So the STLPC club hit the dyno today... (a summary later on)...

Anyhow... back in March 2001, with a

- AEM CAI
- AEM Pulleys
- DC Sport CC Header
- Apex'i Dunk catback exhaust

I hit 172.3 whpr with 142 ft-lb torque. (SAE corrected)

Fast forward to today...
I now have

- Type-S Intake with K & N drop in filter
- S2K TB Port & Polished to 69mm (tapered to 64mm)
- Port matched upper Intake Manifold
- Hondata Style Insulator gasket
- DC Sports CC Header
- AEM Pulleys
- Apex'i WS catback exhaust
- Apex'i VAFC
- OEM lighten flywheel
- ACT HD Clutch
- JDM OEM LSD

And I peaked out after leaning the fuel at 162.2 whpr and 130.3 ft-lb torque.(SAE corrected)

What gives? I checked the compression afterwards and I got 230-230-230-240. My engine has over 200K on it... Any ideas?

Here is my dyno sheet for the 2nd run...


Here are all 4 runs... (not, the first run topped off at 6500 rpm since the car wasn't warm... )



Modified by Keith at 7:42 PM 11/21/2004


Modified by Keith at 7:42 PM 11/21/2004


Modified by Keith at 7:42 PM 11/21/2004

 

what did your tuner have to say,
or did you have one when you dynoed

 

have you replaced wear items, plugs, wires, dist. cap, rotor, etc.? also one thing you may want to check is your timing.

another thing to consider is the type of dyno these runs were made on. Different dynos may read higher or lower, etc. there are alot of factors that could of been off to contribute to your low numbers, if it isn't your car. Have you noticed a recent decrease in power?

 

Maybe the Apexi WS is restricting some airflow that you have seemed to have gained with the mods. The Dunk was alright before with some free flowing air. Was the V-afc at the stock settings.

 

I tuned it myself... based on the a/f ratio.

Plugs, wires, dist, cap, rotor were all changed this summer.

A fellow STLPC member with a base Lude + AEM CAI and VAFC dynoed at 168.8 whpr and 136 ft-lb.

My friend Grant suggested that the OEM LSD has to do with the power loss.

Keith

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Keith &raquo;</TD></TR><TR><TD CLASS="quote">.

A fellow STLPC member with a base Lude + AEM CAI and VAFC dynoed at 168.8 whpr and 136 ft-lb.

</TD></TR></TABLE>

how about the other cars there, were their numbers low? Also what gen prelude was this mentioned above?

 

also the most important question, what does your butt dyno say? If the car is feeling sluggish then you obviously have a problem. if the numbers are just low, i would suspect the dyno itself.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Keith &raquo;</TD></TR><TR><TD CLASS="quote">I tuned it myself... based on the a/f ratio.

Plugs, wires, dist, cap, rotor were all changed this summer.

A fellow STLPC member with a base Lude + AEM CAI and VAFC dynoed at 168.8 whpr and 136 ft-lb.

My friend Grant suggested that the OEM LSD has to do with the power loss.

Keith</TD></TR></TABLE>

Can you post the graph of your 'tuned' a/f ratio? Because the one I see on dynorun #2 is not even close to optimal..from about 4700 on you are running brutally rich and it just gets worse after that.

Other things costing you power:

- Type-S intake from AEM CAI
- WS exhaust from the Dunk

But seriously if that is indeed your a/f ratio that is your major problem


-

 

Another STLPC member who dynoed his Type-SH with AEM CAI, DC SS Header, AEM Pulleys, Apex'i VAFC and Mugen catback exhaust got 170.9 whpr and 135.1 ft-lb.

IDK about the butt dyno... I think the last time noticed a different in the power curve was with the switch from AEM CAI to Type-S intake. But still I feel like I should have got at least in the mid 170 range.... an intake would have have account for that much whpr.

 

Joel,

I gave up after the 4th run since I didn't think it was going to make that much of a diff...

My last run when like this with air fuel (sorry, no chart)

3000 - 13.5
3500 - 13.2
4000 - 13.3
4500 - 13.3
5000 - 13.5
5500 - 13.8
6000 - 13.6
6500 - 12.9
7000 - 12.8
7500 - 12.5

 

type-s intake does not make more top end power than an AEM CAI...it just doesn't.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Keith &raquo;</TD></TR><TR><TD CLASS="quote">Joel,

I gave up after the 4th run since I didn't think it was going to make that much of a diff...

