DP gain worth it?

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Ed's TDI said:
I recently had a 3" custom downpipe, along with 3" stainless exhaust, and I noticed a drop in EGT's over the previous 2.25" that was in the car. There may not be any performance gains but as everyone's been posting the lowering of temps is definitely a positive thing.
What else is different in the new exhaust aside from the diameter?
 

Ed's TDI

Top Post Dawg
Joined
Jan 30, 2001
Location
Victoria, BC, Canada
TDI
2001 Bora and 2016 Touareg
IndigoBlueWagon said:
What else is different in the new exhaust aside from the diameter?
Basically the entire exhaust from the turbo to the tailpipe is new. The proprietary design of the flange off the turbo to the downpipe is specifically engineered to "scavenge" the exhaust gases, creating an increased flow which lends to lowering EGT's, as well as allowing the temp to drop quickly back to normal levels after driving the car hard.

Even after an extended romp at WOT to 200+kh/120+mph (on a closed road under controlled conditions, of course! ;) ) I never saw temps above 1200* F and these dropped quickly once I was off the power and driving normally.
 

Passenger Performance

Vendor , w/Business number
Joined
Nov 16, 2005
Location
Abbotsford B.C.
TDI
83 caddy, soon to be quattro tdi
Ed's TDI said:
Basically the entire exhaust from the turbo to the tailpipe is new. The proprietary design of the flange off the turbo to the downpipe is specifically engineered to "scavenge" the exhaust gases, creating an increased flow which lends to lowering EGT's, as well as allowing the temp to drop quickly back to normal levels after driving the car hard.

Even after an extended romp at WOT to 200+kh/120+mph (on a closed road under controlled conditions, of course! ;) ) I never saw temps above 1200* F and these dropped quickly once I was off the power and driving normally.
Actually it doesn't scavenge, it changes the flow pattern.
 

Farfromovin

Torque Addict
Joined
Apr 9, 2005
Location
Ventura, CA
TDI
03 Golf 2dr- PD150 6m
Ed's TDI said:
Basically the entire exhaust from the turbo to the tailpipe is new. The proprietary design of the flange off the turbo to the downpipe is specifically engineered to "scavenge" the exhaust gases, creating an increased flow which lends to lowering EGT's, as well as allowing the temp to drop quickly back to normal levels after driving the car hard.

Even after an extended romp at WOT to 200+kh/120+mph (on a closed road under controlled conditions, of course! ;) ) I never saw temps above 1200* F and these dropped quickly once I was off the power and driving normally.
That's cold man. Wow. I think I can hit 1200 with a WOT blast through 3rd gear alone... What did it used to be under similar conditions? Your car doesn't smoke much at all at WOT correct?
 

Deevo_3000

Veteran Member
Joined
Nov 3, 2006
Location
Calgary, AB
TDI
2000 Jetta GLS
Farfromovin said:
That's cold man. Wow. I think I can hit 1200 with a WOT blast through 3rd gear alone... What did it used to be under similar conditions? Your car doesn't smoke much at all at WOT correct?
I agree, that sounds very low :eek: , I can hit almost 1200 in 3rd as well.
 

dieselpower04

Veteran Member
Joined
Jun 26, 2007
Location
Outside Tampa, FL
TDI
2004 Golf GLS TDI (sold)
1400*f

I have only hit 1400*F once, which was in 5th gear...needless to say speed was elevated as well. They returned to the normal driving levels very quickly (prob less than a min).

My EGT's cool down very fast, even after light accelerations. I believe my set up flows in and out of the turbo nearly as easy as can be.
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
I hit 1400*F today, going from 70 to 90 MPH uphill. :D
 

diesel-dave

Veteran Member
Joined
Aug 26, 2007
Location
earth
TDI
2003 wagon TDI, 2003 wagon Tdi, 2013 Q7 Tdi
howesje said:
I am hoping to get the Boost from the scangauge. I might get an EGT but not totally sure on that one. Being I am not going too crazy I really don't think I will need that one.

Yes, I should have put the clutch kit and possibly .681 5th gear on my list of mods/upgrades.

The "You guys are killing me" was a joke. I was pretty sure I was going to get a gamet of ideas and real world differences.

As for the DP I think I am going to get one. I was quoted $130 for a high-flow CAT and $345 for a DP. I think it would be worth it to spend the extra $215 for the DP and do away with the CAT.

J.
the scanguage boost is not correct. get something like the McNally boost/egt. it's two guages in one, a clean install, USA made quality product, and its all under under $199 shipped to your door, no regrets. nice tool to have to trouble shoot issues and/ or if you plan to mod.
 
