shadowsniper3006 Posted September 26, 2007 Report Share Posted September 26, 2007 Hey guys, I read the 2 articals in hot rod mag. about the lq9 build up and they are real good articals. So good that i have a lot of questions about the future of my motor, so here is my blah, blah and my questions. First i want to keep stock CI, my goal is to hit 12's on stock cubes N/A, i know it'll be a long road there but thats my goal. So after reading their articals and head and cam testing it made me question some of the decisions i've made and future mods. A lot of my questions regard cam shaft choice. A lot of guys here are running tighter LSA's like 112 and 114, mine is a 113+4(i realy don't know what the +4 means in compared to lsa, i know it's 4 degrees advanced but it's still a 113 cam right...not 117?), they tested alot of LSA's and the higher LSA seem to make the best hp and tq combo. the best i can see is the cams with 114 and 115 LSA's. One cam was .531,.531 210,218 114 lsa and the other was .624,.624 232,236 115LSA. The 114 lsa cam has a very impressive torque climb netting the highest torque at 1500 rpm(almost 350) and the most toque overall at 4800 rpm(463), their dyno only went up to 5,600rpm at which it had 462 hp. the 115lsa with much higher lift and duration has a very low off idle torque like 300 and peaks at 462 tq at 5300rpm. It nets the highest HP at 489 but the 114 lsa cam is up to 20 hp more through the RPM up to 5100, maybe making it the better choice for stock rotating assembly racing?? So i pointed all that out to ask this, did i go the wrong direction with my cam, did i pick a cam for a 7000 rpm 408ci motor. Are my shift points way to high based on their dyno results? My cam is .610,.588 224,228 113+4. Would i get better results in the quarter if i went to a 114 lsa with less duration, like the one tested, but maybe kept the higher lift? I know my cam might have potential, but is it best for what i have now? Second, where should shift points be? should they be at peak tq or peak hp? Should they be above it or below it? If a cam bigger then mine peaked at 5300 in torque should i shift lower then 6300 for the best quarter mile ET. From their dyno results i can see the stock cam peaks out 5400 for HP and the 115 cam is still rising strong at 5600, so is my peak HP to high to use? They also tested the Fast 90mm VS the l92 combo and they came out HP ahead with the l92. Right now i have TEA stage 2.5 heads and the l92 heads flow just as good at .6 lift but flow better at lower lifts(i can't find TEA's testing number to see if the 28" of water is the same they used). So if my already ported heads don't flow as good as the non ported l92's, should i jump ship with the TEA's and run l92's? Or should i keep the TEA's and try decking them and running higher compression(right now at 69cc), or run the l92's and deck them? And how do i know how much valve to piston clearance i have? I know this is lot of bench racing, but i think i have a hard to reach goal and i want to spend my money wisely, and get all the info and knowledge i can get along the way. Thanks much Brad Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted September 26, 2007 Report Share Posted September 26, 2007 The L92 combo is no secret weapon anymore. If you can swap to L92 heads and car intake, I say do it. They have already proven up to 550hp on a 6.0L with proper cam selection and L92's on magazine builds. If 12's are you goal, I think you will need to switch. According to zippy, cam selection is a whole different ball game because of exactly what you mentioned about better flow in the lower rpm range. I'm sure between zippy and a couple others on the board, they can get the right cam for you. I know you already put alot of money into the motor and were very disappointed with the results. When I was speaking with zippy about which route to go, I had started out with just a heads and cam idea, he told me not to expect much more than what you got out of your setup. I then stumbled on the radix, but when I asked him about the L92 swap vs radix, he said L92 all the way. L92 with a cam and a 100 shot could get great times, better than what most, not all, but most blowers will do. And if the radix ever pops my motor for what ever reason, thats the next route I am going...forged 370-408 L92 with N2O. Quote Link to comment Share on other sites More sharing options...
