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Discussion Starter #1
lo guys ive been in my work shop all day today rebuilding my engine and i thought i take some measurement of my cams ive worked out ive got a 9.7 lift on inlet and exhaust and ive got a duration of 256in and 264ex now to be fare i havent built any modded cars before just standerd original stuff so im wondering if any 1 can explain to me the differences in cams and setups
for example is it allways better to have a high lift or is it allways better to have a higher duration or lower
ive looked on the search but nothing is acctually clear why people have gone for the setup that they have . i would like for people to comment on the cams ive got and tell me why they have gone for the cams they have and the differences it will make thanks to all that join into this confersation
 

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Discussion Starter #2
isnt there any 1 on here that knows any thing about cams and the diff types of setups is every1 just guessing ?
 

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you have to choose the cams depending on what turbo you run and what sort of power you want, a higher duration means that the valves are open for longer and a higher lift means that the valve is opened further, basically if you want power further up the rev range you need a higher duration/lift but this come with lumpy idl;e and sometimes hard starting and if you want more midrange power and quicker spool up you would go for the shorter duration but it will seem to run out of puff further up the rev range different turbos and size engine give different drivability so the cams need to match thes to get the best power for example if you have a monster turbo that doesnt come on boost till 6000rpm and all the power is up the top end it makes no sense to have a cam that runs out of puff at 6000rpm!

hope that helps a bit
 

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Discussion Starter #4
hmm i like the way you explained that so how good would you say these cams are with the setup ive got were would you think the turbo cuts in and what you recon the rev limit is what sort of torque and bhp could i run if there is any1 out there that has similar setup could you tell me what sort torque and bhp figures your getting

87mm pistons (not stroker)
t51s turbo and hard pipes
50mm individual throttle boddies (standard is 45mm)
ported polished head
720cc injectors
cams in 256-9.7 lift
ex 264-9.7 lift
 

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vipes:

running a T51, if you want spool up asap go for the 272 with a 11mm lift if u can, off the shelf cams, most peole with t51 go for 290in 290ex 11mm cams or 280's with 10.8mm lift for max power [bit less head work/cost].

depends what u want/compromise, and your RPM limit/ powerband 2.5k to 4k depending on setup with a t51, boosting hard [1.4bar+] around 5500rpm on your current engine 2629cc, or a t51 can boost hard at 5000rpm on a 3L stroker.

id go 2.8hks/Crower with a 9000rpm limit, personally...

anyway,I run a t51 kai.
 

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also,fitting adjustable cam pullys, you can bring in the boost much earlier with a little work when mapping ;)
 

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and upgrade your fuel system bosch044 pumps x2 in tank

or better-
or 1x b_044 to 2L fuel swirl pot, from pot through 2 bosch044 past twin fuel filters to 11mm fuel rail [1 line each end] and return to swirl pot [from centre rail].
 

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going by some dyno charts i have, plus i have 264/264 9.1mm on a T51R, if you want it adjusted on the cam pullys for earliest spool , your 264 exhaust cam will be running out of puff at 7900rpm, and if you want you limit set at 8000rpm it sounds ok :thumbsup:

if you want a higher rev limit go for 272+ exhaust, and upgrade the inlet cam to a 264, or a 280exhaust and 272 inlet etc etc
 

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good info there l now know lm not relly needing those long duration cams after all.
 

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Discussion Starter #13
i allready have the adj cam pulleys and external pumps in the rear but i think i should mention this. i bought this car about 1 half years ago and ive drove it once but what i can remember about driving it was the boost use to come in about 4000rpm and use to hit red line 9600rpm (hence y ive driven it once. oil pump cracked in 3 places)so this is y im asking these question coz i really couldnt understand y this car was so responsive and just fast in general i first thought it most be because of the throttle boddies it has got with the slight head work it has done but then i thought maybe the cams hence y im asking these questions but i think its just the setup in general as a combined unit it works sweet but there is something defenatly different ive driven lots and lots of skylines and i just cant understand the response and power of this 1

so from what you guys has said it seems like this car is making me out to be a liar
 

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Discussion Starter #14 (Edited)
ohh and turby m8 its a hks t51s turbo old type turbo like t45s but just a fraction bigger and that is some good info given there m8 any chance of posting those dyno readings or if any 1 else can with similar setup
 

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pm me your email and i'l send them over. i've saved them from various websites so if u want to post them up here go ahead. i would, but me and comp's lol....

anyway, the headwork may go a long way to improving your cams going to 9600rpm. you may find your torque drops after <8000rpm but the increasing RPM gives you a flat power curve [torque lb/ft X rpm / 5252 = bhp]
(formula, for anyone interested)


btw - that is a huge RPM limit, did u import drag car?/specs

as for the oil pump cracking 1st journey, was it an n1 , nissan, trust etc ?
i see you mention JE pistons, are the rods and crank standard, id find that suprising for a 9600rpm limit? maybe worth re-ckecking rod+crank??

tomei oil pump, massive sump + maybe Accusump [at that rpm! 9.6k!:smokin:]
 

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Discussion Starter #16
bottom end was all standard on this engine all o5u parts. it was just all the top end and accessary that was uprated i.e turbo,injectors,fuel rail,ext fuel pump etc... so when i blew it i obviously had to uprate the parts.im still building it but it took me 1 year to save for the parts and get the machine work done with out getting in trouble with the misses :) i do wear the trousers in my house ..honest

i did have to buy a crank as well coz my original 1 had a crack in no:1 main and the oil pump wasnt a n1 pump but dont be mistaken even the n1 would have cracked in my opinion . so as it goes my bottom end is now je 87mm pistons ,ths rods,oem crank,acl main and big end bearings assembly all balanced ,tomei oil pump,1.5mm restrictor,trust sump extension,n1 water pump and new core plugs

i didnt import the car so i dont know what it was. all i was really told was it was owned buy a top tuner in jap and he kept it as his pride and joy i did think bollox but when i look at it every thing is mint like new all the bushes even the chasis from under not even a dig in it no jack marks 15000miles on the clock interior looks new so maybe there telling the truth full service history in japanesse mind you

as you was saying it is high for the rpm and the turbo didnt feel bad so when you guys were telling me about the duration and lift it sounded like my turbo should have spooled up slightly earlyer than normal but die by 7500 or 8000rpm or am i wrong in thinking that whats so different?
 
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