MAFT Pro Boost Control

[lumpy]

Well, I've been having some issues w/spiking and FC. I've read a lot of info and it helped some, but not completely. Here's a rundown of what's happening and my current settings. Any input would be greatly appreciated.

(From a post I replied to on SF)
Well, I changed a few things and FC is less of an issue, but is still there. Maybe more so when it's cooler outside. One of my problems was TPS spool was at 2.5. I moved it to .74 and it helped a lot. Another one is DC start %.. I've read that the initial "20" was too low and 70-80 worked better for one person. Tried that area. Read an above post and tried around 40-50. Little better, but still spikes. I tried the initial setting of "20" and did a 3rd gear pull and it spiked/crept past my PSI set of 8.5 to ~11 and hit FC.

Here's my settings ATM:

TPS Spool .74
RPM Spool 2496
TPS Start 2.5
PSI Start 4.4
DC Start 20
PSI Set 8.2
PSI Aux 8.4
Gain 8.4
DC Set Aux 45.2

It will usually go to ~10psi. My guess is that w/my mods (no WG shims) that is the base boost now. If I could get a rock solid 10lbs I'd be happy, but once it goes past it'll hit FC. I "should" be using a laptop this weekend and hopefully can get it dialed in that way. Other than that I've been adjusting PSI start and DC start % to alleviate boost spikes/creep. One time where it almost always hits is a good downshift and then WOT or 3rd gear @60 MPH then punch it. I "think" colder air makes a difference too. My MT is usually around 85-110* while driving.

 

[lumpy]

No ideas?? Do the settings look somewhat normal? Any suggested length for the vac lines to the solenoid? Would the WG not open if the lines were on it backwards? Could it be that I'm running out of fuel already? 10psi is fine, but once it hits 11+ I get FC. I know all cars are different, but I've heard of several ppl running 11+ lbs on stock fuel. I will eventually upgrade the pump, AFPR, and injestors, but don't want to right now and still have the FC issue. Could it be the tune in general? With the Pro we're supposed to satisfy VF while tuning and I havend had it hooked to a laptop yet so it's basically at the default/initial settings. I want to take it to a dyno to get a baseline and possibly tune it, but can't yet due to this damn FC.

 

[Shlongor]

That's not in speed density mode is it? I thought the "pro" MAFT eliminated fuel cut or at least put it a wee bit higher than 10 psi.

 

[drjonez]

No ideas?? Do the settings look somewhat normal? Any suggested length for the vac lines to the solenoid? Would the WG not open if the lines were on it backwards? Could it be that I'm running out of fuel already? 10psi is fine, but once it hits 11+ I get FC. I know all cars are different, but I've heard of several ppl running 11+ lbs on stock fuel. I will eventually upgrade the pump, AFPR, and injestors, but don't want to right now and still have the FC issue. Could it be the tune in general? With the Pro we're supposed to satisfy VF while tuning and I havend had it hooked to a laptop yet so it's basically at the default/initial settings. I want to take it to a dyno to get a baseline and possibly tune it, but can't yet due to this damn FC.

so let me get this straight, you have installed the MAFT pro but haven't tuned it? that's just asking for problems. in this case, FCO is doing you a favor- keeping you from jacking up the boost and hurting something. get a WB and TUNE!

based on the above it sounds like you're still on a mostly STOCK setup. jacking up the boost w/o some thought is a recipe for disaster.

 

[drjonez]

That's not in speed density mode is it? I thought the "pro" MAFT eliminated fuel cut or at least put it a wee bit higher than 10 psi.

chances are it is SD....you need the MAP sensor for boost control, running the MAP sensor + AFM or MAF is rather redundant....

no MAFT eliminates FCO. a proper tune + Fout Max should allow you to set FCO at an acceptable level.

 

[lumpy]

Yes, it's speed density. I do have an AEM UEGO with it. W/AFR tracking on it's ~10-11.3:1 @ WOT. Before I had the MAFT Pro I was using a MBC from the good Dr. and it was at ~ 10psi. Same thing though. My car must just not like anything over 10lbs. I've been hoping to use a friends laptop to tune, but haven't been able to yet so I'm saving for one of my own. Yep, mostly stock. intake, dp, no cats, 3" catback, rebuilt head, spec stg 2 clutch.

I changed one thing today. In the setup pg it was set for 2956 (or whatever) for motor size. I changed it to 3.0l and so far today I haven't hit FC. I was rather surprised.

So, besides pulling fuel at say 3500rpm+ at high loads to achieve 11.5 would I look at VF for the low and mid load tuning? I know VF comes in steps, so maybe cruise at 35mph and see where the VF is and pull or add fuel in tiny increments (if it's showing lean or rich) 'till it's about 2.5 at that given load/RPM? From what I've read it seems heavy part throttle tuning is the tricky part, is that correct? I'm eager to learn and tune it myself, I just feel it would be smarter/safer to use a laptop. If I can get it close w/o one then I'll give it a go and fine tune on a dyno. Without a laptop I have 4 things I can monitor. Any suggestions on what four to keep up? Thanks for the response!

-Brian

 

[drjonez]

Yes, it's speed density. I do have an AEM UEGO with it. W/AFR tracking on it's ~10-11.3:1 @ WOT. Before I had the MAFT Pro I was using a MBC from the good Dr. and it was at ~ 10psi. Same thing though. My car must just not like anything over 10lbs. I've been hoping to use a friends laptop to tune, but haven't been able to yet so I'm saving for one of my own. Yep, mostly stock. intake, dp, no cats, 3" catback, rebuilt head, spec stg 2 clutch.

AFR tracking is designed to fine tune your existing tune....i'd suggest getting a good tune down BEFORE activating it.

any old laptop will do, they're cheap!

I changed one thing today. In the setup pg it was set for 2956 (or whatever) for motor size. I changed it to 3.0l and so far today I haven't hit FC. I was rather surprised.

interesting, if anything that should make things more rich.

So, besides pulling fuel at say 3500rpm+ at high loads to achieve 11.5 would I look at VF for the low and mid load tuning? I know VF comes in steps, so maybe cruise at 35mph and see where the VF is and pull or add fuel in tiny increments (if it's showing lean or rich) 'till it's about 2.5 at that given load/RPM? From what I've read it seems heavy part throttle tuning is the tricky part, is that correct? I'm eager to learn and tune it myself, I just feel it would be smarter/safer to use a laptop. If I can get it close w/o one then I'll give it a go and fine tune on a dyno. Without a laptop I have 4 things I can monitor. Any suggestions on what four to keep up? Thanks for the response!

-Brian

you're close. the idea w/Vf is to monitor it and make chances such that it is 2.5V.

yup, using a laptop to log data is certainly the best idea.