I have fully built JDM motor with heads and stage 2 cams with long tubes and high flow cats with stock eaton getting 16 to18 pounds

i was wondering if any one is running 3 inch exhaust from header back with or without cats if so how do you like it and was there any gain also hows the sound

i plan to run 2 mufflers and a x pipe with custom 3 inch tubeing

thanks for any info

 

Im sure there are guys running this setup. I do know that ls1speed.com (they sell ford parts too) carries an ATR 3" exhaust for our trucks. I dont know if anyone offers an off the shelf set of headers/xpipe thats 3" but maybe someone who knows will chime in.

 

I know with Ramairsvt's built moter they did a dyno pull after removing everything past the collectors, and didn't gain anything. So I don't think you would gain much more than noise.

 

I made a 3" exhaust system myself using stainless mandrel U-bends and 4 mufflers. Didn't do a before/after dyno... but can say the Kook's stepped headers with this exhaust is much louder than my full Bassani system. I like it, not sure if the neighbors do .

Here's a pic before it was completely finished. I added a H-pipe tube in front of the 2nd mufflers and of course put some tips on it.

 

As far as gains...
I added the 3" exhaust, stepped headers, and stageII cams (up from Crower regrinds, not stock) at the same time.

On the Eaton I went from a 7.5-7.6 1/8th mile to a 7.3. Not sure how much had to do with the exhaust but I'm sure some of it did.

 

Bad as L built a full 3" system that he was running on his truck, which I bought from him, and installed a few weeks back. It consists of Kooks LT's that he put Dynatech Race Merge collectors on (then high-heat titanium coated), No Cats, but it has Burns Stainless Race Bullets in the mid-pipes, an H-pipe, and dual oval magnaflows. Everything from the headers out is all 3". It has to be the best sounding exhaust I have ever heard on an L. It has a great deep, mellow tone at idle, and on the highway with the cruise set it is surprisingly quiet with no drone at all. When you get on the gas it sounds mean as hell. It doesn't blaat or backfire.There is a video here of my truck on the dyno, but the guy that video'd this for me was unfortunately on the wrong side of the truck. You can get an idea of how deep the sound is though. It's a 26,8MB download if you want to listen to it.

Click on this link, then Right click, save as on the dyno_vid.wmv file.:

http://www.ayresweb.com/dyno/

BTW that was my truck dynoing 468 / 534 STD with the KB, but I had my Apten street tune in because my new tune wasn't ready yet. My MAF pegged at 5000 and the AF started going up so he got out of it.

 

Might I suggest keeping whatever exhaust you got and going with custom Electric cutouts right after the headers (before cats) This way you get free flowing exhaust and you can flip the switch and get your qieter regular exhaust.

search for QTEC

 

thanks for all the info

 

Shock the truck sounds very good. Anychance you have a pic of your setup? Truck sounds so good it almost makes me want to order headers and do a custom midpipe w/ the same setup you have. Let me know what you have!

 

There is a custom 3" exhaust system with 1 3/4 inch headers on ebay.

 

Cutouts are for Fbodies. PLEASE don't put them on a lightning.

 

I ran my headers open on dyno and lost 30 HP. Runs done 20 minutes apart.

 

I've seen them on a very high quality built lightning and I must say I was most impressed with this truck.

SO I'll say its a vary viable route for the least restrictive and LOUDEST exhaust there is

 

which truck? what was the HP and what were the mods?

 

I am running a custom 3 inch stainless twin exit exhaust with custom crossover using 3 inch metal random technology cats and Corsa Viper mufflers and tips.

I am amazed at how many compliments I get from the system. It sounds like nothing I have ever heard before and I love it. Too many changes at the same time as the exhaust to do a fair comparison but i wouldn't do it any other way.

https://www.f150online.com/galleries...1247&anum=7603

TB