Stage 1.5 vs 2.5 5.3L heads...how to choose exhaust valve size?
11-20-2005, 10:07 PM
#2
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1.55 is fine, unless you get a BIG cam. If not, I've read it could hurt performance to go too big.
Get a matched package. That's more important than flow numbers, etc.
My 1.5 package runs great. No dyno or time slips yet though.
Get a matched package. That's more important than flow numbers, etc.
My 1.5 package runs great. No dyno or time slips yet though.
11-20-2005, 10:41 PM
#3
The cam is spec'd to LPE's GT2-3......207/220 .572/.579 118.5 LSA.
Already had the cam and want to keep it because of the stock idle, can't hear a thing. I'm still wondering if I should jump to LS6s, but figured with a small cam, the 5.3s would be better off. LMK what you think now that you've got the specs.
Already had the cam and want to keep it because of the stock idle, can't hear a thing. I'm still wondering if I should jump to LS6s, but figured with a small cam, the 5.3s would be better off. LMK what you think now that you've got the specs.
11-20-2005, 11:10 PM
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Originally Posted by Pimpium57
The cam is spec'd to LPE's GT2-3......207/220 .572/.579 118.5 LSA.
Already had the cam and want to keep it because of the stock idle, can't hear a thing. I'm still wondering if I should jump to LS6s, but figured with a small cam, the 5.3s would be better off. LMK what you think now that you've got the specs.
Already had the cam and want to keep it because of the stock idle, can't hear a thing. I'm still wondering if I should jump to LS6s, but figured with a small cam, the 5.3s would be better off. LMK what you think now that you've got the specs.
11-20-2005, 11:18 PM
#5
Originally Posted by FUN LS1
That's not a big cam, go with the stock valves 5.3 heads.
How much loss/difference in power are we talking about here? Where in the powerband?
11-21-2005, 12:01 AM
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The bigger valves won't hurt, they'll help, just not as much at the low end as the high end of RPM band, and the 208 intake duration doesn't suggest a very high power band. In fact, those Stage 2.5's are just crying out for a bigger cam, like a 224/224 114. You can still get a good idle witha good tune. Personally, I's want something a lot bigger, but I love the lope...
11-21-2005, 12:35 AM
#7
If it's in the high end, then great.....I'm most concerned with how fast the car goes at WOT!
I'm looking for the car to turn the fastest street/track 1/4mi runs while keeping that completely stock-like idle and running GM heads. I would go AFR, or even some more extreme LS6/243s if I were going with a more radical overall setup (mainly bigger cam & stall). I figured the 5.3s would be the best bet (esp. for the money), and the Stg. 2.5s would bump the powerband higher, therefore, turn a faster time.
I'm looking for the car to turn the fastest street/track 1/4mi runs while keeping that completely stock-like idle and running GM heads. I would go AFR, or even some more extreme LS6/243s if I were going with a more radical overall setup (mainly bigger cam & stall). I figured the 5.3s would be the best bet (esp. for the money), and the Stg. 2.5s would bump the powerband higher, therefore, turn a faster time.