GARRETT VNT15 TurboKompressor HOP UP BIGTIME!

TDIMeister

Phd of TDIClub Enthusiast, Moderator at Large
Joined
May 1, 1999
Location
Canada
TDI
TDI
That's great news, Skypup!

This will definitely launch the TDI's performance credibility. No longer will TDIs be synonymous for green-freaks and ECO-geeks


Puts new meaning to VWoA's TDI slogan: The Diesel That Burns Rubber.

Your findings will be headlines in the VW enthusiast community for a long time to come, and may even convert some previously "gas only" VW performance nuts.
 

TDIMeister

Phd of TDIClub Enthusiast, Moderator at Large
Joined
May 1, 1999
Location
Canada
TDI
TDI
A postscript is in order here:

Skypup, it'd be great if you could get dyno numbers before/after your modification, and put to rest any "seat-of-the-pants" guesses on the output of your two TDIs.

Plus we should consider doing a formal round-up comparo of all the TDI tuning chips/boxes, and put to rest once and for all which solutions give the best bang first and foremost, and then the best buck.

Plus what's the status of Garrett Lim's TDI chip development? A custom map to take advantage of the added boost should be good for a few added HP.

Also, do you get any engine error codes after the mod?
 

Gary Miyakawa

Admin Emeritus
Joined
Feb 24, 1999
Location
Roswell, Ga
TDI
1998 NB TDI
Tdimeister,

My Garrett chips are sitting in Atlanta waiting on me to get back from Omaha. I'm SUPPOSED to be going home tomorrow but who knows... I will post what I find out and the Dyno results when we make the runs (I missed saturdays runs)...

I'll get with Skypup and determine how to make the changes so I can make that change while on the dyno to give us an idea of where we are.

Gary
 

roadrunner

Well-known member
Joined
Oct 2, 1999
Location
Houston, Tx. 77074
One more thing, what kind of problems could surface from this modification? Will the turbo run wide open all the time causing failure. Could we blow a head gasket? Really poor fuel mileage? I guess it sounds too good to be true - am I sounding like ric? Why would VW have set the vacuum control on the ECU so low from the factory? When I read this I went straight into my garage to start working and after a few minutes of pondering I just could not bring myself to do it. Why does my TDI look at me like that whenever I have a tool in my hand?
 

TDIMeister

Phd of TDIClub Enthusiast, Moderator at Large
Joined
May 1, 1999
Location
Canada
TDI
TDI
Why did VW de-tune the US-market TDI? To meet NOx emissions, simple as that. Higher boost and power output means higher peak cylinder pressure and temperature, both contributors to NOx emission.

During normal operation, fuel consumption should not be affected, but take advantage of the added boost for more power, and you can be sure you'll burn more fuel. The 1st Law of Thermodynamics cannot be broken.
 

Peter Cheuk

Gasser :P
Joined
Aug 31, 1998
Location
Daly City, Calif., USA
TDI
'06 Jetta GLI
Wow, (sob) but, what does that mean for us poor A3 TDI owners ? (sob)

Looks like I will have to (sob) upgrade my turbo. (sob) To make matters worse, VWoA (sob) won't let me buy a TDI because (sob) I live in California. (sob)

Why, why, why??? Waaaaaa!!!!

X-Mas is around the corner. What do I want from Santa this year? A Garrett VNT15! (Hint, hint
)
 

dzlfrek

Member
Joined
Aug 24, 1999
Location
Manchester,NH, USA
Great Find SkyPup,
I only have three questions?
1) Do we need to have a wett chip installed to allow the ECU to recognize and handle this increase in power?
2) With this serious increase in torque, do you think our transmissions can handle all this new found power? I remember the first generations of the earlier 5sp manaul front weel drive Ford Taurus SHO had severe transmission and clutch problems with all the power from the Yamaha V8?
3) How much does the new exhaust help?
Hope to try this once car is broken in. 5,000 more miles to go.
 
M

mickey

Guest
Oh, man! You're killing me, SkyPup! Now I have to do this to my Bug!

One question: What do you suppose would be the effect of altitude in this equation? If I set up my turbo to perform exactly the same as yours, do I risk over-revving the turbine? I wish I had a more detailed understanding of this kind of thing.

For those of you worried about compromising the drivetrain's long term reliability, I'll give you my stock answer: Anything you do to increase the performance potential of the engine will result in decreased longevity IF you make regular use of the power. It just stands to reason. SkyPup's monster machine is under no more stress than a stock 90 hp when he's just cruising along minding his own business. It's only when he opens the thing up that the engine experiences "extra" stress.

