Tuning Help! New blower, HPX....

[Senator]

Need some advice about tuning my new setup. I'll try to keep it short.
My first boosted vehicle and major tune.
1998 Cobra body
Built 4v WAP engine (C heads)
AOL3 98 Cobra computer
T Trim, Treadstone IC, Tial BOV
#80 injectors, a1000, 8AN lines, div x rails, regulator
HPX MAF (brand new)
SCT X3

Car is dumping fuel (93oct for now). Tuner said he cut the injectors in half.
took it down from 40psi to 30psi of fuel with 1:1 boost reference on the regulator.
Can't get the AFR under control.
We're essentially cutting all the fuel out of it and electronics still say we are still crazy rich.

Does the HPX need any sort of calibration table since it was brand new, or can it be tuned directly with the SCT software?

What can I do/ask the tuner so that we don't get into the "throw money and parts at it" game, until it's fixed? Should I ask him for a datalog to post up here?

 

[Senator]

The tuner never asked for the 30 point transfer function table I see floating around for the MAF. Does he need that or is he just changing values on the sct software probably?

 

[DSG2NV03]

Yea, I would throw up a datalog and let us take a look at it. I assume you are tuning in closed loop? (looking at STFT). You don't have a wild setup, so it shouldn't be that bad.

 

[Senator]

Yea, I would throw up a datalog and let us take a look at it. I assume you are tuning in closed loop? (looking at STFT). You don't have a wild setup, so it shouldn't be that bad.

Ok I will get him to email me a log Monday to post.

I'm still kind of concerned that he never asked to the MAF trans-function for the HPX MAF. Do some tuners just set the values themselves?

It just doesn't make sense that we're pulling all the fuel out of it and it's still super RICH.

 

[DSG2NV03]

Did you make sure you have ZERO vacuum leaks? I guess some tuners could get it right inputing them, but most, like myself, just use the value files SCT provides in Advantage to get in the ballpark.

Did your tuner scale or use BP modifiers? I know I had to scale my MTF by like 80% to get it in the ballpark.

 

[04sleeper]

So you did not make any changes in the tune for the HPX?

There's your problem right there.

Not only do you have to change the MAF Transfer Function, High/Low Slopes, Engine displacement. But you must also scale the MAF for the change in MAF housing size.

I would start with the BA500 value files to get you started and scale from there. It's going to take some work with datalogging to get it dialed in.

 

[Senator]

So you did not make any changes in the tune for the HPX?

There's your problem right there.

Not only do you have to change the MAF Transfer Function, High/Low Slopes, Engine displacement. But you must also scale the MAF for the change in MAF housing size.

I would start with the BA500 value files to get you started and scale from there. It's going to take some work with datalogging to get it dialed in.

I don't think my tuner did. He only said he was cutting the injector cycle down and I lowered the baseline fuel to 25/30PSI. He said nothing about the mass air, except if I soldered it correctly.

I was going to use PMAS' 2nd gen maf tool (excel) from here to get the 30pt set. That's similar to the BA5000 value file right?
Link to Excel file:
http://www.pmas-maf.com/resources/PFLHPXtool.xls

 

[watman02]

should be tuning in open loop. so the ecm is not attempting to change anything while ur tuning. he needs to dial in the maf first!

 

[Senator]

Ok tuner just told me that the 80# are too big for that setup and can't be tuned. I need 60s. The HPX is too big because it's for cars with 1000hp. He also wants me to take off the intercooler because it won't make high boost. I was not given a datalog.

Thoughts? Setup in first post.

 

[04sleeper]

Find another tuner.

 

[01yellercobra]

Find another tuner.

+1

I have 80's and didn't have any problems tuning them. And anyone recommending the removal of an intercooler should be smacked.

 

[01yellercobra]

should be tuning in open loop. so the ecm is not attempting to change anything while ur tuning. he needs to dial in the maf first!

Depends on what part of the transfer you're tuning.

 

[Senator]

Thanks for the input guys. I built the car myself, but I have no experience with tuning outside of the Bazzaz system for bikes. I knew something was fishy when he told me the HPX was too big for my setup.

 

[watman02]

Depends on what part of the transfer you're tuning.

i understand but it sounds like he was still attempting to get the car to idle and run properly. i could have missread it.
I would get a new tuner as well!

 

[Senator]

i understand but it sounds like he was still attempting to get the car to idle and run properly. i could have missread it.
I would get a new tuner as well!

That's correct.

Car is back at home. Said it was drivable under 4K rpm, but didn't idle was completely eratic. Had to make 2-3 stops on the way home to make sure it wasn't going to die.

At least I know what questions to ask the next tuner this next time around.

 

[Dash808]

So much bad information in this thread....

1. 80lb SD injectors are junk. Anything over 60lbs and you should be using Injector Dynamics. If you only need 60's then your fuel delivery is overkill too.

2. You don't have to give the tuner a MAF transfer function, LOL. He's a tuner. He should know how to dial in the MTF just fine.

3. Which HPX MAF are you using? How big is your intake housing?? If you're using a 5" tube & ba5000 MAF then yeah would be too big.. HPX3500 & 4" tube would support big power and still have drivability.
You have a huge fuel system, big (and crappy) injectors... you must be looking for big power....

3. You can tune in either OL or CL just fine. The PCM is only learning when adaptive learning is turned on..... Which it won't be during the tuning process.....

 

[01yellercobra]

I've been running SD 80lb injectors for a couple years now. They work just fine for me. Saying they're junk is just your opinion.

 

[Senator]

UPDATE:
Still trying to get this thing tuned on 93 before we do E85.
Working with a new tuner, but not having much better results.

Started off fresh with the BA5000 value file and now it doesn't want to idle.
Giving it barely any pedal, it's in the 9.0-9.3 AFR range.
As soon we unplug the HPX it idles perfectly smooth and has an AFR of 13.5-14.0.

What would cause this?

 

[watman02]

sounds like mtf table problem or a maf problem in general . are they tuning in open or closed loop?

 

[01yellercobra]

Sounds like the MTF just needs to be adjusted. I had to pull about 20% fuel to get mine to idle.