Stalling in traffic with 272 cam gears
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Evolving Member
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Joined: Jun 2005
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From: Pittsburgh & Herndon
Originally Posted by EVOlution561
I am getting cams put into my car this week. I got the HKS 272/272's with the AEM cam gears. A professional installer will do the job for me. Did you install the cams yourself?
I love the cams now that I have the idle adjusted...the car is running perfect.
Originally Posted by gt420hp
I went to Buschar racing in Wakeman, Ohio to have my cam gears installed, the HKS Cams, and the fuel pump. I will warn you that they are not big fans of adjustable cam gears, but I was very happy with the install. They would not tune my car while I was there since I am using the Vishnu Xede....
I love the cams now that I have the idle adjusted...the car is running perfect.
I love the cams now that I have the idle adjusted...the car is running perfect.
Thread Starter
Evolving Member
iTrader: (5)
Joined: Jun 2005
Posts: 203
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From: Pittsburgh & Herndon
Originally Posted by KazzEvo8
Idle adjusted by the screw?
Originally Posted by Ludikraut
-4 intake, -1 exhaust.
l8r)
l8r)
Originally Posted by gt420hp
I went to Buschar racing in Wakeman, Ohio to have my cam gears installed, the HKS Cams, and the fuel pump. I will warn you that they are not big fans of adjustable cam gears, but I was very happy with the install. They would not tune my car while I was there since I am using the Vishnu Xede....
I love the cams now that I have the idle adjusted...the car is running perfect.
I love the cams now that I have the idle adjusted...the car is running perfect.
Originally Posted by Jeff_Jeske
I understand that tweaking cam gears can definately help recover vacuum. However most camps outside of Vishnu claim CG are a waste and a solid idle can be achieved without them.
EDIT: I went with 272s and helix cam gears. I picked up 30WHP and 23TQ pretty much across the entire RPM range using the -3/-3 settings. I didn't lose spool, torque, or horespower anywhere in the band. Idle is choppy but doesn't stall.
Last edited by Jeff_Jeske; Mar 2, 2006 at 08:51 AM.
Originally Posted by unclecomfort
On my tomei cams gear, it stated 1 mark is 2 degree. When you say -4, does it means -4 mark (-8 degree) retard or -4 degree (-2 mark) retard?
l8r)
Originally Posted by Ludikraut
I am not familiar with tomei gears, so I'm not sure what you would set them to.
l8r)
l8r)
Hi guys, any other comments?
I have Vishnu cam gears, and with 272s in my car they were set at -4/-1 (i.e. 4 hash marks left of the center line and 1 hash mark left of the center line).
For reference purposes, here is a pic of a Vishnu cam gear set to -5:
With the 280 cams in my car now, my cam gears are set to +2/0.
l8r)
P.S.: the red dot on the Vishnu cam gears indicates TDC (yes, it's a confusing design).
For reference purposes, here is a pic of a Vishnu cam gear set to -5:
With the 280 cams in my car now, my cam gears are set to +2/0.
l8r)
P.S.: the red dot on the Vishnu cam gears indicates TDC (yes, it's a confusing design).
wow...thks...that's very informative. Thks. Hopefully Vishnu can come in and explain if the setting in your pic is a 5 degree or 10 degree.
It seems like a 5 degree which means I have to set the TOMEI at 2 1/2 mark as per mark is 2 degree.
Thanks a lot.
Calling Vishnu Calling Vishnu.... can you help enlighten me?
It seems like a 5 degree which means I have to set the TOMEI at 2 1/2 mark as per mark is 2 degree.
Thanks a lot.
Calling Vishnu Calling Vishnu.... can you help enlighten me?
What you should do is take a close look at your tomei gears and see if their markings are the same spacing as the Vishnu cam gear markings. The markings on the cam gear shown are literally one degree each. It should be fairly obvious when you compare the "slices" to each other (i.e. a -10 to +10 section on the Vishnu gear vs the tomei gear). If the Tomei gear really does only mark two degrees per marking, then the -10 to +10 slice will be twice as big as on the Vishnu.
