LX200

I am doing a CAI and tune for 93 Octane. Now, i am looking to help on the backpressure side.

So, I really don't want to do mods if I am just wasting my time. For instance, running 93 Octane and a CAI, am I just wasting my time to put on an axle back muffler? That is, do I have so much restriction in the headers, converter, etc, that a muffler does not matter?

1. Will axle back get me anything if I don't do anything else?
2. Will Cat back provide much more benefit than axle back? How much more? Twice as much or 10% more?
3. Are headers much more of an impact than any muffler change, and if I DON'T change the muffler but do headers, is this a waste because I am still using a constricted muffler system.

I think you get the drift of what I am asking.... what changes REALLY have an effect, and which ones are a waste if done alone.

tino

Did the CAI, did the 87 Octane, waiting on JBA Headers and H exhaust (in transit)......, I'll tell you as soon as I install them... (1 week or so)

fazm

Axle back is a pretty big gain on the 4.0's I did the headers for sound, wasnt lookin for performance, even though i got it over 5k.

LX200

So this means the pipe to/from the cat converter is not that bad a restriction, but the stock muffler is a bad restriction?

fazm

ya, the "catback" pipe flows nicely, probably no gains seen in replacing it.

LX200

Fazm, thanks.

Harry_F

also even with more flow the 4.0 needs some back pressure. unless u have F/I or N02. so my bet is that the guys with cut-outs are loosing hp. just my guess though.

fazm

just low end hp prolly.

tino

wouldn't openning the intake CAI aleviate some of the lack of back pressure?

rmays06

I've been thinking about doing axle backs but have heard many different oppinions, My ?'s do they improve preformance at all? Or is it just an upgrade for sound? I'm thinking JBA's I've heard them and they sound the best IMO. Any thoughts!