2000 4.3 procharged with cam tuning issue

orih_cz_kay

Member
I have been trying to get my 2000 4.3 procharged mustang with cam tuned; however, the tuning on the low rpm isn't so smooth.

Included is what the dyno graph looks like. Notice that at the lower rpms the lines are wavy.

At idle and low rpm the car seems to buckle, or studder. But seems to smoothen out while under boost or at the top end rpm under boost. What could be the possible problems?

Some problems I am thinking are:
1. Dirty fuel injectors, however, why would the graph smoothen out at the top end?
2. My MAF (SCT BA-2600) is a 90mm MAF, while the air intake piping before and after the MAF are 75mm. Could that transition from 75mm to 90mm and back to 75mm cause a sensing problem? Maybe surges in the air?
3. 8.8:1 compression with the aggressive cam will cause the low end to be rough?
4. Or just bad tuning?

Mods include:
-Wiseco forged 4.3 Long Rod pistons (8.8:1 compression)
-4.2 crankshaft
-SCAT forged stroker H-beam rods
-Comp Cams custom grind cam (224/230 .54/.54 114)
-Ported upper and lower intake
-SuperHeads w/ 1.94/1.56 stainless steel valves w/ 918 springs/retainers
-Procharger P-1SC at ~6psi w/ 2 core intercooler w/ procharger big red race valve w/ SCT BA-2600 MAF w/ SCT X3.
-MAC shorty headers w/ 2.5 in. off-road h-pipe w/ Flowmaster super 44's w/ 2.5 in. tailpipe w/ 3 in. stainless steel tips
-Limited Slip Differential w/ 4.10 gears
-SPEC Stage 3 clutch
-SFI billet aluminum flywheel
-BBK 65mm throttle body
-American Racing Black Redline Shelby Rims (18x9 upfront and 18x10 in the rear) w/ Falken 452's
-B&M precision sport shifter
-Auto Meter Phantom Vacuum/Boost gauge and Auto Meter Sport-Comp wideband sensor
-Eibach Pro-lowering Springs
-Eibach 35mm front tubular sway bar and Eibach 25mm rear sway bar
-MSD Super Conductor 8.5mm spark plug wires
 

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vsixxer24

Active Member
Here is my dyno sheet. A little wavy but not as bad as yours..



You have a very similar setup as mine. I had a fueling issue before and after the P1 was installed. But after chaning the fuel lines, filter, and pump, that all went away. Just started to lean out in the 4500 range ( as you can see in the graph)

My problems I had with idling before the P1:
car doesnt get passed 4k rpms | V6Mustang.com
And fixed after P1 and fueling issue resolved (for the most part):
car doesnt get passed 4k rpms | Page 3 | V6Mustang.com
 

orih_cz_kay

Member
What size and brand fuel injectors are you using? That is the key ingredient.

39.5 lb injectors. and not sure what brand...

what lb injectors do you think i should go to with my set up? i plan to tune to 6400 rpm. (comp cams said up to 6500 rpm was the power band, but i wanna stay safe at 6400)

thanks for the quick reply!
 

orih_cz_kay

Member
Here is my dyno sheet. A little wavy but not as bad as yours..



You have a very similar setup as mine. I had a fueling issue before and after the P1 was installed. But after chaning the fuel lines, filter, and pump, that all went away. Just started to lean out in the 4500 range ( as you can see in the graph)

My problems I had with idling before the P1:
car doesnt get passed 4k rpms | V6Mustang.com
And fixed after P1 and fueling issue resolved (for the most part):
car doesnt get passed 4k rpms | Page 3 | V6Mustang.com

your first video showed pretty much the same problem as mine. except mine was a little more distinguishable. you can hear and see it in this video:

what injectors are you using? and did you solve your problem?

thanks for the quick reply!
 

6 Shooter

Well-Known Member
39.5 lb injectors. and not sure what brand... what lb injectors do you think i should go to with my set up? i plan to tune to 6400 rpm. (comp cams said up to 6500 rpm was the power band, but i wanna stay safe at 6400) thanks for the quick reply!

Think of injectors like bust size. Every woman has different sized breasts which require different sized bras. Every injector size and every brand of fuel injector has different value files to make the injectors work correctly at both idle, in between and WOT. If you do not know the brand, the most likely, the wrong value file has been loaded into the tune which is causing idle wandering. Another possibility with idle wandering is air reverberation due to different sized inlet tubing where air is bouncing back and forth in front of the MAF. Clocking the MAF correctly based on turns in the inlet tubes will help improve idle as well.

