How good are your BLMs??

[tonys87]

I recently noticed that i was getting a little knock at low boost. so I went through the Scanmaster and noticed that my blms were at 138 in park. I found some vacuum leaks and one of them was at the 3 bar map
i fixed all of them with all new fittings and hoses. the blms are now down to 130-131 and zero knock.
how much better can the blms get? is it actually possible to get them set at 128? and does it really matter?

 

[we4Mateo]

+/- 10 from 128 is great. I'd be more concerned with cruse BL's than idle BL's, but good work on the vacuum leak none the less.

 

[tonys87]

what should good cruise blms look like? i have never really payed much attention to those.

 

[we4Mateo]

what should good cruise blms look like? i have never really payed much attention to those.

They should also be +/- 10 from 128 so anywhere from 118 to 138 is within spec. Anything above 128 and the car is adding fuel and anything below 128 then the car is taking fuel away so within 10 of 128 is spec with a TurboTweak chip. There are a few ways to adjust BL's if needed but scan first and see how they are.

 

[we4Mateo]

What size turbo are you running? Those are nice hp figures for 16psi. You can probably run more boost with your alky setup too...

 

[tonys87]

I'm running a GT6765 dbb turbo it's a older model from 08. I'm turning up the boost as soon as I get some tuning tools I ordered. All I have now is the scan master and a 5.6 chip from TT. I ordered a WideBand and a power logger and I also wanna get a newer chip from Eric with more adjustability. my tuning capabilities are limited but I'm learning. So as soon as I get that stuff, I'll start cranking up the boost.

 

[bison]

Those numbers mean about nothing in open loop. When in closed loop if the chip is burned correctly you should be able to get 128 in closed loop. If you need a little fine tuning you can drop the fuel pressure a little. Changing the fp will leannor richen it whatever amount you change it.

 

[tonys87]

bison, so by dropping the fuel pressure a little it would make the blms drop a bit? its set at 43 line off. i thought that the ecm was adding fuel? do to it being a little lean?

 

[turbo nasty]

Leave it alone at 130-131. Its fine

 

[tonys87]

Leave it alone at 130-131. Its fine

i most likely will. the original question was asked because if it is possible for it to be set to 128 then MAYBE i might still have a small leak some where else.

 

[TurboDave]

Like nasty said, leave it alone. People put way too much stock in trying to get perfect 128 BLM's, when in reality, you never will see the perfect number, not all the time anyway. There are too many variables, including weather and other external variables. Improving the BLM can be attained by a change in fuel pressure, or by a change in adjustable chip parameters. To lower BLM you would raise fuel pressure, and vice-versa. Changes can be made in the adjustable chips like the Extender/Commander chips or the Turbo Tweak chips to adjust the fuel curve to move the BLM's also.

Yours are near perfect leave them alone.

 

[tonys87]

okay..thanks