WS6HUMMER

iTrader: (19)

I read the sticky and it says that a lower LSA could cause boost to bleed off, I have a TR224 on a 112 could this cam be the cause? Its not that much just a pound or two only at higher RPM levels. Here's an HPT log if you'd like to see, I'd just like to know for sure whats causing this.

Aster

iTrader: (9)

I am sure it will bleed off a couple PSI on you. My old setup was a 228/234 XER lobe on a 112+2 LSA. I was down 2 - 3 PSI from what oher people were getting with the same blower/pulley size with a stock type cam.

calongo_SS

iTrader: (7)

I do not think that cam is the cause, it has right around 0 degrees of overlap. Doesn't seem like enough overlap to bleed off any noticeable amount of boost.
Anyway, in a turbo setup WG is referenced to manifold pressure so even if the cam bleeds off boost the WG should close more and spin the turbo a little more and make up for the difference.

If your WG / boost controller is not manifold referenced I would move the vac line so it is.

Sluggish

iTrader: (10)

I am having the same problem. I drop from 12# to 10#. I was thinking maybe my Boost controller is ****. It has coarse and fine adjustments. The fine is completely useless and changes nothing. I am baffled on the problem.

WS6HUMMER

iTrader: (19)

Thanks!
The boost controller is a Turbonetics manual, I have it referenced down stream from the intercooler before the trottle body. I just read the instructions for the boost controller again and noticed that its supposed to be down stream from the throttle body. Guess I can tee off the BOV signal coming from the brake booster line.......right?

calongo_SS

iTrader: (7)

Anything after TB should be ok. Brake booster should work fine. A good manifold reference is pretty critical.

WS6HUMMER

iTrader: (19)

Thanks again.

ls1290

iTrader: (20)

Remember that overlap is not only caused by lower LSA, but also the amount of duration on the intake and exhaust. Between the LSA and size of the durations of the cam, you will be loosing some boost at the end of the exhaust stroke.

WS6HUMMER

iTrader: (19)

That makes sense, thanks.

Grr

iTrader: (2)

I ran a 224/224-112 and it was the best cam i have ever ran. It did not bleed off boost at all, but it did flow a ton of air. In fact mine was bigger than most 224s as it was a 283/293 adv duration with .565 lift. It is far from the cams fault, there is a problem in the piping or boost control

WS6HUMMER

iTrader: (19)

Its got to be my boost controller reference, I have the signal coming from the charge pipe before the TB and Turbonetics instructions says it is imortant that its referenced from after the TB. Dont know how I missed it but I did.

WS6HUMMER

iTrader: (19)

Got the boost controller hooked up the right way this evening. Took it out to make a log and OH MY GOD!!! Is it way faster, I cant keep the tires from spinning!! It spools in a fraction of the time it used to, the boost dosent bleed off, & the boost curve is way more smooth now. Thanks again.