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Precious gets tuned

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I too hate long post and this one is that so beware.


Well my dyno day has come and gone and I have mixed results. I am actually a bit disappointed and it started right from the base run. I'll start by saying this is a new experience for me and I might be misunderstanding somethings and if I am please feel free to correct. Maybe it will make me feel better.


One of the reasons for a tune was I thought I had a detonation problem. The problem would occur at tip in from a cruise around 2000-2500 RPM and between gears under a hard shift. The tuner was able to duplicate the problem on the dyno during the base run. Then he opened up the car for the base run and was so surprised by the results he did an second base run to back it up. If you look at the chart below you can see the base run produced 351 RWHP and a 311 Torque number. Using 15% adjustment that is 413 at the flywheel, only 399 if you use 12%. I was very disappointed.


SAI, where is my advertised 462 HP?


That isn't what surprised the tuner. What surprised the tuner was that the A/F mixture didn't even show up on the graph it was well below 10. Me being a dummy, I said that maybe the intent was to keep the engine real rich and safe. The tuner said but it could be too rich and cause another set of problems. He did his thing on the laptop and Preadator handheld and ran it again.


This time the results gave me a smile and was the only part of the session where hope was on the rise. After another two passes, the numbers came up to 390 RWHP. I thought wow cool, a 40HP jump for a half hour of tinkering with the computer. The tuner showed me the A/F and it barely broke above 10 around 4000 RPM. I was thinking cool maybe there is more left in, maybe I can back up other owners numbers. of 485-505 HP. Back to the laptop and back to the dyno.


The tuner ran the car up and came up with final results (perhaps). As noted below, a max RWHP of 403.6 HP and a Max Torque of 370.1. If I do the math right using 15% loss that is 474.8 HP and a torque of 435.4 (458.6 & 420.6 if you want to use 12%). I was still disappointed thinking about those other owners numbers. However, I came home, took a nap and looked at those numbers again and perhaps they are fine. I told the tuner my number one priority was a healthy and safe engine. If we could improve, on the 462 in my mind, then great. Looking at it now I think we did. Maybe?


I do consider that there are several factors that effect overall numbers (octance, temperature, humidity, and even the dyno). It was probably around 75-80 in the shop. I have no idea the humidity. The gas is the wonderful 91 octane CA summer blend. Below is the graph. Those that know, anything you see? My feelings aren't easily hurt. That isn't the end of the story, look for more below the graph.




After the tuner was done with final run he poked around the engine some more looking at the set up and noted the intercooler was really hot in his opinion. We, looked at the reservoir levels for both the radiator and the intercooler and thought they were low, not dangerously low but not what they should have been. He topped them off and then noted that the coolant for the intercooler wasn't circulating. He trouble shot and discovered the fuse for the intercoolers circuit pump was missing. Now I was disappointed in SAI, concerned for my car (1000 miles without an operating intercooler) but relieved he saw that, otherwise dummy me would have just thought the intercooler was always meant to be that hot.


He located and installed a fuse. The intercooler began circulating and cooled off. He made one more pull on the dyno after that. The results showed about a 11.5 A/F ratio but the numbers fell about 5 HP.


Finally, I left the shop tired, I work nights and had only a few hours sleep for my morning appointment, and disappointed in the final numbers. However, just a small turn onto the street and straight line to the first stop light showed me the positive. A new found 50 HP and no detonating were much appreciated and made a big difference. All in all after a few hours rest and contemplation, I think I am satisfied with the results........at least for a little while.

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LMAO, thanks nutty boy.....the name comes from my wife who decided within 15 minutes of being handed the keys to the car at SAI that the car was my precious, ala Lord of the Rings. When I told the story on Shelbyautos, the members started refering to my car as Precious.


Grabber, yes I am going to SAI. I am already working on some issues with them to include that the intercooler scorches my hood blanket and leaves residue. It was the first car they had heard of that problem and now maybe we know why.

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Well, I took Precious to a very experienced performance shop in South Orange County. I asked them to take a look at the installation and make sure everything was correct. They found nothing else wrong with the SAI installation. They looked it over and recommended changing to a colder range spark plug then the stock ones and putting it on the dyno to take a look. Plugs were changed and made a run. The tuner found the car was fine but a bit conservative. He tweaked the timing a thousandth, leaned the engine a tad, changed the rev limiter and removed the 145 MPH speed limiter. Back on the dyno. Drinking down the California 91 octane summer blend Precious produced 441 RWHP and 399 pounds of torque. It was 93 degrees and a max boost of 9 pounds.



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