Cam choices
01-08-2016, 11:12 AM
#1
Cam choices OK, Some of you know that I am building a turbo LQ4 for my truck. I bought a TU2 cam for it here on the forums but apparently this is too big of a cam due to overlap and I would have to run a good twin setup or a huge single. I haven't decided which way I am going yet. Plus I don't want to turn the crap out of this engine due to it being a SBE build.
What I want is the most aggressive cam I can get but still be able to run an S475 or S480 sized turbo if I go with a single and not have to worry about backpressure issues. Its a race truck and it should sound like one. Its not going to be any fun making 900 or so rwhp and it idles like my wife's stock truck.
So post away and help me choose a cam. Martin, Speedinc ect.. Come on in.
What I want is the most aggressive cam I can get but still be able to run an S475 or S480 sized turbo if I go with a single and not have to worry about backpressure issues. Its a race truck and it should sound like one. Its not going to be any fun making 900 or so rwhp and it idles like my wife's stock truck.
So post away and help me choose a cam. Martin, Speedinc ect.. Come on in.
01-08-2016, 01:20 PM
#3
Weight is 3350 with driver right now. This will change some. I will be removing stuff up front like fender wells and some minor items. But I will be adding all the turbo stuff and a full cage later. So total will increase unfortunately.
Trany is currently up in the air. If I am going to street drive it, which is most likely then I will probably go with the TH400. I currently have the 4l80e which I have heard can handle pretty good power. I might stick with this and get a convertor for now until the next trany is built. If it turns into a pure strip truck I will then go to a PG.
I know, the details are important. I have done this a bunch of times with getting my converters for my dragsters. I just don't have it nailed down just yet. And it should be fine with whatever I go with right now since I can stall for what it needs later. And I am not after a pure 100% go as fast as possible at the track kind of time right now.
Trany is currently up in the air. If I am going to street drive it, which is most likely then I will probably go with the TH400. I currently have the 4l80e which I have heard can handle pretty good power. I might stick with this and get a convertor for now until the next trany is built. If it turns into a pure strip truck I will then go to a PG.
I know, the details are important. I have done this a bunch of times with getting my converters for my dragsters. I just don't have it nailed down just yet. And it should be fine with whatever I go with right now since I can stall for what it needs later. And I am not after a pure 100% go as fast as possible at the track kind of time right now.
01-12-2016, 05:41 PM
#4
The cam selection would depend on whether you chose the S475 or the S480 and what size turbine wheel, exhaust housing and downpipe is being used. Each of those turbochargers is capable of supplying a different amount of airflow at different pressure ratios based on their compressor and turbine wheel arrangement along with what exhaust housing is being utilized.
Your engine will need a certain amount of airflow to create and sustain the power you need to run the E.T. you're after at your trucks race weight. Both turbo's mentioned will have different characteristics in terms of the amount of airflow they can supply at a given engine speed.
The cam needs to be matched as best as it can be to what the turbo is able to supply in terms of airflow, and the RPM in which the turbo can supply that airflow.
Your engine will need a certain amount of airflow to create and sustain the power you need to run the E.T. you're after at your trucks race weight. Both turbo's mentioned will have different characteristics in terms of the amount of airflow they can supply at a given engine speed.
The cam needs to be matched as best as it can be to what the turbo is able to supply in terms of airflow, and the RPM in which the turbo can supply that airflow.