So, first up, find out what brand of injector. 39s are marginal for your setup. 60s would be much better and safer. The problem with 6 cylinder motors is that they need more fuel per cylinder than a V-8 with the same HP. To keep the motor cool, you must deliver more fuel per cylinder than the V-8 guys. To solve the fuel delivery problem with forced induction requires upgrades to the wiring, fuel pumps, and possibly fuel filters, fuel rails, and fuel lines. And, all of these individual adjustments except for wiring size and fuel line/rail size must be accounted for in the tune.
 

orih_cz_kay

Member
Think of injectors like bust size. Every woman has different sized breasts which require different sized bras. Every injector size and every brand of fuel injector has different value files to make the injectors work correctly at both idle, in between and WOT. If you do not know the brand, the most likely, the wrong value file has been loaded into the tune which is causing idle wandering. Another possibility with idle wandering is air reverberation due to different sized inlet tubing where air is bouncing back and forth in front of the MAF. Clocking the MAF correctly based on turns in the inlet tubes will help improve idle as well.

So, first up, find out what brand of injector. 39s are marginal for your setup. 60s would be much better and safer. The problem with 6 cylinder motors is that they need more fuel per cylinder than a V-8 with the same HP. To keep the motor cool, you must deliver more fuel per cylinder than the V-8 guys. To solve the fuel delivery problem with forced induction requires upgrades to the wiring, fuel pumps, and possibly fuel filters, fuel rails, and fuel lines. And, all of these individual adjustments except for wiring size and fuel line/rail size must be accounted for in the tune.

ahh ok. would seimens 60# injectors be good?

and what do you think about the surging/buckling? could that be a cause from the MAF? my the intake does have lots of bends and turns. but my MAF is also 90mm while before and after it is 75mm. could that cause the surging/buckling?
 

JTsStang

Boosted V6
It's not the injectors at low rpm unless it's the tune is off. Yes the injectors are small for the setup but I'd look at the maf. Are the headers glowing red? Check in the dark. Are the imrc's deleted? does the tune compensate the extra timing needed for this mod?

Can you datalog it? If so log it and send a copy of the log to [email protected]. Maf ad counts, sprak advance, short term fuel, long term fuel, pressure drop across injectors, fuel pump duty cycle, rpm, iac duty cycle, etc... log as much as you can. Btw...who tuned it?
 

vsixxer24

Active Member
your first video showed pretty much the same problem as mine. except mine was a little more distinguishable. you can hear and see it in this video:

what injectors are you using? and did you solve your problem?

thanks for the quick reply!

Deka's 60lbs. I do not know if it solved anything, threw a rod through my oil pan and am in the middle of rebuilding the engine before having anything new installed. After the P1 and fuel line upgrade, the idling went away and it ran great.
 

orih_cz_kay

Member
It's not the injectors at low rpm unless it's the tune is off. Yes the injectors are small for the setup but I'd look at the maf. Are the headers glowing red? Check in the dark. Are the imrc's deleted? does the tune compensate the extra timing needed for this mod?

Can you datalog it? If so log it and send a copy of the log to [email protected]. Maf ad counts, sprak advance, short term fuel, long term fuel, pressure drop across injectors, fuel pump duty cycle, rpm, iac duty cycle, etc... log as much as you can. Btw...who tuned it?

a local guy near me. he tunes all SCT products. he uses the SCT XCAL3 on my car.

i'll see if i can get a datalog. although i think the XCAL3 is linked to his computer. not mine.

im trying to get rid of the low rpm buckle/surging... it's annoying to drive in parking lots and in traffic...
note: this car is not my daily driver. it's just my county has A LOT of traffic...
 

orih_cz_kay

Member
Deka's 60lbs. I do not know if it solved anything, threw a rod through my oil pan and am in the middle of rebuilding the engine before having anything new installed. After the P1 and fuel line upgrade, the idling went away and it ran great.

wow... that sucks.

yea im looking at siemens deka 60# injectors. what fuel set up do you have? rails? pump? filter? lines?
im running the focus svt pump but stock everything else, except injectors.
 

6 Shooter

Well-Known Member
Siemans 60 are a good choice. Unless you are bumping up against 500rwhp. At that point, you will need to go with 80s or 98s like I have. When you go with larger injectors, you will need an immediate tune to compensate for the larger fuel delivery to each cylinder.

In the past, tuning was a nightmare for years with different sizes of intake tubing. The best setup would be to go to VMP tuning and purchase an HPX slot style MAF which you cannot exceed until you get close to the to the 700 whp area. The 90 mm size of your maf in relation to your 75 mm 3" tubing is the problem. Air will bounce back against the choke down point and cause the maf to jump up and down. You need consistent tubing size from the intercooler to the throttle blade, else what you are experiencing. BTW, there is a good, stable value file in SCTs inventory for the Siemans 60. The bra will fit the boobs.

By the way, you are also at the max of the Focus pump at 300 whp. A way to stretch it out a bit is to go with a wiring upgrade. I have instructions. A lot of guys in that hp range and higher have had to go with Cobra fuel tanks and twin fuel pumps. For comparison purposes, my twin pumps flow twice the volume as the Cobra pumps.
 

orih_cz_kay

Member
ahh ok. my MAF problem makes sense. im thinking of going with the vmp tuning 75mm housing with the SCT BA-5000 slot style sensor.

what tuners do you guys use? im using the SCT XCAL3 with a local tuner. are there any email/datalog type tuning companies you'd recommend that use the XCAL3?
 

