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XP or S1X

well i was just wondering if anything else would break due to higher reving...humm maybe i should look at some different cams. but i see you got the car together huh..
 


The 3800 is pretty sound to rev high. The bottom end is, at least. The valve train is what needs to be able to keep up. Plus having enough potential to feed/exhaust the cylinders at 6k+ RPM.
 
so i wouldent be throwing out any bearings or anything like that above 6k?? and all i would need is stiffer and bigger valve springs??
 
This thread needs some proof :) I too would like to see some dyno numbers on these 2 cams or more opinions...Tranny man told me to run the S1X in his opinion it was a better cam and you would see better results???
 


fratzke7 said:
This thread needs some proof :) I too would like to see some dyno numbers on these 2 cams or more opinions...Tranny man told me to run the S1X in his opinion it was a better cam and you would see better results???
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Trannyman is right IMO. I can only tell you on a daily driver (no dyno or hard documention) the S1X even with 2.93 gearing felt more impressive than my current XP with 3.29 gears. Tuning is a big thing, and both of my setups were tuned by those that truely know tuning, so we can throw out that variable.

As far as how high to rev, look at the dynos and see where the peak HP is being made, just like Bio mentioned. IIRC the ones I've seen, have peaked before 6K. Going much above that is not going to help, unless when it shifts it's not dumping you high enough into the powerband. Even then I'm sure there is a balance between losing HP by revving too high and not dropping high enough into the RPM after the shift.

The PRJ LL cam looks real promising. Don't discount it out yet. Someone Paul just setup with this cam posted some results over on the big board...looked pretty good to me.
 
jacobmh27 said:
and what cam would be better with Stock heads for a More Daily Driver feel with not so muck MPG Loss
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VS, XP, or S1X. I really didn't pay attention when I had the S1X, but on my way home from Trannyman's place after he did the 3.29 gears and XP cam, I got 33 MPG @ 65 MPH through central IL.

VS has the smoothest idle but is the lowest HP maker. XP is very good, but IMO because it bleeds off too much boost, isn't the greatest on the low end torque. S1X idle is the roughest of the three, but makes great HP and still feels strong in the low rpm low throttle position range.

side note: it has been pointed out before that the clearances are pretty tight when using the XP with stock heads. However, most running the XP, like I am, have stock heads.
 
After driving a few cars with both cams i would say the S1x is a far better cam, especially cars with stock gearing. Peak HP numbers mean nothing when you have very little power below 3500. Boost bleed off is to much with an XP. Both work with stock heads just fine as long you use #105 springs and aftermarket retainers. If using nitrous or 3.29-3.69 gears then the XP seems to be a better choice depending on a few other factors. Most people have to run a 3.0 pulley just to get 10-11 PSI with the XP.....its not optimal to have to spin a blower that fast for those boost levels. A headers primary size also play a big part of where torque and peak power will be.

Ron vogel made a chart with all of the 1/4mile times and which cam works best with differant gearing.

Dont worry about what RPM the blower is still able to make power till. Its the horrible high RPM breathing design of the series II that will hold you back. its just not ment to rev that high...no matter what cam or heads you have. If you want to rev high get a series I.
 
what about a series III??? and if i have 3.29 gearing the xp might be better then?? im liking the s1x because i like my low end power. but then again i want to be competitive and make good power along with the other cams..
 
blowfishRus6 said:
what about a series III??? and if i have 3.29 gearing the xp might be better then?? im liking the s1x because i like my low end power. but then again i want to be competitive and make good power along with the other cams..
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I have 3.29 gearing and an XP, but still think the low rpm low throttle postion is lacking compared to the S1X. Unfortunately that is where 90% of my driving takes place.
 


IndeedSS said:
I have 3.29 gearing and an XP, but still think the low rpm low throttle postion is lacking compared to the S1X. Unfortunately that is where 90% of my driving takes place.
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okay. strait up performance, WOT. do you think the S1X makes about the same power as the XP??
 
okay. im more looking for a cam to work around 1500 to about 6000k and the xp seems like it works a little higher in the rpm range. i guess dyno sheets would settle this for me. does anyone have any links??
 


im on it...there was a pdf file of a desktop dyno that compared a bunch of cams one was the xp and i belive the s1x was on there too...if i could find it...im still looking so sit tight
 
im on it...there was a pdf file of a desktop dyno that compared a bunch of cams one was the xp and i belive the s1x was on there too...if i could find it...im still looking so sit tight
 
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