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IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
I find EGTs climb faster in 5th than 4th. I experimented a bit at the track with shifting to 5th on one straight at about 110-115 MPH. Holding 4th would cause EGTs to sit at about 1625, but they would start to climb rapidly from there with a shift to fifth. Needless to say I backed off.
 

milehighassassin

Top Post Dawg
Joined
Mar 18, 2005
Location
Fort Collins, CO
TDI
2005 Golf TDi PD, Reflex Silver
diesel-dave said:
the scanguage boost is not correct. get something like the McNally boost/egt. it's two guages in one, a clean install, USA made quality product, and its all under under $199 shipped to your door, no regrets. nice tool to have to trouble shoot issues and/ or if you plan to mod.
It is correct after you remove atmospheric pressure, which varies depending on your elevation. There is a mod with SGII (X-Gauge) so that it will display the correct (atmospheric pressure removed) boost level. What Scangauge shows is what the ECU sees.
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
diesel-dave said:
the scanguage boost is not correct. get something like the McNally boost/egt. it's two guages in one, a clean install, USA made quality product, and its all under under $199 shipped to your door, no regrets. nice tool to have to trouble shoot issues and/ or if you plan to mod.
How is the scanguage MAP or boost (MAP - 1ATM) not correct? It comes from the MAP sensor in the IC.
 

Farfromovin

Torque Addict
Joined
Apr 9, 2005
Location
Ventura, CA
TDI
03 Golf 2dr- PD150 6m
Alright, you got me. I thought you were referencing the South Park episode at the carnival but Super Troopers is pretty good too! LOL
 

diesel-dave

Veteran Member
Joined
Aug 26, 2007
Location
earth
TDI
2003 wagon TDI, 2003 wagon Tdi, 2013 Q7 Tdi
milehighassassin said:
It is correct after you remove atmospheric pressure, which varies depending on your elevation. There is a mod with SGII (X-Gauge) so that it will display the correct (atmospheric pressure removed) boost level. What Scangauge shows is what the ECU sees.
I understand that but after using a quality guage and electronic pressure sensor I got a different reading. Im getting that reading off the pressure entering the intake. not the map sensor.

i also did the "mod" so the scanguage reads in psi..side by side they are different. "fact", thats all im stating. the scanguage never reads boost fast enough for the vnt function for me.
 

diesel-dave

Veteran Member
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Aug 26, 2007
Location
earth
TDI
2003 wagon TDI, 2003 wagon Tdi, 2013 Q7 Tdi
Bob_Fout said:
How is the scanguage MAP or boost (MAP - 1ATM) not correct? It comes from the MAP sensor in the IC.
I understand that but after using a quality guage and electronic pressure sensor I got a different reading. Im getting that reading off the pressure entering the intake. not the map sensor.

i also did the "mod" so the scanguage reads in psi..side by side they are different. "fact", thats all im stating. the scanguage never reads boost fast enough for the vnt function for me. __________________
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
I've not seen more than a 0.5 PSI difference, if even that, between the MAP data (from the SGII and VAG-COM) and boost at the intake manifold (from my boost gauge). YMMV
 

turbobooster

Veteran Member
Joined
Apr 22, 2006
Location
IN
TDI
2000 Golf GLS 5-speed (sold); 2011 Golf TDI 6-speed manual
My scangauge and boost gauge agree with each other all the time as well, as long as the boost is held steadily enough for the scangauge to get a stable reading.

If your boost gauge is reading lower, you may have a leak in your boost tubing.
 

milehighassassin

Top Post Dawg
Joined
Mar 18, 2005
Location
Fort Collins, CO
TDI
2005 Golf TDi PD, Reflex Silver
My SG and my boost gauge are pretty damn close. For me I would say the difference in them is the elevation at which I am at. I am anywhere from 4500' up to almost 12,000'

The higher you go the lower atmospheric pressure is.
 

howesje

Active member
Joined
Jul 9, 2008
Location
Colville Wa
TDI
2003 Jetta Wagon
I have the scangauge and for me the boost reading is all I need. Again, I am putting some "minor" mods but nothing too crazy. I think for me the scangauge will work just fine even if it is off by a lb or 2.

By the way did I mention how much I love this scangauge. I am glad it was on the top of my list of mods/upgrades. It is kinda fun trying to get the highest trip MPG and Daily MPG. Very cool.

Now it is time to save for the nozzles and tune. Then the DP, .681 5th, skidplate, etc. Seems every time I try to make a list it gets a little longer.

J.
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
diesel-dave said:
Ymmv? maybe my MAP is bad?
YMMV = Your Mileage May Vary

Could be the MAP. Got VAG-COM or use the MAP-display on the SGII to see what it shows at idle.
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
diesel-dave said:
mine's all wires no vac lines
Mine's digital too.

Ensure the hole where it's tapped into the maifold isn't leaking.
 
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