Newbie question for 97Cobra P1SC FAST tune?

[Spud]

Hi there,

The TurboBuick.com forum was the most highly reccomended forum from anyone I spoke to in the Mustang world concerning FAST in particular. I recently installed a SpeedPro FAST B2B with W/B O2, and also have an LM-1 installed to monitor and assist in tuning.

I'm currently running about 10psi with a 3 core intercooler, and all the usual B.S.. I just had it tuned by a local shop that specializes in FAST tuning and paid big bucks for them to do so, just so I could have a decent base to work from. Once back I immediately installed a smaller pulley (3 inch approx) which was down from the 3.7 inch which produced about 10psi max. What should I have changed in my tables to accomodate the increase in boost? The afr looked decent as I ran it, but it stumbled/sputtered a bit when I put my foot in it, but otherwise felt strong. I assume because the boost is happening sooner with higher numbers that the VE tables for the base AFR need to be adjusted???

Does anyone have a VE table or a .gct file for a blown application I might be able to peruse and compare mine to..?(mustang or other?) I can certainly post the resultant .gct file from the local shop if prudent? However, I'd prefer to e-mail it to anyone that asks or is willing to share & compare info....

Any other reccomendations would be helpful. I'll update my sig so that the car details are visible for anyone who wants to know.

Spud

 

[TurboTR]

No, the VE numbers down low should remain pretty much unchanged if they are correct to begin with. What you have to determine is, did they map it correctly for the new, higher boost level now, since this will take you "higher" (higher load) into the maps? You can extend the known good curves by eyeball and get it very close for the new boost level, but since you did not test it before at the new, higher boost level then you have to make sure. Also, make sure the timing map continues to roll off with increasing MAP (boost).

As for stumble when you put your foot into it, this is not uncommon IME, listening to various aftermarket ecu equipped cars staging at various race tracks It depends on if you mean a tip in stumble, or just the VE mapping is not yet good enough though. Assuming everything else is correct and it's a tip in stumble, basically it's because of too much or too little tip in fuel. There is an analog of the carb accelerator pump called AE fuel vs delta TPS. That's the accelerator pump shot if you will, and has to be correct. What can make it tough is that 1st the VE table must also be correct, including in the cells that it moves through during a tip in. The two have to be "right", independent of each other basically. IME usually both are off, and one is used to try and cover for the other if that makes sense. There are also some related compensation tables, like AE enrichment vs coolant temp, AE enrichment vs throttle position, etc. Of course with so many variables in the mix it can get a bit overwhelming. Personally I have not seen the need for using the AE fuel vs delta MAP and just zero it out.

I've seen log files from 7 sec outlaw 10.5 turbo stangs that were so far off in tip in fuel that they went pegged, misfire rich for ~ a full second after tipping in hard during staging. Easily heard from the stands as it stumbles hard on tip in (with a puff of black smoke). The thing about the FAST, high load mapping is relatively easy (TG, and that's what separates it from other systems IMO); it's the driveability stuff down low that can be challenging, as with any aftermarket ecu.

If you'd like, send the log files and .gct file and we'll take a look- see.

TurboTR

 

[norbs]

The problem you will encounter on the tip in is, if you hit the gas a few times it will load up with fuel. I have yet to see a fast system adjusted propery to eliminate that problem. Either it stumbles or its pig rich. I have adjusted the tables for months trying to cure this, and know of other several other "local users" run into the similar problem. It could be just that i am not skilled enough to get it right.


I also have run into the same problem with the gen 7 Dfi, but managed to cure it in 5 minutes using aux. TPS fueling. This allows to add extra fuel right off idle, but remove the fueling over a tps %. Nice little feature. IMHO

However back to the cobra Guy. He should be doing some low boost datalogging and see how bad the o2 correction is and keep adjusting those cells in that area until the 02 correction gets close as possible to -5 % for now.

 

[Spud]

.gct and log File for your perusal...

