Xerzex

thanks for helping me post them hx_guy & sackdz!

dynorun001 - I really liked the power I had down low on this run. It seems that I really lost alot of power (but not torque) in my midrange on my later runs.



dynorun007 - this is where we could have stopped but we messed with the tuning after this and it took a while to get it back.



dynorun021 - I actually did 22 runs but the last one we moved the VTEC point back way to far and just put it back to where it was on this run.



[Modified by Xerzex, 4:42 PM 12/18/2001]


[Modified by Xerzex, 9:09 PM 12/18/2001]

Xerzex

come on guys... I hate the little red X

HX_Guy

S&P500ITR

The only thing I don't like is how Rolo doesn't know how to scale the torque axis the same as the WHP axis. It kind of Over exaggerates the torque curve a bit.



[Modified by S&P500ITR, 8:43 AM 12/18/2001]

HX_Guy

What in the world happened to the last few runs? Something os definately not right..way way too choppy. What gear did you dyno in?

TypeR0207

Best x-over for stock cams is around 5,200-5,300, it is hard to tell where yours is because of the erratic lines on the plots.

Xerzex

dyno'd in 4th gear...
it was pissing me off cause the curve was nice and smooth, and then we made so many changes that the ECU was getting pissed i think. It put a huge nasty wave (way worse than what you see) in the air-fuel curve around dyno 15 and we tried to smooth that out. We reset the ECU a few times and that helped. I knew you guys were gunna say that. Do you think it was because we changed so many things? Or maybe that we weren't letting it cool down enough?

What about how jagged the curve gets? is that because i need new spark plugs? or cause it was just getting hot?

Xerzex

i believe its set at 5,800 for the cross over. I don't really want to change it with out being able to see what it does, but i think your right that it might help with that loss of power back there.

The next day when i was looking over the charts i was upset with how wavey the air-fuel curve was and also about the lower end power i lost off my base-run. But after waiting all day to dyno and then going through all that, i was just ready to get the hell outta there.

HX_Guy

For one thing..dyno in 3rd gear! 4th gear wil lcause jagged lines that that..and will put way more load on the engine, as well as get the engine way hotter since a run in 4th takes quite a bit longer then 3rd.

Also, jagged lines sometimes are associated with the engine not getting proper fuel/spark.

Xerzex

thank you... I need these tips for next time. So is the wavey air-fuel really bad? And should I be shooting for 13.5-14 all over? I'm not quite sure about this. I let them do it.

HX_Guy

Shoot for whatever makes more power

No two engines will be exactly the same..so you cant use a general rule like "13.5:1 will be best"
Hell...my N/A B20 likes a 12:1 mixture...which is usually considered very rich for all motor.

xjohnx

ehhhhhh, dynoing in thrid gear will inflate your #'s though b/c of the gear ratio, you're supposed to dyno in the gear closesto a 1:1 ratio, which in the ITR's case, is 4th.

HX_Guy

Blah..inflate my ***. Do a run in 3rd vs 4th and tell me what happens, when I dynoed my car the numbers were within 1 HP and 1 FT-LBS of each other all the way across (GSR tranny)

HX_Guy

Actually, it was even closer then that.

3rd gear HP = 173.6
4th gear HP = 173.0

3rd gear TQ = 151.2
4th gear TQ = 151.0

And...the 3rd gear pull lasted 8.3 seconds while 4th gear took 16 seconds!!
So doing 20 pulls in 4th is like doing 40 pulls in 3rd...which would you say is better on the engine?


[Modified by HX_Guy, 9:11 AM 12/18/2001]

BryanSprinkel

nice #'s man,

Bryan

Xerzex

good point

TypeR0207

Yeah, my 3rd and 4th (in my R) were always within 1-2 hp of each other.

The x-over setting of 5,300 worked best for me, and that was with trying 5 or 6 different points.

The way to do it is to set your c-over at 7000 (max of the V-AFC) do a full pull, change the setting to 3000 (lowest you can go) and do a full pull. You then overlay the two plots and see where the torque/hp lines cross. These are the places you want to try to set it.

For me, this was at 5,600, 5,200, and 4,500 or so. 4,500 is way to low, and caused it to bog, 5,600 is basically stock (5,700 actually). But 5,300 smoothed out the midrange and gave a much better transition to the larger lobes.

For fuel, you basically want to "bell curve" the settings. I started at -5% at 2000, then progressed up to -3% at the x-over, then went back down to -5% at redline. The stock R fuel map is aggressive and rich, especially for stock cams, so you need to lean out the entire band typically. Since you have an air/fuel meter built into the dyno, this will make it easier for you.

Don't sweat the small up and down spikes, it means they probably have the graph on the dyno set to minimal rpm points typically.

HX_Guy

Good into on how to find the X-Over point...Ill need to rememeber that when I dyno my car

TypeR0207

Hehehehehe, another VTEC convert.

We WILL have everyone back from the dark side!!!

Hukd Up

nice numbers! i gotta get me one of those things!