Got my VEC2...and....WOW!!!!
- Thread starter Anaconda
- Start date
LETHAL GTS
Viper Owner
Yea you're not kidding. Your car is getting dangerously lean at 5000rpm. Nice torque numbers, but I would have expected a little more HP. Hey *** do I know LOL!
I also noticed you first run you have 5 less horses than your last run, but you have more lbs of torque on your first run and 5 less on your last run. Interesting, very interesting.
I also noticed you first run you have 5 less horses than your last run, but you have more lbs of torque on your first run and 5 less on your last run. Interesting, very interesting.
sbkim
Enthusiast
Thanks for the dyno post. Looks like you picked up serious amount of torque!!! I presume you have more power to be had if you leaned out the car? How did you measure the AF? is it still accurate to put the sensor at the muffler?
v10kingsnake
Viper Owner
anaconda, i think you need to do some research on your results to find out why they are nothing to be happy about. i am not trying to down your apparent high here but i personally know of several that have picked up plenty more numbers then this with just the vec2 PROPERLY tuned. i have a 97 with just filters and smooth tubes and borla catback on my first dyno and i spun 440+rwhp and over 490ftlbs torque. i would be well over 500 with the vec 2 for sure. i realize our cars and dyno can vary but look at the difference here!!!i really thought that you had a gen 1 when i saw the numbers before i looked at your sig. i am sure you should have an easy high 400 in her no problem so look these missing ponies. see yah.
The program card had a program from our sample files on the CD. It gets you in the right direction, but there's power left to be made by tuning.
The AFR should be tuned to 13.0 and the timing advance can probably be increased further.
If you need assistance tuning for maximum power, let us know.
Regards,
Sean
The AFR should be tuned to 13.0 and the timing advance can probably be increased further.
If you need assistance tuning for maximum power, let us know.
Regards,
Sean
v10kingsnake
Viper Owner
bro, unless your next round of mods is right around the corner, and your not planning on running the car much i would get some tuning now to optimize what you have. your car is running so rich i would think you plugs are wet with fuel.
LETHAL GTS
Viper Owner
I stand corrected! Thanks.
let us know if you get rid of the breaking up at the higher rpms. seen several na creampuffs do this. does it break up when you drive it on the street? have you smoothed it out any? the pre vec graph seemed pretty smooth.
John
John
It sputters at 5000 RPM, yeah.
I decided to break down and get the car tuned at Roe. I'm gonna go there on Thursday. I was gonna wait until I get my next round of mods and get it all done at once, but I figure it won't take too long to get the guys there to straighten the car out as it is.
I decided to break down and get the car tuned at Roe. I'm gonna go there on Thursday. I was gonna wait until I get my next round of mods and get it all done at once, but I figure it won't take too long to get the guys there to straighten the car out as it is.
Purdue_Boiler_Viper
Enthusiast
Very interesting. What are your next set of mods?
Purdue_Boiler_Viper
Enthusiast
Holy [******] Batman! Why not just go for twin turbos?
If I did twins, I would still need to replace the pistons, I would still run water/****, and I would still do the roller rockers. It would cost more.
Besides, I had twin turbos on one of my Mustangs. I've had a nitrous car, a twin turbo car, but no supercharged car (even though I have installed superchargers).
Besides, I had twin turbos on one of my Mustangs. I've had a nitrous car, a twin turbo car, but no supercharged car (even though I have installed superchargers).
Joseph Dell
Enthusiast
I've tuned over a dozen of these VECII cars and for some reason they all have that V somewhere up after 5k RPM... some closer to 5600, while others closer to 5200 or 5400. Very strange.
I wonder if there is a way to get rid of this? I can _move_ it by taking timing out... but in many cases, that isn't what needs to be done...
JD
I wonder if there is a way to get rid of this? I can _move_ it by taking timing out... but in many cases, that isn't what needs to be done...
JD
That is strange. Notice on the second run, where it was the stock calibration, there is no spike. There wasn't anything on the previous dyno either.
It's easy enough to tell because the car sputters on the dyno. I actually did notice the problem before, when I was at Roe on the test drive. However, I wasn't looking at the tach, and just assumed that I hit the rev limiter. I thought the car was fine, but that it was my fault.
Anyway, let's see what happens tomorrow. Hell, I could always make a trip up your way. I'd love to see your car, and it isn't that far...
It's easy enough to tell because the car sputters on the dyno. I actually did notice the problem before, when I was at Roe on the test drive. However, I wasn't looking at the tach, and just assumed that I hit the rev limiter. I thought the car was fine, but that it was my fault.
Anyway, let's see what happens tomorrow. Hell, I could always make a trip up your way. I'd love to see your car, and it isn't that far...
