dr_hunt Posted October 4, 2006 Share Posted October 4, 2006 Why would you want to spin it past 6K anyway? You break things at high rpm's! His graph shows the HP and TQ dropping after 6K. Time to shift baby! Nice engine, great results, enjoy! Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 4, 2006 Share Posted October 4, 2006 For road racers you want to ride ride at the peak of the hp curve, so that when you shift you just have to pull the car over the hp crest, then shift again. I would figure a drag racer would be faster doing the same, but I am not a drag racer. The "problem" if you want to call it that, is that he redlines right at peak hp. If he could just get a little further, then with a relatively close ratio trans he could stay between say 375 and 403 hp even between shifts. If he shifts right at 403 hp then he might drop down to 330 or 350 hp when he hits the next gear. At least that's what I seem to remember in a thread from about 2 or 3 years ago that was all about gearing and hp curves, etc. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted October 4, 2006 Share Posted October 4, 2006 Yup, which is why we built my LS1 to make the peak power around 6K with a reev limit of 6750. The plan was to be able to spin the motor to about 6500 and shift, keeping it in the meet of the power band without dropping off to much. It's still hard on a motor running constantly at those RPMs... Friend of mine running in the SCCA Runoffs this year has an LS6 motor in his 2002 Z06. He missed a shift at Memphis and in the dyno session the following week they noticed about 12HP Peak loss... Further investigation showed broken valvesprings on two cylinders. Granted, that was a missed shift, but from what he's telling me, they go thru a LOT of valvesprings in T1. And they are spinning those motors up to 7200RPMs for 30 minute races. Mike Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 4, 2006 Share Posted October 4, 2006 That begs the question: Are they limited to stock valvesprings in T1? Quote Link to comment Share on other sites More sharing options...
Mikelly Posted October 4, 2006 Share Posted October 4, 2006 They sure are, which is even more maddening... There are a BUNCH of known failure issues on the C5s in T1, which is why they're getting the snot kicked out of them by the Viper and why they're getting moved to T2 next year... Scca finally got enough buyers to commit to building/ fielding the new Z06 next year, so all the 2004 and older C5s and all the NON-Z06 specific C6s are getting bumped to T2... huge shuffle in the platforms is in the works for many of the classes next year... Don't buy a used race car, or build a new one before things shake out with SCCA in November. Mike Quote Link to comment Share on other sites More sharing options...
silicone boy Posted October 5, 2006 Share Posted October 5, 2006 Heck, that ain't nothin'. My Honduh Civic makes that kind of power with a cat back and a cold air intake. I run 9's in the quarter and outrun Mustangs, Vettes all the time. My friend with a Viper won't race me. Quote Link to comment Share on other sites More sharing options...
ULISES Posted October 5, 2006 Author Share Posted October 5, 2006 Heck, that ain't nothin'. My Honduh Civic makes that kind of power with a cat back and a cold air intake. I run 9's in the quarter and outrun Mustangs, Vettes all the time. My friend with a Viper won't race me. This is why I have the Festiva,For guys like you.... Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted October 5, 2006 Share Posted October 5, 2006 Heck, that ain't nothin'. My Honduh Civic makes that kind of power with a cat back and a cold air intake. I run 9's in the quarter and outrun Mustangs, Vettes all the time. My friend with a Viper won't race me. LOVE THE SIG!!! Quote Link to comment Share on other sites More sharing options...
silicone boy Posted October 6, 2006 Share Posted October 6, 2006 This is why I have the Festiva,For guys like you.... I don't trust Festiva's. I've had my head handed to me on more than one occasion. Quote Link to comment Share on other sites More sharing options...
z ya Posted October 8, 2006 Share Posted October 8, 2006 Sick numbers.....Very nice ride! Quote Link to comment Share on other sites More sharing options...
dead2me Posted October 8, 2006 Share Posted October 8, 2006 did you have to change valve springs to run that cam, or did the stock LS2 springs handle it ok? Quote Link to comment Share on other sites More sharing options...
