misterp Posted May 25, 2005 Report Share Posted May 25, 2005 interesting i didn't know that about long tubes and f/i. The sound of my exhaust pretty much sucks right now in spite of having good quality long tubes and the corsa touring. At WOT it is loud. So shortie or mid length headers will improve sound quality without sacrificing power? You're not happy because it is loud at WOT? or because the exhaust sounds 'ringier' or 'raspier' at idle? or both? Overall sound volume at WOT would probably be best attenuated with a change of muffler. Factory SS manifolds appear to perform like aftermarket shorties, and shorty headers sacrifice low and mid-range torque for better fit in tight engine compartments. The shortest header I would personally consider would be something like the TOGs or ASMs... Also, headers made of thicker material will be quieter (less pipe ringing) at idle, but most aftermarket headers are made with weight savings in mind so the tubing can be thin, it depends on the manufacturer (ie Hooker headers use very thin tubing and really have a ring to them). Mr. P. Edit - I agree with SSLink, on FI you are exhaling a hell of a lot of gas (compared to intake charge) so OEM manifolds are ditched for headers with larger primary tubes. Link to comment Share on other sites More sharing options...
2nd Sierra Posted May 25, 2005 Report Share Posted May 25, 2005 yes thanks for the reply. I am running cats but they are the high flow variety that come with the dynatech system. I prefer a more 'refined' tone myself and switched out the corsa sport muffler to the corsa touring with good results but the radix w/ 3" pulley just makes it sound like a drag racer any time I jump on it. A nice deep rumble would be nice but I guess it's not worth the time, money, or effort at this point. Anyway back to the original point of the thread.....any idea how your cam might work with my radix and stock lq4 heads? interesting i didn't know that about long tubes and f/i. The sound of my exhaust pretty much sucks right now in spite of having good quality long tubes and the corsa touring. At WOT it is loud. So shortie or mid length headers will improve sound quality without sacrificing power? sorry about the thread hijack btw <{POST_SNAPBACK}> "Sound quality" is pretty subjective and pretty much in the realm of personal opinion. However, longtubes definitely make an exhaust system louder and IMHO also have a tinny resonance. If you're looking for an awesome musclecar/NASCAR sound there's nothing wrong with the "quality," but if you want a more refined tone that doesn't bleed everyone's ears as you drive by and sounds a little more OEM I think shorties are a nice compromise. With any header you will pick up a little increase in valvetrain noise but I can tell you it's not bad with my coated JBA's. The theory about longtubes and blowers/turbos is that the exhaust scavenging properties are not as useful with forced induction. Also, most FI guys choose cams with higher LSA's and less overlap and this also makes less use of the strengths of LT's. I am no exhaust guru but I have been told that with FI gains are more from the increase in primary diameter than from an increase in primary length. I am sure there are many who would disagree and I honestly have no hard evidence myself to back up the contention. On my setup the Touring muffler is quite tame except at WOT. Since you already have longtubes I am not sure it would be worth it to go to shorties or back to stock manifolds. You might lose power going down in primary diameter to what is available in shorties. You may want to try just mounting another straight-thru muffler like a Magnaflow in line with your Corsa to get the overall noise level down. Just a thought - are you still running cats? That also makes a big difference in sound level and rasp. Hope this helps. <{POST_SNAPBACK}> Link to comment Share on other sites More sharing options...
SSLink Posted May 25, 2005 Report Share Posted May 25, 2005 Anyway back to the original point of the thread.....any idea how your cam might work with my radix and stock lq4 heads? <{POST_SNAPBACK}> Should work great. Lingenfelter designed the cam to work in their Radixed Corvettes. Stock smooth idle, good off-idle and off-boost torque, lots of extra pull from 4000-6000 RPM. Again, lack of overlap helps build boost. Big intake duration not really needed for power with FI. High lift and bigger exhaust duration are the tickets. A lot of Vette and F-Body guys use this cam with the ATI Procharger, too. It's a good blower grind with great street manners. Link to comment Share on other sites More sharing options...
FuelSlut Posted May 26, 2005 Author Report Share Posted May 26, 2005 thanks for the help SSLink, right on the money with that one... (good to see you knew what i meant about the whole header situation), I'm running a 2.9" pulley as we speak... not extremely interrested in running with much smaller of a pulley. The whole scaveging thing we were going at all relates to volumetric efficency at the cc, stock at somewhat of 33%, blown at 100% and stock with headers is a step up... get what im sayin? The whole "primary size" also helps either way you go f/i / n/a. I guess what i'll end up doing is a lil bit of work to these heads, a better breathing intake setup (a.k.a volant) and give a good long hard look comparing these cams. thanks again for the help guys... George Link to comment Share on other sites More sharing options...
wkdivr Posted May 27, 2005 Report Share Posted May 27, 2005 Man, that LPE cam SSlink is talking about sure sounds like a sweetheart with the Radix. Wonder how it would work with the new Crane "Quick Lift" rockers? Link to comment Share on other sites More sharing options...
misterp Posted May 27, 2005 Report Share Posted May 27, 2005 yes thanks for the reply. I am running cats but they are the high flow variety that come with the dynatech system. I prefer a more 'refined' tone myself and switched out the corsa sport muffler to the corsa touring with good results but the radix w/ 3" pulley just makes it sound like a drag racer any time I jump on it. A nice deep rumble would be nice but I guess it's not worth the time, money, or effort at this point. You'll be happier if you change mufflers. The Corsa's are straight-thru designs, no baffles *at all* so they rely entirely on wave cancellation for noise abatement. When the RPM is 'in motion' (versus RPM holding steady) there is basically little or no noise cancellation. I'd look for a premium baffled muffler. Mr. P. Link to comment Share on other sites More sharing options...