KenH
Enthusiast
Have you noticed this problem being heat related in any way? Runs good when air temps are cool, but have the problem when things heat up?
Joseph Dell
Enthusiast
In Atlanta, it is always hot. 
JD
JD
KenH
Enthusiast
I was stationed in Augusta for a while, so I hear what your saying.
I had the same type of issue with the VEC2 when my car was NA. In my case it would break up heavily when it got hot out, but run OK in cool weather. I did a lot of troubleshooting and came up with the following conclusions.
VEC2 installed, but running stock settings - ran OK all the time
VEC2 installed and running modified timing - ran bad, especially when warm
VEC2 installed and running modified fuel settings - ran bad when warm
VEC2 installed on timing circuit, but bypassed on fuel injector circuit- ran OK with modified timing advance.
VEC2 installed on the fuel injector circuit, but bypassed on the timing circuit- Ran bad with modified timing advance.
I never fully sorted it out and the fixes that came out for the VEC2 which fixed some of the other systems never fixed my problem. Once I installed the SC, I had to sort through a number of problems including this one.
In my case, the root cause of the heavy breakup in the 4000-5000 range when hot seems to have been related to the stock fuel injector connectors. Changing to the MSD type seems to have fixed that problem for me (knock on wood since every time I think I have all the kinks worked out, something new comes up).
My theory is that the VEC2 fuel injector drivers create an injector waveform that is harder for the stock injector connectors to handle and this problem gets aggravated when conditions get hot. What doesn't make sense to me is why the VEC2 running stock settings would run OK unless the driving waveform is fundamentally different somehow under those conditions.
I could be completely out in the weeds on this, but have you tried changing the injector connectors on any of the NA cars that show the problem by chance?
I had the same type of issue with the VEC2 when my car was NA. In my case it would break up heavily when it got hot out, but run OK in cool weather. I did a lot of troubleshooting and came up with the following conclusions.
VEC2 installed, but running stock settings - ran OK all the time
VEC2 installed and running modified timing - ran bad, especially when warm
VEC2 installed and running modified fuel settings - ran bad when warm
VEC2 installed on timing circuit, but bypassed on fuel injector circuit- ran OK with modified timing advance.
VEC2 installed on the fuel injector circuit, but bypassed on the timing circuit- Ran bad with modified timing advance.
I never fully sorted it out and the fixes that came out for the VEC2 which fixed some of the other systems never fixed my problem. Once I installed the SC, I had to sort through a number of problems including this one.
In my case, the root cause of the heavy breakup in the 4000-5000 range when hot seems to have been related to the stock fuel injector connectors. Changing to the MSD type seems to have fixed that problem for me (knock on wood since every time I think I have all the kinks worked out, something new comes up).
My theory is that the VEC2 fuel injector drivers create an injector waveform that is harder for the stock injector connectors to handle and this problem gets aggravated when conditions get hot. What doesn't make sense to me is why the VEC2 running stock settings would run OK unless the driving waveform is fundamentally different somehow under those conditions.
I could be completely out in the weeds on this, but have you tried changing the injector connectors on any of the NA cars that show the problem by chance?
Joseph Dell
Enthusiast
The NA cars haven't had as much of an issue as the SC cars. Most of the cars I've been tuning are SC cars. Done a few NAs and those seem fine and the owners are OK with not revving past 5400 or 5600... the SC cars are another story.
Interesting theory. I wonder if we will ever see some resolution to these issues...
JD
Interesting theory. I wonder if we will ever see some resolution to these issues...
JD
In Atlanta, it is always hot.
Hotlanta, yeah. Jacksonville is pretty uhhh warm too.
Keep in mind, the outside temperature was twenty degrees hotter than before. The heat index has been like 106 degrees here this week. I think it was 108 at the time of the dyno.
Ken
The injector connectors were one of the 20 or so changes I made trying to alleviate the breaking up. JD has tuned my car as well and like he said, on mine, timing seemed to help some but never allowed us to go past 5400 rpms with some sputtering prior to that as well.
I am "now" doing some mechanical changes trying to see if that is the issue as I have troubleshooted every conceivable electrical avenue I can think of, but I think it is a moot point as there are too many other na cars out there having the same issue.
John
Anaconda - keep us posted.
The injector connectors were one of the 20 or so changes I made trying to alleviate the breaking up. JD has tuned my car as well and like he said, on mine, timing seemed to help some but never allowed us to go past 5400 rpms with some sputtering prior to that as well.
I am "now" doing some mechanical changes trying to see if that is the issue as I have troubleshooted every conceivable electrical avenue I can think of, but I think it is a moot point as there are too many other na cars out there having the same issue.
John
Anaconda - keep us posted.
KenH
Enthusiast
John, I'm curious if you are still running the '01 PCM or if you have tried swapping it out for an older one.
