Lost 40+ RWHP any ideas?

[1 Bad Snake]

I recently installed new 1.7 Rollers on my Gen 1 and I went back to the dyno I used in May, and I lost 42 RWHP and 51 RWTQ.
Does anyone have any ideas as to why this has occurred. It was cooler this time than last by 20 degrees. I also had them hook up an exhaust sensor and I am running lean for some reason. Please post your thoughts as the car is at the shop being looked at, and I would like to have some ideas of what they should be looking for.

 

[JonB]

The very first thing I would checkis that the throttle cables are still adjusted correctly.

While tech-inspecting G-1 Vipers I ALWAYS get the owner to show me his TBs are opening fully. Your 1.7RR install may have un-adjusted them.

Simple to check...and to fix

p.s. Install any thick floormats lately??

 

[Gerald]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by JonB - PartsRack:
The very first thing I would checkis that the throttle cables are still adjusted correctly.

While tech-inspecting G-1 Vipers I ALWAYS get the owner to show me his TBs are opening fully. Your 1.7RR install may have un-adjusted them.

Simple to check...and to fix

p.s. Install any thick floormats lately??

<HR></BLOCKQUOTE>
Stoopid question here. But what does floor mats have to do with this, other than perhaps the gas pedal not being fully depressed?

You would be suprised at how much HP you can loose if an engine is heat soaked. In my S/C car, I swear if I dynoed it in cold weather (below 70 degress) instead of this 95 degree FL weather, it would easily be ABOVE 800 RWHP


Gerald

 

[Eddie N]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Gerald:
Stoopid question here. But what does floor mats have to do with this, other than perhaps the gas pedal not being fully depressed?


<HR></BLOCKQUOTE>

i'm pretty sure thats exactly what jon b was getting at.. it happens more often than you would think..

follow the instructions at the web site below for throttle cable synchronization...
http://www.viperclub.org/instructions/tsynch.html

- eddie -

 

[RedGTS]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>what does floor mats have to do with this, other than perhaps the gas pedal not being fully depressed?<HR></BLOCKQUOTE>

That's exactly what they have to do with it, and it's apparently more common with Vipers than you would think.

 

[1 Bad Snake]

I do have thick floor mats, but I removed the driver side because it interfered with the clutch. I will have them check the throttle cables. As for the heat soak, it was 20 degrees cooler when I lost the power. So if anything my car might have been even stronger than the last dyno showed. Plus, I just had my entire cooling system replaced, including new hoses, radiator and coolant. The car was running at a consistent 190 to 205 under heavy accelerations, stop and go traffic or cruising on the highway. Thank you again for the suggestions anything else would be appreciated.

 

[LPE 383]

You might want to have your tech make sure your fuel supply (injector pw, fuel pressure, etc) is adequate for the increased air flow of the new rockers.

 

[1TONY1]

And are the 1.7 rockers adjusted correctly?

 

[MES]

That's a bunch of HP to lose. What's your before and after HP also what other mods do you have? Just some ideas that you can check.

1. Throttles fully open, have someone mash the gas petal then look under the hood to see if the throttle hits the stops

2. 400/10=40 (i.e. if one spark plug is disconnected/bad/not firing then your going to lose about 40 HP)

3. Rockers not properly adjusted

 

[1 Bad Snake]

Thank you all for your replies, it appears as though I had two fouled spark plugs. I thought this was unlikely since I just changed all the plugs a month ago. For all that replied
THANK YOU!!!!!