Boost Guage only going to 10psi? - Page 3

Slo-Mo-Shun · #31 (**permalink**) 02-29-08, 11:54 AM

Quote:

Originally Posted by WillySTS

Sorry to hear about the door sill damage. I've worked in dealerships since 1970. Unfortunately, only a relative few of the technicians are like us, that is, they don't care as much about your car as you and I do.

. . . .

Moral of the story is that dealerships have all sorts of people working in them, they are not all "pros" as the should be.

To this general indifference, one has to add the technical complexity of a modern engine, especially one like that in an STS-V. The engine is rare enough that the techs never learn it; every time you turn it in to the dealer, you get a "rookie" even if he's been working on Caddies for 20 years.

I don't think there is any cure for the syndrome of increasing complex machines operated upon by techs that are being overwhelmed by a cascade of new technology. When the V12 on my BMW first had trouble, I checked out a couple dealers and quickly decided that nobody there was competant to work on it. So I learned it myself and had to do everything from pulling the heads to resoldering ECU's. That was a 1993 car (no new BMWs are fixable IMHO) and it was simple compared to the STS-V. All we can do is cross our fingers and hope nothing goes wrong, I'm afraid.

PS: If the STS-V is complex, can you even imagine trying to decipher a bug in one of these new hybrid cars? You'd need at least double masters degrees in electrical engineering and computer science.

CIWS · #32 (**permalink**) 02-29-08, 11:57 AM

Well it looks like this dealership is going to get to hold class on/using my car, or at least greatly increase their experience with pulling one of these engines in and out. I only hope in the end it gets back to normal.

Here's the sheet from yesterday showing two of the stock runs done on the car a little over a week apart before they pulled the engine and then the one from yesterday.

PSRmark · #33 (**permalink**) 02-29-08, 01:36 PM

Quote:

Originally Posted by CIWS

Got the car back Tuesday afternoon from them replacing the damaged panels and having them look at the engine to see if they could find anything wrong to answer why the HP was down. They said they did not find anything wrong. So I took the car back to the dyno today to have another look and sure enough the car only dyno'd to 309 rwhp

On top of that we discovered there is now another new oil leak coming from the just replaced crankcase seal in a different location on the engine.

I was told they did in fact have to remove the supercharger and basically completely remove the engine from the car in order to replace that seal. Now it appears that will all have to be done again. This engine has 4300 miles on it (and aging fast).

I'm willing to guess that they didn't support the supercharger on its proper fixture, and now the cable that runs along the bottom of the S/C is probably bent. I wish you luck in getting them to actually fix it, I dont think the cable is listed seperatley from the S/C.

The leak in this picture seems to be coming from the crankshaft seal. just an FYI.

PSRmark · #34 (**permalink**) 02-29-08, 02:13 PM

here are some pictures of our S/C on the fixture, if you look at the bottom you can see how low that cable hangs down. The unit weighs about 75lbs if memory serves me correctly.

this is the bypass solenoid/vacuum diaphram, it hooks to the cable at the front of the S/C.

This is a picture of the S/C with the lid removed, you can see the bypass valve that is attached to the cable.

if for any reason the vacuum/pressure hoses are plugged in incorrectly, it could cause similar concerns.

CIWS · #35 (**permalink**) 02-29-08, 02:55 PM

Thanks for the added info Mark, it's greatly appreciated.

CIWS · #36 (**permalink**) 03-03-08, 03:37 PM

Well they are requesting to get the car back tomorrow.

"We would like to get your car from you on Tuesday and run a couple of diagnostics on it, primarily looking at the MAP sensor readings."

I had passed on the tech info you posted here Mark, along with the pics. So it looks like they're going to start some other diagnostics to see if they can track the problem(s) down. Plus I'm sure they want to look at the new leak and determine it's source.

PSRmark · #37 (**permalink**) 03-03-08, 06:03 PM

Quote:

Originally Posted by CIWS

Well they are requesting to get the car back tomorrow.

"We would like to get your car from you on Tuesday and run a couple of diagnostics on it, primarily looking at the MAP sensor readings."

