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-   -   Dyno Plot analysis.. Please... (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/dyno-plot-analysis-please-37491/)

Want2race Dec 7, 2001 11:14 PM

Dyno Plot analysis.. Please...
 
http://216.227.34.77/dynoplot.jpg
Why is it getting choppy above 6k ? ?

thats @ 8psi and yes i am disappointed!

Want2race Dec 7, 2001 11:18 PM

my mods.. The pettit intake and fmic are not installed!

Bacon Dec 7, 2001 11:21 PM

ignition?, plugs &wires?

Want2race Dec 7, 2001 11:23 PM

Plugs are 2k old.. Wires are 1500.. The wires are from crane cams. The 8mm wires. Ignition is stock!

pp13bnos Dec 7, 2001 11:37 PM

I'm by no means an expert, but i would think its either a weak coil, or maybe lack of fuel. I could be and probably am wrong.:rolleyes: Was there a wide ban? CJ

dis1 Dec 7, 2001 11:43 PM

You definitely have a problem. Not only are you breaking up but your power is really low too. Those are practically stock numbers. As others have said check your coils and fuel system and if I were you I wouldn't get frisky with the gas pedal until you fix the problem.

capt. bill1 Dec 8, 2001 12:18 AM

This is the same kind of thing I just saw on my dyno plot. But I did not have the big dips above 6000 just going flat with a slight build of HP. Talking with M2 it's either lack of fuel (which I saw on the wide band as a lean 12.4-12.6 air/fuel ratio), ignition, (doubtful as the leading coil, plugs and wires are new) or the ECU is seeing something it doesn't like and is changing you'r timing. What was you'r air/fuel ratio at 6000+ rpm and full throttle?

skotx Dec 8, 2001 08:55 AM

You're losing about 15 HP at the changeover. For the dyno sheets that I have seen where guys pull 300 or so this drop does not occur, but instead HP and torque both shoot up (obviously). I get that drop at the changeover too.

http://tiger.towson.edu/~csaftn1/dyno.html

http://www.rotarypowered.com/img/pic...comparison.JPG

What boost pattern are you seeing? Does it look like your secondary is coming online ok? I've got a similar problem... lots of mods and a near-stock Dyno pull. I just haven't had the time to troubleshoot boost problems. Why are you only running 8 psi?

spyfish007 Dec 8, 2001 03:37 PM

Remember what I have told you 100 times .... stock ignition sucks! hint hint ...... also be sure the CAS tab is bended out (only like 1mm!!) and you are not double tiggering.

Want2race Dec 8, 2001 06:37 PM


Originally posted by spyfish007
Remember what I have told you 100 times .... stock ignition sucks! hint hint ...... also be sure the CAS tab is bended out (only like 1mm!!) and you are not double tiggering.
Whats the CAS tab ????

dis1 Dec 8, 2001 09:28 PM

Stock ignition sucks??? This is NOT what I have heard countless times from every tuner and big shot I know. Most say leave the stock ignition alone unless you want problems. I know of more than a few racers that are producing huge numbers on stock ignition. It is one of the strong points on this car. This said if it's not working properly then it will still cause problems.

In regards to the dip at change over the first graph that is linked is mine (thanx skotx:)) The other guys that dynoed with me that day that also produced similar results did have the dip. The only conceivable reason I can think of as to why I don't is that I removed the pill in the turbo pre-control line. The first and only other time I dynoed I did have the dip but I also only had a few mods. I think most cars that produce over 300 hp still have the dip. I wish I could say for sure why I don't but since it's a good thing I'm not trying to fix it:)
cvs

RTS3GEN Dec 8, 2001 09:52 PM

Check the wires, and make sure they all match(resistance). Also, consider if the temp was up(Low engine temps can lower power and cause condensation inside the trochoid housings). You may also want to check that the Fuel Pressure is rising properly with the boost. As for the dip in switchover point, if the turbos are still sequential, that's normal. I just dynoed at 347 at 13.4psi and I lose about 17 hp at 4500rpm, then the power shoots up 82hp in 240rpm-WOOOSH! Good luck with the problem. It could also be running too rich. If the computer is expecting higher boosts(maps) the lower maps may just be "really" rich maps for street driving and the more agressive maps at higher boost for max power and safety. Many different scenarios to play out. Good Luck Mark.
ART


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