Geoffrey

I've tuned an engine that had a carbon fibre copy of a GT3 manifold with the resonance flap but set on top of 6 ITBs. Was interesting but would have wanted to see back-to-back tests with just the ITBs. Whenever the resonance flap switches, there is a several hundred RPM torque drop as the airflow equalizes in the manifold.

dfinnegan

I drive my car year round, summer and winter, rain and snow, short trips and long hauls . . . if you need a test mule I'd be happy, no thrilled, to help you out!

Geoffrey

So, yesterday I went to a test and tune session at Lime Rock Park to test the car to see if everything was good enough to go to the Watkins Glen club race. Because this last week has been thrashing to get the car ready, dynoed, I was not as prepared as I usually am. I did not have enough time to align the car after the deer hit so the car was not that fun to drive. I spent most of the day tracking down an ABS problem which turned out to be a bad RF sensor, likely from when I hit the deer. Unfortunately, I flat spotted my RF tire to the cords on the first session because the car is simply undrivable without ABS. I also spent some time trying to get the alignment to a point where the car felt Ok to drive. At the end of the day, looking at the data, my fastest lap was a 54.6 which is almost 2 seconds better than my previous best of 56.5. Some of that difference comes from a repaved track which is much smoother, but the rest is from the new engine. Below is a trace of the front straight which is 2069ft long as I've defined it in the MoTeC, so it isn't a super long straight. The black lines are the old engine and the colored lines are the new engine. I picked a lap from my previous engine where the corner entry speed was the same. As you can see, with the new engine, the top speed is 5mph quicker AND I lifted 141ft sooner than the lap with the previous engine. Had I not lifted, I might have picked up 1-2mph. The thing that I find interesting on this graph is you can notice the shifts in the speed trace on the old engine where you cannot to the same degree notice it on the new engine. Unfortunately my preparation is not to the degree I'd like, but I'm going to the WGI race tomorrow and we'll see how things go after I align the car at the track.

J richard

Geoffery, are you running the factory 964 abs? the rs unit?

Geoffrey

The 964 RS (Cup) and Street ABS is the same 3 channel non racing unit. I am running a 993 GT2 Evo racing 4 channel unit in my car.

J richard

I was just wondering how the car is undriveable without the abs...it is pretty easy to flatspot a tire with the abs off but it never was that bad...

How was the rest of the race?

Geoffrey

try running a very light, very stiff car.

J richard

I'd, love to......

Scotty964cab

Beautiful!

DarinB

Geoffrey,
This might be a dumb question, but why don't either of the hp/tq curves intersect at 5250? Is this a scaling issue when two different curves are compared?
Darin

NineMeister

Yes, it's because the HP scale and the Torque scale are different. If both read from 0 to 500 the curves would cross at 5250rpm.

DarinB

Thanks Colin. By the way, I saw a set of your heads and one of your rockers in person the other week. Very trick parts, indeed.
Nice job Geoffrey! Keep up the good work, guys.
Darin

NineMeister

Thanks Darin. Parts that perform as well as they look, eh?