detjoe Posted September 26, 2007 Report Share Posted September 26, 2007 good post as I am lost w/my current mod future. I went kind of budget cam and now wish I could have planned it better. cam someone simplify the lsa and the addition of degrees??? what is a 113+4 compaired to a 117 or a lower lsa?? Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted September 26, 2007 Report Share Posted September 26, 2007 The +X means that the cam is ground with X degrees of advance built in. Mechanics have been installing cams X degrees from top dead center to get more power. Some cams were isntalled +3 degrees from TDC, some 4, etc. Some cam designs now incorporate this into the design and you install the cam at 0TDC, but if it has +4, it is like you installed the cam +4 from TDC. I hope it isnt that confusing and I might be having trouble explaining it because I dont 100% understand it myself, but that is the jest of it. Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted September 26, 2007 Author Report Share Posted September 26, 2007 The +X means that the cam is ground with X degrees of advance built in. Mechanics have been installing cams X degrees from top dead center to get more power. Some cams were isntalled +3 degrees from TDC, some 4, etc. Some cam designs now incorporate this into the design and you install the cam at 0TDC, but if it has +4, it is like you installed the cam +4 from TDC. I hope it isnt that confusing and I might be having trouble explaining it because I dont 100% understand it myself, but that is the jest of it. so the cam is still a 113LSA just installed 4 degrees advanced, and is NOT the same as a 117LSA+0? how does instaling a cam 4 degrees advanced differ from adding 4 degrees timing via tuning? Brad Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted September 26, 2007 Report Share Posted September 26, 2007 You are confusing two different types of advance. Timing advance in tuning controls how far in advance the spark occurs. Whether it be 18, 20, 25* before TDC. Tuning can not control when the valves open or close because they are a mechanical event. So to control exactly when the valves are opening and closing in relation to other events in the combustion cycle, you can install the cam "advanced" so the VALVES open and close differently in relation to TDC. Again, not text book explantion, but good enough you should get the idea. As far as your question goes, a 113+4 is not the same as 117+0. The angle between lobes is still the same regardless of the +4 or +0. The angle on the 113+4 cam is 113 and the angle on the 117+0 is 117. Basically what the +4 does is move the events to happen earlier. Quote Link to comment Share on other sites More sharing options...
Vortec MAX Posted September 26, 2007 Report Share Posted September 26, 2007 There are two articles? I think I have one. The article I have does a base run on a stock LQ9, then adds headers, a tune, some different intakes, and finally some Crane roller rockers in 1.8:1 ratio. Is this one of the articles you are talking about? Mike Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted September 26, 2007 Report Share Posted September 26, 2007 No, there is an LQ9 article relating to the L92 heads and intake swap. Quote Link to comment Share on other sites More sharing options...
WI_Dave Posted September 26, 2007 Report Share Posted September 26, 2007 You are confusing two different types of advance. Timing advance in tuning controls how far in advance the spark occurs. Whether it be 18, 20, 25* before TDC. Tuning can not control when the valves open or close because they are a mechanical event. So to control exactly when the valves are opening and closing in relation to other events in the combustion cycle, you can install the cam "advanced" so the VALVES open and close differently in relation to TDC. Again, not text book explantion, but good enough you should get the idea. As far as your question goes, a 113+4 is not the same as 117+0. The angle between lobes is still the same regardless of the +4 or +0. The angle on the 113+4 cam is 113 and the angle on the 117+0 is 117. Basically what the +4 does is move the events to happen earlier. So if I am understanding right a 113 installed at 4 degrees off tdc is the same as a 113+4 installed at tdc. A +4 just makes it so you don't have to install it different? Quote Link to comment Share on other sites More sharing options...
Vortec MAX Posted September 26, 2007 Report Share Posted September 26, 2007 No, there is an LQ9 article relating to the L92 heads and intake swap. What was the date on the mag? I'd like to get a copy. Mike Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted September 26, 2007 Report Share Posted September 26, 2007 It was an LS2 6.0L, pretty much the same thing as an LQ9, except obviously aluminum and the comp. ratio. Its a 6.0L block... http://www.gmhightechperformance.com/tech/...gine_l92_heads/ Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted September 27, 2007 Author Report Share Posted September 27, 2007 It was an LS2 6.0L, pretty much the same thing as an LQ9, except obviously aluminum and the comp. ratio. Its a 6.0L block... http://www.gmhightechperformance.com/tech/...gine_l92_heads/ not the same...i think hot rod magazine, october(with "Barn finds" on the cover) and november(with "bodywork makeover" on the cover) the november goes in depth with cam tests and heads thanks for explaining the lsa and advance of cam. now i wish i had a 114 or 115lsa. Brad Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted September 27, 2007 Report Share Posted September 27, 2007 So if I am understanding right a 113 installed at 4 degrees off tdc is the same as a 113+4 installed at tdc. A +4 just makes it so you don't have to install it different? Correct. Quote Link to comment Share on other sites More sharing options...
zippy Posted September 28, 2007 Report Share Posted September 28, 2007 Wow, that's alot of questions in one. I'm not sure where to start to be of help... Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted September 29, 2007 Author Report Share Posted September 29, 2007 hey zippy, i was hoping you would stop in here! I'm sure you know everything that the articals tested but if you haven't read them it's a pretty good artical with head flow numbers, and like 5 diff. cam changes. but anyway, do you think the l92 is a better way to go then the fast 90 and my tea heads, or maybe ported and decked l92 heads? And do you think an agressive cam, or one with my specs, would produce better on a 114 or 115 lsa to put the power in a more usable range for a stock cubes motor? And were in the torque and HP curve do you want to shift, at peak TQ or at peak HP, or above either? by the way, i just got back from the track and ran a 13.46@99 with the OBX long tubes and no tune update Thanks! Brad Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.