Author Topic: Boosting while cruising? (Read 2634 times)

NastyNate · « **on:** April 15, 2009, 03:17:16 am »

Hey guys this past weekend I did a N/A to turbo swap on my 82 Jetta 1.6 diesel. Everything went well and pics are soon to come but I have a few questions. The plastic piece on the stock turbo intake manifold is the blow off valve correct? My issue is when I am cruising on the highway at about 70 mph my car is boosting at between 3 to 4 psi the whole time. Does it sound like the BOV piece is just stuck and if so is there a way to fix this problem. Or is that just normal because I feel like this would be bad for my turbo. Anyway everything else with the car is golden it started right up and I am reading between 600-800 degree's for egt temps and its boosting to 8 lbs no problem. Running a straight downpipe and this thing is def turnin heads. Thanks for any info and like I said pics will be up this weekend.

ccoxva · « **Reply #1 on:** April 15, 2009, 07:57:03 am »

Every setup is diff but you shouldnt wory about the constant boost on the road.Normal on most vehicles, just instant boost!!

Vincent Waldon · « **Reply #2 on:** April 15, 2009, 11:56:54 am »

What you've described is perfectly normal... some small amount of boost on the highway as the engine works to overcome wind resistance... and then you should be able to get upwards of 10 psi with full throttle going up a hill.

If you can't get the full 10 psi then there's an issue... exhaust/intake leak, sticky BOV or wastegate, damaged turbo etc.

NastyNate · « **Reply #3 on:** April 15, 2009, 01:12:01 pm »

Ok cool but like I said it just had me worried the constant 3 lbs of boost while cruising. Then after that I have no problem building 8 lbs with full throttle. It makes this car actually drivable in normal traffic. Also my boost gauge never reads vacuum which is very strange to me. So like I said its just always at a really low boost. I am used to cars that blow off the boost while cruising and only build it when mashing the throttle. Was I correct about the piece on the stock turbo intake manifold being the BOV? Shouldnt I hear some blow off then while shifting? Thanks for the info guys.

saurkraut · « **Reply #4 on:** April 15, 2009, 01:51:44 pm »

Quote from: "NastyNate"

Ok cool but like I said it just had me worried the constant 3 lbs of boost while cruising. Then after that I have no problem building 8 lbs with full throttle. It makes this car actually drivable in normal traffic. Also my boost gauge never reads vacuum which is very strange to me. So like I said its just always at a really low boost. I am used to cars that blow off the boost while cruising and only build it when mashing the throttle. Was I correct about the piece on the stock turbo intake manifold being the BOV? Shouldnt I hear some blow off then while shifting? Thanks for the info guys.

Yes, that is a blow off valve. But its for full booste reliefe in the unlikely event that the waste gate should fail at full throttle, full load. It a POS that was later deleted on newer engins. I think Blackboostedtruck is selling some block of plates. Buy one and throw the OEM one in the Scheiße can.

There is no throttle plate in the intake. So it won't do the super cool "woosh" thing that the "Fast and Furious" wannabees do.

Also, at you earliest convieniance, install a 2.5" exhaust susten, turbo to rear buper, and an EGT probe. Actually, do the EGT first, and you'll see the bennifit of the 2.5" exhaust after you install it. You'll see higher boost and lower EGT at a 70MPH cruise and probably see an increase in MPG, if you can keep your foot out of it.

Always remember, for a turbodiesel: boost cools, fuel heats

NastyNate · « **Reply #5 on:** April 15, 2009, 02:02:47 pm »

Sorry for the newb questions I am no stranger to the turbo world just to the diesel world. Cool ya we already built a 2.5" downpipe and intake for the car and I have the egt probed right in the center of the exhaust manifold and its reading between 600 and 800 while cruisin at 70 MPH. The oil temps never get above 100 degrees at its highest and it boosts with no lag at all. The car is awesome love it and I will post pics this weekend. Thanks again.

Vincent Waldon · « **Reply #6 on:** April 15, 2009, 02:27:23 pm »

Quote from: "saurkraut"

There is no throttle plate in the intake. So it won't do the super cool "woosh" thing that the "Fast and Furious" wannabees do.

This is also why you're not seeing any vacuum... the diesel intake has no restrictions (unless your airfilter gets dirty) so nothing to pull a vacuum against.

This is one of the reasons why the diesel design is more efficient from a fuel consumption perspective actually... in general there's always enough air.

saurkraut · « **Reply #7 on:** April 15, 2009, 02:40:29 pm »

No Problem. Just forget all the turbo gas motor stuff you learned. Little of it applies. For instance, if your lean in a turbo gas motor, you burn things up. To fix it, you add fuel. On a diesel if you lean, it runs cool. Ad fuel to the point that your blowing black smoke, and you'll melt stuff (valves, pistons, turbine blades).

I was dinking around with my '79TD last year, and I could get it to bury the boost gauge (30+ PSI) and the EGT would not break 1,000 F. Boost is your pal.

These engines will take a boat load of boost and deliver surprizing power.

ccoxva · « **Reply #8 on:** April 15, 2009, 06:48:41 pm »

What turbo kit did you install?? I am interested in doin the same thing to my 1.6.

NastyNate · « **Reply #9 on:** April 16, 2009, 02:58:27 am »

I just did the stock exhaust manifold and intake manifold off the 1.6L diesel and a T3 turbo off a VW. Then I took the fuel filter housing off an 89 cabby i had sitting around and made custom oil feed/return lines for the turbo. Then we made a 2.5" intake with a cone filter and a 2.5" downpipe. Thanks again for the info fellas I am now understanding the motor a ton more. Pics will be up this weekend.

Smokey Eddy · « **Reply #10 on:** April 16, 2009, 06:58:56 am »

Quote from: "Vincent Waldon"

Quote from: "saurkraut"

There is no throttle plate in the intake. So it won't do the super cool "woosh" thing that the "Fast and Furious" wannabees do.

This is also why you're not seeing any vacuum... the diesel intake has no restrictions (unless your airfilter gets dirty) so nothing to pull a vacuum against.

This is one of the reasons why the diesel design is more efficient from a fuel consumption perspective actually... in general there's always enough air.

And also why you can run zero boost control like me

Smokey Eddy · « **Reply #11 on:** April 16, 2009, 07:01:13 am »

Quote from: "saurkraut"

No Problem. Just forget all the turbo gas motor stuff you learned. Little of it applies. For instance, if your lean in a turbo gas motor, you burn things up. To fix it, you add fuel. On a diesel if you lean, it runs cool. Ad fuel to the point that your blowing black smoke, and you'll melt stuff (valves, pistons, turbine blades).

I was dinking around with my '79TD last year, and I could get it to bury the boost gauge (30+ PSI) and the EGT would not break 1,000 F. Boost is your pal.

These engines will take a boat load of boost and deliver surprizing power.

I too found this out very recently. If you try disconnecting the intake from the turbo and driving around the block you'll see the EGT significantly higher. I'd say 50% higher at least.
the "surprising power" is very real... broke my cv's

but the new ones came today!

:lol: