About a year ago, i was running 15.1-.2 at the track consistantly. Then i installed my VAFC and got it dynoed. Numbers are in my sig. Anyways do to lack of free time, it was a year before i got a chance to go to the track and test out the new set-up. My first run was a 15.6 @ 88mph. I was completely confused as how the hell i got tha number. Anyways, the second run was felt perfect, 2.1 60' and the car seemed to be pulling hard. Result was 15.4 @ 89mph? IM shifting were i always did 7400 rpms and even checked the VAFC for confirmation. But the car just seems weak. After that run i called it quits and i knew something was wrong. So, today i did an entire engine check up, check the VAFC wiring, checked valve adjustments and other minor tests.

Throught out the past year, i have noticed the car hesitating slightly in the low end, and loss of power in the top end. But i havent had any CELs, only 2 that were ATTS related. (codes 33 35 and 43). I know the VAFC was tunned accordingly and the A/F ratio was good also, but what could be causing the wack times? The car has 85k miles. Some of the things i believe might be the problem are:

1. Ignition issues, Plug wires and dissy cap and rotor? Coil?
2. Fuel/Air: Injectors? Fuel filter?
3. Exaust: Cat?
4. Clutch : slipping?

How can i test the clutch to see if it is still good? I know my release bearing is bad because i can hear it whistleing at idle, but would that affect the car this much?There also has been a noticable "sweet" smell from the exaust, which tells me the fuel mixture might be messed up. All i know is im confused about what the problems is. My car should be running mid 14s by now and i actually went back in times............

 

well track conditions wil vary from day to day.

Best thing to do would be to hit the dyno again and see what's up.

 

maybe try getting a tuneup? (ign parts, plugs wire, cap, rotor)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by satan_srv &raquo;</TD></TR><TR><TD CLASS="quote">well track conditions wil vary from day to day.

Best thing to do would be to hit the dyno again and see what's up.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EGPrelude &raquo;</TD></TR><TR><TD CLASS="quote">maybe try getting a tuneup? (ign parts, plugs wire, cap, rotor)</TD></TR></TABLE>

there are many other variables like these that can mess with your time. Did you only tune for peak power and lose a significant amount in parts of the powerband? If you are making more power than before tuning then it's some other outside variable, either your driving, track conditions, temperature/weather, clutch, tires, etc. Tons of things that affect your times. You should try a few runs with your stock settings and your tuned settings if you can on the same day so that the conditions are relatively the same and you can compare then.

 

i had the low end problem a long time ago as well, and once i had changed my spark plugs because they were allllllllllllll dirty and like dieing out, i felt the diff. a bit. i dont konw if that affects it or not, but once taht was changed, it didn't have this certain lag it would have before the new plugs before 4k's rpm. and just last week i changed my clutch cuz it blew out on me, and now it is very responsive adn a whole lot quicker. no slipping or ne lag, just picks up evne in the low end with a bit of pressure on the gas pedal. try those 2 because they ended up helping my problems and they seem kind of the same as yours.

 

you know you can shift at 8K and your car will be able to handle it fine. Keep those rpms"s up! At the track in fontana, i ran a 15.29 @90

good luck

97 SH

I/H/P...

 

maybe you gained weight. jk ...try messing with the vafc, or maybe you need new tires or new something

 

One thing that could likely be causing poorer performance after dyno tuning your V-AFC is the fact that A/F ratios will be noticably different on the street than on the dyno. On a dyno your car isn't moving and usually has just a fan blowing some air in front on the radiator. When on the street and at speed your car will likely run more lean than at the dyno. So if you leaned out the car on the dyno a lot to improve power you're likely "too" lean on the street, causing loss of potential power.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Inextricabledrvr &raquo;</TD></TR><TR><TD CLASS="quote">you know you can shift at 8K and your car will be able to handle it fine. Keep those rpms"s up! </TD></TR></TABLE>




shift where your power peaks.

 

Well the car gained power throughout the entire power band, and as far as tires they are the same tires ive always used. Track conditions were fine, weather was nice and cool, and extreme low humidity. I know its the car for sure, im gonna have to wait to change out my plugs, igition wires and coil. Also gonna get a new clutch. Im gonna take the car to a different shop and get it dynoed again, just to make sure everything looks good.

 

You're not alone. I had a V-afc installed/dyno tuned on my 4th gen. Ran slow times just like you did. I got home, removed the Vafc, and I swear the car runs so much better.

If you have the time, I suggest you remove the Vafc to see if that makes a difference.

Goodluck

 

If i just set all the settings on the VAFC to 0 and the VTEC crossover to stock, wouldnt that just be like if it was uninstalled? Ive checked the wires over and over to see if i could see something lose or unplugged but nothing. I just dont see how the car can be slower after the VAFC install, unless it was tuned wrong but why would it make the power it did?

 

check your ignition timing when u put a afc in the fuel curves are different u may need to advance ur timing 2 degrees. do u have cam gears???

 

no i dont have camgears...i didnt think the VAFC will affect your timming.

 

This makes no sence to me, how could my car be slower if it is making more power than before? And its not like it gained low end and loss top end, it gained power throught out the entire RPM range.

 

[QUOTE=There also has been a noticable "sweet" smell from the exaust, which tells me the fuel mixture might be messed up. : [/QUOTE]

Sounds like a blown head gasket. That could affect performance. I would check that first.

 

Yeah but wouldnt a blown headgasket affect your compression? The compression came out 185 across the board. Plus the coolant is perfect, although i do burn alot of oil. But dont most 5gs do that anyways?

 

sweet smell might be coolant!

 

What kind of values do you have entered in the VAFC for wide throttle?

Also you say you car was tuned on the dyno, do you know what your A/F ratios were?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sherman &raquo;</TD></TR><TR><TD CLASS="quote">Sounds like a blown head gasket. That could affect performance. I would check that first. </TD></TR></TABLE>

That smell could be from a burnt clutch. Check around the front right wheel, if the smell is strongest around there it's probably the clutch.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike1627 &raquo;</TD></TR><TR><TD CLASS="quote">

That smell could be from a burnt clutch. Check around the front right wheel, if the smell is strongest around there it's probably the clutch.</TD></TR></TABLE>

If its the clutch that would explain teh shittier time, haha only time i went to the track was right after my swap and i ran a 16.8 at 92mph... thats piece of a clutch ahha

 

i had the same problem,i was doing that time 15.4 in the quarter mile i got a v-afc then i started doing 15.6

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Revi-Ra &raquo;</TD></TR><TR><TD CLASS="quote">
How can i test the clutch to see if it is still good? I know my release bearing is bad because i can hear it whistleing at idle, but would that affect the car this much? </TD></TR></TABLE>

get on the highway in fifth at about 35 or 40 and floor it,
see if the rpm's increase w/o the speed increasing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by codeh22a4 &raquo;</TD></TR><TR><TD CLASS="quote">i had the same problem,i was doing that time 15.4 in the quarter mile i got a v-afc then i started doing 15.6</TD></TR></TABLE>

So did you ever figure out the problem?