I'm having a bit of difficulty with my brakes now after the 383 rebuild. The cam is the comp cams 224/236 114 lsa cam, runs good, idles at 850 rpm. At which point I see 8 - 10" of vacuum.
I have a bit of a soft pedal and it pushes through to the hard spot with out much effort and no hint of wheel lock up, in fact I need to push with just about all I can muster to get the some lock up.
Once going, I see around 15 - 16" of vacuum on deceleration and the brakes do perform better, though not up to what the brakes were capapble of before the new engine combo. Lock up is very difficult.
Brakes have been bled completely out to the four corners. Still not satisfactory.
Soooo .... anyone else out there running this cam, 224/236 on a 114 lsa need to run a vacuum canister?? Or, are we just having a lot of trouble getting the air out of the ABS box??
thx for any input
LWM
95 Silver TA 11-19-2003, 10:28 AM My friend Maldo had this same problem when we did his motor with the same exact cam. He bled the brakes at all four corners and the pedal was still kinda soft and he did not think it was too good, Then he pulled the car in and re-bled the brakes and it was much better (back to normal).
You should try re-bleeding the brakes again.
Hope that helps,
Claude
BOOST FED 95Z 11-19-2003, 12:36 PM I am having the same problem, using the same cam. I have re-bled mine and the results were no better.
Scott
MEAN LT1 11-19-2003, 03:13 PM I have the same cam and I gert the same amount of vacume as you do. Although its alittle harder to lock the brakes up, it isne tthat bad.
95silvert/a:
Our club has met your freind Maldo and have welcomed him into the club.
rskrause 11-19-2003, 04:13 PM Mine's fine, but it's on a 116LSA.
Rich Krause
95 Silver TA 11-19-2003, 04:31 PM Originally posted by MEAN LT1
95silvert/a:
Our club has met your freind Maldo and have welcomed him into the club.
:) Thats great. I heard you guys are having a F-Body meeting tonite, mabee one of you guys can talk him into putting the blower back on his car, now that he is finally settled in Florida.
If he does not listen to you, Race him after the meet....And put a couple of cars on em, I am sure that will get him thinking about putting that blower back on there :lol: :lol: :lol:
Wish I was down in Sunny Florida with you guys :D
Later,
Claude
Maldo 11-19-2003, 04:32 PM Hi I also had the same problem … but I also upgraded to ls1 brakes… I had to bleed the system a couple of times before the brake pedal was normal. (no problems know)
Oh you also need to bleed the abs unit (it has two bleed screws if not the brake will feel spongy )
Maldo
Maldo 11-19-2003, 04:53 PM Originally posted by 95 Silver TA
:) Thats great. I heard you guys are having a F-Body meeting tonite, mabee one of you guys can talk him into putting the blower back on his car, now that he is finally settled in Florida.
If he does not listen to you, Race him after the meet....And put a couple of cars on em, I am sure that will get him thinking about putting that blower back on there :lol: :lol: :lol:
Wish I was down in Sunny Florida with you guys :D
Later,
Claude
Punk :irk: yeah I know .... i miss the boost ... but I could not trust myself to drive normal :D .. and did not wnat to chew up any parts before i got settled becasue i don't have any place to fix it :confused:
95 Silver TA 11-19-2003, 07:08 PM Originally posted by Maldo
Punk :irk: yeah I know .... i miss the boost ... but I could not trust myself to drive normal :D .. and did not wnat to chew up any parts before i got settled becasue i don't have any place to fix it :confused:
:cry: :cry:
Excuses...Excuses..Quit Your Cryin :D
I dont have any place to work on my car either but the back of the apartment on my back (yeah....real redneck style) and I have to deal with the cold NJ winter too so I dont want to hear that :bs:
Put that blower back on there you Wuss!:p
And Go back to Enjoying Life :cool:
Later Broh....
Claude
96 WS6 11-19-2003, 08:47 PM Originally posted by rskrause
Mine's fine, but it's on a 116LSA.
Rich Krause
Does a higher LSA mean more vacumn at idle??? I had comp grind mine on a 115 instead of 114. Combo told me I should see ~15 in/hg at idle. I don't know that for a fact because I haven't got the car running yet but I should know by the end of the week.
rskrause 11-19-2003, 10:09 PM Originally posted by 96 WS6
Does a higher LSA mean more vacumn at idle??? I had comp grind mine on a 115 instead of 114. Combo told me I should see ~15 in/hg at idle. I don't know that for a fact because I haven't got the car running yet but I should know by the end of the week.
Yes, more LSA = more vacuum (all else equal). I doubt you will see 15in though. More like 12.
Rich Krause
Check for vacuum leaks. I have that same cam and it pulls 14" of vacuum at idle. Never had a problem with spongy breaks.
