"split BLM mod" ?? What's that?

 

Yeah what is that?

 

So what would be programmed differently for the bigger throttle body? (besides any idle air stuff)

 

Here is the split BLM mod....
http://www.noid.org/~lj/PCM%20Tutorial/SplitBLMinfo.htm

 

 

I watched as a local ImpySS owner swapped out his stocker for a 58mm at a local dyno, and gained about 15rwhp. His a/f did change, and with further tuning he could have picked up some more. He's running a CC306 cam, and very high flowing heads. The only stock part of the top end of the engine was the TB.

 

It's not really that complicated.

If a 48mm opening will supply sufficient airflow that the stock TB is not the limiting factor in the engine's ability to make horsepower, a bigger one will not help.

But if the engine has big enough improvements to the cam/heads/exhaust that it can make use of more airflow than the stock 48mm TB can supply, changing to a larger one will make a difference.

How much difference will be determined by how much more airflow the engine can use.

It seems like people prefer a one-size-fits-all answer to these questions. There isn't one, usually.

 

You only go the 58 when you are making quite a bit of power 400+. Other than that you aren't going to gain a darn thing..........it's like breathing..........you can only inhale so much air when you breath......having more air does no good if you can't get it into your lungs..........same thing with a motor.

Just like you don't need a K&N filter the size of a 5 gallon bucket do you?........lol

 

No, but this does meant hat those of us making 290-310RWHP will pretty much see NOTHING for our $350 "investment". It's good info.