Enough vacuum?
Enough vacuum? Ok I'm getting a hard pedal on the brakes on my car and I'm thinking it's because of my cam. I'm getting about 70-74kPa at idle. Now this is my manifold pressure right? What is that in terms of vacuum and is that what's causing my brake issues? Thought I might need a vacuum canister.
Ok I'm getting a hard pedal on the brakes on my car and I'm thinking it's because of my cam. I'm getting about 70-74kPa at idle. Now this is my manifold pressure right? What is that in terms of vacuum and is that what's causing my brake issues? Thought I might need a vacuum canister.
70 kpa pressure is 30 kpa vacuum(almost 9 inHg of vacuum)
considering stock is around 30kpa pressure at idle...70 kpa of vacuum(20-21 ish inHg of vacuum)
way to get a manual vacuum pump, and connect to your brake booster... then pump the vaccum out till you see when your pedal gets feeling good again, then suppliment the system with a separate vacuum pump, mechanical, electrical...your choice.
or just deal with the pedal feeling like it does, or switch to a manual brake system with the right valves and plunger to get the feel you desire.
that doesnt really matter....
pretty much any cam that has 4* overlap or larger will have very little Idle Vacuum(meaning it idles higher up in the manifold pressure values.)
cam overlap kills your vacuum
even a 224 cam has some vacuum issues
pretty much any cam that has 4* overlap or larger will have very little Idle Vacuum(meaning it idles higher up in the manifold pressure values.)
cam overlap kills your vacuum
even a 224 cam has some vacuum issues
i had a cam that had 25 or 29*(cant remember offhand, its one of the 2) of overlap and didnt have no brake problems
AGreed. However, with my ms4, I had 9 inches at idle and my brakes worked fine. No difference between pedal with the stock cam.
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Verdad Gallardo get a tune that has a proper amount of spark at idle may help a little, but its not going to be enough to get you back in the same kpa range as stock to have decent vacuum.
Do you think a vacuum canister will help any or will I just have to get a vacuum pump to get a feel back in the brakes?
Last edited by marksboy7; Nov 26, 2012 at 07:13 AM.
