After 2 years of screwing around with the car and many false starts, we have had success with our ITB/ MS1 Megasquirt setup. This past Monday we went to Shannonville with the latest tune in the car and the latest version of base code. It started fine (a first!!!!!) and in the first session ran okay, but I was suffering from a bunch of misfires, surges and stumbles. We took a look at the Maps and the Autotune results. Dave Salt, who built the Megasquirt and wired the car, made the changes and I went out again.

It really cleared up and started to go very well. I was making some serious power and the car ran well to about 8500 but then started to break up. We still had a bad stumble at around 5000 with some severe mid and part throttle surging. I came in and we checked the logs. Dave tweaked the MAP a bit more, leaned it down some in the upper bins, 5,000 rpm to 8,500 , increased the pump shot duration and leaned out the above 9,000 rpm bin. We then added more fuel to the car and I went out again.

WowOwowOwow...........

The car hit a sweet spot in the tuning. It flat out flew. It pulled strong from about 4500 rpm, but as the rpms hit about 7500 rpm it just screamed. I was able to pull with a Z06 Vette on huge Hoosiers, on the straights and out corner him. Coming on to the front straight, I could drift the car like a V8 car. It just wanted to rev to the moon. I ran the car for over 30 minutes without a peep, misfire or cough and it was better on the last lap than the first. I have to say I was tickled to death with the performance. All of the work and struggles are near the end. The car flat out flies and above 7500 rpm it seems to get crisper with a different note and the rate of pull continued to grow until the driver chickened out at about 9200. We just have a few issues to deal with now.

First, the car is going so much quicker that the brakes on the car won't work. I need to finally put on the set of 4 piston calipers and bigger rotors. At the track, I was pushing on the pedal as hard as I could. It wouldn't lock a tire, the pads weren't fading and the pedal wasn't soft. The front pads were wearing so fast that after a total of about 75 minutes on track, I used up a set of front pads (Hawk Blues). The fronts were wearing so fast that after the day, the front wheels were completely black and the dust went down both sides of the car. At least 3 times I went way off line, just because the car wouldn't stop fast enough based on the new speed I was getting. This is a good and bad problem.

Secondly, in a number of the tighter corners I could blow the back tires off the car if I used all the motor that was available. I need stickier or bigger back tires if I race at Shannonville. Maybe I need to go up to a 245x15. Keep in mind this is a bridge port NA 13B.

Finally, I need better shock control. There is so much more in the car now. I need to control it better. Luckily I have a set of new 3 ways in the garage. I just have to make a proper mount for the rears.

Somedays life is very good. I can hardly wait for Mosport on the 20th. Thanks to everybody in this section for their help and especially to Muythaibxr for everything he has done to make this easy enough to allow us to develop and run a completely off the wall setup. 4 Throat ITB's all the
way.

Eric

 

WOW thats so dang cool to hear. after speking with you about your ITB setup at 7 stock and hearing the probs you where getting. i dont know that i would have had the patience to work out all the details and hold on like you did, i know for a fac that N/A ITB are fast and responsive driving DJ55b car seeing how it pull hard through all the RPM rages and his 12A street ported would keep up to my street proted 13BTII FB setup i figured with your setup it should be crazyer!!! and by the sounds sounds of it. it sure is
ya traction and braking will be your next big thing for sure..
9200RPM should sound SWEET