6 Shooter

Well-Known Member
Many who have posted on this website have not been happy with mail order tunes. Most of those types of tunes are inadequate and have drivability issues. Some have had motors destroyed. My best recommendation is to find a tuner that will give you a copy of your tune in .mtf format. If they will not, keep looking until you find one that will. A tune in a .mtf format can be read by any tuner. Many of the other guys use a slight variation of that format which is so proprietary that that guy is the only one in the world who can view and change it. Thus, you are married to the guy and must go back to him repeatedly. And, IMHO, there are many so called tuners that are really amateurs who have no clue about how to solve some drivability issues.

XCal3 are really good handhelds. They can data log to a PC or load a tune after changes have been made using the SCT ProRacer package, which in my opinion is the way to go. There will be many issues that come up over time that require tune changes and the mail order ones will not cut it.
 

vsixxer24

Active Member
wow... that sucks.

yea im looking at siemens deka 60# injectors. what fuel set up do you have? rails? pump? filter? lines?
im running the focus svt pump but stock everything else, except injectors.

Sure does! I have the SVT focus pump as well, -8AN lines, trickflow inline with 20 mircon filter, stock rail for now.

ahh ok. my MAF problem makes sense. im thinking of going with the vmp tuning 75mm housing with the SCT BA-5000 slot style sensor.

what tuners do you guys use? im using the SCT XCAL3 with a local tuner. are there any email/datalog type tuning companies you'd recommend that use the XCAL3?

I have a TwEEcer RT tuner along with an Xcal2 handheld. You should be able to datalog with your xcal3, it doesnt link to the computer, it locks to the cars ecu/pcm.
 

JTsStang

Boosted V6
ahh ok. my MAF problem makes sense. im thinking of going with the vmp tuning 75mm housing with the SCT BA-5000 slot style sensor.

what tuners do you guys use? im using the SCT XCAL3 with a local tuner. are there any email/datalog type tuning companies you'd recommend that use the XCAL3?
Don't throw parts at it. Log it and let one of us check it out. We will be able to tell if the maf is the problem. For email tuning Justin at VMPtuning.com has really good tune file for the procharged v6. If you can get him to tune it.
 

Sideshow Bob

Active Member
ahh ok. my MAF problem makes sense. im thinking of going with the vmp tuning 75mm housing with the SCT BA-5000 slot style sensor.

what tuners do you guys use? im using the SCT XCAL3 with a local tuner. are there any email/datalog type tuning companies you'd recommend that use the XCAL3?

That's what I have, well it might be the VMP-5000 slot style It's a nice looking housing. I found 3.25" OD pipe on ebay that is 3mm thick wall pipe. That makes the ID 75mm same as the housing.
 

douglass

Active Member
After looking at your data log, it looks like you are running out of fuel past 4500 rpm or you need to have the tune checked. your a/f is in the 14s and that is not good. The a/f should be around 11.3-11.7 during WOT. Your 39lb injectors are real close to max assuming your hp is close to your torque. As some other members suggested try and get a data log. If you own an sct tuner and a laptop your all set. the log software can be downloaded for free from sct's web site.
 

orih_cz_kay

Member
Many who have posted on this website have not been happy with mail order tunes. Most of those types of tunes are inadequate and have drivability issues. Some have had motors destroyed. My best recommendation is to find a tuner that will give you a copy of your tune in .mtf format. If they will not, keep looking until you find one that will. A tune in a .mtf format can be read by any tuner. Many of the other guys use a slight variation of that format which is so proprietary that that guy is the only one in the world who can view and change it. Thus, you are married to the guy and must go back to him repeatedly. And, IMHO, there are many so called tuners that are really amateurs who have no clue about how to solve some drivability issues.

XCal3 are really good handhelds. They can data log to a PC or load a tune after changes have been made using the SCT ProRacer package, which in my opinion is the way to go. There will be many issues that come up over time that require tune changes and the mail order ones will not cut it.

ahh ok. yea i have 2 near by SCT tuners. im talking to them now. i'll be sure to ask about the .mtf format.

and currently looking for the 60# siemans injectors. and looking into the MAF problem. thinking of switching out to the 75mm VMP housing with the BA-5000.

thank you. you have been a great help.
 

orih_cz_kay

Member
Sure does! I have the SVT focus pump as well, -8AN lines, trickflow inline with 20 mircon filter, stock rail for now.



I have a TwEEcer RT tuner along with an Xcal2 handheld. You should be able to datalog with your xcal3, it doesnt link to the computer, it locks to the cars ecu/pcm.

are you running a return or return less fuel system?

which do you guys recommend for my set up?
 
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