Hewitt Industries Dual Boost Gauge

kbrenny

Veteran Member
Joined
Jul 9, 2008
Location
Mora, MN
TDI
2002 Jetta wagon TDI
I never got around to installing the Numatics PLS-B filter on mine yet.

I was about to install it today and decided to go another route:



2 1/8" barb to 1/4" NPT
2 1/4" Female NPT to 3/8" female NPT
1 3/8" nipple 2 1/2" long
1 tampon

The tampon was very hard to get completely stuffed into the 3/8" nipple but it was just the right length and diameter so that it was extremely tight.

Now, when I need to replace it, I can just pull the fitting off the end and shove a new tampon in there.

Much cheaper to build, easier to source, and much cheaper to service when needed.

I will let everyone know how it works as time goes by.

If I forget to post results of performance / longevity here in the next few months just shoot me a PM to remind me.
 

dremd

Veteran Member
Joined
May 31, 2007
Location
South Louisiana
TDI
06 sprinter. 03 jetta wagon premium with 6 speed ALH swap, 14 JSW
I'm not very well versed on EMP levels, would a 30 psi gauge be adequate for a VNT 17 car? Or would I have to run the fity,(spelling intentional)? If prefer the 30 for the wider active sweep area, but if need be I can consider the larger gauge.
 

kbrenny

Veteran Member
Joined
Jul 9, 2008
Location
Mora, MN
TDI
2002 Jetta wagon TDI
The 50 psi would be the better choice.

Upon spool up your EMP can be around 1.5 to 2 times your boost levels.

If you were running 22 psi boost you would see an EMP reading of around 33 to 44 psi.

My EMP does not reach the higher end of the 2x the boost, but only because I adjusted the VNT stop screw that way.

I am running 26 psi boost and I get 45 psi EMP very consistently on extremely hard accelerations, but only during spool up of the turbo.

When I spoke with Hewitt Industries while ordering mine they recommended the gauge never be pushed to, or past, it's highest listed value as it could damage the gauge or make it no longer accurate.
 

dremd

Veteran Member
Joined
May 31, 2007
Location
South Louisiana
TDI
06 sprinter. 03 jetta wagon premium with 6 speed ALH swap, 14 JSW
The 50 psi would be the better choice.
recommended the gauge never be pushed to, or past, it's highest listed value as it could damage the gauge or make it no longer accurate.
Much appreciated answer and explination (all of it).
I think I'll order one today.
 

GoremanX

Veteran Member
Joined
Mar 17, 2013
Location
Vermont
TDI
2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Blast from the past! I'm adding my own contribution to this old thread.

I'm using a very similar setup on my BHW, except I chose the Hewitt Industries dual Boost/Fuel Pressure gauge, which also goes to 50psi. This allows me to run an AutoMeter isolator on the EMP line so I'm not running exhaust gas into the interior. The EMP line connects to the isolator in the plenum, and the isolator pushes on an antifreeze solution in a steel braided hose that hooks up to the threaded fuel pressure port on the back of the gauge.

Only problem is, when I ordered the gauge (and the oil pressure and pyrometer gauges), I misread the description and I ended up getting red backlighting instead of the white that I wanted :( D'oh!
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
GoremanX - Thanks for the update. Do you have any pictures/part numbers to share of your install?

Some random updates over the last couple years...

What Kbrenney said about overpressurizing it is true. I pegged the red needle a couple times by accident and now it reads ~5psi high.

The Numatics filter seems to still be working well. It's fogged over and the tube to the gauge is black so maybe the filter media fatigued and broke? Have not taken the time to look into it.

Otherwise am still very happy with the gauge setup.
 

GoremanX

Veteran Member
Joined
Mar 17, 2013
Location
Vermont
TDI
2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
GoremanX - Thanks for the update. Do you have any pictures/part numbers to share of your install?
Fuel Pressure/Boost gauge is in the middle:


This is in my 2001 Audi A4. I don't have a video of it running yet because I'm still having setbacks with the TDI swap.

The rear of the gauge is more complex:


The ONLY good isolator available ANYWHERE is the one from AutoMeter, which uses -4 AN fittings. But all Hewitt Industries gauges use 1/8" NPT fittings. And because of the placement of the gauge, I needed a 90 degree elbow. But of course I couldn't find a 1-piece elbow/adapter, so I had to do it in 2 separate parts that look clunky. Oh well, it's all hidden from view anyways, and it did work fine when I tried it. I have the same arrangement on the oil pressure gauge, because I didn't want to run hot oil into the car.

The gauge can be found here:
http://www.hewittindustries.com/pressure_gauges_fuel-boost_dual.html

I wish they had it in 60 or 80 psi just to avoid pegging the EMP needle, 50psi just barely covers my intended range (33psi boost means 50psi EMP under an ideal tune). There is an 80psi dual boost gauge available here:
http://www.hewittindustries.com/pressure_gauges_boost_dual.html
but I'm not sure how well it would handle the fluid input of an isolator. As mentioned above, I'm not fond of the idea of running exhaust gas into the car. I drive my 2 year old daughter in there.
 
