RickBetterley

Now that I have the dyno pull results from VIR, its a good time to think more precisely about where to set my shift lights on the AIM dash.
Dyno pull chart is attached; not sure I have this graphics insert function figured out yet. I realize that different corners may call for different shift points, but that aside, where should I set my lights (which are green, green, yellow, red, red - that is, 5 different points)?
Thanks in advance; just think, I have all winter to ponder this.

LVDell

Rick, do you have the Strada, Pista, or Pro?

I have the Pista and I have mine set 200rpm below redline for the last red and then another -200rpm for every light all the way.

If you have the pro you can set shift lights for EVERY gear which is very nice since the time to redline is not a linear relationship across gears.

If I am not mistaken there are 5 shift lights. (2 green, a yellow, and 2 red). I'd have to run out to the car to verify.

Circuit Motorsports

Depends on how fast it can go through the gears and a personal preference.

My first light comes on at 5K, below 5K the engine has a huge dropoff in power and usability so I know if I am out of the power. Especially nice to have at new tracks.

From there my top RPM light is right at my 'redline' the engine can go a bit higher but it won't last nearly as long. Once you hit top RPM in an AIM dash all the lights start flashing too which is nice.

After that I have the other 3 at 200 RPM intervals from redline. 64, 66, and 6800.

If the engine revved faster I would spread the intervals out a bit more. I woudn't change them between gears. It's nice to have a consistent reference point of RPM vs. number of lights you see in your periphearl.

EDIT: Misread Dell's post

LVDell

Joe, I just re-read my post as well and see how it could be a tad vague. If you read that I was saying that with the Pro you could configure the set of 5 lights for for 1st gear, and then again for 2nd gear (at different rpm points and intervals if you choose), and 3rd etc etc etc, then you read correctly.

By the way, are you going to be at the track this coming week? If not I'll swing out to your place this Monday before class.

Circuit Motorsports

Saw it and edited my post as well.

I dunno. What's going on this week? If I run the formula car I need to rebuild a caliper, or soil my self in every braking zone.

LVDell

Carolinas PCA 3-day event. Solo on Fri and 2-day DE on Sat/Sun. I'll be up there also on Thursday for a private test day with my race shop.

dhuberty

I have a Race Technology system and work on a Motec system on a Cup Car and from experience I would suggest 300 RPM off the redline. You have to be really quick with reaction time and extremely consistent to stay off the rev limiter with 200 RPM set off the rev limiter. Besides the power band is usually slightly below the redline. If you review your data you will see that you actually hit the limiter for a brief second, but not enough that it is audible. If you look at your RPM traces and zoom in on them you will see they go flat briefly at times with the last light set at 200 RPM off the redline or limiter.

If you can adjust your system by gear this is the best way to do it as not all gears you want to shift at the redline. Also depending on the gear you may want the lights to come on earlier for second gear versus 4th gear. Same for the light ramp difference for different gears.

LVDell

There is not enough HP in the RSA to justify a 300rpm interval but probably in the GT3. Besides, with 5 shift lights, my up-shift timing at WOT is based on the first shift light illuminating and I am actually not getting to the last light before the shift. FYI.....my engineer selected the rpm intervals and if anything they might need to be dropped to 150-175 intervals.

bobt993

Rick,

A little off-subject, but you dyno curve does not look that healthy for a 993. Have you checked the resonance flap solenoid for operation?

Bull

That dyno chart looks very similar to a chart for my 993 a few years ago where we found a vacuum leak had turned it into a non-Varioram car.

997gt3north

- If any of this comes across as "uninformed" please just disreguard this post
- I have 2 turbo cars that have after market custom tunes
- I also have a 997gt3 and have seen both the stock tune (a/f) and have also tried aftermarket tunes (a/f)

- 1st stupid question, is your 993 a turbo or na? (i'm guessing it is na by the dyno chart)
- 2nd question, from a racing class perspective, do you have to run the stock a/f tune?
- i ask these above questions, based on my opening statement about having first hand knowledge about the "best" a/f ratios on my 3 cars that have been tuned to know that in both cases (turbo or na) your a/f curve does not appear to be optimal and you very likely with a better tune could extract more power
- if you have a turbo car, you should likely be richer earlier on and then leaner later (richer early on will get you much better timing, also better when you are at peak torque and then after peak torque you can lean it out for more hp and better fuel economy)
- if your car is na, then your fuel curve is very wierd (from my experience) and you should be able to extract lots more hp in the upper end by leaning it out quite a bit (13.3 range is usually where you want to be)

- if you have no choice and this is stock software, then maybe you want to see if other cars indeed have this curve because you are definitely down on "potential" power


- here is the dyno for a 997gt3 (look carefully and you can see the a/f curves)



This isn't a great chart but it will give you an idea about extracting max hp from a turbo car
- want to get it richer early on to keep good timing at peak torque and then lean it out a bit
- we were trying differnent fueling curves (2 black lines at the bottom) but keeping it richer a peak tq proved the best



paul

Bull

Which is what causes the questions about the air intake on the '95. The computer is expecting more air, but not getting it.

997gt3north

- yup, it was this comment that made me look at the dyno chart and not concentrate on all the shift light answers
- do you have a dyno chart of what a 993 "should" look like?
- i just did a search on the internet and from a few different sites, it does appear that above 5500rpms the car does seem to be 10whp short on power

thanks

paul

Bull

I may have a v-ram '97 around, but not a '95....but I will look around.

bobt993

A 95 does not have varioram, so the bump at higher rpms is not as big. Rick, do you have a LWF, headers, exhaust, any chip? I would expect the dyno should run at least 245 whp. I had a similar problem at the NASA race at VIR and my 96 pulled 228 whp instead of 260. Another club member has a 95 and his resonance flap solenoid was no longer working dropping about the hp you are getting. Check the air temp sensor, clean the mas air-flow sensor, check cyl 3 temp sensor and knock sensors. Also, fuel filter and injectors.