Hi there,

I've read lots on this forum to the point my head hurts, but there's some questions which I haven't found answers to (maybe I'm a crappy searcher or something, I dunno).

I'm looking at putting headers in my car and I've got a bit of a special case because my Trans Am is right hand drive converted, and the steering shaft might cause me troubles, so I'm wondering if I'll have to get some custom headers made...

All other things being equal, at what point are long tube headers better than shorties? Or are they better all round?

Am I right in thinking that the primaries ideally must all be of the correct length?

What is the better Y pipe size, 2.5" or 3"? Is bigger always better?

What effect will headers have on low end torque vs high end performance? My car has great low end torque but runs out of puff at the other end.

Will the carb need retuning? I am aware that I'll have to install a heated O2 sensor.

My car has an LG4 V8 in it and it doesn't behave as a stock car even though I've not done any engine related upgrades to it. I've driven two other Trans Ams from the same year as mine and they feel rather flat compared to mine.

Looking at Summit's website at the Hooker 2055, I'm surprised to see the collector in the middle as I had assumed it would be towards the back of the engine. Are there any issues with the cross member getting in the way? Their website lists these headers for 86-90 cars - do they fit on earlier years as well?

Sorry for all the questions, I want to do this only once and do it right, and have an exhaust system that'll grow with me if I decide to put in a bigger engine some stage later.

 

"Image is a representation of this part. Actual part may vary."

It varies.

A lot.

The 2055's will fit your car, but not your exhaust. Replacing the entire exhaust is a good idea, anyway. I'm sure they didn't take your application into account. They may or may not fit. I have a pic of them on the engine out of the car, but I don't think it shows the right side.

Equal length isn't a particularly big deal, because shorties aren't really "tuned", anyway. You don't need a heated O2 sensor with shorties. Retuning will be minor, if any is needed at all.

With a stock LG4, 2-1/2" at the y-pipe outlet is adequate. But, 3" will support future upgrades. The 2055's would be a good choice for that reason (assuming the RHD doesn't cause problems).

Your engine runs out of puff at the top end because it is an LG4. Exhaust is part of the reason, but only a part of it. The cam is the other big player, as is the air cleaner. To get the most out of it, all of them have to go.

 

Thanks so much for that reply! You've saved me money already as I was all geared up thinking I'd have to buy a new O2 sensor. If you could post that pic you've got I'd appreciate it. It should give me some idea as to how things might fit.

I guess the only other thing I need to know is, is a 3" exhaust going to have any kind of adverse effect on my engine? Could it cause a power loss at some area of the RPM band but improve it elsewhere?

I have improved the car's ET by 0.5s and speed by 2MPH by simply changing the factory air cleaner lid to one from an 84 Trans Am that has the hole in the top for the ram air. All I need is the ducting from the cowl to the lid, not to mention a dual snorkel.