building a 408 NEED A BAD CAM W JUICE
01-04-2008, 09:46 AM
#23
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my heads flow 338 intake and 248ex i have a fast 90/90 compression is 12.1 to 1 but i think my 1 3/8'' jet hots are not doing any good for me! i will get new ones win i get the $ but can't get the car to hook up now so i am working on that before anything!
01-04-2008, 10:03 AM
#24
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I'm just saying, if you're running that much cam and that's all it does, why bother with a cam that big, all you're doing is hammering valvetrain senseless, if the bigger is better theory really was true you should be making about 50 hp more then you are, that cam to me is obviously too big, or there is a big restriction somewhere that it's trying to overcome, and can not.
01-05-2008, 01:41 PM
#27
A stock motor will gain 20 hp from a header upgrade, I can only imagine a 408, 12-1 compression with a good size cam...
That is the first thing I would do and I think you'll be surprised in the gain you make.
I'd look into a 1 7/8 - 2" stepped header, you have the cubic inches and cam to make good use of it. I don't think it's at the level to run a straight 2" primary yet though.
We run a 2" to dual 3.5 exhaust with a 406 and it made right around 780 on the motor with conservative timing.
That is the first thing I would do and I think you'll be surprised in the gain you make.
I'd look into a 1 7/8 - 2" stepped header, you have the cubic inches and cam to make good use of it. I don't think it's at the level to run a straight 2" primary yet though.
We run a 2" to dual 3.5 exhaust with a 406 and it made right around 780 on the motor with conservative timing.
01-05-2008, 03:01 PM
#28
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yeah i was going to get 1 7/8-2'' but then i got my bill from LME for the 408 i was out of $ but thay did a grate job!! I will get the 1 7/8'' i need a diff now so thats next but i will post win i get thim with new #'s! I hope it makes 570rw i am happy with it now i am looking back for my buddys on ther R1's all the time 
01-07-2008, 02:51 AM
#29
yeah i was going to get 1 7/8-2'' but then i got my bill from LME for the 408 i was out of $ but thay did a grate job!! I will get the 1 7/8'' i need a diff now so thats next but i will post win i get thim with new #'s! I hope it makes 570rw i am happy with it now i am looking back for my buddys on ther R1's all the time
01-23-2008, 04:28 PM
#32
I am about to try something a little different for a cam right now. I'll let you guys know if it works out. I am not getting the MPH or ET that I should be getting for the amount of spray that I am hitting it with. I too am running the Jethot 1 3/4" headers. I spoke to the American Racing Headers guys about the new 2" headers at PRI. I need to get me some.
01-25-2008, 09:48 PM
#33
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BTW, OP..... mines fer sale!
01-25-2008, 09:53 PM
#34
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what does that stupid big cam idle like too, that thign must be cranky as hell. 'd love to see what that makes for power and where, as well as what intake you are running.
To be honest,if the 845 rwhp/770 rwtq #'s are with a 300 shot, that big as cam isn't doing you any good at all. Hell my 402 with 1/2 that cam thru a th400 with a 5000 n/a converter makes 480rwhp, which I guarintee would be a good 550 thru a stick. I guarintee if I hit mine with 300 hp of nitrous it's gonna make alot more then 845 too.. hell with a 150 shot it pushed a 3500 lb car to 9.63@139, do the calculator that's in the 750 rwhp range, on 1/2 the nitrous.
To be honest,if the 845 rwhp/770 rwtq #'s are with a 300 shot, that big as cam isn't doing you any good at all. Hell my 402 with 1/2 that cam thru a th400 with a 5000 n/a converter makes 480rwhp, which I guarintee would be a good 550 thru a stick. I guarintee if I hit mine with 300 hp of nitrous it's gonna make alot more then 845 too.. hell with a 150 shot it pushed a 3500 lb car to 9.63@139, do the calculator that's in the 750 rwhp range, on 1/2 the nitrous.
meanwhile those fellas with those peaky big duration cams are hitting peak at 6500.... shifting at 7300 but losing 100-150ftlbs down low... hard to make that up..... except for more nitrous down low? Sound about right?
01-27-2008, 02:01 PM
#35
yeah... I learned something. You are hitting the nitrous at 4krpms and using it with high cylinder pressures to about 5600 or so..... so for that 1600rpms (the most important area in the rpm band to make power) you are making more NA power down lower and with the increased cylinder pressure are making more overall power. I assume the dyno has a taper effect from the torque bleeding off to redline, Never seen one fall flat on its face
meanwhile those fellas with those peaky big duration cams are hitting peak at 6500.... shifting at 7300 but losing 100-150ftlbs down low... hard to make that up..... except for more nitrous down low? Sound about right?
meanwhile those fellas with those peaky big duration cams are hitting peak at 6500.... shifting at 7300 but losing 100-150ftlbs down low... hard to make that up..... except for more nitrous down low? Sound about right?
02-03-2008, 12:45 PM
#38
Ok, I was running a Comp XER 244/248 612/615 on a 111(+3). The car was running a 10.71 @ 125.8 on motor and then on about a 300 shot (max flow for a -4 line), only getting to a 9.51 @ 142. I could really feel the car start to fall down above the 6700 RPM mark. I have been talking to Tony Mamo about swapping cams and going to an LSK lobe as there are higher durations available. He recommended against it as the LSK lobes have huge lift which does not benefit the AFR head (mine peak around .595 on the flow bench). He recommended that I hold off a bit until he could set something up with Crane in order to try some of their lobes which offer more duration while keeping the lift under control. I also ran this by JPH who was the only one that I saw was running or talking about Crane Cams. Both JPH and Tony Mamo cam up with the same cam without knowing that I was talking to the other so I decided to give it a shot. It's a Crane LSHS 246/256 624/624 on a 114(+2). This thing pulls to the moon. It will be a bit before I have track times to back this up but I did line up next to an 8.80 @ 154 MPH TT TA with solid prep and no traction issues and beat him. See video in the Street Racing section.
Last edited by 98Z28CobraKiller; 02-25-2008 at 10:36 PM.
