[manndhb3]

Anyone else here install JBA Shorty Headers and a Magnaflow Y on their truck(GEN 4) and notice a loss in pep during acceleration? On a positive note, I have def noticed that I am getting about 15ish MPG where I was getting about 12ish MPG depending on how aggressive I was driving!(all stop and go driving on a military post) Anyway, I was just curious to see how many people have experienced this. I would really like some input as to what I could do to get this low end back. Thanks in advance...:smileup:

 

[thunder98110]

You usually loose low end tq with long tubes. Jba claims that you gain an extra 20 torques at 2100rpm. Wait for a tune to come out to get back anyb power you may have lost.

 

[snrusnak]

What size pipe before and after the y pipe?

 

[manndhb3]

What size pipe before and after the y pipe?

Same as before, 2.5 in 3 out

 

[manndhb3]

You usually loose low end tq with long tubes. Jba claims that you gain an extra 20 torques at 2100rpm. Wait for a tune to come out to get back anyb power you may have lost.

I have the Shorty, not long tubes...I am pretty positive it is the Y that is causing the loss based on some other threads I have read.

 

[snrusnak]

That's surprising, I wouldn't expect any loss in torque with shorty's going in to stock size exhaust. The diameter of the pipe is mainly what controls exhaust gas velocity, which effects torque. With the longer and larger primary's you do lose some velocity but normally it's not noticeable with shorty's.

 

[moparornocar72]

Do u have a cold air intake or different throttle body?

 

[manndhb3]

Yes I have a CAI and a TBS(just got it for the whistle and it was only 90 bucks)

 

[will51]

Strange, I just installed JBA's, Flowmaster 50 series muffler, and K&N intake and noticed an MPG gain, but no low end loss. I don't have a Y pipe though.

 

[TheSatinPumpkin]

maybe its leaning out a few points and needs to get a tad richer to compensate the additional flow.

 

[chefred112]

drive like you stole it..let the pcm learn the new characteristics and it will come back...

 

[Big Boi]

drive like you stole it..let the pcm learn the new characteristics and it will come back...

I hope so!

I installed the Magnaflow Y pipe today. And I notice a loss in low end. Ive been running the SC 93 tune for a week now. And I immediatly noticed that the tires dont chirp as much when shifting from 1st to 2nd at WOT. It'll roast the tires from a dead stop without any problems (Just put 2k miles on my rear tires in one week :hah.

Did notice a nice bump in mpgs though.

 

[chefred112]

mine did the same thing..not sure what mod I had put on but after a week or so after I did it, I got in my truck and it just jumped when i didn't expect it to...

 

[irnwkrkev]

Normally long tube headers gain torque in the low end more then shorties which show most of their gain up high.

With that said I lost a bunch of torque in my 02 durango 4.7l with a change to a 3" single exhaust. When I added shorties and a magnaflow y-pipe with high flow cat and stock diameter mandrel bent pipes it picked all of it (low end torque) up and then some.

Makes me think that 4.10's and posi will be my next mod before hitting the headers (long tube or shorty with y-pipe).

 

[S.C. Express]

^^ If you want to go fast, gearing and LSD make the most difference. My Dad had an 02 SS Camaro with the 6 speed. A few simple bolt ons, exhaust intake chip. Then he swapped the stock gearing, forgot what it was...3:23 or something like that. First swap was to 3:73, made a nice change but the mechanic did not mesh the gears correctly and they whined. So that was all the excuse he needed to put the 4:11's in. That Camaro would jump sideways iif you dumped the clutch in 4th gear. 4th gear topped at 120mph with two more gears to go. The gear swap easily made a 14.5 second car jump to a high 12 second car in the quarter. It embarassed quite a few $50k Corvette's.. Best part was he averaged 28mpg on the highway!

 

[snrusnak]

02 SS stock runs 13.7 1/4 mile IIRC, just saying. My buddy's 01 z28 ran 13.8 stock. He had 2.42 gearing or something like that. He swapped to 3.55's, tune, intake, exhaust, headers, runs 13.0. Auto trans. He's about to do a 6 speed conversion.

 

[Redhemi03]

If your not runnin a tune that gonna be a lot your problems, I'm running long tubes with no cats and full 3 in off road y pipe with a magnaflow dump with a super chips tuner and I have tons of torque, headers with no tune will kill you

 

[hemibigblack]

Change fuel octanes twice. Go between the two and also your pcm WILL evaluate the numbers for you.