, do you want a small 2 gallon nailer compressor at 40psi or a 30 gallon compressor at 110psi? It's two different variables that afford two different things. If you take that same 40psi on a 30 gallon compressor(bigger reservoir), you still take forever to get the lug nut to break loose @40psi, but you'll be able to use it many times before the compressor kicks on to build pressure again.
Though my comparison is a difference of positive vs negative pressure, a larger reservoir(or adding one when one doesn't already exist) doesn't make it easier to push the pedal, it just means you can push the pedal more times before it gets even harder to push.
Many newer GM cars now have a supplemental vacuum assist pump on them because of variable valve timing and other reasons, take a look at how those are setup, or even take one off a car in a salvage yard and mirror the setup in your car. Under the battery tray is a great location, if you look on the other side, you'll see another vacuum reservoir there already for accessory operation (HVAC, Cruise, etc.) though I wouldn't use it for the brakes because the ports are rather small, I'm just mentioning it so you can gather mounting ideas.
06-27-2016, 11:55 AM
#19
Supreme Member
Re: Advice on vacuum pumps.
Comp custom grind, lift I .544 E .541 duration @ 50 I 236 E 242 109 center and 113 lobe separation. Your right about the stock brakes, I may try a can first and then a pump. I just stuck $10.000 in the motor and front end suspension, and still need a better custom tune. (I'm taking it to TPIS in July) I think better brakes will be next year. I'm pulling 10 in hg right now at 1000 rpm.
Good brakes are expensive for sure and an increase in vacuum will help you get by for the short term. What about one of the little brake vacuum boost pumps used by VW/Audi on many of their models? I have just been in on a thread concerning Fly N Bye over on the Aftermarket Vendor Review forum. Heard of another company http://bigbrakeupgrade.com offering brake upgrades for the 3rd gen, for when you decide to take that step.
You are running the Holley HP system? Doesn't it allow for tuning of the timing table? I run old school Accel DFI gen 6. Great old Motorola ECM and top quality harness and components. The map cells are large because of the old 8 bit technology. Makes it hard to really fine tune fueling, but it works pretty well. Right now my start up and warm up fuel is off again, since redoing the fuel system. But tuning the timing and/or fuel tables is as easy as plugging in my laptop.
06-27-2016, 01:43 PM
#20
Re: Advice on vacuum pumps.
Your cam specs are very close those of the ZZX. I imagine your loss of brake performance is the same that I experienced after installing the new engine.
Good brakes are expensive for sure and an increase in vacuum will help you get by for the short term. What about one of the little brake vacuum boost pumps used by VW/Audi on many of their models? I have just been in on a thread concerning Fly N Bye over on the Aftermarket Vendor Review forum. Heard of another company http://bigbrakeupgrade.com offering brake upgrades for the 3rd gen, for when you decide to take that step.
You are running the Holley HP system? Doesn't it allow for tuning of the timing table? I run old school Accel DFI gen 6. Great old Motorola ECM and top quality harness and components. The map cells are large because of the old 8 bit technology. Makes it hard to really fine tune fueling, but it works pretty well. Right now my start up and warm up fuel is off again, since redoing the fuel system. But tuning the timing and/or fuel tables is as easy as plugging in my laptop.
Good brakes are expensive for sure and an increase in vacuum will help you get by for the short term. What about one of the little brake vacuum boost pumps used by VW/Audi on many of their models? I have just been in on a thread concerning Fly N Bye over on the Aftermarket Vendor Review forum. Heard of another company http://bigbrakeupgrade.com offering brake upgrades for the 3rd gen, for when you decide to take that step.
You are running the Holley HP system? Doesn't it allow for tuning of the timing table? I run old school Accel DFI gen 6. Great old Motorola ECM and top quality harness and components. The map cells are large because of the old 8 bit technology. Makes it hard to really fine tune fueling, but it works pretty well. Right now my start up and warm up fuel is off again, since redoing the fuel system. But tuning the timing and/or fuel tables is as easy as plugging in my laptop.
07-01-2016, 11:03 AM
#21
Supreme Member
Re: Advice on vacuum pumps.
That looks like quite a pump. I'm thinking of the small electric pump used by GM, VW/AUDI, Volvo and others. Funny thing, I had a 07 Suburban in two days ago with this pump and have now have an 08 Volvo C30 in my bay with the very same pump. They're installed by the manufacturer to boost vacuum to the brake booster for increased brake power immediately following an engine start. These are pretty good pumps. I don't see many failures on them. Have to think that they are less expensive than the billet unit from CVR. Certainly much more compact, maybe more durable too. Since they are a factory installed item, they should be available through the OE and discount parts channels.
07-01-2016, 03:31 PM
#22
Re: Advice on vacuum pumps.
Looks like a Hella pump? The only selling point for me on the CVR pump is, they claim it's 20% less noise and vibration than other pumps. I installed a $40 canister reservoir and it did help on brake feel the second and third pump, but I'm still leaning towards a pump also.
07-01-2016, 05:51 PM
#23
Re: Advice on vacuum pumps.
Looks like a Hella pump? The only selling point for me on the CVR pump is, they claim it's 20% less noise and vibration than other pumps. I installed a $40 canister reservoir and it did help on brake feel the second and third pump, but I'm still leaning towards a pump also.
07-01-2016, 06:15 PM
#24
Re: Advice on vacuum pumps.
I hear ya, but CVR makes racing products and i think they are comparing to aftermarket pumps. No my car is not quiet by any means, but i also don't wan't to hear or feel much for vibrations. If you look at "factory" pumps, they are quite spendy, and I don't think i want a used one.
07-05-2016, 02:06 PM
#25
Supreme Member
Re: Advice on vacuum pumps.
I hear ya, but CVR makes racing products and i think they are comparing to aftermarket pumps. No my car is not quiet by any means, but i also don't wan't to hear or feel much for vibrations. If you look at "factory" pumps, they are quite spendy, and I don't think i want a used one.
EDIT: Just for the heck of it, I checked on line for the GM OE pump. It's $80 on ebay for the OEM replacement pump.
Last edited by ASE doc; 07-05-2016 at 02:15 PM.
07-30-2016, 10:19 AM
#27
Re: Advice on vacuum pumps.
Well, so far I bought a Jegs vacuum canister and that helped, but I still think a pump and new brakes bill be the answer. I can now get 2 good brake applies, but any after that and I'm down to like a manual brake.
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