MEAN LT1 11-20-2003, 03:46 PM Originally posted by CJ
Check for vacuum leaks. I have that same cam and it pulls 14" of vacuum at idle. Never had a problem with spongy breaks.
Damn CJ 14!, I dont come anywhere near that. I get about 11 with the car in neutral and about 10 in gear.
Originally posted by MEAN LT1
Damn CJ 14!, I dont come anywhere near that. I get about 11 with the car in neutral and about 10 in gear.
I guess you need to check for vacuum leaks also :D :D
96 WS6 11-21-2003, 08:20 AM Just got the car running last night and it makes 14 inches at idle.
Originally posted by 96 WS6
Just got the car running last night and it makes 14 inches at idle. :shock:
Even with the stock cam I only saw 15 - 17" of vacuum at the 650 rpm idle. With the 224/236 cam 8" of vacuum at 850 rpm is what I see. Could it be altitude related? I'm at 3,500 feet and the altitude compensator device usually calls it 4,500 feet.
Had the GM Tech tool on the make sure the ABS box was opening its valves correctly so as to facilitate a proper bleeding. Still not satisfactory, so a vacuum can will be going on.
Hope that does it, or else that means there really is some air in there, somewhere deep inside, where only a GM dealer can exorcise it ... :eek:
LWM
96 WS6 11-21-2003, 01:17 PM LOL you need Pope Goodwrench to bring the air demons out. Anywho, I saw exactly 20 inches at idle with the stock cam. It's probably altitude related but I still think 14 inches is good for a cam of this size. I just need to adjust the rockers and bleed the coolant system some more, give it some miles then let er rip!
97WS6SCharged 11-23-2003, 01:55 AM What kind of static compression are you guys running with this cam? Could the lower compression be causing less vacuum at idle? Just curious as I'm planning to put one in my car (stock bottom end, 10.4:1 compression) in the next few months but it has to have good brakes cause I drive it every day. I'm seeing between 18-20 inches at 1k idle now. Hopefully, I'll be able to keep using this cam when I punch it out to 383 CID in a year or two (hopefully 2).
Can went on, and no improvement :(
Can't say I wasn't expecting that, however, their is light at the end of the tunnel. It is now more apparent that there is indeed air in the system.
Bled the brakes down again to all 4 corners, now you can "pump up the pedal" at an idle. There is hope.
Just thought I'd give an update.
LWM
Up from the dead thread pile ...
Final update, problem is 99% solved.
Went to see Pope Good Wrench, they power bled the system and homed all the pistons in the ABS unit, turned the rotors, replaced the pads and then harmed my Visa card to the tune of $250. :eek:
No change ... went back to the boards and got into the adding timing idea ...
Set the idle up to 875 rpm in gear.
Added 5 degrees of timing on closed throttle.
Added 2 degrees of timing in the 400 - 4000 table up to 80 kpa.
Also a few more miles on the engine may have helped things a bit.
Now on deceleration I normally see 14 - 16" and the engine speed while decelerating is around 1,500 rpm. That gives enough vaccum for a good hard stop.
In short the above changes have given me around 2" of vaccum, just enough to tip the scales in my favor.
Now you know
LWM
Roadie 03-19-2004, 02:26 PM good info. I have that cam in a new shortblock waiting to go in the car. we'll see just how useful this stuff is. :)
96TurboTA 03-19-2004, 04:54 PM What did the additional timing do for the idle? Does it idle a bit smoother? I've got that cam in my turbo 383, and the cold start idle is lumpy, and the exhaust stinks a bit until it warms up.
Originally posted by 96TurboTA
What did the additional timing do for the idle? Does it idle a bit smoother? I've got that cam in my turbo 383, and the cold start idle is lumpy, and the exhaust stinks a bit until it warms up.
Idle seems a bit smoother, definitely easier to get it going off a dead cold start. My cold start is an almost flood condition unless I give it 1/8th throttle. Something to do with the cold start enrichment and 42#SVO injectors. I also cut back the AF ratio in the cold parts of that table by a point, that also helped reduce the black smoke and rough idle when cold.
I think that the 875 rpm in gear idle value has more than a lot to do with idle smoothness. It also tends to "creep" a bit more than I like, but, WTF, did I get this thing this far to worry about excessive creep off idle?? Not me ... :)
I'm thinking that it could probably tolerate another 3 - 4 degrees of timing in the closed throttle table and another 2 - 3 degrees of timing in the 400 - 4000 rpm table, especially under part throttle conditions, that is less than 75 - 80 kpa map values.
I might try that, but for now, I can get the ABS to come into play before I get the dreaded "hard pedal".
It's all good
LWM
|
|