DeXter did a great job (Here) of explaining how to calculate the proper location of the holes you need to achieve the advance or retard you want. You don't need to drill 8 holes in each gear. Just do the math and drill what you need. I wouldn't just eyeball it and use a hand drill on it. I have a 3-axis mill and I might just start selling the gears if I get enough interest (and gears are easy to get). I'd take it to a machine shop - probably wouldn't cost much and you can be sure it's done right.alkemyst wrote:How can you get 12 degs adv though? Only gears I know of are JWT and have a +/-10 range.
again though, how you getting 12 degs adv. Surely you have not tested this.RexAtHighSpeed wrote:
DeXter did a great job (Here) of explaining how to calculate the proper location of the holes you need to achieve the advance or retard you want. You don't need to drill 8 holes in each gear. Just do the math and drill what you need. I wouldn't just eyeball it and use a hand drill on it. I have a 3-axis mill and I might just start selling the gears if I get enough interest (and gears are easy to get). I'd take it to a machine shop - probably wouldn't cost much and you can be sure it's done right.
Vinnie, no doubt you've done a lot of testing on this. Do you stand by your earlier claim that 240/248 (e.g. stock S13) makes the best power, or have you found something possibly better for NA power?Bigvinnie wrote:Advancing 12 degress isn't possible on INT, because that would put MAX valve lift right at TDC between stroke 4 and stroke 1. However the intake cam can be retarded 12 degress. What you would need to do is retard the INT cam by 1 more tooth, then advance the cam gear 7degress to give a 12degree retard on INT.
360/19 tooth = 18.94 degrees between tooth count.Then Advance 7degrees on adjustable cam gear 18.94- 7 advanced degrees = about 11.94 degrees or almost the equivelant of 12 degress retarded.
BigVinnie, do you just make this stuff up as you go along? You obviously don't have any idea what you are talking about. You would have to advance the intake cam more than 120 degrees to have peak lift occur at TDC. Heres someone else who advanced the cam aggressively and lived to talk about it... http://www.240sxforums.com/for....html His car runs pretty well and he also put up a spreadsheet showing where his measured peak lift and valve events occurred at. Remember that the difference he saw between 3 teeth and 4 teeth retarded is in crank degrees. My car has the intake at 110 (ATDC) and the exhaust at 108 c/l (BTDC)Bigvinnie wrote:Advancing 12 degress isn't possible on INT, because that would put MAX valve lift right at TDC between stroke 4 and stroke 1. However the intake cam can be retarded 12 degress. What you would need to do is retard the INT cam by 1 more tooth, then advance the cam gear 7degress to give a 12degree retard on INT.
360/19 tooth = 18.94 degrees between tooth count.Then Advance 7degrees on adjustable cam gear 18.94- 7 advanced degrees = about 11.94 degrees or almost the equivelant of 12 degress retarded.
You obviously don't read over your FSM then. INT valve in stock placement already opens 1degree prior to TDC. So if you advance 12 degress more on a 240 or 248 cam then the higher valve lift is at TDC...Thats not making it up, it's in the FSM, you can count the degrees yourself.RexAtHighSpeed wrote:
BigVinnie, do you just make this stuff up as you go along? You obviously don't have any idea what you are talking about.
Yeah...If you can afford it PDM cams kick a$$. Other than that, no one to date has beat my stock NA dyno using 240/248 cams. Or Scotts dyno using 240/248 cams. when some one brings up a dyno with bigger HP numbers using the 248/248, then I'll believe it when I see it. Until then people are still trying to figure out INT cam placement of the exhaust cam 248....Hype wrote:
Vinnie, no doubt you've done a lot of testing on this. Do you stand by your earlier claim that 240/248 (e.g. stock S13) makes the best power, or have you found something possibly better for NA power?
So its obvious that you are running 240/248, but do you have any advancing on it or just stock location. Right now i have intake, high flow cat, and 3in catback. I'm running 248/232 with 2.5 deg advance on the intake,. Do you think that 240/248 would be better?Bigvinnie wrote:Yeah...If you can afford it PDM cams kick a$$. Other than that, no one to date has beat my stock NA dyno using 240/248 cams. Or Scotts dyno using 240/248 cams. when some one brings up a dyno with bigger HP numbers using the 248/248, then I'll believe it when I see it. Until then people are still trying to figure out INT cam placement of the exhaust cam 248....
My cams are in the stock position.sticky_steve wrote:
So its obvious that you are running 240/248, but do you have any advancing on it or just stock location. Right now i have intake, high flow cat, and 3in catback. I'm running 248/232 with 2.5 deg advance on the intake,. Do you think that 240/248 would be better?
You couldn't of said it any better...alkemyst wrote:
Personally it's looking to me that most people that made the best power were using 240/248 cams. For every success story of 248/232-240-248, you will find 10-20 problem installs....and you are lucky to find any dyno proof other than the same 1 or 2 being quoted.
Nope, as a result you can see that OBD2 KA24de's run just fine without butterflys. The MAPS K and CAS values between OBD 1 and OBD 2 aren't that much different from each other. Ignition timing on OBD 2 KA's is just slightly more aggressive and offers a slightly different K value from OBD 1 KA's. Which is a dead give away looking at the differences in the diameter sizes between the G60 MAF for OBD 1 KA's, and the G70 MAF for OBD 2 KA's. So for OBD 1 KA's that aren't bound so much from base ignition timing the distributor can be advanced to compensate, if you can't use an ecu tune/modification.The end result in removing the OBD 1 butterfly's is that the brown solenoid located behind the head on the fire wall should be removed. Any vacuum lines before the solenoid should just be capped off.gingerbredman wrote:i was thinkin.. a 248/248 setup allows for increased top end range, so i'm kinda thinking about throwing it back in for the turbo. would the stock cams hinder the power up top with the turbo considerably?
ugh.. i just want to get it right this time is all.
and as far as the butterflies go i have a couple Q's as i've heard so many opposing stories about them.
1. does removing them affect idle, or low end beyond concern?
2. the butterflies run off of vacuum right? if they do, what happens if the vacuum line isn't hooked up? do they stay closed?
I did the work myself. Had to use a dremel snake to get into the runners.You probably won't believe how far off each runner diameter is stock. To ok alot of hours to make each runner consistent and of the same diameter.Hype wrote:Looks clean man. Did you have it done at a shop or did you rig up some kind of system to push media through the mani? I hope you haven't touched anything else on the car since your last trip to the rollers. Interesting to know what benefit all your effort on manifold flow gets you.
boost is the way to may big power on anything. However some are just happy with a bit more power for a fraction of the coststicky_steve wrote:All of these cams that are talked about in this thread is for the dual cam setup. If your looking for an aftermarket single cam then jim wolf technologies makes one for around $375.00.
http://www.jimwolftechnology.c...tID=2
I have no idea about the HP gains though. To tell you the truth about the single cam motor, if your looking to make big power on the single cam, then go boost. Its better to throw the same amount of money at boosting then it would be to try to go all motor.
If you are using a proper 248 exhaust cam, your 232 exhaust cam goes right back in the same way...keep it in the same alignment.thefralix wrote:i did the 248/248 cam swap but dont really like difference from stock. if i go back to putting the stack exhaust cam(232) back in what do i need to do to set it up.