Dyno Results!

At the Memphis 98 gathering of the F-body mailing list, Hypertech supplied us with a chassis dyno. It cost $25 bucks for 3 runs. I have never dynoed before so I have no results before the TPI swap. During this run, my base timing was set at 0*(long story behind this) and the weather was in the high 80's almost 90's. I now have my timing at 8* which gave me the low end I was lacking. There was also a stock 305 TPI Iroc which dynoed and he pulled 175hp at the rear wheels. Mine pulled 225 which is about 50hp at the rear wheels more than stock. Not too impressive considering the mods but remember the above factors. Below is the chart of my 3 runs.

My first run was the best. It is in red. My peak power was around 4800rpms. My peak torque was around 3300rpms. If you add 15% drivetrain loss to this it would equate out to be 259hp and 317ft lb's torque at the flywheel.

New dyno #'s from 11-21-99 at MTI in Houston, TX.

The 1st pull was on motor only and the 2nd & 3rd were on an 80 or so shot of nitrous. I thought the jetting I was using was good for a 100hp but on the dyno I only made like 68 more RWHP(78flywheel) over normally aspirated. However, look at my torque.....is that awesome or what! 448rwtq and if you add 15% for drivetrain losses that comes to 515ft of torque at the flywheel. The spikes on the chart are most likely false knock which retards the timing. So I calculate that my engine is making about 276hp and 355torque on motor and on an 80 shot the engine is making about 352hp and 515torque at the flwheel. Not to bad for the anemic 305!!!

11/20/03 - New Dyno #'s from the latest round of modifications.

This is a before and after result of some topend modifications. This included porting the intake base, runners, and cylinder heads....Also, increasing throttle body to a 58mm and using 1.7 rockers. If you notice you will see valve float at 5700rpms. This was my fault as I had to much preload set. Something else to mention, look at where the peak power is now at. Before it was flat from 5-6k rpms and now it starts to hit a peak around 5600 or so. This may actually change again once I reset my lifter preload and due some more tuning. A/F ratio was around 13.0.

This dyno was taken to see what kind of gains I could get from changing the Spintech muffler to a Hooker Aerochamber. The Red graph shows the gain through the muffler and the blue is through an open cutout. I think the muffler actually helped more as I had more cool down time when the cutout test was done. Still getting valve float though after readjusting the valves. Will reshim the springs next.

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