Anyone need a tune after Long Tubes on sohc???

[grantur01]

Well i just read an article in the Mustang Enthusiast mag about a guy who had a 97 cobra and got long tubes and only picked up 8hp and 4ft/lbs. They found out his air/fuel ratio was not good for his free flowing exhaust. After a dyno tune with a diablosport chip he picked up 19 extra hp and i think 19 extra ft/lbs!

So here is my story:
Before BBK Long Tubes 1/4 mile was [email protected]
After BBK Long Tubes 1/4 mile was 13.4'[email protected]

I should have a least seen a little increase in mph. but i guess its my factory tune. Anybody else have experience on this??? My next mod will prolly definately be the SCT-4 chip. Modular Depot is by my house so i can get it tune easily. Well thanks for any replies in advance

 

[jstreet0204]

If all of your other fi components are in good working order, you should not need a tune unless it is to less it is to legthen the pulse delay for the o2's if you are having idle problems. That s not to say that you don't have something else wrong that could be fixed with a tune.

 

[grantur01]

i see what ur saying but in the article once they adjusted the air/fuel and timing they got the extra 19 ponies and 19ft/lbs

 

[Tony01GT]

Did you disconnect the battery? Your computer should take care of your A/F for the most part, but will probably run a little rich with long tubes. I have similar mods as you and I ran a slow(MPH) 13.3 N/A. All I had was Longtubes, o/r H, magnapacks welded in, nitto 315's, gears, upper intake and TB, and superchips tuner, basically. I was very heavy too, with 275's up front, full length subframe connectors, etc.
And I have an auto, so i can only launch at like 1k haha. So i have minus few things that you have and a few different things so we should be pretty close so thats not that bad.

 

[Mike97gt]

Well i just read an article in the Mustang Enthusiast mag about a guy who had a 97 cobra and got long tubes and only picked up 8hp and 4ft/lbs. They found out his air/fuel ratio was not good for his free flowing exhaust. After a dyno tune with a diablosport chip he picked up 19 extra hp and i think 19 extra ft/lbs!

So here is my story:
Before BBK Long Tubes 1/4 mile was [email protected]
After BBK Long Tubes 1/4 mile was 13.4'[email protected]

I should have a least seen a little increase in mph. but i guess its my factory tune. Anybody else have experience on this??? My next mod will prolly definately be the SCT-4 chip. Modular Depot is by my house so i can get it tune easily. Well thanks for any replies in advance

well for one always use adjusted times. even small differences in weather can throw your times and mph off.

get the weather for the exact time you ran you will need temp,humdity,baro pressure and the track altitude ( where it is compared too sea level) this is what you need too get a DA number density-altitude number you can plug that into a calulator (i know modular depot has this stuff) and with that you will have corrected times.

but you probally don't have the weather for the runs huh?

first thing i do when i go home is get the weather and figure out my DA number.. i have a weather site i go too that has info in one minute increments you will be surprised how much humidity can change in a hour or so.

i go this far and i still suck at the track in my defense the numbers i ran suck for me. i run good times in other cars. i just got a little pumped because it was my first time in 2 years that i got too run at the track. and traction sucked for everybody that night (opening day)

 

[grantur01]

thanks for the replies

MIKEZ28 - I ran the 13.5 in the dead of July.. guessing 75 degrees. Then after the long tubes i ran the 13.4 same mph roughly in 45 degree weather. As far as I know.. humidity would have been far less.. the mph should have shown my gains if there were any. Thats why i'm quite convinced my tune is bad. The other thing is that my 02 sensor wires got wrapped around the driveshaft somehow and ripped the wires apart. I'll shut those off with the sct-4 though.