Do I have a boost leak? BT log inside!

blisstik · 12-04-2011, 06:24 PM

First off, mods are GIAC S2 FBO with stock cat-back and no meth. I did some logs last night and if I did them right, I was peaking at ~11PSI! That worried me so I went ahead and cleaned my FMIC and DVs today. I used about 1.5 gal of the cheapest gas and 2 liters of distilled water to rinse them out. I also went from using t-bolt clamps to stock Helix worm clamps.

The attached log shows a WOT run on 2nd and 3rd. It shows that I peaked at about 15.5PSI when throttle was about 100%. I know GIAC S2 peaks at about 16.5 so is this normal for it to boost 1PSI less? It's about 57 degrees outside.

Also, you'll notice that boost spikes during shifts. I think that is normal but damn, ~20PSI!

Now back to the question. Any chance I might have a small boost leak?

Jeff@TopGearSolutions · 12-04-2011, 06:34 PM

You should be logging the waste gate duty cycles.
The T Bolt clamps are BETTER then traditional worm clamps.
You will see less boost in colder temps compred to hotter temps assuming GIAC follows the same load targeting as the stock DME.
Boost spikes between shifts are completely normal. There isnt an actual spike of boost in the engine, its read pre throttle body. When the throttle body closes no air enters the motor therefore there is a false reading on the T map which reads boost. Perfectly normal.

The most beneficial information is read from 3rd gear only FYI. You wont hit the same boost in 2nd gear compared to 3rd. Same goes for 4th.

blisstik · 12-04-2011, 06:51 PM

Thanks Jeff. The t-bolts are a little more tedious to tighten. I need a set of ratchet-style wrenches, plus I never gave the Helix worm clamps a chance. Helix swears they have no problems so well see.

What is the value for wastegate duty cycle using the BT tool?

Jeff@TopGearSolutions · 12-04-2011, 06:57 PM

Quote:

Originally Posted by blisstik

Thanks Jeff. The t-bolts are a little more tedious to tighten. I need a set of ratchet-style wrenches, plus I never gave the Helix worm clamps a chance. Helix swears they have no problems so well see.

What is the value for wastegate duty cycle using the BT tool?

I'm not sure. You would need to compare to someone modded similar in similar conditions. However, everyone has different stiffness in terms of wastegates so even their information wont go as far as you would think. The reality is it doesnt appear to be leaking seeing what was provided in the log. But you should be comparing wastegate duty cycles before and after changes on your personal vehicle is the best way.

As far as T bolt clamps go, they are the best of the best. Worm clamps are prone to not only ripping silicon couplers, but they dont tighten evenly around the couplers causing boost leaks. They (worm clamps) are better suited for non boost applications.

Sears is running some great sales on tools. I highly recommend their 120+ mechanics tool set. I've modded dozens of cars with a simple set like that. Worth its weight in gold.

cn555ic · 12-04-2011, 06:58 PM

How are you offering DIY service if you don't even own a good set of tools!!

FastBimmerN54 · 12-04-2011, 07:02 PM

Quote:

Originally Posted by cn555ic

How are you offering DIY service if you don't even own a good set of tools!!

Glad I wasn't the only one thinking that..

blisstik · 12-04-2011, 07:43 PM

Come on guys. This is completely off topic. I have tools, just not the fancy ratcheting wrench. Here's two more 3rd gear pulls with WGDC logged.

12-04-2011, 06:24 PM	#1
blisstik Lieutenant Colonel 151 Rep 1,677 Posts Drives: E92 Join Date: Jul 2009 Location: California iTrader: (14)	Do I have a boost leak? BT log inside! First off, mods are GIAC S2 FBO with stock cat-back and no meth. I did some logs last night and if I did them right, I was peaking at ~11PSI! That worried me so I went ahead and cleaned my FMIC and DVs today. I used about 1.5 gal of the cheapest gas and 2 liters of distilled water to rinse them out. I also went from using t-bolt clamps to stock Helix worm clamps. The attached log shows a WOT run on 2nd and 3rd. It shows that I peaked at about 15.5PSI when throttle was about 100%. I know GIAC S2 peaks at about 16.5 so is this normal for it to boost 1PSI less? It's about 57 degrees outside. Also, you'll notice that boost spikes during shifts. I think that is normal but damn, ~20PSI! Now back to the question. Any chance I might have a small boost leak? Attached Images
	Appreciate 0 Tweet Quote

12-04-2011, 06:34 PM	#2
Jeff@TopGearSolutions 3441 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	You should be logging the waste gate duty cycles. The T Bolt clamps are BETTER then traditional worm clamps. You will see less boost in colder temps compred to hotter temps assuming GIAC follows the same load targeting as the stock DME. Boost spikes between shifts are completely normal. There isnt an actual spike of boost in the engine, its read pre throttle body. When the throttle body closes no air enters the motor therefore there is a false reading on the T map which reads boost. Perfectly normal. The most beneficial information is read from 3rd gear only FYI. You wont hit the same boost in 2nd gear compared to 3rd. Same goes for 4th.
	Appreciate 0 Quote

12-04-2011, 06:51 PM	#3
blisstik Lieutenant Colonel 151 Rep 1,677 Posts Drives: E92 Join Date: Jul 2009 Location: California iTrader: (14)	Thanks Jeff. The t-bolts are a little more tedious to tighten. I need a set of ratchet-style wrenches, plus I never gave the Helix worm clamps a chance. Helix swears they have no problems so well see. What is the value for wastegate duty cycle using the BT tool?
	Appreciate 0 Quote

12-04-2011, 06:58 PM	#5
cn555ic 441 Rep 18,331 Posts Drives: 335i Join Date: Jun 2007 Location: US iTrader: (6)	How are you offering DIY service if you don't even own a good set of tools!!
	Appreciate 0 Quote

12-04-2011, 07:43 PM	#7
blisstik Lieutenant Colonel 151 Rep 1,677 Posts Drives: E92 Join Date: Jul 2009 Location: California iTrader: (14)	Come on guys. This is completely off topic. I have tools, just not the fancy ratcheting wrench. Here's two more 3rd gear pulls with WGDC logged. Attached Images Last edited by blisstik; 12-04-2011 at 08:31 PM..
	Appreciate 0 Quote