« previous next »
Pages: 1 [2]

Author Topic: Optimum Position for EGT Probe On Manifold  (Read 6686 times)

Reply #15October 17, 2008, 09:17:02 pm

rabbitman

  • Veteran
  • Offline
  • ***
  • 2787
Optimum Position for EGT Probe On Manifold
« Reply #15 on: October 17, 2008, 09:17:02 pm »
Quote
If you have 3 cyl running 600 and one running 1200deg it will show up on your EGT as a higher reading than the 600 deg thus the "Combined stream" application.


Good point, so if you got one injector with a bad spray pattern or whatever it "should" show up, then you'd have to guess at which one it is.  I'll keep that in mind for when I drill the mani for my vnt-15.
Probably drilling 6inches from the head were they all meet won't affect the reading too much anyhow as the exhaust gasses are moving perdy fast.
Logged
'82 Rabbit, I put on a euro vnt-15, 2.25" DP, 2.5" exhaust, the result.....it whistled.

I removed the turbo, made a toilet bowl 2.5" DP, the result....it was deafening. Now it has a homemade muffler up front and a thrush in the rear, the result.....less loud.
Watch: AGENDA, GRINDING AMERICA DOWN
Reply #16October 18, 2008, 08:49:26 pm

79rabbit4dr

  • Guest
Optimum Position for EGT Probe On Manifold
« Reply #16 on: October 18, 2008, 08:49:26 pm »
And tapping one for each cyl would probably be overkill, esp on my stock '81 1.6 NA. and by the time i get to upping the power it'd be better to upgrade to custom/ceramic coated headers anyway, right?
Logged
Reply #17October 20, 2008, 12:16:10 pm

Jet A

  • Junior
  • Offline
  • **
  • 125
Optimum Position for EGT Probe On Manifold
« Reply #17 on: October 20, 2008, 12:16:10 pm »
Quote from: "rabbitman"
Quote
If you have 3 cyl running 600 and one running 1200deg it will show up on your EGT as a higher reading than the 600 deg thus the "Combined stream" application.


Good point, so if you got one injector with a bad spray pattern or whatever it "should" show up, then you'd have to guess at which one it is.  I'll keep that in mind for when I drill the mani for my vnt-15.
Probably drilling 6inches from the head were they all meet won't affect the reading too much anyhow as the exhaust gasses are moving perdy fast.


One bad injector WILL show up as a hole in the piston..... :shock: not on the egt gauge. Especially if you push your egts!
Logged
85 vw golf NA ----> 2b TD  Daily Driver
Converted to hydraulic head (Thanks zukgod1)
td04 turbo, Zex nitrous (for the big hills), PITA motor, fresh rings w/ ceramic pistons.
Custom Intake and Exhaust
Ported and polished head
Dipricol EGT, FP, Boost,
Autometer, Oil Temp, Water Pressure
Reply #18October 20, 2008, 12:54:29 pm

zukgod1

  • Veteran
  • Offline
  • ***
  • 2817
Optimum Position for EGT Probe On Manifold
« Reply #18 on: October 20, 2008, 12:54:29 pm »
Quote from: "Jet A"
Quote from: "rabbitman"
Quote
If you have 3 cyl running 600 and one running 1200deg it will show up on your EGT as a higher reading than the 600 deg thus the "Combined stream" application.


Good point, so if you got one injector with a bad spray pattern or whatever it "should" show up, then you'd have to guess at which one it is.  I'll keep that in mind for when I drill the mani for my vnt-15.
Probably drilling 6inches from the head were they all meet won't affect the reading too much anyhow as the exhaust gasses are moving perdy fast.


One bad injector WILL show up as a hole in the piston..... :shock: not on the egt gauge. Especially if you push your egts!





It WILL show up on the gauge LONG before there is a hole in the piston.

Providing you are starting out with a healthy engine you will have a baseline, using that baseline you will know if there is a problem. Your EGT's will go up even with one bad injector.
Logged
dan

99 Golf TDI (now CNG powered) , 82 TD Caddy
Reply #19October 21, 2008, 10:11:47 pm

8v-of-fury

  • Guest
Optimum Position for EGT Probe On Manifold
« Reply #19 on: October 21, 2008, 10:11:47 pm »
Quote from: "rabbitman"
Quote
The sender needs to be as close to the head as possible and in the combined exhaust stream.


Why do you say that? Seems to me if you put it too far from the head just to get all four cylinders it would read cooler because of the extra distance from the head.


Yup.. your exactly right.. :D
Logged
Reply #20October 22, 2008, 12:44:55 am

gldgti

  • Veteran
  • Offline
  • ***
  • 488
    • http://scramjetsite.8m.com
on this topic - but a bit of a hi-jack
« Reply #20 on: October 22, 2008, 12:44:55 am »
ok, apart from diagnosing a bad injector, lets say you have an egt guage to keep a general idea on how your current "tune" is affecting things.

i'm still using the stock k14 turbo on my aaz with stock manifold, which is the 3 bolt type with flange on the end just outside number 4 cylinder for EGR stuff.

now, i will be sticking my egt probe in the junction when i change to t3 and a 4 bolt mani soon, but for now its mounted in a blanking plate where the egr used to be. i see good response on the guage (within the same gear) and so far max EGT i've seen has been 520C (970F) (20psi, accelerating at WOT 4th gear up hill to 70mph).