I don't have a website to direct a link to, but I can attach the files to an e-mail and send.

Thanks for your replies. Very informative and I can see why the Ford guys reccomend coming here. Must make you GM fellas blush a bit from the compliment? Anyhow, as stated above, I do have the log file I did yesterday when I put the 10psi 3.75" pulley on it, but then after the drive I put the 15+psi pulley back on (3" diameter). I hi-lited the entire spark field and then held the function key and lowered the spark that is shown on the current calibration to where it's at 20 total advance (10 degrees advance is base timing on the mods). I assume that means that I'm only advancing it by 10 degrees..? I also moved the down low VE tables. In the FAST manual it explains how one should be within + or - 5% correction from the VE tables, and so in closed loop you can hit the "L" key to automatically correct as long as the bubble isn't influenced by surrounding cells, so at a steady RPM in the closed loop range (C-com 1.2 for WP)... Otherwise, my FAST O2 sensor has a reading of almost 1 point lower than the LM-1. So, I'm wondering if possibly the O2 sensor is bad on the FAST? When the LM-1 reads 11.9, the Fast realtime shows 10.5 or something around 1 point lower.

When you say the tip in fuel, that would be in the AE (acceleration enrichment) and so I'll look at that as well. In the meantime, if you had an e-mail you would allow me to send you the files to, I can send them right away. My e-mail is steve.terry@atkinson-terry.com BTW.

Thanks again,

Spud

 

[norbs]

you can send everything you got to me , i will have a quick look.

norbz@sympatico.ca

 

[Spud]

files sent..

e-mail with files sent. Please let me know what you think..? The log was again with the 10lb pulley, and I have the 15+ on there now, so???

Spud

 

[norbs]

I have no mail?

 

[norbs]

Had a quick look. Your o2 parameters are a bit off. No closed loop until 3500 rpm, o2 gain is 40 is a bit high, try 25. lower the high closed limit to about 1500 for now. That is why your not seeing a good correction on your logs becase its swinging in an out of closed loop. Keep working at it.

 

[Spud]

Logs...

Thanks... I will keep working at it. I put the 15psi+ pulley on last night again and remembered that I had turned up the fuel pressure a bit without changing any settings, so that threw things off quite a bit. With 65 on the VE tables for the idle, at 39-40psi at the rails it was about 15.2 afr. So, instead of adjusting the pressure again, I decided to implant another VE table I had from a Turbo setup for a 4v and it worked great for the low end idle at about 90 on the low end. What I'll have to do is do some road work on it, but that's kinda hard unless I can talk a buddy into coming with me to drive it while I'm on the laptop.

The TTCAL .gct file you see is the one that the local shop made up for me, and my only concern was that it looks entirely different then what FAST's manual or help shows as an ideal VE map (peak at the peak torque with a plateau and then tailing off at higher RPM a bit...) The .gct file they set up looked a bit suspect that's all. Anyhow, thanks for the input and I'll try and adjust as you specified and see how that does it...

Thanks,

Spud

 

[TurboTR]

Originally posted by norbs
The problem you will encounter on the tip in is, if you hit the gas a few times it will load up with fuel. I have yet to see a fast system adjusted propery to eliminate that problem. Either it stumbles or its pig rich. I have adjusted the tables for months trying to cure this, and know of other several other "local users" run into the similar problem. It could be just that i am not skilled enough to get it right.
I also have run into the same problem with the gen 7 Dfi, but managed to cure it in 5 minutes using aux. TPS fueling. This allows to add extra fuel right off idle, but remove the fueling over a tps %. Nice little feature. IMHO

Norbs it is pretty straightforward to get it right. There is no inherent reason the FAST should load up with fuel on tip in- it's just not all set right yet in that case.

The FAST also has AE fuel vs TPS position, which appears to cover what you indicate above with the DFI.

PS Spud you'll find that the DOS sw is much easier to tune the car with on the road than the Windoze stuff is. There was an older version of sw that had the "L"earn key enabled but I think it was eventually removed. I still use it...

