Airboat Chris

iTrader: (1)

Hey guys my buddy and I built a clone of the Mast LS7 427 SS BLACK LABEL 675HP. We bought the Mast M120 ecm with the Black label tune already installed. We are having a idle issue and come to find out Mast uses a 92mm tb and we are using a fast 102 tb. The program is written for a 92mm tb. From researching the web it looks like we need to change the ETC Area Scalar. The problem is I can't find that setting in the program.. Am I not looking in the right place? Or does Mast do it in a different way?

I tried searching this forum but couldn't find any help..

I've sent Mast a few emails about it but they have not responded so before I called I figured I would ask here first..

Thanks for any help!

Airboat Chris

iTrader: (1)

Well I guess since no one replied, no one has experience with Mast M120 tuning..

I called Mast and got a hold of tech support.. He couldn't tell me what parameters to change instead he emailed me a "102 file" and had me try that.. I loaded it and fired off the engine. I needed to do the 20 min break in so I immediately brought it up to 2k. After the 20 min I let it come back to a idle and it seamed to idle fine, then I tried to give it gas and it falls on it's face.. You have to easily give it throttle in order to get the rpms to increase. In another words the throttle response is horrible!!! I figured it just needed some finial tuning and it would be fine. Now this morning I go to fire it up and it idles like crap, and it acts just like it did with the original tune in it.

I am at my wits end.. NOW we know we should have done more research and went with the GM ecm since there seams to be more support for that unit. HOWEVER in my mind.. I just can't get past the fact that the ONLY changes we made to the Black Label base was a 102 tb and a FAST LSX intake instead of the FAST ls7 intake and 92mm tb. Every other component is identical so I can't help but think a few changes to the Black Label tune should be simple and have us going but I guess not

Should we switch the engine to the ls7 intake and 92 tb so we can keep the black label tune? Should I call MAST AGAIN and try another tune? Or should we start all over with the GM ecm/harness and add the MAF..

Here is a run down of the combo and we are running it in a airboat.
Specs:
Type: LS7 7.0L
Displacement: 427 Cubic Inches
Compression Ratio: 11.4:1
Cam: Mast Custom 3-Bolt Core Cam
Heads: Mast Black Label LS7 305cc Heads
Mast 3 bolt Custom Hydraulic Roller Cam
FAST LSX Intake Manifold
FAST 102 Throttle Body
Bosch Dead Headed Fuel Rail
Bosch LS7 Fuel Injectors

Any help would be greatly appreciated! Thanks!

NicD

iTrader: (7)

Buy a controller that actually works and is intended for your application like a GM production ECM. Those controllers were originally designed for simple single state engine conditions like water pumps, etc and they were adapted to do what MAST is doing. The simple fact that you cannot change what you need on your own would have me throwing it out the window. I have dealt with that controller on another project here in town on a customers car and it was terrible. The throttle body scalar isn't a simple change like in the GM controllers as it's integrated with estimated airflow tables, etc which is why they have to do it on their end and it's not in the software for you to change.

Airboat Chris

iTrader: (1)

That is some interesting info. Thanks! This was a expensive lesson on what to use when going FI. I just thought since their set up costs about double of what other setups cost it would be twice as good.. Not the case at all...

Now for the good news... I ended up getting a hold of Jeremy at Fastproms in Tampa. He was more than willing to help, even though he had no prior "Mast software" experience. Long story short Jeremy is the man! It runs absolutely awesome now!

I have another airboat going together now and I'm gonna run a ZL1 supercharger on a LS3 and you can bet I'll be using the GM ECM this time!