Low dyno numbers with headers
 

About a year ago when I had my car first dynoed I made 278/312 with a Moroso CAI and Borla catback. I stil had my cat on with the stock Ypipe and manifolds.
I recently put on FLP long tube headers and an Aeromotive AFPR. I dynoed this past weekend and only gained 8hp and 5ft/lbs with them? What gives?:confused:

My a/f showed 12.8 down low, then at peak hp it was at 13.1.
I do not show any unusualy knock under WOT and my graph is mostly smooth.

Any ideas? Please help

Im not sure but your car was really strong with just CAI and Catback. BTW 287rwhp isnt bad for headers and CAI. Not eveyone dynos 300rwhp.

Hey Joe heard about your troubles from Matt, the guy with the loud ass black LS1 T/A with duals. Did you take a run at the track sunday? Anyway, as long as you dont have any leaks or wires touching headers, which I'm sure you check already, I would suggest a chip since the car is SD and cant really compensate for the extra air that the engine is probably using. Did you try increasing fuel pressure when you where on the dyno? Just some ideas though I do know that the 3rdgen guys usually recommend a chip, after those kind of mods, for best power. Did you try asking this question over at the SD forum? They might have some ideas if you dont get anything from here.

Jeremy- yes I ran Matt at the track. He had Major traction probs. My best run of the day was a 13.4@104 and it has a little more in it. I think I can hit a 13.2@ 105 with less gas in the tank and a cooler day.

I will have to try the SD forum. I did however tune the AFPR with the wideband. I dont really see how a chip would help me since the longblock is stock, but I will have to see if Rooster has any ideas

Just curious, but how much did it gain in the midrange? Peak numbers aren't everything, and if your car picked up some good midrange, it will still be a good bit faster.

How were conditions compared to last time, and were both pulls at the same facility (I assume MC?)?

-Chris

Numbers should be comparable b/c thye both should be SAE corrected.

Anyways, i have almost identicle mods to you and traps are almost the same which is a good number to compare power.

Some of us are slower and others faster. We just happened to get the short end of the stick.

The idea for the chip is so that the ECU has a better idea of the exact amount of air coming in the engine. From what you said your a/f was it sounds like you were slightly lean and might be able to pick up some numbers with a little fatting up top.

Heres the SD forum:
http://pub26.ezboard.com/b93fbodymessageboard

You wont gain any power with the AFPR...and you may have lost power from a year ago....unlikely but possible..

his car is a 93... therefore it should respond to the AFPR when ours wont.

Joe i think you could benefit from a custom chip seriously!

Jeremy- the AFPR will make up for the extra air coming in.
And FYI that is the old SD board, this is the new one http://sdf.mogmhp.com/

Chris- I went to that new dyno in south overland park. www.ragingmotorsports.com
But they are both DynoJets.

Ah yes...should take a look at the sig next time.:o

Is there anymore information I might be able to give you guys to help me figure out why my car is such a dyno turd?
BTW a buddy of mine went from this dyno to another dyno the following day and this dyno was 2hp off the other one. So I figure its not the dyno that is giving me the low numbers. (for being wrong anyway)

Re: Low dyno numbers with headers
 

Im thinking you should gotten a little more power from that set up. i dynoed 287/316 on a dynojet with shorty mac headers, kn, cutout, not cat, hypertech chip, and 3.73's on an automatic 93Z28 with 115,000 miles. it was a dyno jet.

how many passes did you do? i did 3 pases and they were NOT smooth at all, they when up and down the whole way and they were different.
maybe you have some bent valves? springs?? hows does the chart look? what did you do to the fuel pressure? i need to get a fuel pressure regulator.

I dont really have anything to say to ya joe, except that sucks. I just figured I can chime in because I can. Let me know if you need any help doing anything, but I am sure you and griff will have that covered. Just look at it this way, at least you have a moter in your car.:D