Look at it this way: The 115 hp Pumpe Deuse engine available in Europe uses basically the same block, crank, rods and pistons as our 90 hp engine. These components were beefed up for the new A4 engines precisely to accomodate the increased power output of the Pumpe Deuse design. A Wett chipped 90 hp, boosted to 115 hp without any other mods, is making a little less torque than a Pumpe Deuse so you're obviously well within the designed capacity of the engine.

Now...what about going nuts with the thing like SkyPup has done? By tinkering with the machine, and assuming the actual power output is what he estimates it to be, it's now making as much power as a CHIPPED Pumpe Deuse. Wetterauer is careful not to make any kind of guarantees on the subject of longevity, for obvious reasons, but their (admittedly small) database on the subject indicates the engine can handle it. Remember, too, that the 140 hp European Wett chip is intended for use on the Autobahn, where sustained high speed full-throttle driving is a daily reality. In the US, particularly back East where SkyPup lives, full-throttle will only happen during the occasional jackrabbit drag race against some hapless Corvette. (Wishful thinking, I know...) Most of the time the engine will be no more stressed than ususual.

So...will it last as long as a stock engine? Probably not. Will it blow up at 75,000 miles? I doubt it. With proper care it'll probably last several hundred thousand miles. Of course, a sudden catastrophic failure could occur, but that would mean that there was some "ticking time bomb" sort of defect just waiting to rear it's ugly head, and it would have done so eventually even if the engine remained stock.

If you plan to mess with this mod, my best advice would be to install a good boost gauge like SkyPup did. An exhaust pyrometer would be a good idea too. Get careful "before" and "after" measurements, and remember: 140 hp/225 torque is probably about as far as you'd want to go, since that's what Wetterauer has already done with good success. Beyond that, you're a true TDI "Columbus" and you can let us know how far you get before you sail off the edge of the earth!

-mickey

p.s. Remember, also, that SkyPup has more money than God... Something to think about before you f**k up your only ride to work!

p.p.s. Two words: SYNTHETIC OIL!!!! And keep it scrupulously clean! The more you push the envelope, the more vital becomes careful maintainance. A Mercedes CART racing engine is a hell of a machine, and comes complete with a small army of highly trained technicians who hover over the thing after every race like mother hens. A Bengal tiger stalking through an orphanage would not receive more rapt attention. I guarantee they are not using old fuel they found in a rusty farm tractor, or guessing how long they can go on the same crankcase of oil before it turns to clay. Anybody planning to venture out on the edge of TDI performance would do well to heed this advice.

I have spoken.


[This message has been edited by mickey (edited October 10, 1999).]
 
S

SkyPup

Guest
Well, things certainly do change every now and then, sometime for the better and sometimes for the worse.


I guess the most earth shattering change that I have experienced lately in TDI World is when I was working on my 99 Jetta installing my new Techtonics Tuning 2.5" cat back stainless steel exhaust system and I thought I'd fiddle around with the turbocharger some. This "fiddling" has let me on to some very BIG TIME HORSEPOWER and TORQUE increases this past weekend. With the stocker OEM TDI putting out 90HP and 155 lbs of torque, and my Wetterauer software upgrade raising that to 115HP and 185 lbs of torque, I figured that my Techtonics exhaust upgrade added another 8-10HP and another 15-20 lbs of torque for a current grand total of 125HP and 200 lbs or torque give or take a few.

Well, yesterday when I was fiddling around with the turbocharger I saw the name "GARRETT" stamped in larger letters on the compressor housing (it appears to be stainless steel as it has not rusted at all while the cast iron exhaust manifold containing the turbine is all rusted). Looking closer on the side of the turbokompressor on the side facing the right front passenger wheel, there is a ground down flat section on the kompressor that states:
"VW-AUDI VNT15" along with the serial number and some more words, "MADE IN FRANCE."

Since that verification of my hypothetical beliefs that indeed the USA TDI's had the EuroSpec Garrett VNT15 turbo is now completely true beyond ANY shadow of ANY doubt. It changed my way of thinking about my tubo hop up plans on my 99 TDI JETTA and my 98 TDI NB. Mostly because now I know there is NO WASTEGATE on either of my TDI's and the turbo boost pressure is not regulated via a wastegate like the Garrett GT15 turbos on the previous A3 TDI's (that is probably why the differnent HP and Torque designations between the A3 and A4 TDI's, A3's are 90HP at 4,000rpm and 149 lbs torque at 1,900rpm, while the A4's are 90HP at 3,750rpm and 155 lbs of torque at 1,900rpms).

