So I ordered the TSP 1 7/8" stainless LT's with their y pipe to replace my 1 3/4" Pacesetters and TSP 3" duals (12" bullets). I am going with a custom single 4" exhaust with a Magnaflow routed out the back of the car.

My question is should I get the Flowmaster 3" into 4" merge and have it fabbed into the TSP y pipe to make a smooth transition or is the TSP adequate if I just cut off the necked down section of the merge? After having the 3" duals for so long, I am fearful of rasp and I def don't want any "choke" points in the system. I am wanting a "toned" or "refined" sound

Any advice would be greatly appreciated as I do not want to have to go down this road again.

 

I'm bumping this up for ya. I'm also interested to know. I think I am going to do a Mufflex 3.5 off of my TSP Y. I think I read somewhere that the TSP is 3.5 before the neck down, hence my decision on the 3.5 vs the 4. I didn't want to cut up the y pipe for a different merger. And at my power levels I think the 3.5 will be more than enough.

 

I am going to go ahead and do the FM merge I guess. Do it once, do it right.

 

Are you going with their y pipe to save money? Theirs is 3" outlet which makes no sense to use if you are going to have a 4" exhaust. If you go through the added cost of a 40 or 50 dollar flowmaster merge plus the trouble or more more money if have to pay someone, then you may want to consider the mufflex y pipe also

 

^^ I think Mufflex Y pipe is designed "only" for Hooker LT's.

 

I can confirm that hooker, jet hot, pacesetter, ebay stainless headers, all will interchange with any of your run of the mill y pipes. I have mix matched them all. I had tghe mufflex on my pacesetters as well as ebay stainless headers. They all exit in roughly same position.

 

I should have probably looked into the mufflex y pipe, but I already have the TSP here. I am getting the merge installed by a buddy of mine that is a fabricator (he is also doing my custom 4" exhaust).

 

I have tsp's 1 7/8 headers and bought a mufflex y-pipe that has the flowmaster 4" to 3" merge and it did not fit. From what I remember it did not line up with the passenger side.It could have fit if I cut and welded new pieces, but for what I spent on the mufflex y-pipe it would be cheaper to buy a tsp y-pipe and replace their merge for the flowmaster merge. That is the route I am in the process of.

 

Glad to hear that I am not wasting any money then.

 

The tsp merge is 3 1/2"


https://ls1tech.com/forums/generatio...ad-y-pipe.html

 

This. The Mufflex pipe is pricey. If one is going to hack something up, it'd be more economical to get the TSP Y and throw in the FM merge.

I had asked TSP leisurely in another thread if it would be possible to get their Y with a 4" out. They did not respond (I'll give the benefit of the doubt that they missed my question), but I believe they could sell several.

 

Agreed!