Get the Headers...then what?
Champion
Joined: Apr 2007
Posts: 2,570
Likes: 0
RE: Get the Headers...then what?
Not to thread jack, but.... If you did ditch the stock y-pipe, what if you decided to go with this??
http://store.summitracing.com/partde...p;autoview=sku
I have an 01 ram, and was hesitant on buying because I didnt know if it came with the ypipe tubes to manifolds, and secondly because it says for 99 and below. What sort of modifications would need to be done to go to a 01 ram? just curious.
http://store.summitracing.com/partde...p;autoview=sku
I have an 01 ram, and was hesitant on buying because I didnt know if it came with the ypipe tubes to manifolds, and secondly because it says for 99 and below. What sort of modifications would need to be done to go to a 01 ram? just curious.
Champion
Joined: Aug 2005
Posts: 3,313
Likes: 8
RE: Get the Headers...then what?
On 2nd gen OBD-II computer systems
the two things that 'adapt' are
the AFF (short term adaptive fuel factor) and
AAF (long term added adaptive factor)
and they only work at part throttle.
At wide open throttle there is no 'learning'
and the computer uses its WOT tables with the MAP and IAT.
No O2 sensor at WOT either.
As little as 4 psi of backpressure in the exhaust at WOT will generally cut the effectiveness of headers in half.
The stock 2nd Gen y pipe, catalytic converter and muffler creates about 7psi of backpressure...a little less on the Indy style factory muffler.
Kenne Bell says in their tech notes that removing the 2nd gen exhaust behind the cat outlet showed about a 16 hp gain on their in house rear wheel dyno. I think I remember where some DML experimenters found that replacing the cat with a straight pipe yielded another 4 hp.
Buying some copies of the official Mopar Performance Magnum cylinder head intake and exhaust porting templates off eBay and doing a job yourself (or hiring a professional like KRC, Revsearch or Shady Dell Speed shop)
is probably the first mod to spend money on.
the two things that 'adapt' are
the AFF (short term adaptive fuel factor) and
AAF (long term added adaptive factor)
and they only work at part throttle.
At wide open throttle there is no 'learning'
and the computer uses its WOT tables with the MAP and IAT.
No O2 sensor at WOT either.
As little as 4 psi of backpressure in the exhaust at WOT will generally cut the effectiveness of headers in half.
The stock 2nd Gen y pipe, catalytic converter and muffler creates about 7psi of backpressure...a little less on the Indy style factory muffler.
Kenne Bell says in their tech notes that removing the 2nd gen exhaust behind the cat outlet showed about a 16 hp gain on their in house rear wheel dyno. I think I remember where some DML experimenters found that replacing the cat with a straight pipe yielded another 4 hp.
Buying some copies of the official Mopar Performance Magnum cylinder head intake and exhaust porting templates off eBay and doing a job yourself (or hiring a professional like KRC, Revsearch or Shady Dell Speed shop)
is probably the first mod to spend money on.