After realizing these facts it dawned on me to scope out the Variable Nozzle controller on the VNT15. Sure enough it was located between the compressor and the turbine and there was NO WASTEGATE outlet on the turbine side since the Variable Nozzle actuator is smack dead in the center of the two assemblies. Knowing from watching my AutoMeter Turbo Boost guage for the past month, that the boost is increased in repsone to throttle increases and torque increases, I knew then that the ECU wastegate controller solenoid was not pulsing a wastegate open like on the A3's, instead it is opening the vanes on the turbine wheel and constricting the nozzle to speed up the turbo. Indeed, that was exactly what is happening, step on the gas and from the get-go the Variable Nozzle actuator is pulling down on the vane controller with pulses of vacuum from the ECU. Closely inspecting the vane controller on the VNT15, I could easily see that there is an adjuster on the actuator with a screw up or screw down adjustement to change the parameters on the VNT turbine vanes and nozzle. So, adjusting it three turns to the right produced same maximum compressor pressure (about 16-17 PSI) with much slower ramp up speed giving an anemic feel to the engine, however adjusting it four turns to the left produced ungodly increase in turbo compressor max (28-30+ PSI) with instant resonse (scary!
). I liked the peak boost alot but felt it was too dangerous an overload for the engine so I turned it back one full turn to give me a max of 26 PSI peak boost, which is about 10 PSI above the Wetteraurer programmed peak boost. It immediately reaches peak boost in an instant and then is pulled down by the ECU to about normal sustained max of 18PSI, which is real strong too.

So now with my peak boost mods to the turbo, I figure my 99 Jetta TDI is putting out about 140HP and about 235 (250?) lbs of torque, it is ungodly how fast it goes through the gears now. The rpm limiter comes on so fast I hardly have time to shift as the engine roars through the rev range. The tires are gripping the pavement trying hard not to break loose as the sound of the turbine and compressor screaming up to max boost are heard over the roar of the engine. Who says the USA can not have EuroSpec power, I've got it right NOW??? In addition, I also installed my other VDO boost guage in the 98 NB TDI and boosted its kompressor max to 26 PSI too, it is an absolutely unreal screamer now. This is what I always wanted from these cars and now I have it. ABSOLUTELY TOTALLY SATISIFIED with the VW TDI powerband - no further performance mods needed, except an electric fan installed on the rear of the intercooler for even more serious power.

For those of you who can never believe anything and are always questioning reality, I have sent Fred photos of the mod, as well as the install of the Techtonic Tuning exhaust system for him to post on the board.

BTW, I refuse ALL responsibility for anyone attempting this mod. You do it on your own and you are responsible for what you do, NOT ME. There are too many variables involved with this for some backyard mechanic to take it on without instantly destroying his engine.

------------------
99 JETTA TDI HERR WETTERAUER TORQUEMEISTER
98 KAFER WETT SPEKTAKULARE TURBOKOMPRESSOR
97 KTM 620 ADVENTURE RALLY PARIS-DAKAR SUPER THUMPER
ICH LEBE MEIN TECHORAD VW TDI'S MIT DIREKTEINSPRITZER TURBOKOMPRESSOR




[This message has been edited by SkyPup (edited October 13, 1999).]
 

Keith

Veteran Member
Joined
Mar 13, 1999
When getting way serious like this, get an EGT guage and tap it into the header before the turbo.

Skypup, have you gone through the 10k service yet? If so, disconnect the EGR and your boost will stay high. Sounds like the ECU doesn't monitor boost on the A4 cars. How much stock boost increase did you get from the TT exhaust?

Still want more power, get the compressor housing machined for a bigger compressor wheel. Low-end response should remain good and high end performance will really improve due to cooler compressed air per psi of boost.

Keith.
 