I had passed on the tech info you posted here Mark, along with the pics. So it looks like they're going to start some other diagnostics to see if they can track the problem(s) down. Plus I'm sure they want to look at the new leak and determine it's source.

That is good news. I'll keep an eye on this thread to see what they say.

Mark

Blades · #38 (**permalink**) 05-30-09, 08:07 PM

I'm going to bump this thread up and confirm what d3 was saying.. I'm seeing ~165-168kPa tops.. assuming baro pressure is ~102 or 101.5kPa.. thats about 9 to 9.6 lbs tops. Thats -peak-.. For the most part, it behaves like the .6 bar wastegate spring on my truck! Not in the way of a turbo, but it seems to be right around that boost level. (162ish kPa)

Gotta ask tho.. was the D3 measurement w/ or w/o headers?

PSRmark · #39 (**permalink**) 06-01-09, 03:55 PM

The numbers I supplied were based on factory specs.

ssstealth · #40 (**permalink**) 06-02-09, 09:54 AM

Has anyone here actually data logged the boost with something other than the DIC gauge? I would be interested to see how those numbers compare.

Blades · #41 (**permalink**) 06-02-09, 10:36 AM

Yes... See my post.. Comparing the two would take some time.. definately a unique conversion from 'bars' to kPa hah hah. nerdy joke. Max boost will also vary on the temp drop of the boosted air.. (ie before/after IC).

I suppose you could program the boost control solenoid to limit boost at a given value and then see what it registers at on the dash.. I'm not really up for that tho. I wonder if the boost control solenoid gets its "signal" from. If its before the IC, upping the stock limit of 12psi would let us see a little bit more boost.. If its 12psi after intercooler, we don't see that anyways so theres really no need to worry about changing the max boost (via control solenoid).

PSRmark · #42 (**permalink**) 06-02-09, 01:41 PM

Quote:

Originally Posted by ssstealth

Has anyone here actually data logged the boost with something other than the DIC gauge? I would be interested to see how those numbers compare.

I've had the Tech 2 on it as well as a mechanical boost data log on the dyno, the numbers matched from kPa to the mechanical reading. Both readings read before the intercooler. The dash however is to inaccurate to read. Don't count on that for your source of boost...its more for flash than anything.

PSRmark · #43 (**permalink**) 06-02-09, 01:45 PM

Quote:

Originally Posted by Blades

Yes... See my post.. Comparing the two would take some time.. definately a unique conversion from 'bars' to kPa hah hah. nerdy joke. Max boost will also vary on the temp drop of the boosted air.. (ie before/after IC).

I suppose you could program the boost control solenoid to limit boost at a given value and then see what it registers at on the dash.. I'm not really up for that tho. I wonder if the boost control solenoid gets its "signal" from. If its before the IC, upping the stock limit of 12psi would let us see a little bit more boost.. If its 12psi after intercooler, we don't see that anyways so theres really no need to worry about changing the max boost (via control solenoid).

We use to install voltage clamps on the map sensor to trick the cars into thinking we were only making 11psi when we upped the boost on our cars...Now however, custom tunes like EFI live and HP tuners have that option to change the values now.

Blades · #44 (**permalink**) 06-02-09, 08:56 PM

So, if you measured before the IC cooled down the charge (and thus dropped pressure) and it was equal to the MAP reading minus baro... then how is the pressure measured after the IC? The boost control solenoid does not actually measure boost, correct? It gets a DC % command from the ECM which sends that signal to "open up" under certain conditions.

What is the SCIAP? Just the normal atmospheric air pressure as it enters the SC? I guess the name SuperCharger Inlet Air Pressure is kinda self explainatory.. yet I'm confused as to how the pressure before/after IC is measured. Is our manifold air temp (IAT2) sensor a TMAP?

ssstealth · #45 (**permalink**) 07-05-09, 11:26 PM

I just ran V-Day III at Summit Point and had the Magden system hooked up for the day. I recorded all of the data from my runs and the max boost recorded all day was 10.54424. Other notes from that capture moment were that the speed was 104.39 mph, the rpms were 6393, and the water temp was 239 degrees.