I have a 87 Trans Am with a Ls1/t56. It has all of the bolt ons with a TR230/224 cam. I do not have a tune. Here is my problem. The car is running like crap. It seems to run good until the car warms up, then it idles lower and backfires (sometimes very badly) and sometimes dies. I am not throwing any codes.

I have the EGR, AIR, Evap, Rear O2s, and all of that fun stuff tuned out. Could this be becuase of the open headers? I am using the LS1/Third Gen headers from Hawks Third Gen with no piping added on, just straight headers.

I also took the car around the block. Seemed to not have the power it should and ran worse as the car heated up.

The car runs and idles good if the engine is cold.

Please help

 

perfectly normal when u try to run open headers on a car that is tuned to run on a full catted exhaust system on stock manifolds. your computer is going nuts trying to dial in your air/fuel mixture. your 02 sensors are also going nuts. you dont feel any power cuz u have no backpressure which leads to a big loss of low end power. dont u plan on completing the exhaust system?

 

thats going to happen 99 times out of 100. run duals dumped atleast. or if your leaving it like that for a while get a tune.

 

Na man......it should run great on open headers. The trick is to add a little bit of pipe to keep ambient air from going back up into the headers and confusing the O2's. Can you check your STFT's? I bet it runs somewhat okay in open loop until the O2's come online. As far as making power, the less "backpressure" (I hate that word) the more power you will make if you can get the tune right. Anybody who says you need "backpressure" to make power is crazy

You do need a tune though to be running that cam and headers. You are leaving alot of power on the table if you don't!

 

get it tuned and it will be fine,just put some turndowns rite off the headers,then the o2s will read properly

 

+1 on a little extra piping and tune. should set you straight.

 

(referring to you^)

 

Thanks guys. I am getting exhaust done within the week.

 

getting the exhaust done isn't gonna be enough. That cam NEEDS a tune. There's no way around that.

 

+1 on getting a tune, putting on an actual exhaust will help some but getting a tune after a cam is crucial to get the most power.

 

I am also getting a tune very soon.

 

If you're running a cam on a stock tune that's your answer right there.