I have an 88 GTU that my friend and I put headers onto along with a mildy ported UIM and LIM. We took the ACV and dash pots and all that junk out. A gutted cat is suposed to go on.

So far I haven't driven the car after we've installed everything because of an excessive amount of smoke comming off the headers. We want to burn it off while it's in the driveway rather than start a fire on the road X]

A few things that have come up as unexpected:

The holes that feed the Dash pots with exhaust air...we didn't cap taht with anything so air is comming out. What should we do? cap it or ignore it?

The headers are EXCESSIVELY loud and sound like *** (aka very bad). The RB header has a welded extension that connects to the stock exhaust system for now. I think the noise could be comming from the holes we left open on the LIM? It's hard to tell with the headers right next to them!

If we put on Ebay junk mufflers or something would we get a deeper noise (please please!!) or just get MORE annoying (weedwacker sound)?
We have an HKS car back but haven't installed that yet because we don't have the Y-pipe to go laong wiht it. It would have to be custom fit to the stock y-pipe so we're holding off.
Any exhaust guru's out there ahve any suggestions?
-grant

 

Ice Mark Ice Mark Ice Mark Ice Mark

 

or RETED RETED RETED RETED

 

Dashpots? If you're talking about the things that connect to the split air pipe on the cat that get opened by exhaust back pressure, those are your Actuators for your 6pi system. If you took them out leaving the holes in your manifold, YES you need to cap them. At one point i tapped mine and put in bolts, worked just fine and was a tight seal.

The header makes your car louder, that's probably what you're hearing not the holes.

I have cheap ebay mufflers on my car (BOMZ evo style) with an RB header and test pipe and custome 2.5" piping, it is extremely loud, no way around it.

 

put a resinater in there that'll quite it down a little

 

lol dashpots thats a good one... thoose are 6-port actuators.. you need to find a way to open them at 4000 rpm or your car will have less power then before you put on the header. I reccomend a line from the airpump with a bleed valve (get a cheap plastic one from the aquarium section of a pet store) T 'ed into it to ajust the rpm the open. There are other more innovative and precise ways of opening them you can search for, but that methods worked fine for me for years.

 

Yes you really want to operate the aux ports.
On your S4 the acutators pull on the levers to open them.
It widens the power band.

Check out the cheap "turbo pac" silencers & bombs setup pictures & sound file at the links in my sig below.