Finally dyno tuned my motor today. I'm very pleased. Picked the car up A LOT driving it home.

Quick breakdown:
1973 plymouth duster
forged 5.7, 11.6:1 compression, 03-08 GTP Extreme heads, Hilborn intake, custom shorty headers welded by me (around P/S box), 218/224 on 113.5+2 (xfi exhaust lobes- very mild)
TKO600 standard tranny, ford 9" floater rear, 3.60:1 gear with locker, heavy wheels all around.
Megasquirt 3x engine management tuned by me.
straight 30 weight conventional oil for all pulls.

We started the day in the 370's (rwhp) using a modified stock 5.7 timing curve. We kept adding timing until it dropped power, and backed it down 2* to the previous higher point. Ended up with more timing in the higher rpm range than most. I wanted more peak torque, but I am very pleased with where we ended up. ~300 rwtq from 3,000-7,000 will do just perfect for road racing.

added: Mustang Dyno

All on 93 octane unleaded. No knock sensors. Craig at Bumbera's was listening, and I was doing the same through a microphone clipped to the knock sensor point on the block. Neither of us heard any knock the entire day, including when we tried 2* on top of our final curve just because (dropped power across the board, did not knock though).

Honestly, I did not expect the motor to pull this high with this little cam. I expected the hp peak to be below 6000 rpm, as that's where this cam peaked on 5.7's & 6.1's with a normal intake. Guess not with my build.

A couple back to back runs at the end:


And my timing curve. DON'T YOU DARE use this curve and expect it to work - way too much timing for most - you'll blow your motor

Point worth noting: I marked TDC on my balancer and put my timing light on the motor to verify what the MS3x is commanding is what the motor is seeing. I found 1-2* of retard (light vs commanded) at 15-18*. That is within the range of measurement error, though it's very possible that the engine sees timing at 10% less than commanded. All I want you to take away from this curve is adding timing after peak torque was VERY beneficial for my motor. Further, this is the actual MBT for my motor on 93 octane, and MBT was reached before knock. Every motor is different so what worked on mine may not work on yours. Disclaimer: I'm not liable if you blow your motor trying to run 30*+.

Awesome!

Car & Motor:

Nice build, what do you have for suspension and what size wheels do you have.

If I didn't know any better, I would say your about half serious about this road racing deal Nice results

Very cool car!

damn, that is cool

Good looking car and good numbers from the 5.7

Great looking machine!

Nice, very nice!

Thanks fellas!

The suspension is set up for road racing. 1.04 TB's, road race leaf springs, front and rear sway bars, RCD shocks. Wheels are 18x9.5, with 265/40/18's.

I'll have it on the drag strip next weekend, the Texas mile a week after that, and the road course a month after that.

Why would a different intake make such a big difference in how much timing your particular engine could take? Most guys seem to make best power in the 20-24 degree range. Isn't it ususally the chamber design that has the bigger effect on timing?