Whats a better cam?
TR Balla Donor Supreme
Joined: Jul 2000
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Jay may analysis is this:
the only way to prevent valve float on a higher lift /duration cam, is reduce ramp speed and harmonics. Harmonics are less of the issue here...that has more to do with stresses placed on the rockerarms and lifters. valve float is more of a function of ramp speed of the cam. If you have a 2 cams that are opening the valve for a duration of 264-266 degrees (essentially the same) the one with the slower ramp speed to control valve float is going to open the valve slower. the degree of the cam doesnt measue how long the cam is at max lift...only how long it is open. the slower ramp cam will spend more time at 0-90% open and less time at 100% open. Maximum breathing occurs at 100% open not 0-90%. I'll take the HKS for this reason...faster ramps...but more time at 100% open.
That and i just dont like JWT. Their ECU programs have proven themselves to be garbage tiome and time again. If they cant program ECU's then i don't see how they can possibly design cams...programming ECU's is ALOT easier than designing cams.
the only way to prevent valve float on a higher lift /duration cam, is reduce ramp speed and harmonics. Harmonics are less of the issue here...that has more to do with stresses placed on the rockerarms and lifters. valve float is more of a function of ramp speed of the cam. If you have a 2 cams that are opening the valve for a duration of 264-266 degrees (essentially the same) the one with the slower ramp speed to control valve float is going to open the valve slower. the degree of the cam doesnt measue how long the cam is at max lift...only how long it is open. the slower ramp cam will spend more time at 0-90% open and less time at 100% open. Maximum breathing occurs at 100% open not 0-90%. I'll take the HKS for this reason...faster ramps...but more time at 100% open.
That and i just dont like JWT. Their ECU programs have proven themselves to be garbage tiome and time again. If they cant program ECU's then i don't see how they can possibly design cams...programming ECU's is ALOT easier than designing cams.
THE HAMMER
Joined: May 2002
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Re: Whats a better cam?
Originally posted by gsxxxr750
JWT s3
JWT s4
HKS step 1 256
HKS step 1 264
THis is for an s13 redtop
JWT s3
JWT s4
HKS step 1 256
HKS step 1 264
THis is for an s13 redtop
You have a greddy intake manifold on a T25, and now you want cams..
The problem I see is this.. Your moving your powerband into a place where your turbo can no longer breathe and loses boost (high rpm). The more you move it up there, the worse off you will be. I really think the extra kick you got was almost produced by lag (with the football), because you went from 10-20ftlbs less torque at the same RPM, and then ramped up to maybe a 5hp gain for the last 1500 rpm or something, and the difference was greater than before when it was a steady curve.
I just see it as you hurting youself and making yourself slower. I could maybe understand if in the future you were to get an upgraded turbine, but why didnt you save and do the turbine first? and then the other powerband altering mods later.
Just my $.02
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Thread Starter
Is That Turbo? Psssst!
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chin has cams. and his 1/4mph was at 116. thats high and i am getting a bigger turbo. i am asking my questions so i can put together a series of parts that work well together
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1 h4d c4m5 \^/17h 7h3 570ck 7u|2b0 4|\|d m4d3 270\^/hp. My53lf, ch1|\|, 4|\|d 4 9:1 c|2 m070|2 4|23 7h3 0|\|ly 725 p0\^/3|23d 513'5 1'v3 533|\| 70p 250 \^/hp. 7h3y 4|23 d3f1|\|473ly u53ful, bu7 y0u \^/1ll b3 k1ck1|\|g y0u|253lf 1f y0u d0 |\|07 7u|\|3 17 b/c y0u \^/1ll b3 m4k1|\|g L355 7h4|\| 7h47 \^/17h0u7 7u|\|1|\|g 0|\| 4 \^/1d3b4|\|d.
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[QU073][1]0|21g1|\|4lly p0573d by g5><><><|2750 [/1]
ch1|\| h45 c4m5. 4|\|d h15 1/4mph \^/45 47 116. [/QU073]
1 h4v3 70 4dd|2355 7h15. 7h3|23 15 |\|0 \^/4y 7h47 h15 c4|2 7|24pp3d 116mph. 1m p05171v3 17 \^/45 4 fluk3. \^/17h h15 \^/31gh7 4|\|d g34|25, h3'd h4v3 70 b3 pu5h1|\|g 1|\| 3><c355 0f 350\^/hp 1|\| 0|2d3|2 70 pull 7h053 7|24p5. 3v3|2y 07h3|2 c4|2 \^/17h 7h47 50|27 0f hp 7|24p5 4|20u|\|d 108-110 47 m057.
ch1|\| h45 c4m5. 4|\|d h15 1/4mph \^/45 47 116. [/QU073]
1 h4v3 70 4dd|2355 7h15. 7h3|23 15 |\|0 \^/4y 7h47 h15 c4|2 7|24pp3d 116mph. 1m p05171v3 17 \^/45 4 fluk3. \^/17h h15 \^/31gh7 4|\|d g34|25, h3'd h4v3 70 b3 pu5h1|\|g 1|\| 3><c355 0f 350\^/hp 1|\| 0|2d3|2 70 pull 7h053 7|24p5. 3v3|2y 07h3|2 c4|2 \^/17h 7h47 50|27 0f hp 7|24p5 4|20u|\|d 108-110 47 m057.