... you must sit and meditate upon this ...
l8r)
... you must sit and meditate upon this ...
l8r)
by the way, I seems to recall now. Someone was telling me, a degree on cam gear = 2 degree at the crank.
I believe that is what TOMEI meant. That means, a degree on the cam gear is a degree on the cam gear... I guess this should be right...
really appreciate your help!!!
I believe that is what TOMEI meant. That means, a degree on the cam gear is a degree on the cam gear... I guess this should be right...
really appreciate your help!!!
I just put 272's and cam gears, My car is also idling lump and when i turn the steering wheel it looses some power so it wants to stall but i don't let it. It has stalled twice on me, but now I am used to it and know how to handle it. I am also thinking about raising idle to 1000 RPM's
Originally Posted by EVOlution561
I just put 272's and cam gears, My car is also idling lump and when i turn the steering wheel it looses some power so it wants to stall but i don't let it. It has stalled twice on me, but now I am used to it and know how to handle it. I am also thinking about raising idle to 1000 RPM's
Try what I posted above.
Originally Posted by razorlab
I added approx 6 degrees timing at idle that slightly tapers off back to zero at approx 1750rpm, idle, low and med load, via ECU+, you can do this via the XEDE as well. This smoothed out my idle and gave me half of the vacumn I lost back.
Originally Posted by gt420hp
TUNING TIP: With more aggressive cams (and more overlap), you will lose vacuum. How much depends on the cams themselves. With our HKS cams, we went from about 17 in/Hg (0.6kg/cm2) at idle with the stock cams to about 14.5 in/Hg (0.5 kg/cm2). With the A/C and other accessories running and on the brakes, this could get as low as 11.5-12 in/Hg (0.40-.0.42kg/cm2). You can see how that could cause a problem with stalling.
Since the stock vacuum is on the weak side already, you may find your Evo wanting to stall at idle with aftermarket cams, particularly when driving. Letting off the gas and immediately hitting the brakes is a prime example of the most likely time this will happen (power brake booster uses vacuum to operate). You may want/need to adjust the idle up a hair and possibly add some fuel in with a management system at idle to help "catch" it before it wants to stall when you let off the gas.
The quickest way to adjust the idle is to use the idle air by-pass screw on the top/back of the throttle body. It is basically a big Phillips screw (with an o-ring around it) and it controls how much air by-passes the throttle plate at idle. Obviously, the more air allowed into the intake, the higher the idle will be. Counter-clockwise turns increase idle RPM, while clockwise turns decrease it.
We bumped our idle up to ~950RPM and added 16% fuel at 800RPM just to give it that extra little bit of help. Obviously, you will need to re-tune the rest of your fuel curve to take full advantage of the new cams.
Since the stock vacuum is on the weak side already, you may find your Evo wanting to stall at idle with aftermarket cams, particularly when driving. Letting off the gas and immediately hitting the brakes is a prime example of the most likely time this will happen (power brake booster uses vacuum to operate). You may want/need to adjust the idle up a hair and possibly add some fuel in with a management system at idle to help "catch" it before it wants to stall when you let off the gas.
The quickest way to adjust the idle is to use the idle air by-pass screw on the top/back of the throttle body. It is basically a big Phillips screw (with an o-ring around it) and it controls how much air by-passes the throttle plate at idle. Obviously, the more air allowed into the intake, the higher the idle will be. Counter-clockwise turns increase idle RPM, while clockwise turns decrease it.
We bumped our idle up to ~950RPM and added 16% fuel at 800RPM just to give it that extra little bit of help. Obviously, you will need to re-tune the rest of your fuel curve to take full advantage of the new cams.
My car doesn't stall but I would like a bit smoother sounding idle.
How dangerous is it to add 6 degrees of timing at idle?
Wouldn't adding 16% more fuel foul the plugs fairly quickly?
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