I have a blow through 12a using a mikuni 44phh carb. My problem is that I lean out. I have access to 2 itb's that are 42mm and have 2 injector bungs in each itb and was planning on fabing a way to mount them to my side draft manifold. Is it a valid assumption to think that since the itb's have no chokes the air flow from the turbo should be as sufficient as it was with the mikuni leaving me with the same issue of going lean but now with the defense of 4 injectors and MS II to help tune it out?

Please excuse me if this is a dumb question I'm new to MS and ITB's.

 

With the MS, the only reason you'd go lean is if your injectors aren't big enough to handle the amount of air you're flowing.

Ken

 

Thanks, so you dont think I have to be concerned about 2 42mm itb's not flowing enough air if the mikuni 44 had no issues with air flow?

I plan on at least matching the primary and secondary injector sizes of OEM TII running sequential since I'm running a stock S4 turbo at 10 psi.

 

I'm not sure what most people run for ITBs so I can't answer that question, but honestly I'd be more worried about running out of turbo if you've done anything interesting to the engine related to porting.

Ken

 

the 12a i'm running now is stock port, the 12a in my sig is street ported and the victim of a cracked end plate due to leaning out and detonation... hence i need to learn more about fuel mngmt...

I was always satisfied with the boost being produced up to 12psi through the mikuni which had the restriction of the venturis... would you think 2mm less on the itbs would have more of an air flow restriction than the mikuni with venturis?

I'm so fascinated with MS maybe I'll just take a crack at it... I'm a software developer since 1988 and just love this so far...

 

Trying to determine whether I need MSII or I can just use MSI all I want to do is control the fuel coming through the itb's. I know I will need other sensors such as TPS IAT CLT... already have a wideband... but I'm not going to get into ignition yet so it looks like MSI will do right?

 

The issue with MS1 is that we (the developers) are no longer actively developing on it. With MS2 there are also features which can help with ITB tuning. One such feature is blended tables.

MS2 is getting some features backported from MS3.

Ken

 

MS2 it is. Pricing at DIY now has an unassembled MSII kit on PCB 3.0 at about 250 but assembled at 400 (+150 for assembly) I'm a newbie at this but is that assembly really worth 150 if I have some basic soldering skills? In no way I'm I questioning DIY but it's more of a budget concern on my part.

 

If you've assembled a few electronic kits before and enjoy spending 8 hours behind the soldering iron, then the unassembled kit is a fun way to go. But otherwise, the $150 for assembly is well spent.

http://www.youtube.com/watch?v=OdHTKP2Evfk

 

After looking at this video and reading the assembly instructions online I realize I must have been out of my mind thinking I could assemble this. 150 is worth it. I ordered the unassembled kit from DIY Autotune on Friday night and sent them emails to hold shippment. Going to pay them for the assembled MegaSquirt-II EMS System - SMD PCB3.57.