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BigVinnie 07-14-2008 10:45 PM


Originally Posted by alkemyst (Post 369514)

248 (+2.5 adv) / 232 cams
Power is down and I don't know why.

Bingo... It's the advancement of the 248 cam on (INT)
Using the exhaust cam on intake already poses an advancement somewhere around 1.75 degrees. This means that valve lift is opening way before top dead center.
You will want to try setting the exhaust cam 248 at the 4 tooth method as provided and add a 2 degree retard, this will open the valve after top dead center, and make ALOT MORE POWER. You may actually want to try adding more retard than 2 degrees, due to the 232 cam on exhaust, it will make for a better valve overlap...
Right now I use the stock cam set up of 240/248 which the intake valve opens 1 degree prior to top dead center.

alkemyst 07-19-2008 09:59 PM

just dialed it up today to 2.5 retarded. Have to find out in the morning (damn RTV curing :)).

Some of the tools should go back and correct the misinformation given out. Some even have totally changed the numbers they were quoting yet never say 'hey disregard the other stuff, I was wrong'.

Also A LOT of the math is just plain wrong.

Hopefully this fixes my power loss...if not I am going to go back to 232/232. I really wanted to try 240/248...but every dude that mails me cams somehow sends a damaged one (missing an end) or just throws them in a box with no packing and they arrive fuxored. My last ship at least got me a good 248 cam.

BigVinnie 07-20-2008 10:14 AM


Originally Posted by alkemyst (Post 369810)
just dialed it up today to 2.5 retarded. Have to find out in the morning (damn RTV curing :)).

Some of the tools should go back and correct the misinformation given out. Some even have totally changed the numbers they were quoting yet never say 'hey disregard the other stuff, I was wrong'.

That sucks!!!! People with the wrong information can actually do harm to your engine!!!!


Always remember with the KA engine you will probably make more power retarding the intake cam. The KA uses a very long cylinder, and a very long crank rotation, this leaves a lot of room when the highest lift of the valves opens. The more retard you add to an intake valve the more it is like super charging the engine since the cylinder becomes like a suction cup, and also because in maximizes volumetric CC's at the highest point of valve lift.

I don't agree to much with using the 232 exhaust cam. What will normally measure your peek rev range is a much higher lift and duration exhaust cam.
With a 232 as your exhaust cam it will make a lot of low torque power, but probably show a peak RPM drop off at about 5850 RPM showing low HP numbers.

KFL 09-27-2008 02:18 PM

There was a dyno day recently and 2 of my buddies dynoed their stock Ka's with full bolt-ons. There is something wrong.. with the car though..TQ drops then picks back up.. I have to say its some error on s13 248 cam install. As everything else is basic bolt-on exhaust,header,pulley,intake,driveshaft etc. My other buddy who dynoed also had the same issue tq drop off. For the cams I believe it was the 4tooth method for exhaust..not sure what else.I will be checking this car out soon enough since its missing power..mainly tq. (that dip mainly concerns me..)
http://home.comcast.net/~kfl007/dyno2/arthur.jpg

BigVinnie 12-25-2008 07:10 PM


Originally Posted by KFL (Post 373498)
There was a dyno day recently and 2 of my buddies dynoed their stock Ka's with full bolt-ons. There is something wrong.. with the car though..TQ drops then picks back up.. I have to say its some error on s13 248 cam install. As everything else is basic bolt-on exhaust,header,pulley,intake,driveshaft etc. My other buddy who dynoed also had the same issue tq drop off. For the cams I believe it was the 4tooth method for exhaust..not sure what else.I will be checking this car out soon enough since its missing power..mainly tq. (that dip mainly concerns me..)
http://home.comcast.net/~kfl007/dyno2/arthur.jpg


It's probably your knock sensor. If you are using a low grade octane fuel the knock sensor will back off your timing under load. Knock sensor is in use until about 3200RPM. Thats where your dip predominantly occurs is where the knock sensor is during closed loop.
Was your engine upto operating temprature?

alkemyst 01-24-2009 11:19 PM

I am wondering now if my knock sensor may be why I am low on power.

I have no codes, however; my power (dyno on the first page of the thread) drops to 3200ish rpms....

I may swap it out.

sav180 01-27-2009 06:32 PM

try a different cam set-up and bump up the cr


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