Well...hit the dyno today! I can say that Im very pleased with the results!
I had a total of 15 runs...including a new baseline before I started any tuning.
I then started tuning the exhaust cam... -1,-2,-3. The power at -2 and -3 was teh same..no gaines so I left it at -3 on the exuats cam.
Then I moved to the intake side and tired +1,+2,+3,+4...and kept making power! Crower said +/-4 is max before piston/valve contact..so I left it at +4.
I then went back to the exhaust..and tired -4 and gained yet some more!

Heres the horsepower results!


...and the Torque results!


Not too bad at all huh?
My nly other question is - does the top end seem "restriced" by something since it ended up in the same place as before? Maybe its time for a better header and bigger TB?

 

What are your current modifications?

 

Lets see here...

B20Z - NON-VTEC
Crower 62404 cams
Crower dual valve springs
Crower TI retainers
Skunk2 cam gears
3" diameter cold air intake
99-00 SI DC Sports 4-1 header
Tanabe exhaust
Stock cat
B&M fuel pressure regulator @ 44 psi (w/ vacuum)
Apex S-AFC
96-98 LS ECU

I think thats about it for things that contribute to power.

 

Success is a wonderful thing. The drop in topend power is more than likely due to 1. your heads design, consider a good p&p job in the future
2. Try using a header with a 2.5 inch collector and a 4-1 design, this may cause you to lose midrange but the gains in top end should make it worth it.
3.Get a testpipe made for track use, this will definately help.
4.How is your fuel at the top-end, are you leaning out, are you running too rich?
5. Uh damn you are making good power.

 

Well...at 6000 RPMs the A/F ratio was 13.6:1...at 6500 it was 13.9:1 and at 6900 it was 14.2:1

Should I try adding some more fuel to the top end or does that look good?

 

You will more power if you richen up the top end. Max power is usually between 12 and 13:1 a/f ratio.

Oh and I have been thinking about your bog when you hit 2nd gear...if you don't give it as much throttle when you hit 2nd the tires won't spin so hard that they spin so hard. You'll be able to feel it when they're hooking up and will learn how to feather into the full throttle, maintaining the slight spin that will give you the best traction.

 

14.2 is way too lean poor motor

 

I did get an A/F Ratio read out as well.
I think the top end is a little on the lean side.

Heres all the condition info and A/F Ratios:

Acceleration from 2600 to 6900RPM, interval = 100.00RPM
Absolute barometric pressure : 28.55 in.Hg.
Vapor pressure : 0.29 in.Hg.
Intake air temperature : 101.5 °F
Gear Ratio : 94.69 RPM/MPH
Correction Factor : 1.07 SAE
RPM AIR/FUE
2600 17.4
2700 16.6
2800 15.2
2900 13.7
3000 13.3
3100 13.5
3200 13.7
3300 13.8
3400 13.9
3500 13.9
3600 14.0
3700 14.0
3800 13.9
3900 13.8
4000 13.7
4100 13.6
4200 13.4
4300 13.3
4400 13.2
4500 13.2
4600 13.3
4700 13.5
4800 13.7
4900 13.9
5000 14.0
5100 14.0
5200 13.8
5300 13.6
5400 13.4
5500 13.3
5600 13.3
5700 13.4
5800 13.4
5900 13.5
6000 13.5
6100 13.6
6200 13.7
6300 13.7
6400 13.8
6500 13.9
6600 14.0
6700 14.1
6800 14.2
6900 14.2

Is that too lean in the top end? The guys at the dyno told me that is about right...should I shoot for around 13.5?

 

yeah that is lean for the top, richen it up

 

14.6 is stoich. You will want to run rich a/f ratios to be safe. Try around 13-13.5.

Nice dyno btw.

[Modified by Eeepers, 8:32 PM 8/26/2001]


[Modified by Eeepers, 8:33 PM 8/26/2001]

 

140ft/lbs...........damn............good stuff!!

 

140ft-lbs is very nice. The same as my freinds turbo Civic Si.

 

140ft/lbs on your freinds SI with turbo is pretty cool but 140ft/lbs to the wheels NA is awesome........

 

I agree. That's why I posted it. It think it's crazy how much torque these b20 setups can put out.

 

Its 141..not 140! Haha....just playin

 

lol My bad dude.

 

HX_Guy:
When you advanced the intake cam, did you re-set the ingition timing back? It sounds like you may have been just advancing the ignition timing. +1 degree intake cam = +2 ignition timing.

 

Yes I did adjust the ignition timing every time that I made an adjustment to the intake cam.

 

Good stuff HX!

As sort of a digression, does anyone have an "approximate" idea how much would be gained in power going from too lean to an appropriate A/F ratio.

For example, when I baselined a couple weeks ago, I made ~180 HP and ~120 TQ. TQ was very low for some reason, gotta get a real header and fix cam gear setting. We had accidentally set cam gears to +6/+2 (!!) thinking it was +3/+1... Anyway, I thought I was running too rich, so I leaned it out just before going on dyno. My A/F was (brace yourself) 15-16! I almost crapped in my pants. I immediately richened it after the dyno runs 5-10% across the board with VAFC. Car felt much better. Keep in mind, I was not running around with the really lean A/F, I leaned just before dynong

Anyway, car feels better after richening, so I think I'm down to 13:1 or so now... That should be worth a few ponies/TQ at least, right? I was fairly dissappointed with my runs, but at least I know the header, cam gears, and fuel were all wacked.

For HX, if he richens up ~1 A/F "point," how much would he gain (1-2 HP?)

Thanks,

FB

 

Actually...I gained accorss the board by leaning out the mixture when I first got there. If I could get dan Winpep to work right Ill post the results of 44 PSI vs 48 PSI fuel pressure.

 

interesting...

I've also heard people say "leaner is meaner," but I thought the best power is usually in the ~13:1 A/F ratio range. You were at 14:1 or so, which is still richer than stoic though, so that prob didn't hurt you... I was running a lot leaner than stoich!

I think my big problem beside the header (currently Neuspeed 4-2-1) was that my cam gears are so advanced. My peak TQ is probably very low in the rpm, it stays flat, but I'm not getting a nice boost in upper rpm. I'm gonna try to set gears to +3/+1 or so soon and play with fuel a little. I prob have nearly 10 HP peak, and if I can still have decent midrange that will help my overall perf quite a bit. I'll try to dig my dyno up and scan or take a digi pic of it...

Thanks,

FB

 

Holy shiznitz! +/-4 is max before piston/valve contact?!?! Why do they make 'em go to 10?
Maybe that's why my old F22 never felt the same after my AEM cam timing gear sliped to 10 (can't picture in my head right now if it was plus or minus - whichever direction the timing is gonna go when some slack-*** mechanic doesn't tighten it enough) with bullfrog cams.