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dyno sheet for xp cam build



Overkill said:
You're running 3-4 psi more in the first video and I can tell you're running a different supercharger pulley. Did you test your valve spring theory without changing any variables?
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Both runs are on a 3.0 pulley. It was just way colder in the first video. Obviously, you can see that the valves floated.
 


90s have a very high seat pressure and full extend.
105s are a great spring to use with the XP, Can be safely ran on the stock chain and has enough pressure for the cam. No need to overcomplicate things
 
the boost gauge flickers that one time, and it sounds like the car is starting to shift, so i'm wondering if the two actions correlate.
 


Those who shift on a dyno with an auto at WOT are those who don't understand locking in a gear (such as 3rd at a low speed) to do the pull are those people who shouldn't be running a dyno.

Especially the ones that just floor it at 20 and run it to 200 mph.

SWEET NUMBERS
 
GTPpower said:
Both runs are on a 3.0 pulley. It was just way colder in the first video. Obviously, you can see that the valves floated.
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I can see the blip you mean and that shouldn't have happened but to say they went away with the 130s in that video comparison there's obviously a boost factor at play, and I would have liked to have seen a scan with a wideband AFR to see other factors were at play.

I'm not trying to be a dick about it, don't get my intention wrong, but as mentioned I have a lot of first hand positive experience using LS6 springs and a lot of success, so someone telling me now that I was doing something wrong I have difficulty with without some very definitive rationale. You've given the best counter arguement so I'd like to know more.
 
ADecker said:
90s have a very high seat pressure and full extend.
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90# and 105# IS THE SEAT PRESSURE RATING.

ADecker said:
105s are a great spring to use with the XP, Can be safely ran on the stock chain and has enough pressure for the cam. No need to overcomplicate things
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XP cam, 105# valve springs and a stock chain and tensioner is not a recipe for a durable setup. I remember one customer who ran that setup and replaced his tensioner after a couple years of service time, describing it as doing the replacement just in time.

On the flip side, I've had two customers who did double rollers, Rollmaster doubles, who had their chains stretch so much it finally wanted to jump a tooth, chipped the gears and the motor failed. One was after only 3 years of service time but 60k+ miles. By comparison, several motors I was building 8-10 years ago with the JP double roller chainsets, including my own GTP, are still going strong. When Rollmaster bought JP and the quality went to crap, I was disappointed because JP seemed like the right choice.

Anyhow, we can debate springs and chains all day long, I'm still convinced that many builds will have a 3-4 year lifespan. If we were more LS like with our parts availability, we'd do 130-150# springs, a trunion upgrade in our rocker arms, and a strong durable timing chain and non of this would be a debate.
 
Overkill said:
I can see the blip you mean and that shouldn't have happened but to say they went away with the 130s in that video comparison there's obviously a boost factor at play, and I would have liked to have seen a scan with a wideband AFR to see other factors were at play.

I'm not trying to be a dick about it, don't get my intention wrong, but as mentioned I have a lot of first hand positive experience using LS6 springs and a lot of success, so someone telling me now that I was doing something wrong I have difficulty with without some very definitive rationale. You've given the best counter arguement so I'd like to know more.
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It's not only me though. Lots of people have experienced the same thing I have. All the great engine builders will always recommend 130's. Tischler, PRJ, Janice, etc.
 
GTPpower said:
It's not only me though. Lots of people have experienced the same thing I have.
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Any links or names?

All the great engine builders will always recommend 130's. Tischler, PRJ, Janice, etc.
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PRJ would put 130s on anything, he and I had our fair share of bantering 10+ years ago. I can understand a motor shop like Tischler suggesting 130s for good measure but I don't know how many 3800s they actually set up from scratch or their long term results.

Again my concern on the 130#s is quality, and timing chain life. I'd consider the PAC 1218 130#s, they have a good rep, but you'd never see CompCam 130s in my engine again due to failure issues, and Manley springs for the same reason. I don't think there's any timing chain on the market currently that you can anticipate will last more than a few short years, which 130s don't help with. I had extensive experience with GM LS6 springs without these issues, on 2.x pulley 12-13psi 6200rpm shift point cam and cam/rocker packages, no boost spike/valve float/trouble making horsepower issues, I never had a spring failure, I trusted the quality, I never saw a need to go for anything else. When I switched to Vortec valves, I ran 110# factory LS7 springs, again not an issue, they worked great, and I trusted the GM factory quality.
 


I didn't read thru the whole thread but I have a dyno sheet from my run, are you still looking? It's from my Fiero with a L67 Gen V N* XP cam 140# springs, 3.1 pulley and a double roller chain on a Mustang dyno. I have a copy of the run I can post but he did let off early because he felt fuel pressure was dropping, since then I upgraded my pump but won't be back for another run till next week.
 
JCircs said:
I didn't read thru the whole thread but I have a dyno sheet from my run, are you still looking? It's from my Fiero with a L67 Gen V N* XP cam 140# springs, 3.1 pulley and a double roller chain on a Mustang dyno. I have a copy of the run I can post but he did let off early because he felt fuel pressure was dropping, since then I upgraded my pump but won't be back for another run till next week.
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post it up, that would be great.
 
5DC971A6-B6EF-407B-ABAC-CCE2764CA39D.jpg

This was done on a Mustang dyno (the heartbreaker) not the final tune, as you can see it was still making power at 5750rpm when he shut it down. With the current setup it revs to about 6250 before shifts but he seen it slightly loosing fuel pressure, I since upgraded the fuel pump to the DW300 and need to go back for final adjustments.
 
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