My last run when like this with air fuel (sorry, no chart)

3000 - 13.5
3500 - 13.2
4000 - 13.3
4500 - 13.3
5000 - 13.5
5500 - 13.8
6000 - 13.6
6500 - 12.9
7000 - 12.8
7500 - 12.5</TD></TR></TABLE>

there is your problem. from 6500-7500 your airfiuel ratio is BELOW 13!!! that is nuts man, it should be more like 13.5 all the way. That's a huge loss on power there. And you are obviously disappointed with the peak numbers, so there it is right there.

12.5

 

Look how your torque curve takes a major **** right at 6500rpms and drops like a rock...too much fuel. It's causing your peak power to be at like 6800 too, that's pretty poor.

Were you adding fuel or something? the a/f ratio seems so low

 

I don't think it's going to make a HUGE diff... no?

Look at a STLPC's member's chart after we did some corrections...

His peak whpr came at 7000 with a afr at 12.9.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Keith &raquo;</TD></TR><TR><TD CLASS="quote">I don't think it's going to make a HUGE diff... no?

Look at a STLPC's member's chart after we did some corrections...

His peak whpr came at 7000 with a afr at 12.9.</TD></TR></TABLE>

12.9 is a BRUTAL air fuel ratio. That guy is also throwing away power.

And yes it makes a huge difference.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Keith &raquo;</TD></TR><TR><TD CLASS="quote"> My friend Grant suggested that the OEM LSD has to do with the power loss...Keith</TD></TR></TABLE>

No, the LSD has nothing to do with power loss, only power transmission. It's probably fuel related like the others have said.

 

DUDE ya got 200,000 miles on the car!! HP will drop off. There is prolly build up on some of the parts... Injectors not flowing just right...
THe only way to get that power "back" is prolly a rebuild.
Good luck! Good to see another Honda Kicking out some good #'s with that kind of age!

 

200K km... or 120K miles... if the injectors weren't flowing right, I wouldn't have been able to run so rich. As well, my compression is spot on.

 

Keith and I talked just a little while ago, and it seems that we were losing power (or at least I was from baseline to best run), down low when it was leaner. I did gain quite a bit way high (7000rpms) leaning it more. Hmm...lots more tuning to do.

 

12.5 is turbo car territory. Get back to the dyno.

 

That top end looks horrible. At the end of my dyno runs my torque is no lower than it was when it all started (always greater than 115 lb/ft from 2000 rpm to redline) Either your ignition system is dying, your fuel system is clogged, or just something is off.

 

I doubt that... it has to go through more gears (helical) before reaching the gears... there is some power lost involved.

Keith

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Keith &raquo;</TD></TR><TR><TD CLASS="quote">I doubt that... it has to go through more gears (helical) before reaching the gears... there is some power lost involved.
</TD></TR></TABLE>

Actually it doesn't "go through more gears" as the only time the internals of the diff even move are when the two drive wheels are rotating at different speeds. Under straight-line operation a tranny w/ LSD and one w/o should have almost identical drivetrain losses. The only time you might see a slight difference is while turning or while experiencing wheelspin as the LSD is attempting to equalize power to both wheels.

I think you should listen to the other posts and revisit your a/f tuning...if you look closely at all the charts you posted the torque curves closely follow the a/f's. Observe that the most power is made when in the 13.5-13.7 range...I'd bet that if you pulled fuel that you'd see a decent bump in power up top.

--Ian

 

Who said I wasn't listening? I plan to revist the dyno and lean out the top end (6500-7500rpm). But look at this.. anything below 6500, the power did not increase from going more lean.

First run...
RPM HPR Torque AFR
3500 80.7 121.0 13.2
4000 95.3 125.1 13.5
4500 105.7 123.4 13.2
5000 120.1 126.1 12.9
5500 135.5 129.4 12.9
6000 149.0 130.5 13.1
6500 159.5 128.9 12.8
7000 158.6 119.0 12.3
7500 145.4 101.8 11.6

Last run with corrections...
RPM HPR Torque AFR
3500 78.3 117.5 13.2
4000 92.8 121.9 13.3
4500 105.6 123.2 13.3
5000 119.2 125.2 13.5
5500 136.5 130.3 13.8
6000 148.6 130.1 13.6
6500 159.0 128.5 12.9
7000 160.5 120.4 12.8
7500 150.8 105.6 12.5

Differences...
RPM HPR Torque AFR
3500 -2.4 -3.5 0.0
4000 -2.5 -3.2 -0.2
4500 -0.1 -0.2 0.1
5000 -0.9 -0.9 0.6
5500 1.0 0.9 0.9
6000 -0.4 -0.4 0.5
6500 -0.5 -0.4 0.1
7000 1.9 1.4 0.5
7500 5.4 3.8 0.9

 

i agree with the rest. you wanna be about 13.5 all the way to the top.