ULISES Posted October 8, 2006 Author Share Posted October 8, 2006 Sick numbers.....Very nice ride! Hey, Were you on the yellow Flagged Z @ kingdom? The LS2 Z had to be raced on street tires,Someone took the key to my lock's out of the car and there was no way to install them.I tried my best to get them installed but I was rushing since friday.There is alway's a next time. Even if we had installed them there was no time displayed so there was no point.It did better than we thought on street tires though,That Q45 rear diff is a good way to put the power down. Quote Link to comment Share on other sites More sharing options...
1 tuff z Posted October 9, 2006 Share Posted October 9, 2006 ulises, do you have any pics of the front mount you fabb'd for the q45 diff install you could email me? Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted October 9, 2006 Share Posted October 9, 2006 Hey, Were you on the yellow Flagged Z @ kingdom. If you mean the yellow Z with purple flags on the side that was me.... LARRY Quote Link to comment Share on other sites More sharing options...
ULISES Posted October 9, 2006 Author Share Posted October 9, 2006 Springs were changed for this cam,I dont know if the stock ones would hold. I dont have pictures of the diff mounts,I will take some the next time my car goes on a lift. It was the yellow Z with purple flags. Quote Link to comment Share on other sites More sharing options...
280Z28 Posted October 10, 2006 Share Posted October 10, 2006 ULISES - I was like some SERIOUS numbers for an LS2, thinking it was stock. :haha: Nice cam that must sound amazing. These motors have some trouble with the stock bottom end at high RPMs. Here's me letting off at 6500 because I don't want to blow it up. Quote Link to comment Share on other sites More sharing options...
LS1 240Z Posted October 10, 2006 Share Posted October 10, 2006 These motors have some trouble with the stock bottom end at high RPMs. Here's me letting off at 6500 because I don't want to blow it up. they dont have issues with 7000 or even more RPMs, based on that dyno sheet you should go higher in the RPMs LS1, LS2, LS6 springs should only be used with the stock cams or with a cam with smaller specs. comp 918s are good for cams up to .6 lift, for antyhing more than that patriot gold duals are the best budget minded choice for up to .650, comp 921s are very expensive, but also great Quote Link to comment Share on other sites More sharing options...
280Z28 Posted October 11, 2006 Share Posted October 11, 2006 they dont have issues with 7000 or even more RPMs, based on that dyno sheet you should go higher in the RPMs LS1, LS2, LS6 springs should only be used with the stock cams or with a cam with smaller specs. comp 918s are good for cams up to .6 lift, for antyhing more than that patriot gold duals are the best budget minded choice for up to .650, comp 921s are very expensive, but also great The valvetrain is fine. Patriot dual springs and trickflow pushrods. It's the rod bolts that are the problem - they're stock and taking a beating with that power level, but they're supposed to hold up as long as I keep the revs down. If 7150 is the limit, sure I'd make 10 more hp to rev to 7000, but that's not really a safety margin before the second big bang Quote Link to comment Share on other sites More sharing options...
LS1 240Z Posted October 11, 2006 Share Posted October 11, 2006 i dont want to sound like an ass but i know my LSx ♥♥♥♥. 97-00s have the weak rodbolts that stretch and break at higher RPMs. 01-04 LS1s and all gen 4 motors have much better rod bolts that have seen 7k in several cars. if you go on LS1tech look at what all the other LS2s are reving to. i know a kid around here that reved his 99 LS1 with cam, bolt ons and nitrous up to 8100, it lasted that way for a couple of years before it finaly gave out. i put katech rod bolts in the motor i built so that i can spin to 7500 or more Quote Link to comment Share on other sites More sharing options...
280Z28 Posted October 11, 2006 Share Posted October 11, 2006 Mine's a 99. I didn't realize they changed them later; I'm using ARP in the new motor anyway so that should be off the mind. I'm curious how much his curve stays up if he ran it to 7k. :hmm: Quote Link to comment Share on other sites More sharing options...
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