89 k1500 5.7 cam change

dselliott1 · Post by **dselliott1** » Sun Feb 13, 2011 4:39 am

I am very new to tuning and recently rebuilt the engine in my truck with a different cam and I need to tune it. I am thinking about doing it myself but need some guidance for sure. If anyone has any suggestions I would love to hear them. Thank you.

EagleMark · Post by **EagleMark** » Wed Mar 02, 2011 2:06 pm

Depending on the cam specs it could be very easy or very time consuming. Basically what throws the entire stock tune off is a reduction in manifold vacuum. So what are your cam specs?
What is you intake manifold vacuum at idle?

Six_Shooter · Post by **Six_Shooter** » Wed Mar 02, 2011 3:18 pm

I have a few years experience tuning, and just a couple weeks ago, I tuned a friend's car, that all he changed was the cam, from the previous tune, and it took me a couple hours to get it to idle almost stock, even though the cam has plenty of duration, over 274* IIRC, and without the tune would not idle well at all.

Now a first time tuner I would expect this to take a little longer, and you might have to start over a couple times. But if it runs decent as is, as in, idles pretty steady and near stock idle RPM, you won't have to change much, but if it's such a wild cam that it doesn't want to idle very well at all, then you'll be spending more time.

Tuning a vehicle yourself is quite rewarding and you can learn even more about how an engine functions by doing so.

One site that has helped me, is the DIY PROM forum on TGO (www.thirdgen.org). There is a lot of information there and plenty of people talking from real hands on experience.