Header and Y pipe help

[Aeroboy]

Hey after recently seizing up my engine im having it rebuilt and it should have a bit more of a kick than the stock engine, i was looking into upgrading the exaught manifold to headers. Is this necessary or will the stock manifolds be fine? The engine should be making around 420-450hp at the crank.. Also do you need to get a Y pipe when you get headers? Can you get just a Y pipe with the stock manifolds and what advantages does the Y pipe give? All in all im just looking for suggestions on any header and y pipe setup, if any.

[BlackLT1Z28]

To answer your intial question. If you get shorty headers, you can use the stock y-pipe. But if you get mid or longtube headers, you will need a new y-pipe. Longtubes free up the most power and if that's what you're going for, I suggest going that route. Shorties are regarded as worthless by most.

As far as y-pipes, they usually provide more low-end torque than top-end power. This is evident with the difference in true-dual setups as opposed to y-pipe setups. Both are good and effective, ones not really better than the other.

Now, why did the engine seize up in the first place? Because you need to determine that before you rebuild the engine, or else it could happen again. And what engine, your LS1?

[nhraformula]

with long tubes you need a y pipe.

[Wesman]

with long tubes you need a y pipe.

Or a true dual exhaust system.

TD's will give you more power and sound much better than any Y-pipe setup, so go that route if you can.

[Aeroboy]

Now, why did the engine seize up in the first place? Because you need to determine that before you rebuild the engine, or else it could happen again. And what engine, your LS1?

I let it run too low on oil like a moron

And its not going to happen again.

[jag42420]

Or a true dual exhaust system.

TD's will give you more power and sound much better than any Y-pipe setup, so go that route if you can.

I second that. I'd go duals now, and add headers later.

Comparing the cost of a y-pipe with a catback to a true duals kit, there is not a huge cost difference. The duals will sound and perform better.

The most restrictive part of our exhaust systems is the flat, restrictive factory y-pipe. You have to change it out when adding headers, which actually inflates the power gains seen from most header installs. With that said, headers will definitely make more power than the stock manifolds, and are a great performance improvement. You just won't notice them as much as you would a good duals setup.

[nhraformula]

I second that. I'd go duals now, and add headers later.

Comparing the cost of a y-pipe with a catback to a true duals kit, there is not a huge cost difference. The duals will sound and perform better.

The most restrictive part of our exhaust systems is the flat, restrictive factory y-pipe. You have to change it out when adding headers, which actually inflates the power gains seen from most header installs. With that said, headers will definitely make more power than the stock manifolds, and are a great performance improvement. You just won't notice them as much as you would a good duals setup.

the factory y pipe is not as restrictive as you say. guys have kept the stock manifolds and put on y pipes, with no more than a 5 horsepower gain.

[Wesman]

the factory y pipe is not as restrictive as you say. guys have kept the stock manifolds and put on y pipes, with no more than a 5 horsepower gain.

Put it this way...Y pipe = garbage. Its not about restriction as much as its about flow, sound, and efficiency. You can use a 4" Y-pipe and have virtually no restriction, but its still a much less than optimal design.

How does it make any sense, from a performance and sound perspective, to take two banks of cylinders, run them into one big pipe, and then split it off again into 2 tailpipes at the back?? Its just totally pointless.

I wish there were more aftermarket dual exhaust systems available for LS1s, they really aren't that hard to produce. You just run 2 smaller pipes in the same location as the larger stock Y-pipe. It seems like everyone just all too willing to settle for different variations of Y-pipe systems though. The only real dual system that is widely available is the Bassani, and its quite expensive.

[jag42420]

the factory y pipe is not as restrictive as you say. guys have kept the stock manifolds and put on y pipes, with no more than a 5 horsepower gain.

Y-pipes are hands down more restrictive than duals. The smooshed factory y-pipe is more restrictive than a good aftermarket mandrel bent one. Most people tend not to modify their factory y-pipe when installing headers, because the aftermarket y-pipes are better.

My point is that the y-pipe change yields power (regardless of exactly how much). Most people tend to stack that power gain from the y-pipe onto the header gain. Therefore actual headers gains are typically less than 'advertised'. Headers and a y-pipe will not yield as much power as less restrictive true duals will.

My suggestion was true duals over catback and y, then headers later, not that y-pipes really matter.

[BlackLT1Z28]

My suggestion was true duals over catback and y, then headers later, not that y-pipes really matter.

Why would you get a true-dual system first, then headers? That makes no sense, you would have to create another true-dual system again to fit the headers from the stock manifolds.

And y-pipe aren't that bad like some of you make them out to be. Some guys are running 700-800hp street cars with a y-pipe setup.

[nhraformula]

Most people tend not to modify their factory y-pipe when installing headers, because the aftermarket y-pipes are better.

wtf are you talking about?
you say most people tend not to mod their factory y pipe when doing headers, then you say aftermarket y pipes are better

[nhraformula]

My suggestion was true duals over catback and y, then headers later, not that y-pipes really matter.

you make zero sense. you say a person should first put on duals before doing headers.
if you did that, when you do put on headers, they will not match up and youll have to replace piping.