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SkyPup

Guest
I'll post some pics today, Fred got them ready fast (he's such a great help!). Mickey, be sure to get a boost guage before you do this, it is much more dangerous at your altitude for certain. Here, I have no signs of surge or choke, either on WOT going up or closed throttle coming down. The power is SO SERIOUS that now I am encountering significant torque steer with the front wheel drive system under full load - TOO BAD 4-MOTION aint't here!!! Also, this has got to be the maximum that the clutch can handle without breaking, no powershifts here, only smooth release and then throttle application. I wish I had an exhaust pyometer to closely monitor the exhaust temp, but like someone mentioned, I am not on the Autobahn full out all the time, at best 20 seconds of turbo application will put you twice the maximum speed limit so as always, the turbo is not on much, only under acceleration (towing might not be a good idea with this though). Also, NO ECU codes or lights set off either. The ECU has a torque alogrithim that runs the turbo through the wastegate solenoid vacuum. Under high load torque (1,2,3rd gear WOT you get max boost to 26-28 PSI) while running out 4th or 5th maxs out about 20-23 PSI). At 110 mph cruising it takes 18 PSI to maintain that speed due to the air friction, while cruising at 70 mph only takes 3-4 pounds, at 60 only 2-3. The torque must be higher than what I said it is, more like 250 lbs.
I'll work on posting some pics.
BTW, I believe that the Wetterauer Software enhanced Fuel Maps allow the BOSCH VP VE37 to do a good job, but now way would it work without these enhanced maps, DO NOT TRY THIS without WETT or something to get more fuel. Also, the Techtonic Tuning cat back exhaust is a work of art. There is absolutely not cut off or let up in power production on the upper end, it keeps building and building way past 4,000. I took it to 5,000 and hit the rev limiter and it SCREAMED BLOODY MURDER the entire time. Simply unreal. This is the way VW TDI's were meant to be!!!

------------------
99 JETTA TDI HERR WETTERAUER TORQUEMEISTER
98 KAFER WETT SPEKTAKULARE TURBOKOMPRESSOR
97 KTM 620 ADVENTURE RALLY PARIS-DAKAR SUPER THUMPER
ICH LEBE MEIN TECHORAD VW TDI'S MIT DIREKTEINSPRITZER TURBOKOMPRESSOR
 
S

SkyPup

Guest
I am getting a digital temperature probe to analyse the intake air temp prior to going into the compressor, after the compressor, and after the intercooler. I think lowering the intercooler temp will allow even higher more sustained high boost levels. We have a nice Atkins digital temperature probe but I need to get a longer wire to read it in the car under operation. This data will assist my next step in maximizing the intercooler operations. Since this is totally FREE horsepower to be found by lowering the temps somewhat. Below 8PSI not intercooler is needed, from 8-15 (which is high boost for sure) an intercooler is definetly needed. From 15-25 PSI is very high boost and a very good intercooler is needed!
 

morty

Veteran Member
Joined
Sep 11, 1999
Location
Sunny Arizona
TDI
00 Golf Silver
WoW!

I'm simply speechless! I can't believe you have turned that Jetta into a firebreathing monster. I love your wheels. I love the exhaust set up. Is there any way you could record it and let us hear it..(drool, drool)

Morty

------------------
Waiting for 2000 silver/black GOLF GLS TDI w/lux pkg, heated seats, and Monsoon.

morty
 
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SkyPup

Guest
Keith, thanks for the tip, I will try that right away. I bet I'm blowing boost OUT the EGR valve as is. We'll see, if it was, I will have more sustained boost.


Jonathan's cooling fan set up for the intercooler is next too.
 

Peter Cheuk

Gasser :P
Joined
Aug 31, 1998
Location
Daly City, Calif., USA
TDI
'06 Jetta GLI
Skypup, on my A3 TDI, there's a pressure line that goes from the intercooler pipe to the ECU so that the ECU senses the amount of boost that the motor's making after the intercooler. Does the A4 TDI use this too? If so, can't you bleed this line like I did and get the sustained boost to be a few PSI more for even more power?
 

GoFaster

Moderator at Large
Joined
Jun 16, 1999
Location
Brampton, Ontario, Canada
TDI
2006 Jetta TDI
We want dyno numbers!


Having blown a couple of head gaskets on various engines in the past, I wonder what the head gasket in this one is good for? Are better head gaskets (and possibly bolts) available?

Brian
'96 Passat TDI (bone stock, wishing for $$ to buy a tuning-box, spent it on the FZR400 instead)
 

Olli

Veteran Member
Joined
Feb 19, 1999
Sounds great SkyPup, but you need to go and get that car on a dyno. I believe that you claimed 15-20 ft/lbs of torque increase from the exhuast, did TT quote that number? Or is that just your guesstimate? I can understand if you don't want to invest the time or money @ the dyno if that is the case why not get a G-Tech?


Olli
 
M

mickey

Guest
Theory: To maintain a constant level of boost, the speed of the turbine must increase proportionally with altitude.