I thought my profile showed the email addy, but here it is- turbotk2001@yahoo.com

TurboTR

 

[norbs]

I guess i just have been adjusting it wrong all these years. Spud the dos version is buried in the windows version of c-com wp. You just have to find cc.405.zip and install

 

[Spud]

E-mail sent

Thanks again guys. TurboTR, I just sent you an e-mail of the attached .gct files and the log for you to check out. I'll look on my CD rom for the DOS version of the C-com and give that a try. However, I thought that the "L" key was a part of the C-com WP that I have, as it's in the Help section???

Anyhow, I'll continue to play with it. I sure do love the FAST system for all it's flexibility though, and I'm starting to develope an affinity for you GM fellas too.

Regards,

Spud

 

[norbs]

if you have the latest version of wp the l key is in there also. Its just that the dos version is easy to manage then windows. On the windows version you must manually close each window as you open it .On dos you can just hit the next shortcut key and don't have to worry about open windows slowing down the data stream. Believe me its easy to get many windows open in wp and get caught up in clutter Your best way of dialing it in is a 3rd gear pull, gear changes, acceleration, will make it hard to say" it needs fuel here or less fuel there."

 

[Spud]

Thanks again for the input.

I found the DOS version of c-com and have it on my laptop now. Looking through it and navigating around it now makes more sense from learning with the windows version, but I can see how the DOS version would be easier to manipulate when tuning on the road.

Question: With the flat or (dead spot) that happens when I push the pedal, it's only evident with the 3" pulley. How should I be adjusting the AE vs. TPS position, and or AE vs. MAP? It seemed that when I flattened out the angle on the curve for both that the flat spot was de-emphasized? In other words less AE was added as MAP increased and as TPS position increased inclulding rate of the TPS.

Is there anything else you might suggest other than the O2 parameters and closed loop settings? I did that and without the above AE adjustments the flat spot was ever present.

Thanks,

Spud

 

[norbs]

IF the car has an automatic transmisson brake torque it while adjusting the ve map using the l key, through various cells. Just don't sit there to long or you will fry the tranny. The ae fueling is really hit and miss. just save your orginal progam in case you mess it up and make it undrivable.

 

[Spud]

I should figure on putting the crucial details of my ride on my sig. so that all will have more information to go by. Anyhow, it's a 5spd. Tremec (std.), stock with most 96-98 Cobras. So, applying torque is only really do-able on a dyno or road work with a buddy driving or manipulating the puter.

BTW, I took your advice Norbs and TurboTR and installed the MSDOS version of C-com and tried it out. It was on the older laptop that came with the FAST I purchased and it connected right away (I hadn't even tried the older laptop that had this until now, and so now that has purpose and a life where before it was on the shelf). Now I have two laptops I can use, with the newer or the two having the newest WP version as well as the DOS version, and the older of the two with just the DOS. Anyhow, maneuvering through the DOS is easier than the WP version, but that's probably because I'm near 40 and the MSDos was something I actually have prior work experience with because I actually used it in the early 90's. The graphs and log functions aren't as easy to read (no color), but the VE tables and the others are easier to manipulate for dinosaurs like me.

Anyhow, I'll pay special attention to the VE tables when (including the "L" button to adjust) which will be easier now with the closed loop parameters set more reasonable (1800 high and 1300 low limit).

Reading the log files and then adjusting to make those happy is my next challenge, which is something I'll have to learn as I go with. Other than that is there anything you'd advise when logging and then adjusting? I know you want to keep the O2 correction under 5%, but other than that, what about the other tables such as AE vs. MAP etc. from what the logs say?

Thanks again for all the good advice and help BTW. Learning this stuff cold is tough without a little guidance and advice on where to aim. I just never thought of using the DOS version until you mentioned it. Now I'm happy if for no other reason I have a back up computer and another tool for the toolbox so to speak...

Regards,

Spud