[nhraformula]

Put it this way...Y pipe = garbage. Its not about restriction as much as its about flow, sound, and efficiency. You can use a 4" Y-pipe and have virtually no restriction, but its still a much less than optimal design.

How does it make any sense, from a performance and sound perspective, to take two banks of cylinders, run them into one big pipe, and then split it off again into 2 tailpipes at the back?? Its just totally pointless.

I wish there were more aftermarket dual exhaust systems available for LS1s, they really aren't that hard to produce. You just run 2 smaller pipes in the same location as the larger stock Y-pipe. It seems like everyone just all too willing to settle for different variations of Y-pipe systems though. The only real dual system that is widely available is the Bassani, and its quite expensive.

no arguement about duals being better.
problem is unless you want them dumped underneath the car, a set that goes over the axle costs way too much and any gains over the y pipe are not wroth it from a price standpoint.

[jag42420]

Why would you get a true-dual system first, then headers? That makes no sense, you would have to create another true-dual system again to fit the headers from the stock manifolds.

And y-pipe aren't that bad like some of you make them out to be. Some guys are running 700-800hp street cars with a y-pipe setup.

I'd go true duals first, because they'd be the best bang for the buck. Not everyone puts headers on their ride. IF headers were added later, it is not hard to refit the existing pipework to the headers. After my Bassani duals, I decided to add headers. Cost me $25 at the exhaust shop to adapt them.

It is a fact that Y-pipes make less power than duals. Can you get power from a y-pipe setup? Yes, more than the stock setup, but LESS than duals.

[jag42420]

you make zero sense. you say a person should first put on duals before doing headers.
if you did that, when you do put on headers, they will not match up and youll have to replace piping.

Makes plenty of sense unless you intend to buy headers right after the duals. The answer is to refit, not replace. As I stated in my previous answer, $25 is what I was charged. Took him 10 minutes while I watched.

[jag42420]

no arguement about duals being better.
problem is unless you want them dumped underneath the car, a set that goes over the axle costs way too much and any gains over the y pipe are not wroth it from a price standpoint.

I agreed with that statement until I priced it all out and talked to a few people. I paid $779 shipped for my Bassani kit. A y-pipe and catback would have cost me about $600 or better. I considered under axle duals that were going to cost me $300 with mufflers, but decided on the Bassani duals in the end. Here's the thead that changed my mind http://www.ls1.com/forums/showthread.php?t=28815&page=2 . As you can see, the Bassani picked up 15rwhp over the y-pipe and catback. The Bassani also made more power than cutouts in this test http://www.stealthram.com/bassanidualexhaust.htm . It was worth the extra $180 for 15rwhp more, to me anyway.

The guy that talked me into the Bassanis in that thread is running low 11s with stock manifolds and the Bassani duals. I ordered my Bassanis figuring if they worked for him, they'd work for me (stock manifolds) and keep me from having to order o2 extensions and retune the computer for headers. After installing them, I decided to get some Pacesetters anyway and order HPTuners. I have the Pacesetters installed now, but not tuned in. I can tell you that I really noticed the power gains from the duals, but the headers just seemed to make it louder. If I had it to do again I'd be using the stock manifolds with the Bassanis, and spending the $450 I would have saved on a camshaft. Just my opinion, my if I had it to do over.

Everyone has their own opinion. Opinions like assholes, everyone has one and they all stink.

[jag42420]

wtf are you talking about?
you say most people tend not to mod their factory y pipe when doing headers, then you say aftermarket y pipes are better

What I said was "The smooshed factory y-pipe is more restrictive than a good aftermarket mandrel bent one. Most people tend not to modify their factory y-pipe when installing headers, because the aftermarket y-pipes are better."

I should have probably made it more clear and said, "Aftermarket y-pipes tend to flow better, which is why most people use them instead of modifying their factory y-pipes to fit (when installing headers)."

[BlackLT1Z28]

You need a new y-pipe with headers anyways, except for shorties, which aren't worth a damn.

[nhraformula]

What I said was "The smooshed factory y-pipe is more restrictive than a good aftermarket mandrel bent one. Most people tend not to modify their factory y-pipe when installing headers, because the aftermarket y-pipes are better."

I should have probably made it more clear and said, "Aftermarket y-pipes tend to flow better, which is why most people use them instead of modifying their factory y-pipes to fit (when installing headers)."

long tubes wont work with a stock y pipe.

[jag42420]

long tubes wont work with a stock y pipe.

Which is why I said, "Most people tend not to modify their factory y-pipe when installing headers,".

While most people tend not to MODIFY their stock y-pipe, you'll find a few penny pinchers that will. I know one guy in particular that cut his y-pipe, and welded a collector reducer flange onto it for a disconnect, then cut the rear pipe and put a muffler with a turndown effectively dumping it in front of the rear axle just so he could save $$ on a second muffler. $50 junkyard headers & collectors + $5 gaskets + $25 junkyard Flowmaster chamber + $10 pipes + a lot of patience = better flow, more power ugly ass junkyard exhaust. It works though

There are several combinations to choose from for an exhaust system. Like I said, everyone has an opinion.