Need exhaust help

**tt69camaro** · 05-30-2006, 04:28 PM

I have a 98 Trans am w/A4. My goal is to build a car that makes as much HP as possible (with bolt ons) and still pass all emissions with no SES lights. What kind of HP is possible with these guidelines? Has anyone else limited themselves like this to the emission gods?
I would like to know what headers are available that I can still pass all OBD2 emission laws. Or am I stuck with the stock stuff? I am considering building a true dual exhaust but don't know if it is worth my time over a cat back (magnaflow probably)? Any and all advice is welcome!

**nhraformula** · 05-30-2006, 05:05 PM

clear any codes via hp tuners or ls1 edit software and youll pass everytime.
pipes from the cats back dont make you pass or fail a emissions test.

**tt69camaro** · 05-31-2006, 05:43 AM

How much is LS1edit?
I had no SES light on but they still pulled a code for the air pump. Had to buy a new one for $200 before it would pass inspection. There goes $200 I could have used for go fast parts. I would also like to know what kind of HP is to be expected from LT's and a catted Y?

**nhraformula** · 05-31-2006, 06:55 AM

im not sure how much a tuning program goes for. i take my car to the shop for that.
as for LTs, i gained 30 rwhp with a tune.

**tt69camaro** · 05-31-2006, 08:40 AM

30 RWHP is respectable! Is that number based solely on LT's or the whole exhaust front to rear?
What do you pay for a tune?

**Transam388** · 05-31-2006, 08:58 AM

Things like LS1 Edit are not cheap and unless you REALLY know what you are doing you can mess things up bad. Also, code readers and such can delete codes BUT until the computer gets enough cycles through it if you delete them and go right back to have it inspected the computer will say it does not have enough data and they won't pass you. I already tried that. You can do a lot of bolt ons and get some good power but you will run into SES codes with exhaust. High flow cats will set of your O2 sensors normally the rear ones so you would use O2 sims for that. Stuff like EGR though you do have to remove that from the scanned sensors. As others have said usually it is a good idea to just pay anywhere from $350 to 500 depending on the shop, to have it custom tuned. You will get more HP and can have codes that will be thrown removed. Most places also once you have a tune will redo the tune to a degree for a much smaller fee $75 -150.

**nhraformula** · 05-31-2006, 12:05 PM

Originally Posted by tt69camaro

30 RWHP is respectable! Is that number based solely on LT's or the whole exhaust front to rear?
What do you pay for a tune?

thats adding headers and y pipe (catless)

**nhraformula** · 05-31-2006, 12:06 PM

tune was 350. any retune after that is 125

**JEB** · 06-01-2006, 08:03 PM

tt69camaro, you could go with true duals using the stock manifolds and catalytic convertors with both pipes going over the axle and out the rear from beneath the bumper in the stock location. By using the stock manifolds and catalytic convertors your car will be street legal and will not throw any codes. If you use straight through, noise cancelling mufflers, the exhaust note will be a great sound but will not be overly loud as long as you tread lightly on the gas peddle. You will also put up about a 5 percent increase in horsepower.

**tt69camaro** · 06-02-2006, 03:09 AM

Yes, That was the plan, but I can't find a bolt on exhaust so I will probably just go with the Magnaflow. In doing further research the Bassani fits only 00-02 F-bodies. Not sure what the difference is but that is what they said.