Still have a top end issue

[Florida240sx]

Car is choking out in the top end. Crower v2 cams.....Just installed a 3" BRM exhaust form Greg I have a test pipe not cat. So exhaust is flowing very well.I don't hear spark break up.... 1st and 2nd is no problem I can redline easily...Any ideas?????? Cam timming is the only thing I can think of...

[NateDogg]

It's easy to get the cam timing wrong because the FSM directions are brutal.

Do you have a wideband?

What is your total timing?

[Florida240sx]

I have a wideband. Wideband reaidngs stay constantish...and boost is still at full pressure. But no more pull.... better now than before with this new exhaust that flows.Maybe car needs more ventalation to get the air???I still can't find otu how to check cam timing. I know cams are on the corrct teeth but says when tightening you could be off a couple degress... Any way to check? Without taking off valve cover?? Any other ideas?

[KATwo40]

Man, I'm tellin' ya', the best way to get those cams right is to toss the directions out the window.

Forget the timing marks and all that garb...

Once #1 is TDC, align so that the lobes are nearly 180* opposite each other, pointing toward the ports on the head (intake point out, exhaust pointing out).

Now, here's where most get it a little off...

Make sure that, with this alignment, the DRIVER side of the chain is tight, the TOP of the chain is tight and the PASSENGER side of the chain has the slack.

Snap the tensioner in place, rock on.

What turbo are you using, BTW, and how much boost?

[coolbone28]

do you happen to know what your vac is at idle?

[Poor_S13_Driver]

Try pressurizing the system for boost leaks? Seems like that wouldnt really matter since you said you have no problems in the first couple of gears. Just a thought though

[Bosrudorfer]

Try a boost controller

[Florida240sx]

No boost leaks. So how I got about fixing cam timing?Valve cover off break loose the cam bolts. Turn cams a bit and then retighten? Or do I have to remove the whole front system. I hate timing that's why I had someone else build the motor.

[coolbone28]

Whats your vac at idle? It can have a direct correlation with your cam timing. and as far as changing it, you do what you said. No need to take your whole front engine apart just make sure the cams are pointing directly away from eachother after you put the cam gears on. Also bad cam timing would probably give you crappy, rough idle.

[Florida240sx]

What if the ditributor is off one tooth? My car ran crappy when that happened before.... But idle was real bad.... Think I'm taking off the valve cover Sunday. Anybody have any clues on what else it could be? Besides cam timing..... I want my car to be boosting the right way.As it is car runs fine and is choking out. Timing starts to advance. Air/fuel ratio stays in check in mid 11's-12's

[Florida240sx]

Is there a possibility that my distributor is off one tooth? Car wouldn't idle then right? Timing gun shows 20 degrees.... holds idle perfect. Going crazy.

[KATwo40]

20* and good idle = proper distributor installation.

When you check the cam timing, aside from making sure the lobes are 180* from one another, be sure that they are pretty much parallel to the head deck. You want the exhaust side almost pointing directly at the side of the head where the valve cover sits.

[Florida240sx]

Someone posted up abotu a shop that did a full KA-T build and had the same issue. runnign 15+psi and making like half power. Wish I knew more about the problem. It was a cam problem....For instance on the DYNO I had 161hp and 193ft*lb at 10psi Power DROPPED after 4000rpms....I got 3" brm exhaust now and a test pipe so isn't an exhaust restriciton.... Boost gauge keeps constant pressure from the fpr so it isn't an intake restriciton. Got to be cams....I'll make a new thread Sunday with pics when I take the valve cover off.

[NateDogg]

I think we should re-name this ka-t forum to 'Florida240sx' Diary'.

I hope the cams are off so you can fix it.

[LEMHEAD16]

Someone posted up abotu a shop that did a full KA-T build and had the same issue. runnign 15+psi and making like half power. Wish I knew more about the problem. It was a cam problem....For instance on the DYNO I had 161hp and 193ft*lb at 10psi Power DROPPED after 4000rpms....I got 3" brm exhaust now and a test pipe so isn't an exhaust restriciton.... Boost gauge keeps constant pressure from the fpr so it isn't an intake restriciton. Got to be cams....I'll make a new thread Sunday with pics when I take the valve cover off.

Those numbers seem incredibly low 161/193. 10 psi should net you more than that especially since you are at sea level. What kind of Dyno was that on? Whats your compression numbers like?

[Florida240sx]

Haven't checked compression. Car doesn't smoke at all. Power was made up to 4000rpms(right when full spool is) where it then takes a plunge Yea my friend at 5psi stays on my a55 when I'm at 12psi.