AEM Cam Gear tuning

[d_fl8ted1]

we have been working on a 1997 gs eclipse with the 420a engine. we installed stage 1 crower cams, with aem tru time cam gears, the engine also has a venom intake, venom fuel rail, complete exhaust, cold air intake, high flow aem fuel pump and regulator, unorthodox racing crank pulley, and a zex nitrous wet kit spraying 125 shot,,, can anyone give me what they think the best setting for the cam gears are? we have them set at 8 degrees retarded right now(both intake and exhaust), it seem to feel more powerful but our gtech dyno shows this upgrade slowed the car down one second in the 1/4 mile times,,,, please help
thank you

[Import2nr99]

pretty sure that 5 degrees is the setting to go for. don't quote me. Someone like 95gsxracer would probably be able to tell you for sure. and give you a good reason why.

[d_fl8ted1]

is that 5 degrees retarded or advanced

[Import2nr99]

"On a 2g with original cam and crank angle sensors you cant adjust your base timing. Its set to 5 degrees. If you move the cam angle sensor (on the 95-96 its behind the intake cam gear, but on 97-99 like yours you can see it on the pass side of the valve cover) the ECU will figure it out and base will still be 5 degrees.

IF you convert to a 1g CAS you can adjust base timing without the ECU knowing it. The loggers will still report timing thinking there is a 5 degree base. So if you advance it to 10 degrees, and the logger/ECU says 20 degrees, its really 25

Also note that the reason people that swap to 1g 6 bolt motors in 2gs get random misifre CELs that cripple the car is the 1g CAS. So if you go to the 1g cAS you need to do the BS POS hack job baro wire mod, or get DSMlink. If you have DSMlink you can use the 1g CAS, but then again, if you have DSMlink you dont have to change your base to adjust timing, lol


So the short answer is yes, you can change your base, but its a huge pain in the ass. With a turbo car you dont want tons of timing anyway. I use the stock ECU timing maps...

Hope that helps."

*taken from a previous post written by 95gsxracer*
not sure if thats what you're looking for. but as far as my knowledge goes, thats the best I can do for you. try searching the forum and see if you can find exactly what you need. Good luck

[ashah000]

I could be totally off... but 95gsxracer was probally taking about a gst or a gsx. And he is asking about a gs. So it could be different.

[Import2nr99]

true... didn't think about that.

[d_fl8ted1]

so basically we still have no answer, please dont tell me that you can not adjust the timing with these cam gears????? also is that 5 degrees retarded or advanced

[Import2nr99]

well all I truly know is that you advance for low end power and retard for higher end power. so depending on what your goal is you can go from there. it sounds like you have a dyno at your disposal, so just play around and see what works out best for your car.

[kjewer1]

The quote taken above was about ignition timing. This is a question about cam timing. Both are seperate parameters, but some what connected. Changing the timing of your cams changes the intake cams position relative to the crank. On a turbo 2g, the ECU will figure it out and keep base at 5 degrees. Not sure if NTs do the same thing. So be sure when you change cam timing your ignition timing hasnt been adversly affected. The ECU may not know so dont go by a datalogger, use a timing light.

For the original question, I have zero experience tuning cam gear timing. My position on this is if you bought cams that suit the goals for the car, and they are quality cams, you shouldnt have to play with cam timing. Anything you can adjust with cam gears can be built into the cam profile (with the exception of regrinds, which goes back to what I said about quality ). For example, people have found on the turbo cars that the Web cams are not ground on center, so you need to use adjustable cam gears to get them to perform the way the cam designer intended it to. With higher quality HKS cams, they are right on center.

I wouldnt waste time using cam gears to try to make a ton of extra power. Just to shift the power band around a bit. Drop it lower for autox or street driving, or move it higher for drag racing, etc. But again, cams can be chosen to suit whatever goals you have for the car in the first place, unless there is a very limited selection for the car in question.

Wish I could answer the question better, but I have never bother to educate myself in cam gear timing. Good luck.

[daniellebrian7]

hey dlf8ted 1 what kinda horsepower or you running on that thing do you know ? how much were the crower cams ?......also you can call aem the number is on there site and they will let you speck to a tech i know they might have the answer if not just play with it on the dyno ....?