VEC2 results on Stage 2 heads

Jack B

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The car is a 97 with Balengers and T&Ds. Although the car is set for nitrous, the following are for NA operation only. This car has over 100 dyno pulls, therefore, all hp increases are well documented.

The car pulled a consistent 445 hp with headers, no cats and the T&D's. The car also had a max pull of 452 prior to installing the heads. This is SAE corrected, therefore, conservative. I could play with the smoothing and go to STD protocol and get 465 from the same (452) pull.

I did ten pulls in a little over two hours on Thursday. The temperature was 85 and the humidity was 95%. In affect the hp was a little off from the heat soaking and bad conditions. I did an initial pull with the car cooled off and the hp was 457. That was disappointing to say the least after installing very aggressive heads. We did a second pull just to verify the first pull, the same numbers came up. To set the stage these pulls were with OEM timing and fuel mapping and no VEC2.

The next eight pulls were mostly adding fuel and advance via the VEC2. The peak hp numbers were coming at 5600 rpm, whereas, prior to the heads they came at 5200. To make a long story short, the last pull was a strong 500 hp and 522 ft-lbs. The VEC2 extracted an extra 40-50 from my set-up. Obviously the BTR heads were the foundation of the increase, but, without the VEC2 I couldn't use them.

Here is the interesting point, we ended up with a perfectly flat 13:1 A/F, however, at peak torque, the injectors were flat open and couldn't deliver anymore fuel. In other others, on my car the injector have a limitation of 500 rwhp, 575 flywheel hp. Another issue was the erratic hp curve prior to using the VEC2, it ended up very smooth after adding fuel. In summary, at some point around 450 hp the viper fuel and timing map severely limits any further NA hp increases. The combination of headers, rockers, exhausts and heads totally leaned out the A/F, without any way to add fuel you cannot get out all the hp.

In the next couple of weeks I will be adding 50 lb injectors, my feeling is that with a cold engine and sufficient fuel this combo will pull 525 hp. That is almost 75 rwhp from heads and a VEC2.
 
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vegasviper

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Great info. I would like to see results on a bone stock GTS.

Would HP be more than Vec1
 

jp

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Jack, with 75psi fuelpressure and Gen2 injectors did we find the max power to be about 550 rwhp at 100% duty cycle. Next week will we ad a VEC2 and larger injectors. Do you have any numbers for your ignition curve, I need something to start with.
 
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Jack B

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VegasViper:
There is no comparison between VEC1 and VEC2, they are totally different. The VEC1 is limited by the inability to independently control a/f and timing. WOT gains are very minimal.


JP:
I am putting the fuel and timing numbers into a spreadsheet and will post later this week. I am concerned about the fuel numbers since the injectors were basically wide open. I was also thinking about increasing the fuel pressure, however, I believe the larger injectors are a better route. I may also install the booster circuit. I am already running a 255 LPH pump.
 
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