TBS TOOLS

[Xclimation]

I bought this for $15.99 USD from Harbor Freight: https://www.harborfreight.com/fuel-pump-and-vacuum-tester-62637.html

I actually bought 2 of them. I plan to use these to sync my throttle bodies. I was going to first hook each one of them up to each throttle body to see if they are calibrated the same. Turn the right throttle body screw 3/4 turn Then hook each one of them up to each of the throttle bodies then sync them.

Any issues with using these gauges for this? Be nice if it works as each gauge is only 15.99
Thank You in advance!


[Edited the thread title - CW ]

 

[2daMax]

Re: TBS question/opinion

The page didn't show up nicely but hope the gauges and "averaging" type or the needles are damped because the vacuum pressure fluctuates crazy fast.

I bought a couple of analog gauges for vacuum. Not useful because the needles were moving so fast up and down. I ended up using low tech manometer made of 4mm ID fish tubing filled with ATF oil. Even then the meniscus were moving but I can still spot the level.

 

[gv550]

Re: TBS question/opinion

I've not tried using vacuum gauges, so this is just my opinion. I think the needles will bounce too much to get a consistent measurement, and low price implies low quality and the two gauges may not read the same anyway. But hey, you have them so give it a try and report back.
A differential manometer is the accepted method of balancing throttle bodies, pretty accurate and fool-proof, and easy to make with $10 worth of clear tubing and some ATF.

 

[magic]

Re: TBS question/opinion

I think you will find that the needles on these gauges will be fluctuating all over the place. I would also question the accuracy. I have been using a Carbmate TS-111, about $95 on Amazon. It seems to do the job and it's easy to use.

 

[Xclimation]

Re: TBS question/opinion

Okay...y'all convinced me....I'm going to make one with the ATF fluid and clear tubing....

I looked into buying the ts-111 but it looks like they are no longer make and I did find one for $134 USD
Then the Twinmax and Carbtune pro which I think may not be made any longer and remaining ones are high price for something that I won't use often.

Thank You for y'alls feedback!

 

[Checkswrecks]

Re: TBS question/opinion

You can use separate gauges if you do two things. First, get a couple of cheap little C-clamps. Put one on the tube of each gauge and squeeze till you damp out the fluctuating readings. It's fiddly because there's a fine line between not enough, too much, and too little. You'll also want to do this for your clear tubing with ATF to damp the bouncing.


Then switch each gauge onto the same vacuum source to make sure they have the same calibration.


That said, I went to a CarbMate a long time ago and never looked back.

 

[XTZELEE]

Re: TBS question/opinion

Web sites for carbtune.com and twinmax.co.uk seem to be up and running at the moment

 

[2daMax]

Re: TBS question/opinion

You can use separate gauges if you do two things. First, get a couple of cheap little C-clamps. Put one on the tube of each gauge and squeeze till you damp out the fluctuating readings. It's fiddly because there's a fine line between not enough, too much, and too little. You'll also want to do this for your clear tubing with ATF to damp the bouncing.


Then switch each gauge onto the same vacuum source to make sure they have the same calibration.


That said, I went to a CarbMate a long time ago and never looked back.

Never thought of this. Good idea.

 

[Checkswrecks]

Re: TBS question/opinion

This was once when I used clear tubing and coolant and the vise grips are doing two things. They are at the exact middle of the length of tubing because finding that point is important when using this method. They also are hanging from a piece of safety wire that was twisted to nearly close the tube, which provided the damping.


This works, but takes a while to fiddle with. As soon as you can get tot he ports on the injector bodies, the Carb-Mate and other devices have the sync done in no time.

 

[rid34fun]

Re: TBS question/opinion

I use vacuum gauges with the dials, and I put in a nylon valve you can buy real cheap to close off the vacuum to the point the dials stop moving and show the vacuum. Then balance and then swap the gauges so you can see if there is any difference in settings. Simple.