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Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
That is a bit "clunky" as you say :). Do you have a link to the AutoMeter Isolator you use?

This one maybe? https://www.autometer.com/media/2650-1124.pdf

I like the isolator idea - maybe it will keep the exhaust tube from freezing up in the winter (although it didn't freeze up last winter).

I did pause a bit when running the exhaust tube into the cabin, however figured that if any significant exhaust gasses were coming in through a broken tube, it would melt off in the engine compartment long before any significant amount of gasses built up inside the cabin since there would now be exhaust flow in the plastic hose.

I agree with using it for the engine oil - that would make a huge mess if it leaked!

I do wish the EGT gauge was a bit faster to respond.

Your setup looks good in the vents - Does your Audi have red gauges (my 03 TT and 04 A6 both have red backgrounds) so maybe it won't look out of place?
 

GoremanX

Veteran Member
Joined
Mar 17, 2013
Location
Vermont
TDI
2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Yep, that's the isolator I use. Hewitt Industries used to sell one, but apparently they had a high failure rate so they stopped selling them. Kinda odd for a company that sells only mechanical gauges...

I may have finally found a 1-piece AN to NPT elbow adapter, which would unclutter that setup. I'll order it tomorrow and find out.

My first car (a 1988 Toyota Tercel) had a tiny exhaust leak that managed to get sucked up by the cabin ventilation fan. The only way I noticed it was because I'd get super tired on drives longer than 1 hour. I almost died this way because I was close to passing out at the wheel. And this was a tiny N/A gas engine, not a turbodiesel with highly compressed exhaust. I'm not taking any chances with exhaust in the cabin. Those push-in plastic fittings don't inspire confidence.

The EGT gauge is only as fast as the thermocouple it's hooked up to. I went with a thermocouple that's well known for being very fast and accurate. Sadly, I can't remember the brand name or where I bought it. I'll try to remember to search more thoroughly tomorrow. I just know it wasn't a Hewitt Industries thermocouple.
(edit: found it, it's here - http://www.aircraftspruce.com/catalog/inpages/micro1pyroprobes.php?clickkey=1299199 - part number 10-01478)

My A4 has white gauge backlighting and red pointers. Only pre-facelift B5 A4's had red backlight. So these gauges look out of place :(
 
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[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
(33psi boost means 50psi EMP under an ideal tune)
you need a better turbo, my junky setup is running 38/45

Gauges are just a bourdon tube in there, nothing that is fluid or gas specific. use your boost gauge as an oil pressure gauge, use an oil pressure gauge on your air compressor.

My boost gauge is from a well pump, it has a vacuum scale labeled "well depth in feet"
 

GoremanX

Veteran Member
Joined
Mar 17, 2013
Location
Vermont
TDI
2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
you need a better turbo, my junky setup is running 38/45
I have no idea what my turbo can run. I have yet to run the build for more than 200 miles with a horrible tune, and the car's back on jack stands. It's a GTB1756VK which the seller tells me I should be able to run 35psi out of. I figured 33psi would give me the kind of performance I'm looking for with a little headroom. One of these days I'll be able to actually drive the damn thing.

Gauges are just a bourdon tube in there, nothing that is fluid or gas specific. use your boost gauge as an oil pressure gauge, use an oil pressure gauge on your air compressor.
There's no real way to pre-fill the tiny plastic tube with coolant for the isolator line. There has to be NO air in the line for the isolator to work right. The threaded port of the boost/fuel gauge is more adequate for that purpose. But if I can get a max of 45psi on the EMP line like you do, then the 50psi max isn't such a limiting factor after all :D
 
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[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
There's no real way to pre-fill the tiny plastic tube with coolant for the isolator line. There has to be NO air in the line for the isolator to work right. The threaded port of the boost/fuel gauge is more adequate for that purpose. But if I can get a max of 45psi on the EMP line like you do, then the 50psi max isn't such a limiting factor all :D
My comment there was more in reply to this one:

"but I'm not sure how well it would handle the fluid input of an isolator"
 

GoremanX

Veteran Member
Joined
Mar 17, 2013
Location
Vermont
TDI
2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
I get that, I'm just pointing out that there's more than one reason for my use of a fuel/boost gauge over a dual boost one. I didn't go into all the details in my earlier post for brevity.
 

Rub87

Top Post Dawg
Joined
Dec 10, 2006
Location
Belgium
TDI
Ibiza '99 90HP
Damn this is just what I need. now they need to make metric dials lol 0-3 bar boost and 0-6 bar for EMP
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
So, I've been noticing some "inconsistencies" with my pressure gauges and decided to plumb them all together in parallel with a reference gauge and see how they compare. This is probably something I should have done originally, but didn't so shame on me.

The results were not great :( unfortunately.

