How can I get a little more performance out of my XJ6?

 

Lots of ways. What's your budget and how much improvement do you want? I can suggest thing from "virtually free" (advancing camshaft timing) to several thousand dollars (transmission and differential changes, and fuel injection modifications). :-)

Since you mentioned "little", for a couple hundred dollars you could get a low restriction air filter, replace the front mufflers with straight pipes, and advance the cam timing. You'll probably see a 10-15 hp gain....just enough to feel a dfference.

Cheers
DD

 

Doug, I'd love to replace the front mufflers with straight pipes, and advance the cam timing. Are there any noise consequences for removing the front mufflers? I already have a K&N air filter, and I dont know how to advance the cam timing. Is it terribly complicated? Thanks Doug.

 

go to the driven man's website for my info than you can shake a stick at. google it

 

There is a noise increase, yes....a bit sporty, not obnoxious.

As far as air filters go, I had something like an open element filter in mind, not merely a K&N replacement type.

Advancing the cams is easy. There are timing notches on the front of each cam. Turn the engine over by hand so that the timing pointer is at top dead center and the cam notches are perpendicular to the plane of the cam covers. There's actually a tool for this but you can eyeball it if you are really careful.

OK, that's square one. Now, turn the engine over so the timing pointer is a 8º before top dead center. Next, turn the cams so the notches are once again "straight up"....perpendicular to the plane of the cam covers. You've now just advanced the cam timing by 4º. This won't really add more power but it'll increase lower rpm torque and response....more of the power will be on hand at a lower rpm, where you'll feel it most. Power over 4500 rpm or so will actually be less...but you don't spend much time there anyway, right?

Oh....to adjust the cams you remove the clips that hold the inner cam gear to the outer cam gear and slide the wiggle them apart. The cam can now be rotated. If you've never done this before you might want an experienced helper looking over your shoulder...or at least read up on cam timing/cam gears in your shop manual.

Its a lot easier to fathom when you have the cam covers off and are looking at everything.

Cheers
DD

 

If you're real ambitous and comfortable messing with valvetrains, you can port and polish the intake runners. Check out the pointers listed under the "heads" section of this article...hp improvements.

I wouldn't recommend doing this unless you have played with intakes and heads before...cheap hp increase, but can come at a price if you goof.

 

Can I simply cut vents or holes in my can that holds the air filter? I do have a K&N.