Should I pay to have the car dyno'd after adding Long Tubes? Does it really need it?

[Pokageek]

Whatdoyall think?

 

[reldapimp]

no spend the money on something else

 

[viridionplague]

you probably dont need it, but it would give a nice piece of info on what bigger headers can do for larger displacement engines.

 

[BlackVert]

one thing about the tune that might make sense to tweak after long tubes is a table called hego delay. it essentially helps the computer determine when to check the voltage at the hegos when it is in closed loop. this is how it checks to see if the amount of fuel it commanded was correct or not. with long tubes, the O2 sensors are usually moved farther away from the exhaust ports than stock, so a good tuner will adjust that table as necessary for long tubes.

without that change, the computer will have a hard time dialing in the injector pulses to get the air/fuel ratio correct. will it be noticeable? maybe, maybe not ... depends on how far they were moved and probably other stuff like spark timing ... there are too many variables to be able to say with any certainty

 

[Zero Signal]

I would ask a tuner what they would charge to only adjust the HEGO delay as Chris mentioned. That could be done in 15 minutes or less with no dyno time needed. But that would require a tuning chip or device which I'm sure you already have.

 

[Bosko5.0]

how much would it cost?

 

[Grn92LX]

Assuming you have a chip, you will need a re tune. Your current exhaust is way too small and the new one is a lot bigger/better and your a/f will definatly be out of wack. This is another reason I prefer self tuning.

 

[5spd GT]

Self-tuning is better for a Sn-95.

The fox ECU is very adaptable, and could take the change no problem.

A dyno would provide more consistent/credible gains.

 

[Pokageek]

ok, thanks guys.

 

[S351Saleen77]

I'm really curious what gains you get with the new headers!!

I hope you dyno again!!

 

[sn-95matt5-0]

so does this mean you actually got the headers in already.

 

[Pokageek]

Yep. I am having them installed early next week.

 

[sn-95matt5-0]

sweet dude cant wait to hear how they work for you.

wat are you doin for a mid pipe?

 

[Pokageek]

Going with a 3" from acuufab.