This is the dyno sheet from my car. Something is definitely going on towards 5500RPM+. Can anyone tell me definitively what it is?

http://community.webshots.com/photo/...62051148VOhVtD

 

Thats a real clear pic of a dyno.. I can tell you what is wrong for sure.. Look in the upper left hand corner of the dyno. Where it says the location.. That is the answer. Just kidding.. It looks like you may have some sort of float.. What springs are you running and with what cam?

 

Hahaha, thanks for the help <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> . Stock Cam and Springs, with only 14K miles on the motor. Definitely float?

 

Thats what it looks like to me. Hopefully the real peeps will chime in..

 

Im no expert, but I dont think that is float. As far as I know with float the power will not drastically drop off like that, it should just get jagged and stop climing (drop a little)?? Anyone else?

 

Float???? With stock cam and springs? I don't think so. I'm no expert, but I have never heard of valve float on a stock motor.
<img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

niphilli </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> As far as I know with float the power will not drastically drop off like that </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">With stock internals. powers is going to drop off @ 5500RPM anyway.

Durs96TA, Is this a LS1 motor?

 

Its a 96 trans-am....hence his screen name. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

Hmmmm Were all of your dyno pulls like this?

Were you watching timing, and air/fuel ratios? Any spikes in those?

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by MEAN LT1:
<strong> Its a 96 trans-am....hence his screen name. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">No, it's a 1998 Camaro SS. The 1996 TA must have been his old car.

 

--------------------------------------------------------------------------------
Originally posted by MEAN LT1:
Its a 96 trans-am....hence his screen name.
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No, it's a 1998 Camaro SS. The 1996 TA must have been his old car.

Thats why I ask instead of assume <img border="0" alt="[jester]" title="" src="graemlins/gr_jest.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Bad02WS6:
<strong> Float???? With stock cam and springs? I don't think so. I'm no expert, but I have never heard of valve float on a stock motor.
<img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have.

 

Could be severe knock retard. Did you notice any high RPM pinging? Any particles come shooting out your exhaust?

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by HITMANSS:
<strong> Could be severe knock retard. Did you notice any high RPM pinging? Any particles come shooting out your exhaust? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I think an ford Emblem came shooting out when they let off the gas <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />

 

Is that what that was Pete?? I knew I heard something from my exhaust. LOL.

Also, the '96 TA was my old car, just haven't gotten around to changing up my screen name. The car is a '98 SS with 14K miles on it. Stock cam, stock internals.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Bad02WS6:
<strong> Hmmmm Were all of your dyno pulls like this?

Were you watching timing, and air/fuel ratios? Any spikes in those? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I was watching my pulls yes, but I really didn't notice anything weird. I have only been to the dyno one other time so I really wouldn't know what to look for. This was the only dyno sheet that I recieved, it was a free day so they didn't do all the hookups.

 

It could be valve float but it could be somthing else as well. Without being there to hear and monitor the car there is no way to tell. The only thing for sure is that you have a problem somewhere <img border="0" title="" alt="[Frown]" src="gr_sad.gif" /> .

<small>[ January 29, 2003, 09:23 AM: Message edited by: Paul @ Thunder ]</small>

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Paul @ Thunder:
<strong> It could be valve float but it could be somthing else as well. Without being there to hear and monitor the car there is no way to tell. The only thing for sure is that you have a problem somewhere <img border="0" title="" alt="[Frown]" src="gr_sad.gif" /> . </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yeah problems suck <img border="0" title="" alt="[Frown]" src="gr_sad.gif" /> . However, Dave from Cartek was in the car and said it sounded/felt like it was valve float, so I'm gonna go with him on this one. Looks like its new valve springs for me.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Bad02WS6:
<strong> Float???? With stock cam and springs? I don't think so. I'm no expert, but I have never heard of valve float on a stock motor.
<img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

niphilli </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> As far as I know with float the power will not drastically drop off like that </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">With stock internals. powers is going to drop off @ 5500RPM anyway.

Durs96TA, Is this a LS1 motor? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">My stock internal '99 peaks at 5,700 and gradually tapers (10HP loss) to 6,200. There is a 50 HP dip in that curve. Looks almost like the car shut off and started again. Make sure and check A/F and KR. My guess is that for some reason you got a whole bunch of KR around 5400 for some reason and the computer pulled timing......A bunch. Could also be an electrical problem with the dyno, on that drop the line should not have dissappeared. Maybe the tires were slipping. Anyway I would trust CARTEKs opinion, they were there in person and have a whole lotta experience.

Good luck <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

<small>[ January 29, 2003, 10:42 AM: Message edited by: niphilli ]</small>

 

Thanks for the advice. I'm gonna have my car ATAPed to check out whats going on. I'll keep you all posted.

Dave

 

I would guess ignition problem. Check plugs, wires, and coil packs. Guy I know had something that looked like that and ended up being a coil pack.

If you've put in bad gas or messed with your PCM at all, then I may check for KR as well.