 

[Xclimation]

Re: TBS question/opinion

I use vacuum gauges with the dials, and I put in a nylon valve you can buy real cheap to close off the vacuum to the point the dials stop moving and show the vacuum. Then balance and then swap the gauges so you can see if there is any difference in settings. Simple.

Went to 2 auto part stores and Home Depot and couldn't find a nylon valve. I'm using 1/4" tubing. The closest I found is a check valve for a fish aquarium. Where would be the best place to find one, please?

 

[rid34fun]

Re: TBS question/opinion

A check valve for a fish tank will work. It just needs to be adjustable to moderate the large vacuum pulses. Something like these...http://www.ebay.com/itm/2pc-Lees-3-Way-Plastic-Aquarium-Fish-Tank-Aeration-Air-Flow-Control-Valve/192228395008

I purchased mine a long time ago from Napa, but it was probably a time when balancing carbs was more prevalent. They make brass ones too that you can screw in vacuum hose connectors of any size, depending on how much you want to spend and how serious of a solution you want

 

[Xclimation]

Re: TBS question/opinion

Have mercy! Did I just cost myself some coinage today attempting a throttle body sync TBS ! Let this be a warning! On the left side where the small hose goes from the throttle body to the Pressure sensor............. The hose wasn't pulling off easy, so I used a pair of angle/bent needle nosed pliers to pull the hose...... I didn't realized how long and how darn fragile the nipple that connects to the pressure sensor is! You guessed it......I broke snapped the nipple! Ordered a new pressure sensor for $86 USD with tax! Gonna get to me in 2 days. So be patient and gentle when disconnecting hose from the pressure sensor on the left side! I manage to glue the nipple back temporarily using the Gorilla glue version of super glue I had laying around. It's hold fine, but I'll replace it in a couple of days.
I connected the Harbor Freight vacuum gauge as I asked about in the original post. I just used one gauge. I'll take the other back. And like Checkswrecks said.......the needle was jumping all over the place! I didn't think it would be THAT jumpy! I did NOT turn the screw 3/4 as I was just doing a preliminary check. I pinched the vacuum hose with my finger and it did stabilize it. Also, giving it throttle stabilizes it. I checked the left side connecting to the glued sensor nipple and T connection going to the throttle body. I got a slightly different result using the same gauge and the same method. We are talking slightly. A 1 or 2 difference in cm Hg at 3k RPM. But again, I did not turn the right side screw. I just wanted to see what the vacuum gauges could do.

I'm not exactly sure what I'm changing when I turn the screw? In reading several threads here; it seems no one is sure what is being changed and if for sure leaving the screw turned at 3/4 is the best thing to do. I'm getting my bike dynoed very soon and the guy dynoing my bike knows stuff; so I'm going to consult with him to be sure of what I'm doing. I know what to do.....just want to be sure of what is being done...

I'm also not sure about pinching the hoses? If I pinch one side ..... doesn't the other side need to be pinched exactly the same? How much force is being used to pinch the hose, does that affect the vacuum pressure?

Before this; I installed catless OEM headers and UNI foam filters. Waiting on rush hour for a test ride.

 

[jbrown]

Re: TBS question/opinion

A common method of stabilizing the pulses is to insert a small orifice. A plastic or wooden dowel that fits in the tube with a small hole through it works.
The size of the hole affects the amount of damping to the pulses, but not the average vacuum. So even if you are relying on pinching the hose, you shouldn't need to be exact in the amount of pinch.

 

[Xclimation]

Re: TBS question/opinion

A common method of stabilizing the pulses is to insert a small orifice. A plastic or wooden dowel that fits in the tube with a small hole through it works.
The size of the hole affects the amount of damping to the pulses, but not the average vacuum. So even if you are relying on pinching the hose, you shouldn't need to be exact in the amount of pinch.

Thank You! I had a feeling this was the case. Do I pinch/damp it until the reading stabilizes?

 

[Checkswrecks]

Re: TBS question/opinion

Thank You! I had a feeling this was the case. Do I pinch/damp it until the reading stabilizes?

Yes