DAVE00

iTrader: (10)

Guys,

Now, I've asked this before and a lot of people here are in agreement that most aftermarket tb's need to be moded to better help with the IAC port esp on large duration cams. Solomon is helping me tune my 383 and so far has done an excellent job, now we are trying to solve the ever present split blms issue. Solomon has recc'd the following tips and diy's to help out, however my older BBK 58mm tb doesn't have the same crossovers into the tb that some of the aftermarkets in the diy's. What options to I have? Drill the hole in the front of the TB as mentioned? Any advice is much appreciated, and here is the links to the DIY's and a pic of my TB so you can get the idea.


http://members.***.net/chipsbyal/page/idle/index.html
http://para.noid.org/~lj/PCM%20Tutor...itBLMinfo.html

transbird95

iTrader: (4)

I have the same Throttle body and Solomon does my tuning. I ended up just drilling the hole in the bbk tb to the same size as the stock one and it seems to be working fine. hope this helps.

James Montigny

iTrader: (13)

I'm interested to hear about this too.

I've had a BBK TB on my car since 2007, Ed has never had a problem tuning it.
This my third build using that TB, I don't see it being an issue this time around either.
I really don't like the idea of shoving a small peice of anything in there, but I do understand why it's being done.

What I don't understand if why BBK would design the TB that way if it caused a problem.

wrd1972

iTrader: (12)

Before modding the idle air circuit, I had horrible split BLMs at idle. After the idle air mod, 128/128 95% of the time and when it is occasionally off, its only a point or two.
https://ls1tech.com/forums/lt1-lt4-m...an-oem-tb.html

DAVE00

iTrader: (10)

Yup, but I'm only off on idle and as you can see my TB does not have the same design as your tb and therefore does not need the added piece to close off the IAC port to the intake. Mine is already closed and mates up to the intake nicely, however, I am pretty sure I need to drill the hole in the front of the TB IAC like on the stocker to open more air up into the IAC passage. This is what Solomon wants me to do to help out. BTW - my cam sits on a 108LSA and is a 230/236 from Lloyd.

jasonisdn

iTrader: (1)

or you could do it the way i did. which ever strikes your fancy.

DAVE00

iTrader: (10)

Pretty much the way I'm going to go. Do you have any pics of when you did your's and how it came out?

jasonisdn

iTrader: (1)

ill post the link but my motor is still out.

https://ls1tech.com/forums/lt1-lt4-m...arket-tbs.html

wrd1972

iTrader: (12)

Wow I see that now. I thought even the BBK had the f'd up IAC passage like all the rest but obviously your does not. Yes drill out the passage to what ever the size of the hole is in the stock TB, maybe someone can measure one for you and post the size. Thats what I did to mine to address the idle air flow issue and resolve the IAC counts but I dont see how this would fix a split BLM like what you have.

The other big possible cause of a nasty idle split BLM is a plug wire or two that has is open or high resistance. I had two left side MSD wires where the conductor had broken at the fold and the spark was jumping the gap to the clip. They measured very high resistance while the goods measured around 120 ohms.