Well I'm going to be doing my exhaust shorty. but came across something that I dont really know.....

where do I go from the 3" collector on the hookers to the 2.5" duals that will go over the axel?

shoudl I do it right where it goes into the tunnel?

would it make a difference where it goes? as the exhaust cools it doesnt need as larg a pipe right?


and is an X a real good idea? or does it matter for equal lenght headers?

 

I like the "X" setup from a performance standpoint. A little more efficient at evacuating the cylinders in comparison to the "H".

What I did is reduce the 3" directly after the "X" to 2.5". Then up and over the rear. Check out the BMR panhard rod relocation kit. Makes everything much easier going this route.

Good luck.

-Mindgame

 

Thanks,

would I see a power caing from an X pipe? what about milage maybe?


I was looking at that pnahard relocation but for 200 bucks I think I could spend less then that to get my exhaust guy to make sure he gets it over and safe.

 

I bought a set of Dynomax header reducers that bolt right up to the header flange and go from 3" to 2.5" right there. You can get them from Summit, for about $20. I think they were part # WLK-88307. Pics are in the sig.

 

is that the best place for it?

I mean I assume that there is a reason there is a 3" collector....

 

Get the 3" thing out of your head. Do 2.5" all the way, it's not going to hurt your performance and you will need the 1/4" of clearance difference.

 

From a flow point of view, I believe it would be best to reduce them at the collector, where the primaries are already merging. Also, that is the tightest area for ground clearance, so every bit you can gain will really help you. Its all up to you, I'm just putting in my .02

 

dude going over the axle is gonna kill the exaust flow. Go under the axle. I am using a 2.5 inch x-pipe.

check out pic of my exhaust
exhaust

 

Dude, it won't.

After the exhaust gets halfway to the end of the exhaust system it just doesn't care which way it turns anymore. The closer we get to the engine, the more critical every turn is. Which brings me to my next point....

I would reduce AFTER the x-pipe. The pipe immediately after the collector is basically an extension of the collector. If you'll venture out into the web and read up on "collector extensions" you'll see that they can have a profound influence on engine performance.

WRT to clearance,
If your collectors are so low that they're gonna rub the ground then reducing the pipe size directly after isn't going to solve the problem cause guess what..... the collector flange (assuming you're using a flanged setup) is still gonna hit.

-Mindgame

 

Thanks, thats what I was thinking, and what I will do, I will 3" and then x it then go 2.5 over.


going under jsut looks crappy.

 

wrong. whatever turns the pipe has to make slows down the velocity of the exhaust gas. The straighter shot it has the faster it will leave the system and the more power you will have. Going over the axle not only looks stupid it is two big turns the gas exiting has to make before it leaves the pipe.

how many under the axle setups have you actually seen? Obviously you havent seen my setup or all the other f-body guys in my town that have the same setup as me and love it. So dot judge something you know nothing about.

 

Sure, I think everyone with a 5th grade education knows that a gas will lose energy as it moves along a path. It's called "head loss". The point I am making is that there is already a great deal of energy/heat lost by the time the exhaust has reached the midway point.

To put theory to test.... on my 68 Camaro I ran 3" dual exhaust front-to-back. I used a Dr Gas x-pipe and the exhaust could be taken apart at the rear section (right after the x-pipe). For grins and fun, I removed the rear section and trailered the car to the track.
Before I post what I found, you might need to know that this car had been running rock solid consistent for a few months prior to this night. The temps and conditions were very near identical to my last outing but guess what.... I didn't see any gains from removing the rear section of the exhaust. Not even a tenth or 1 mph! The car averaged near identical times to it's previous outing. So does it matter? Where would I come up with such an opinion anyways.

I understand... there are those who post what they think and there are those of us who post based on what we've tried. I'm the later and I like to tinker alot.





We could take a poll as to everyone's opinion if you'd like. I do have a feeling that you'll be in the minority for the under-the-rear-exhaust-look though. But I'm not going to knock you for what you like. I personally don't like it but it's your car so have at it.

-Mindgame

 

Sounds like a stare down at the playground is coming.

I vote for Rupert!!!

 

I have seen cars running it under the axle.It looks like Mindgame does know what he's talking about.

 

I looked at your car, under is not what I want to do.


from what MindGame said I'm going ot run 3" duals about half way back into a X and then 2.5 the rest of the way.


Thanks.