I've got a stock '83 Crossfire in need of a new exhaust. I want to keep it looking stock, so I'm keeping the stock exhaust manifolds.

I'm thinking 2.25" Y-pipe coming from the manifolds, into a 3"Catco cat, and 3" pipe back to a Flowmaster (which one? want a nice tone but not really loud), and 2.25 or 2.5" tips.

Any thoughts here? Is this a good setup for my purposes?

 

If it's mandrel bent, and a real "Y" and not a "T" where the two 2.25" pipes come together, it will be an improvement over the stock exhaust.

How many people would see headers vs. manifolds? Or, are your eyes sufficient justification to take that big performance hit?

Well, I guess it would still be CFI, so perhaps it won't matter that much. . .

 

Yeah, I know going with headers is the best way, I'm just holding off on that for now. Actually, I wish I could find someone's old N10 exhaust and bolt it on. Sure would be cheaper than an all new system - and probably pick up 25-30 hp over the stock pipes.

Is the exhaust manifold on the LU5 the same as the L69?

 

I believe they were the same, which would be a good thing. But, I couldn't say that for sure.

 

HEY FIVE7KID,, IS this another crossfire injection slam !! if so than you must slam the single TBI,, Right ???, if not than its just another example of someone not knowing anything about a CFI.---If your going to slam cfi slam the single tbi also.---ITs like saying fuel injection stinks,, and carbs are the great . --I WOULD take CROSSFIRE over SINGLE tbi anyday,, if i had to choose. --The only problem a cfi might be quilty of is coming out in 1982, when the big three auto makers were saying the v8 was done, and they detuned the engine so much

 

I'm sure a crossfire car would benefit as much as an LG4 going to a 3" system... Same engine (more or less).

 

It's not a slam if it's the truth.

The ugly truth is single TBI has more potential than Crossfire. There are all sorts of things you can do with single TBI, but the aftermarket never picked up on the Crossfire. Limitations start with the intake, and you can't do much else if you don't have a decent intake.

 

I went with a custom bent exhaust.

They did a beautiful job. 2.25" pipe coming off the manifolds, nicely Y'd into a 3" pipe and Catco 3" high flow cat, 3" pipe back to a Flowmaster and stock looking 2.5" tips.

Once I figured out that the top plate on the intake manifold was loose, (creating a huge vacuum leak), and tightened it down, this exhaust made a huge difference compared to stock. HUGE!

 

Chazman as i posted in your other thread in the TPI section the LU5's exhaust manifolds are the same as the LG4's.The entire exhaust is the same and is the biggest choke point on the LU5 beyound the small ports on the intake base.Get a set of exhaust manifolds off a L69/LB9/L98 with the matching y-pipe or have the one matched you have now.

The L69 used the same internals and compression as the LU5.The main difference was the L69 used a stouter cam than the LU5 which in turn used a better cam than the LG4.The LU5 has plenty of potential it just takes more work to achieve it.

 

Thanks coolram. The exhaust is already done. I had it custom bent at a local exhaust shop. It's 2.25" off the exhaust manifolds, Y'd into a 3" pipe/3" Catco/3" pipe into a Flowmaster and 2.5" tips. They did a beautiful job.


Tell me more about your car. I've only had my LU5 for about 10 days. Do you have the stock exhaust manifolds on? Did you feel any difference with the Hypertec coil I see in your sig? Any other advise that you can share?

Since getting my car, I've put on the exhaust, tightened the upper intake bolts (guess it created a massive vacuum leak), cleaned the gunk out of the throttle bodies and advanced the initial timing abit. WHAT A DIFFERENCE! Don't get me wrong, it's not going to take down any LS1's, but the difference in power and drivability is remarkable. The 2.93 gears aren't helping me too much though.

The reason I ask you about your coil is, I'm thinking of replacing my ignition module and coil next.

 

You're a fool. You just slammed a long time veteran and respected member of this forum. Your attitude and your comments clearly show your own ignorance. Get your facts straight and show some respect or don't post.