Stated accuracy is +/- 1% from Hewitt's website


I only found 1 of the 6 gauges to be anywhere near that accuracy




My test setup was relatively simple, but I have high confidence in it. I plumbed all 7 gauges in parallel and slowly adjusted the regulator on my air compressor until the pressure stabilized. Then I took a video of each gauge at the common pressure and then went back and watched the videos and entered each gauge's reading into a spreadsheet.




My reference gauge is the white one. I correlated that to a physical reference (U-Tube Manometer) at a handful of points up to ~25 PSI. It's not perfect, particularly at very low pressures, but it's pretty good.


The most concerning thing I noticed is the hysteresis in the movement - most of the gauges are sticky, some making 5+ psi jumps as the pressure is increased or decreased. Video's below of this phenomena.

All Gauges Video: https://youtu.be/daWKdKCLTyc

80 PSI Gauge Video: https://youtu.be/nfWXTBW7JFM

My intent is to share what I've found on the 3 gauges I have. For many applications, this won't be a problem, for others it could be. The information is here for you to make an educated decision.

Questions, comments and suggestions are welcomed
 

GoremanX

Veteran Member
Joined
Mar 17, 2013
Location
Vermont
TDI
2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
I tend to agree with those findings. I have the 80psi and 50psi versions of these gauges. In general, I found that the 80psi one is jittery and unreliable, especially in the lower range. Its response using my MightyVac was extremely disappointing.

The 50psi version is much smoother and more reliable across the entire range. I haven't over-pressured mine yet so mine still works right :) However it's also MUCH louder than the 80psi gauge. The buzzing drives me nuts. I need to add some kind of buffer inline to reduce that buzzing noise.

Ideally I'd prefer to find a 2-needle electric gauge somewhere, but I don't think those exist.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
My gauges rattle pretty good if I don't run restrictors in the lines to them, so having sticky movement isn't as much a concern IMO, the pressure pluses of each cylinder should be continually knocking the gears loose in there.

The one that saw overpressure, looks like it's good and linear, I'd bet the pinion just skipped a couple rack teeth at the end of travel, should be able to gently pull it over the stop and click it over a couple teeth in the other direction, if you can't access the internals directly.
 

Rub87

Top Post Dawg
Joined
Dec 10, 2006
Location
Belgium
TDI
Ibiza '99 90HP
Ive found pretty much the same in my 50 psi one. the rattle is bad. I spend a few hours trying find an optimal restrictor for my emp line. in the end around 0.6mm was the best I could get between slow response and rattle but still at some rpm it rattles pretty badly

also the green needle is pretty much behind at low pressures. luckily I have a electric EMP sensor connected to the ecu so I can log boost and EMP precisely.

Imo the only boost gauge that you can trust and doesn't rattle is a genuine VDO 0-3 bar.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
So I've been running an EMP gauge of some sort or another for over 10 years and have had the water in the tubes freeze which will cause the EMP to not read until the interior of the car gets warm enough to melt the water. Sometimes this causes the EMP gauge to rise to 10-20 psi due to the expansion of the water when it freezes.

Got in my car this morning, gauge read 40 psi until it warmed up (80 psi gauge). Ok, no big deal. Get in the car after work and glance at the gauge and it looks like the boost gauge is reading a few psi high. Nope :( Exhaust needle is wrapped around all the way to the peg and now reads ~20 psi high once it thawed out.
 

Mongler98

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Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
i never understood why anyone would use a gauge that needs to have the fuel, boost or anything come to the gauge. its a tell tale sign of cheep and bad design. Auber gauges are so far superior to anything on the market aside from a stand alone like a heltek dash unit or equivalent.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Auber is much more reliable and you can fit many gauge displays 2-3 of them in the space it takes for one average gauge of the round typical type. Auber multimeter gauges have a relay in them and can be programmed to do whatever you want in any application. No taking fluids or boost into the dash. All 12v systems with 5v sensors. All you can do with a standard cheap gauge is read temps or pressures or other various values like RPM and what not. With Auber you can have things like water/ meth, NOS, C3H8, defuel, and blow off valves, bleeders, timers, you name it all run off 1 or more gauge. For instance I have a water meth injection system I built that runs in 2 stages off 2 gauges, boost and EGT, I also ran a defuel on my MK3 tdi on the brake switch sensor and EGT relay. You can’t do jack with anything else. The displays are not hard to read what so ever, they also outlast any gauge I have ever had to date. Also the customer service is great with them too.
I feel that if you have to take the metered whatever to the gauge, it was built so cheap that they could not afford to put in a circuit to output 5v readout from a sensor.
I tried a few various brans for an air fuel gauge and they all crapped out. I talked with Auber about helping me make a multimeter read out work and we got it working great. They sent me some instructions on how to program it to output a value of 1-15 for the voltage and resistance given from a BOSCH O2 sensor. Cost me $40 and is working flawlessly unlike the cheap POS $150 to$200 gauges that innovate made and there supposed to be the best. NOT
 
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