BenKey Posted May 27, 2005 Report Share Posted May 27, 2005 IMO, if more power is what you want, then you may have to give up "sound quality." Not to the extent of not sounding good, but you seem to worry about everyone else. I'm surprised that your time was as low as it was for stock exhaust manifolds. If you didn't want to mess with your exhaust flow, which I think is even constricted with a Corsa exhaust, then why not do something to bring down your intake temps? They make a supercooler or powercooler (google it), that claims to bring down intake temps enough to get a 50hp gain on lightnings. I have yet to see someone with a radix try one, but many L' guys out there, really fast ones, that do. It was going to be a step I was going to take before I spun cam bearings, so never got there. It's basically, for simplistic explanation, a box that your intercooler lines run through, in a box that can be filled with dry ice, or regular ice, and will cool down your intake temps big time. They run about $500 and it's just a matter of plumbing your hoses over to it in the bed of your truck. We all know that intake temps kill Radix power. The L' use the same Eaton compressor (MP112?) you do. They must know something???? I had planned to run a bypass setup that would use it while I was at the track, then close for normal everyday driving. But, there's no reason you can't keep it in the loop all the time. Link to comment Share on other sites More sharing options...
zippy Posted May 27, 2005 Report Share Posted May 27, 2005 that LPE cam is a very nice piece. before you get into that though i think you may want to look into more injector. Link to comment Share on other sites More sharing options...
FuelSlut Posted May 29, 2005 Author Report Share Posted May 29, 2005 how much more? if its avail. gm part would you have the number? if its a gm part i have no problem what so ever getting ahold of em, thatd be nice zip... if you could help me out there... thanks again guys Link to comment Share on other sites More sharing options...
zippy Posted May 29, 2005 Report Share Posted May 29, 2005 well, it's late and we're here at the shop with the 04'. we put in bigger injectors and worked with the idle issue until it just became a pain in the ass. that was about 12 hours ago or so. we then decided that the best fix to it was a bigger cam. the cam and valve spring swap are being finished up currently. after everyone has slept a bit some tuning will commence and hopefully i'll have some good news to report to ya. with the 2.8 pulley on there and the bigger injectors, fueling it is a cake walk... Link to comment Share on other sites More sharing options...
zippy Posted May 30, 2005 Report Share Posted May 30, 2005 ok, next day. we've changed the injectors again. the 57's we had in there didn't much care for anything below 6ms. it was a constant fight. the next choice was ford svo lightning injectors. just like the cam those were also "laying around" for another project. after the install of the lightning injectors and some mild tuning the truck pulls like hell. unfortunatly due to an issue with 2 bad wideband sensors the remaining tuning had to be done the old school way. the truck now pulls from off idle all the way through rather impressively. traction is now more of an issue than before, but more fun. 2004SS: 2.8 pulley swap, mild cam (specs aren't at hand), 42lb svo lightning injectors. truck already has zippy kit, trailblazer converter, 160 stat, and zippy tune. results... goes like hell and spins nicely coming out... Link to comment Share on other sites More sharing options...
FuelSlut Posted May 30, 2005 Author Report Share Posted May 30, 2005 needless to say, ima need some exact specifications man... numbers, spec, exacts...please please please, dont be like the guy from last night (2002 camaro ss... with a loud whistle at idle...."say hey man, can i see under your hood?" - nah... hood latch is broke...") NOT COOL... ended up twin turbo 2002 ss camaro on stock tires looking for some fun and danger all in one. please zip... give a kid a hand here thanks george Link to comment Share on other sites More sharing options...
wkdivr Posted May 30, 2005 Report Share Posted May 30, 2005 ok, next day. we've changed the injectors again. the 57's we had in there didn't much care for anything below 6ms. it was a constant fight. the next choice was ford svo lightning injectors. just like the cam those were also "laying around" for another project. after the install of the lightning injectors and some mild tuning the truck pulls like hell. unfortunatly due to an issue with 2 bad wideband sensors the remaining tuning had to be done the old school way. the truck now pulls from off idle all the way through rather impressively. traction is now more of an issue than before, but more fun. 2004SS: 2.8 pulley swap, mild cam (specs aren't at hand), 42lb svo lightning injectors. truck already has zippy kit, trailblazer converter, 160 stat, and zippy tune. results... goes like hell and spins nicely coming out... <{POST_SNAPBACK}> What's the difference between the injectors that come in the Radix kit, and the Lightning injectors? I thought the Radix had 42lb injectors. I'm sure liking the way your truck's turning out! Are you planning to catch any of the Power Tour this year? I'm going to do the whole thing, again. Link to comment Share on other sites More sharing options...
zippy Posted May 30, 2005 Report Share Posted May 30, 2005 i'll get the cam specs yet today. i believe it was a 220/224 .571/577. the lightning injectors are also rated at 42lbs. they are rated at 42 though at 43.5psi. the fuel pressure on an 04' is roughly 59psi. calculated out it's rouhgly 49.2lbs or so. with the L injectors i was able to fuel it to black smoke. with the 42's from the radix kit i wasn't able to fuel the 2.8 pulley let alone a cam. Link to comment Share on other sites More sharing options...
wkdivr Posted May 30, 2005 Report Share Posted May 30, 2005 Verrrrry Interesting!!!!! How hard are the L injectors to get to fit. I would suppose you have to change the wiring. So what you're saying, you couldn't get it rich enough at idle to compensate for the leanness at the other end. Link to comment Share on other sites More sharing options...
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