fesgali

I've been reading around and seen things like cam surge, vacum for the brakes, etc that happen after goin to a after market cam.

Could someone explain what they are, why it happens and how to fix them.

Compstall

Jack Nicklaus, errr, NICHOLSON-like smiling in, "The Shining, Tim Allen grunting sounds, among others are some common side effects after a cam install.

Evil Eric

yes, the lope of the cam shaking the whole vehicle has been known to cause looking at people beside you at stoplights with that same wild eyed grin. if you dont get a tune, your idle may not be perfect, it causes my alternator to let the lights dim just a tad when i pull out. i have a few driveline mods that cause me to bog under light throttle conditions though

shoebox

LOL , it may even make Jack Nicklaus (the golfer) to smile like Jack Nicholson (the actor). ROFL

Compstall

So my typo was funnier....damn, oh well I tried, but you still got the point..

fesgali

so whats cam surge? and what is the thing about brake vacuming?

Seal

the car feels like its stutterring, and brake vacum is when it really becomes hard to brake lol (cuz the cam is sucking all the vacumm)

WS Sick

Depending on the size of the cam you may experience NONE of these side efffects.

I had the CC305 and the ZZ9 cam (ZZ9 is very simular to the hot cam, but the lobes are quicker) in my 93 T/A and experienced no surge or brake vacumme loss, but I did have a rougher idle and until the tune was dead on nailed I had an eye wattering exhaust.
In most cases it is the overlap between the two lobes (intake and exhaust) that cause the problems , the more overlap the more serious the effects will be.

fesgali

would a cam like the 230/236 XE or the one right under it experience this problem?

WS Sick

Yes, to a point, the surge could be tuned out almost completely, but if you had say a 3000 stall converter the surge would be almost completely unnoticable. The brakes would work fine, you really would just notice a little extra effort at stopping.

Don't let this stuff scare you away, it is not even probably half as bad as what you are thinking.

fesgali

How could the issues be resolved?

WS Sick

The cam surge will be ther because of the overlap, you can only lessen its impact with tuning, but it will still be a little lumpy. The brakes can be worked around, you can either move to an electric vaccuum pump (expensive) for the booster, or youcan enlarge the vaccuume can that the car has, a coffe can is about right. but I just did nothing but the tune and converter for mine and have no problems with stopping, the effort is slightly greater, but nothing of an inconveinience.

mojorisin

where is the vacuum can? anyone have any pics?

WS Sick

From Shoebox's site.

http://shbox.com/1/vacuum_tank.jpg

Thanks again Shoebox for the excellent info.