This is topic loss of power with an O/R H pipe swap? in forum Tech Talk at Northern California Ford Owners  .


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Posted by 87 4spd GT (Member # 9216) on :
 
Okay so recently I put on a new o/r h pipe when I put on some hooker headers. It seemed like afterwards the low end was gone but the mid range was better. So since I wanted the low end power back I put the stock H pipe back on and now no low end power still. Is this because the comp needs to calibrate and I have only driven it maybe 30 miles since I put the stock H pipe back on. Or is this because of the headers? Are the headers too big for what mods I only have..... CAI, u/d pullies, maf conv, Stage 2 shift kit, 3.73's and timing at around 12?

Any help is more than appreciated....
 
Posted by SPTVENM (Member # 7080) on :
 
ya u probably have to much air flow for the lil mods that u have. u need a lil more back pressure
 
Posted by 87 4spd GT (Member # 9216) on :
 
Well that's what I was thinking was a loss of back pressure especially with the no cats and than with the headers. But is it really that big of a difference where I cant light them up from the start? But mid range is good! And would it be a good time to install my gt40 intake and should that even everything out on it than?
 
Posted by 89 306 (Member # 9042) on :
 
check ur flanges make sure they are all tight and make sure one aint more tight than the other side
 
Posted by 87 4spd GT (Member # 9216) on :
 
well i pretty much checked those again with really not finding nothing wrong, but I would hear an exhaust leak if thats what you are referring too..
 
Posted by Ty (Member # 4920) on :
 
more than likely youve got a leak at the headers. go get some good gaskets and seal em up
 
Posted by 87 4spd GT (Member # 9216) on :
 
after I installed them I went and checked all around the headers to feel for any exhaust escaping "leaks" but couldn't find anything. could a small leak create such a low end torque loss, or would the loss of back pressure be the problem?
 
Posted by 89 306 (Member # 9042) on :
 
thats wat i meant sometimes u think they go on rite but might end up sideways..jus throwin it out there...
 
Posted by 87 4spd GT (Member # 9216) on :
 
looks like I may be getting under there in the next few days, so if everything is tight could the result of having not enough back pressure create losing that much torque. The torque is there when i shift to second it almost barks them. But from the start there is no spin from the tires like before I did the headers and H-pipe.

[ September 16, 2009, 06:53 PM: Message edited by: 87 4spd GT ]
 
Posted by monk (Member # 8912) on :
 
try bumping ur timing to 14.long as u dont hear no pinging u wanna get as much timing as u can out of it.
 
Posted by 92stangLX (Member # 3252) on :
 
quote:
Originally posted by 87 4spd GT:
Well that's what I was thinking was a loss of back pressure especially with the no cats and than with the headers. But is it really that big of a difference where I cant light them up from the start? But mid range is good! And would it be a good time to install my gt40 intake and should that even everything out on it than?
Sounds normal to me. You are trading the low end torque for the mid-range and top end power. If you want a balance then swap in an h-pipe with hi flow cats. You will pick up some more low end and still have a lot more power than the stock h-pipe.

If you want to keep the o/r pipe then put the GT40 intake on and you will pick up a bunch of power. Also, gears will help your low end torque if you don't already have them.
 
Posted by monk (Member # 8912) on :
 
quote:
Originally posted by 92stangLX:
quote:
Originally posted by 87 4spd GT:
Well that's what I was thinking was a loss of back pressure especially with the no cats and than with the headers. But is it really that big of a difference where I cant light them up from the start? But mid range is good! And would it be a good time to install my gt40 intake and should that even everything out on it than?
Sounds normal to me. You are trading the low end torque for the mid-range and top end power. If you want a balance then swap in an h-pipe with hi flow cats. You will pick up some more low end and still have a lot more power than the stock h-pipe.

If you want to keep the o/r pipe then put the GT40 intake on and you will pick up a bunch of power. Also, gears will help your low end torque if you don't already have them.
+1 yes gears,biggest bang for ur buck [burnout]
 
Posted by 707vibrantcobra93 (Member # 4702) on :
 
He is already running a 3.73. I would play with timing a bit make sure u have no vacuum leaks. When was the las tune up so on and so forth.
 
Posted by 87 4spd GT (Member # 9216) on :
 
I am going to go through next weekend and do a tune up on her with new wires cap and rotor, I just at the beginning of this year put some E3 plugs on so they should be fine. And possible play with the timing a bit.
 




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