I was wondering if anyone has any dyno sheets for builds using the xp cam. I want to get an idea of how much power other people put down. can you list your mods too please?
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03-14-2015
I was wondering if anyone has any dyno sheets for builds using the xp cam. I want to get an idea of how much power other people put down. can you list your mods too please?
03-14-2015
One guy I know made 285whp with an xp, l67, GenV, 3.2" pulley, 42.5# injectors, SSIC, N*, and ZZP Dyno tune
Another guy I know made 277whp with an XP, L67, Custom ported blower, 42.5# injectors, 3.4" pulley and ZZP dyno tune. (OPEN DP only because his cat was clogging)
I know you wanted dyno sheets and I dont have one for either build, just figured I would give you an idea with these numbers that I know first hand.
03-14-2015
that is good info, but I'm curious about the different power curves possible from the different valve springs used.
03-15-2015
Valve springs don't create power... : )
anyways...
I know it hasn't been updated for a while... But here ya go...
http://www.3800pro.com/forum/cams-he...-cam-chart.htm
03-15-2015
are you saying an xp cam will have the same powerband regardless of the valve spring used, correct me if i'm wrong, then that would mean the only advantage of a higher lb valve spring is a higher rpm range?Originally Posted by coolone
03-15-2015
You will be able to rev it higher with heavier springs, which will create more power.
03-15-2015
Springs - should be used based on lift, cam design (ramp rates), and yes, maybe to a certain (lesser) degree, shift points. You don't need 150lb springs on .530 lift! What's your plan to rev to? You're only making power through a particular rpm range anyway... So where you going?
Springs don't make power. The cars that made POWER on the XP also had accompanying mods, stageIII heads, etc., that allowed higher lift, increased breathing in/out. Springs only allow it to function correctly. My $.02...
LoL there's lots and lots of threads, web pages and info available to help you select the right springs for your valve train/engine build. You could even call Comp Cams and they'd guide you too. No need to guess!
for the record, dyno sheets are subjective and can be skewed, rendering the results useless. Lastly, even different cars with same mods make different power levels, lol, adding in the tune factor that is. So it would be hard to show a dyno unless you do it yourself on the same engine, same day with different springs. ; )
Last edited by coolone; 03-15-2015 at 09:56 AM.
03-15-2015
I just remember a lot of people saying to use 130 lb springs with the xp cam. I asked around and found plenty of people used 90 lb springs, so since I had them already, I used the 90's. I went with a set of L32 heads ported by Chris Hinson.
Wouldn't the power band be similar on all xp cam builds regardless of the heads/spring combo? or do those 2 variables have greater influence than I think?
03-15-2015
No, because the valves will float with 90's with an xp cam. 130's will make more power with an xp cam and stock rockers on these motors, because they can do a better job at keeping the valves under control.
03-15-2015
No they don't
03-15-2015
I ran an xp with ls6 springs and ti retainers. Yes they do.
03-15-2015
I ran an XP on LS6 springs for 3 years in my own GTP. I revved to 6600rpm on the dyno several times, I made 320whp non-intercooled pump gas which was a record which stood for several years from 2003 onward.
I've also used LS6 springs on other XP builds, Intense Stage 2 N/A, S1x, ZZP GT3 (which is two XP exhaust lobes), an Overkill BBC prototype cam with .544 exhaust lift, roughly a dozen Overkill SBC cam with 1.7 rocker setups with .537 lift.
I'd love to know more about why you had issue with the XP/LS6 combo, at least you speak from your own experience unlike most, but I can assure my experience with LS6 springs is that they are awesome, reliable, make the power the cams should, and don't float valves. My more limited experience with CompCam 130#s was poor.
03-15-2015
I asked around before I used the 90 lb springs and found a lot of people have used them with success. I didn't want to buy into the 130 lb idea that zzp puts out there because at the time, the few dyno sheets I saw, had the xp cam making its peak hp at like 4500 rpm, so I figured revving it higher than 6000 wouldn't add a lot.
03-18-2015
If you expect floating valves to act like a rev limiter then you are rigt... you didnt float valves. You were running into rising boost pressure passed 5500 rpms and stagnant flow readimgs from the maf that wouldnt have happened with the right springs.
03-18-2015
Only reason why I didn't care for LS6 springs was the fact that they chewed the ever living christ out of my dampner on my stock chain after 40k.
I never had mine dyno'd, but I kept my shift points at 6200. I doubt that they'd float around 6k anyways.
For the price of 105's or 130's...I don't know why you'd cheap out on LS6's though.
That's just me.
03-19-2015
My personal experience with 130# CompCam in my own vehicle, when I had the springs tested during a head rebuild, the springs had weakened to 115# at 1.80" when they should be 130ish. I couldn't quote the mileage but it was roughly a year of service time. Very disturbing so I never ran them again.
Using the LS6 springs has nothing to do with cheapening out, I trust the quality, and in my experiences I had none of the issues suggested on this forum.
03-19-2015
Will, care to share your thoughts/experience with L76 springs?
03-19-2015
G8 springs wouldn't be near strong enough for a cam setup...leave them on a rocker car.
03-19-2015
The G8/LS4 springs are the older 2001 spec LS6 springs. I have more limited experience with them but I've been recommending people use them if they're worried about tensioner life due to spring rates. They should be very fine for .500 lift cams like the VS and my SBC cam. Its a minor difference from the LS3/LS6 springs in terms of open spring pressure, they match the 105# spring open pressure at .500 lift.
Some stats I pulled out of my notebook:
L76/L92/LS4 Springs:
90# @ 1.8" (Rest)
264#@ 1.3" (.500" lift)
LS2/LS3/02-04 LS6 Springs:
90# @ 1.8"
276#@ 1.3" (.500 lift)
CC 105 Spring:
105# @ 1.8"
262# @ 1.3"
CC 130 Spring:
130# @ 1.8"
297# @ 1.3"
Also, what happened to a double roller chain and 130# springs after a short duration of use, and why I still don't think we have the right valvetrain solutions in our 3800 community after all these years:
https://www.youtube.com/watch?v=w0TO693MhSo
03-19-2015
My Riviera made 296hp to the wheels with an XP cam. I ran 105lb Comp Cam springs.
-Rob
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