i figured that since (when it counts) the pressure inside the exhaust manifold must be around 30psi and large flow rate, that the probe, wherever its placed, should give a reasonably good reading, even though its only behind 1 exhaust port.

thoughts?
Logged
'77 Golf LS 4 door twincharger project
'91 Golf Cabrio 1.9TD
'94 Golf TD - AAZ, 2.5" Mandrel DP and exhaust, Merc T3 1.6TD boost pin, FMIC, Koni suspension, VR6 Brakes, VR6 Seats, VR6 sway-bars - sadly missed
'07 SKODA Octavia 1.9 TDI PD - Remapped ECU
Reply #21October 29, 2008, 06:47:50 pm

Jettagli16v

  • Veteran
  • Offline
  • ***
  • 344
Optimum Position for EGT Probe On Manifold
« Reply #21 on: October 29, 2008, 06:47:50 pm »
This manafold (pictured)
seems to be different than mine.
I have Garrett T3 (OEM)
and I dont think I have a boss where that one was placed.
Can I use the boss for the heat shield mount (Just a little closer to the turbo flange than the one pictured)?

I am installing a spruce thermocouple (Thanks, GTD!)
Logged
Currently: 81 Caddy 1.9 AAZ, 1995 Audi S6, 78 ASI/Riviera camper bus 2.0, 74 THING 1.8 (resto, coming in 2020).
Reply #22October 30, 2008, 01:33:36 am

79rabbit4dr

  • Guest
Optimum Position for EGT Probe On Manifold
« Reply #22 on: October 30, 2008, 01:33:36 am »
Where is a good place to get these and what brand should I go for?
Logged
Reply #23October 30, 2008, 01:50:17 am

cyrus #1

  • Veteran
  • Offline
  • ***
  • 360
Optimum Position for EGT Probe On Manifold
« Reply #23 on: October 30, 2008, 01:50:17 am »
People seem to like the aircraft spruce thermocouple.  It reacts quickly and is reasonably inexpensive.
Logged
Cody

2002 Jetta TDI
2000 Jetta TDI - R.I.P.
1990 Jetta 8v-Eventually to be 1.6TD
Reply #24October 30, 2008, 08:27:21 am

saurkraut

  • Veteran
  • Offline
  • ***
  • 904
Optimum Position for EGT Probe On Manifold
« Reply #24 on: October 30, 2008, 08:27:21 am »
Here's the Aircraftspruce superfast probe:

Link: Aircraftspruce



And here is a VDO EGT gauge:

Link: VDO Vision EGT Gauge



You'll need the lead wire, so you can either buy the gauge with the super slow VDO probe and use the supplied lead wire.

Or contact Libbybapa and see if he is still selling bulk thermocouple lead wire.
Logged
'79 1.6TD RABBIT
'84 1.5TD RABBIT
'83 Diesel Westy
'86 Audi 5000 Turbo Quatro Wagon
92 Audi 100
'93 Eurovan
'82 Porsche 930
Reply #25October 30, 2008, 10:05:05 pm

rabbitman

  • Veteran
  • Offline
  • ***
  • 2787
Optimum Position for EGT Probe On Manifold
« Reply #25 on: October 30, 2008, 10:05:05 pm »
I have that setup and it works great!
Logged
'82 Rabbit, I put on a euro vnt-15, 2.25" DP, 2.5" exhaust, the result.....it whistled.

I removed the turbo, made a toilet bowl 2.5" DP, the result....it was deafening. Now it has a homemade muffler up front and a thrush in the rear, the result.....less loud.
Watch: AGENDA, GRINDING AMERICA DOWN
Reply #26November 03, 2008, 06:04:24 pm

monomer

  • Veteran
  • Offline
  • ***
  • 414
Optimum Position for EGT Probe On Manifold
« Reply #26 on: November 03, 2008, 06:04:24 pm »
I have the AS probe and gauge just waiting to be mounted and used...
Logged
-1983 Rabbit LX 1.6/1.9 VNT build


Michigan Volkswagen Enthusiasts
www.michiganvw.org
Reply #27November 05, 2008, 03:42:11 am

Smokey Eddy

  • Veteran
  • Offline
  • ***
  • 3468
    • McScrubbins Body Wash
Optimum Position for EGT Probe On Manifold
« Reply #27 on: November 05, 2008, 03:42:11 am »
I ordered prothe's egt gauge and sender. Anyone use this one?
http://www.dieselvw.com/EGTGauge.htm

I think it's hilarious that it goes to 2,400 and then says "warning" after that.
Logged
Ed
Blacked out mk2 AAZ Jetta RIP. You are missed.
White 1999.5 ALH Golf 2dr. Low & wide. Rammed off the road RIP.
Blue 2009 CR140 Jetta CBEA/CJAA. Malone stage 2. EGR/DPF/Exhaust-valve deletes. 2.5" open exhaust. ADP Turbo swap. 1-stage nitrous kit. THROWN ROD
Reply #28November 05, 2008, 10:50:26 am

zukgod1

  • Veteran
  • Offline
  • ***
  • 2817
Optimum Position for EGT Probe On Manifold
« Reply #28 on: November 05, 2008, 10:50:26 am »
Well it says "Type R" so it must be good..
Logged
dan

99 Golf TDI (now CNG powered) , 82 TD Caddy
Pages: 1 [2]
« previous next »