Make sense? If I'm right, I'd better keep things a little more toned-down than SkyPup. And he'd better de-tune that monster if he ever plans to drive in a state where the altitude reaches double digits!

-mickey
 
S

SkyPup

Guest
Your reasoning is 100% accurate. There are less air molecules (isn't it 10% less every 3,000 feet up?) and therefore less frictional resistance to the compressor wheel resulting in greater rpms. Also, the compressor has to work harder to create the same boost, which it will do but at some point it is going to be at a very very high rpm level. Also, the compressor map is affected and the ability of the compressor wheel to hit the surge limit will be increased due to lower air pressure and resultant lower air mass (ie less molecules of air). Surge should be instantly recognized by the sound of multiple sledge hammers pounding on the engine when the compressor takes thousands of high pressure wave hits right before it detonatesand self destructs. The turbo will work at altitude to increase cfm through the engine way above what a normally aspirated engine would be sucking, however there are limits to the max boost. I will investigate this a little further and post some "high altitude" turbo information. But basically what you are concerned about is right on the money. It is very difficult to design turbo operation at high altitudes and also at low altitudes as you could imagine.
 

jrcanoe

Well-known member
Joined
Jun 23, 1999
Location
PITTSBURGH PA
Thanks SkyPup great info and pics. For those lucky enough to have stumbled across Fred's page there is now allmost as much free power here as you can get for 600$ from a chip or box.Can't wait for my next finantial feast(currently in famine) to go from stock to 1.8T class, with twice the mileage, for less than 1000$. I would think airplane turbo companies would have the scoop on Altitude. Wouldn't the obdII give you the air intake temp, thought I saw a site that used a casio to be several gauges say that was coming.
 

Keith

Veteran Member
Joined
Mar 13, 1999
Come on Skypup, bring it on home by detaching the EGR hose. Then you'll post here exclaiming how your car has even more pep. When you need to bring the car to the VW dealer, just reattach the hose and the check engine light will go out within 25-100 miles.

Then put the car on the dyno. We want to see the mean Jetta give the dyno a hernia.

Keep up the ground-breaking great work. How about a VNT25, bigger intercooler and water injection. Then you'll want bigger downpipe, Raceware headstuds, Qauife, sport clutch, stronger axles, custom injector pump, ported head, coated pistons, custom intake, extrude-honed header...

Keith.
 
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SkyPup

Guest
Keith, I will try out the EGR disconnect this weekend as I have had the 10,000 mile check. God knows if I get into all the things that you are into I will be broke but have the fastest VW TDI in North America. As is, my ride is stunning and I am astounded how much power it is cranking out and how GD FAST this little baby is. I can remember when I bought my 2002 BMW in 1976 and was happy to get 120HP from a 2.0 liter gasser and hop it up to 160HP with Schrick 300 degree cam, Stahl headers, dual 40mm Weber DCOE's, etc. This VW TDI is a tiny 1.9 Liter DIESEL that runs just like that Korman Autoworks Stage III Bimmer not some stupid tractor, bus or semi!!! That is really hard to believe as I never in my life thought I would be driving a hyper-powerful diesel passenger car - BUT I LOVE IT NOW and that's a fact.
BTW, no engine error codes or any hassles except fantasies about warped con rods, stretched head bolts, blown head gaskets, pistons with holes melted in them, etc. etc. BUT THEY ALL BE FANTASIES and I'm laughing like hell the whole time.

Don't Boost Me Up Sooty, I Love it Down Here in my HyperTurboed VW TDI


[This message has been edited by SkyPup (edited October 13, 1999).]
 

Osiris

Veteran Member
Joined
May 18, 1999
Location
Knoxville - TN
TDI
New Jetta, 1999, Black/Beige
SkyPup,

Sorry if this sounds like a stupid question.

Your car's aerodynamic structure hasn't changed from what any Joe could buy from the dealer, right (aside from those monster tires)? If my TDI Jetta requires a certain Hp/torque to cruise at a certain speed, then yours would require this too. I doubt that my TDI is pumping out 18 psi to maintain a 110mph speed. At 60mph I doubt there is any boost required (it ticks at less than 2000rpm). This would mean that yours is struggling to keep the speed up, or you are seriously loosing power from somewhere. Does this make sense to you?

Shouldn't your car require less rpm's for a given speed, since your car is putting out so much more power?

[This message has been edited by Osiris (edited October 13, 1999).]
 
