Looking for some wisdom.......

[kjones6039]

I have been working with my MS2 v3 off and on for a little over 3 years now. My first project was a TPI conversion on my 79 Corvette which turned out quite well. http://www.kandlservices.com/tpi

As I recall I ended up using the 2.8 code before I decided to try MS Extra.

NOW I intend to get serious and build some more HP for the old Chevy!

I am currently building a 383 SBC with a 900 cfm Holley TBI w/85# injectors and lots of other $$$$ stuff. For now I intend to manage fuel only with the MS2.

My question is..... should I drop back to the B&G code or continue with MS Extra??

I know the question must sound silly to you guys with the really BIG brains but it's keeping me awake at night. hahaha

Thanks for any thoughts on this.

Ken

[Matt Cramer]

For fuel only? I'd probably stick with B&G code. Fueling isn't very different between the two.

[kjones6039]

Thanks Matt!

I was kind of leaning that way. The only reason I loaded the Extra code in the first place was to see how it would work with my TPI setup and maybe learn a little about it.

I have installed the 2.89 code and will start from there unless you have other suggestions.

Thanks again,

Ken

[MegaScott]

Ken,

The B&G code should work fine for your application,

I have two questions.

1. Why not take full advantage of the system and go ignition control as well. you can get it running with fuel only, then enable spark control...It's not very many changes to get some extra performance and tunability.

2. On your TPI setup, did you have a pusher pump at the tank to feed the Walbro pump?

I have used the Holley 900 on an 351 Cleaveland powered Aussie Falcon estate wagon. We had minor problems with injectors sticking due to the used nature of the unit we had, ultrasonic cleaning of the injectors fixed it. These big injectors are low impedance, to get a more consistent idle, read up in the manual on how to setup and tune the PWM injector driver.

BTW...Nice install on the yellow Corvette...looks great!! I'm surprised you didn't go with an LT style intake on the 383...

Scott

[kjones6039]

Hi Scott,

1. Why not take full advantage of the system and go ignition control as well. you can get it running with fuel only, then enable spark control...It's not very many changes to get some extra performance and tunability.

This is precisely what I anticipate doing. I ran the 7pin HEI setup on the TPI motor. I want to get familiar with the TBI and then take on the ignition later.

2. On your TPI setup, did you have a pusher pump at the tank to feed the Walbro pump?

I used a pusher plus a surge tank which worked fairly well. I anticipate mounting the Walbro back by the tank this time.

These big injectors are low impedance, to get a more consistent idle, read up in the manual on how to setup and tune the PWM injector driver.

I have gone over the PWM info in the manual very carefully and think I have a good grasp of the tuning to get a good idle.

NOW.... a question for you if I may?

How did you handle the issue of delaying fuel to the rear throats until they start to open? Holley does this with their high $$$$ setup. I have considered just turning those 2 injectors on/off based on TPS. Any suggestions?

Thanks for the compliment. I put 5-10k miles on the MS/TPI setup, which I love to shove in the faces of the MegaSquirt naysayers!!

Thanks again,

Ken

[MegaScott]

Hi Scott,

NOW.... a question for you if I may?

How did you handle the issue of delaying fuel to the rear throats until they start to open? Holley does this with their high $$$$ setup. I have considered just turning those 2 injectors on/off based on TPS. Any suggestions?

Thanks for the compliment. I put 5-10k miles on the MS/TPI setup, which I love to shove in the faces of the MegaSquirt naysayers!!

Thanks again,

Ken

IIRC..We had an older Holley 900 TBI, the linkage opened both throttle blades at the same rate, it also had a solenoid style fast idle. I don't remember having to do any tricks like staged injection to make it work...though it wouldn't be that hard to setup staged injection, or a dual table setup.

I like to pull up to those Mustang guys, whip out my laptop and show them how easy it is to tune...they just stand there gawking...

Scott

P.S. Look here for PWM settings...viewtopic.php?f=93&t=36853&start=0 (Lance used one of these a few years back before he switched to port injection)

[kjones6039]

The TB is new (part# 500-19) so I imagine it is a bit different. It uses a GM IAC motor which I will keep. The linkage is fixed (ie. NOT progressive). The Holley software is able to shut the rear injectors off at idle/low rpm. I can think of several ways to do that in MS. With a bit of research/experimentation I'm sure I can work it out

Actually I already imposed on Lance and Matt for some help with settings etc. I know that Lance used one of these TB's before. He fixed me up with some starting numbers for PWM.

Thanks for the help! If you have any suggestions feel free to pass them along. I will no doubt impose on you again along the way.

Ken