12353919 "mild turbo" cam discon..

[TurboGTU]

12353919 gm cam discontinued! This was the "mild turbo" cam. I was trying to order it at gmpartsdirect and they mailed me back saying that it was discontinued.

 

I had to go to the crane web site to order it. crane wants $225(i don't know shipping or if they charge), Gmpartsdirect wanted about $150 with shipping.

 

Anyone know where I could get it for under 200?

[skalor]

I think summit or jegs has it for like $159 or so plus shipping. 8)

 

summits part #s are:

CRN-253901 .427/.454 lift one

CRN-253941 .454/.480 lift one

 

I plan on getting the one with the bigger lift as they both have the 112* of lobe separation.

[z24 turbo 93]

would those mild turbo cams be a good upgrade or not......i plan on running 10 psi

[Chris A]

Unfortunately there isn't a whole lot of cam info for the TGP.

 

I CAN tell you the Crane 2030 was not a good choice for the TGP. Too much duration and not enough lobe seperation in my opinion. I don't know if that "mild turbo" cam will be any better or not. I had reasearched this a little for an engine build, and the best replacment cam would be the 2020. Its a step above the stock cam and should provide a little more airflow without having such "high" duration to affect turbo performance. Most turbo cars with cams use a fairly mild cam, most I know of having a max duration of 212/212. A bigger cam might also do well with a bigger turbo to improve the top end airflow, which is what most of these cams will do for the 3.1. But with the same turbo a big cam just won't flow well.

 

One note is this car quickly had other issues. So we weren't able to get any real numbers with it to try and evaluate that cam.

 

Now, I've called a dozen or more cam guys and each one will give you a different answer. Crane told me to go BIGGER than the 2030. I don't have the specs right now but it had much more duration, I think in the 230 range with the same lobe seperation of 109. Compcams said a custom 210/210 should work well. The most consistent advice I have in my notes is TURBOS DON'T LIKE BIG CAMS. So unfortunately it is a try it and see deal.

 

Chris

[TurboZ24]

Usually the biggest turbo concern is intake/exhaust valve overlap. You want to minimize that as much as possible. Most turbo specific cams also seem to have a longer intake duration than exhaust duration, probably to improve exhaust velocity.

 

Now, for example my cam is 254/246@.05", .62"/.60" lift and 114 separation. The actual intake/exhaust overlap is only 5 degrees, which is small considering the duration of the cam. Now, this is a roller mechanical cam, with a 60-1 turbo also and if I can keep it from shattering differential pins and breaking my custom driveshaftshop.com axles, I might actually raise the boost past 12 psi......

[TurboGTU]

I mainly chose this cam because I knew I wasn't going to spin the engine more than 6.2k rpm. That lobe seperation is a whole lot better than the stock 109. I won't run into valve train problems from coil bind and stress, ect.. and tunning the ecm won't be as difficult as with a "big" cam. Now if only the exhaust ports could flow 200cfm..., had forged pistons, billit rods, 190,k tensil strenth hardware, and a huge ball bearing turbo...then it would be a different story.

 

 

Oh man Curtis...your in a different ball game.. I thought that it didn't matter about the intake time..air would be forced in...exhaust would need bigger lobes. Am I misunderstanding some physics...