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SkyPup

Guest
Cruising 5th Gear at 40 mph - 0 boost
60 mph 1-2 PSI
70 mph 2-3 PSI
90mph 4-5 PSI
110 mph 6-7 PSI

Accelerating 5th Gear WOT at 40 mph - 15PSI
60 MPH - 15 PSI
70 MPH - 18 PSI
90 MPH - 18 PSI
110 MPH 18 - PSI

There is hardly any turbo pressure while cruising at any speed less than 100 mph on a flat surface, a small incline bumps up pressure terrifically. At 60 mph cruising and entering the bottom of a small hill, result is 6-7 PSI. On the interstate cruising 75 mph and running over a giant bridge the boost rises directly in proportion to the torque required to maintain constant speed, could be up to max of 18 here.
BTW, I love having the cruise control set on 75 and cruise down the interstate and watch the boost guage as you go up and down hills, the boost guage is also going up and down as the speed remains constant!
Go out and get yourself a boost guage for your ride, that way you can enjoy it and tell us about it.
 

Peter Cheuk

Gasser :P
Joined
Aug 31, 1998
Location
Daly City, Calif., USA
TDI
'06 Jetta GLI
Osiris, cars with manual transmissions have a fixed gear ratio to maintain speed in any given gear. In other words, when you are driving at 60MPH, your car will be revving at 2100RPM, irregardless if your motor produces 50HP or 500HP if the gearing is the same. It's in the gearing.
 

Craig

Veteran Member
Joined
Apr 8, 1999
Location
Kitchener, Ont., Canada
SkyPup, go back and read your posting. You said you adjusted 3 turns to the left and got no boost change. Four turns to the left (I assume from original-hence one more than above), gave too much. So backing off one turn to 3 give the optimum. You are now back to the first setting of 3 which was no change! I don't get it. Did you mean 4 turns to the right, or 3 + 4 turns to the left?
 
S

SkyPup

Guest
Sorry Craig, you are right. Main tools for this mod are 10mm open end wrench, pair of pliers, shop light, two eyes, two hands, and a brain, and a boost guage (which one did I forget?)


To set the record straight:

First try was Three turns to the RIGHT which resulted in significantly lower response and lower & slower max boost.

Second try was back to normal. Everything okay.

Third try was Four turns to the Left. Yoweeeeee!!!!!!! WAY TOO MUCH 30#+ PSI and climbing when I quickly removed my foot from the throttle and returned home hoping some of the engine was left under the hood.

Fourth try was Three turns to the Left which gave 28psi max. As seen in the photo and that is where my two TDI's stand today at this time. This in itself is extremely high and undoubtedly an overload on the intercooler to the point of being massive overkill in heated turbo boosted air. I seriously doubt that the OEM intercooler can handle over 20 PSI boost without the benefit of a liquid nitrogen cooling attachment as the boost above that is most likely hotter than 400 degrees F. and certainly an intercooler overload.


BTW, be certain, be sure and DO NOT forget to keep accurate track of exactly where the OEM reference point is on the VNT adjustor, lose that and you will lose your mind and your engine too!
 

Craig

Veteran Member
Joined
Apr 8, 1999
Location
Kitchener, Ont., Canada
Okay now that we have that clarified, couldn’t someone without benefit of a boost gauge just turn it to the left 1 or 2 turns and be on the safe side? Someone like Mickey might just do one. BTW, this is the most effective mod yet. It’s FREE! (Unless you blow up your engine of course.)

Anyway, congratulations are in order. You are now making some serious hp and still there are a few things that could be done. As you mentioned, a bigger intercooler (or more effective one). You should move north. It is raining (100% humidity) and cold. Nothing like the coming Canadian winter to keep your air-charge cold! 

Probably the bottleneck now would be your downpipe. This might be the final mod you might consider. As you say, anything more without AWD and you have more problems than benefits. Personally, I think the downpipe would be my final mod. With it you would reach the level of diesel hot rodding that is in Europe. And you did it with good ‘ole Yankee ingenuity. And beat out all the ‘official’ NA VW turners who are doing the 1.8T thing. Well done! You’re just a guy who is ahead of his time. Think of it. You developed the 21st-century hot rod without being an engine mechanic. WOW!!

Wonder what your top speed is now? I shudder to think.

P.S. With that kind of boost, isn’t the fuel more critical?
 
M

mickey

Guest
No WAY I would mess with this without investing in a boost gauge! And I'd have to do some serious research into the effects of altitude on turbine speed. I'm afraid that I'd detonate the poor turbo if I tried to achieve SkyPup levels of boost in this rarified atmosphere.

-mickey
 
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