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justin-overland 02-22-2013 09:32 PM

big cam install help
hi. i wanna get a inertia motorsports srt max camshaft. its 218/223 duration.
i have a few questions.
-what push rods do i need? size? specs?
-what valve springs do i need? specs?
-do i need a tune? if so do i use an actual plug in tuner or could a shop modify my ecu?
-also could the tune be optimized for the cam / cai / and my massive 4in straight pipe?

jeepgcoman 02-24-2013 06:30 PM

Re: big cam install help
What all are you changing, or have you changed?

Several of us have done the cam mod., and I would recommend you first check with the cam manufacturer as to what valvetrain components they recommend. Many of the use stock SRT pushrods and springs. I installed the FRI Engineering Sidewinder cam in both my Hemi's and used all SRT exhaust springs and SRT pushrods. If you're going to pull or replace the heads, it's a no brainer on changing the springs, but if you leave the heads on (like I did on both my Hemi's) you'll need (among other things) a Crane Cams Hemi valve spring compressor (modified) to change them. Since I had the springs off, I also replaced the valve seals, even though they didn't really need it.

Everyone says you MUST have a custom tune done or it won't run. Because of this comment, I tried mine with the stock tune, and it ran fine. Didn't get the maximum power out of it, but it ran and drove down the street fine. Ultimately, depending on how radical your cam is (mine is a relatively mild torquer, MDS compatible cam) you should probably get a Diablosport tuner and a CMR tune specific to your application. I still use the canned tunes, and I am happy with it. I could probably gain more with a CMR though. I am currently running the Superchips 91 tune, and have reset the transmission shift schedules/torque management to suit my needs, using their Advanced TRansmission Tuning Application. IMO, it's worth its weight in gold.

What kind of exhaust headers are you running? No matter what you're running, the 4 in. system may be too big, and cause more torque loss (than the cam will) than a smaller system would. In any case, have fun. If you need any help, I for one will be glad to give you some pointers/hints.

justin-overland 02-24-2013 11:00 PM

Re: big cam install help
ok thanks for the info. im only changing the cam, rods and springs. the exhaust is %100 custom. its oem from engine to cats then custom y pipe to 4in straight pipe the rest of the way. would it hurt the engine to run it without a tune?

jeepgcoman 02-25-2013 02:52 PM

Re: big cam install help
If you're running the stock 5.7 exhaust logs, you're not going to get anywhere near the full benefit out of the cam. If you haven't seen the thread I did on the stock logs vs. the stock LX logs, here it is: Better yet would be custom headers like I did, or get the stock SRT manifolds, which are basically headers. As a comparison my headers are individual tube and have 3 in. collectors, the stock LX's have 2 5/8 in. and the stock WK's have 1 7/8 in. collectors. With either of the logs, you still have quite a bit more restriction than with an individual tube header. There are plenty of writeups about this.

What are the specs. on your cam and does it still retain the MDS? If it is not "MDS friendly", you'll have to pull the heads and change the MDS lifters. If you're just going to change the springs/pushrods with the heads on, as I said, you'll need the Crane Cams valve spring tool. It won't hurt the engine to run without a tune, but if that's your plan, you might as well leave it stock, because you won't realize much gain at all. Mine with the "canned tunes" is quite a bit better but probably not as good as it could be, and if you use a Diablosport tuner you can adjust WOT fuel and timing, which is a plus if you're not planning to get a CMR tune.

justin-overland 02-25-2013 10:04 PM

Re: big cam install help
its the srt max cam by inertia motor sports. duration is 218/223. its says msd is possible with proper tuning. im definitely going to get it tuned just was wondering. also whats the diff from the Diablosport and CMR tune? this is my biggest problem i dont under stand all the tuning stuff.

jeepgcoman 02-27-2013 06:12 PM

Re: big cam install help
The Chip Master Revolution (CMR) tune is a product of Diablosport. It is a custom tune that is tailored to your specific vehicle, after you have done some data logging (with the DS tuner) so they can make the proper adjustments. You may want to get with the Inertia Motor Sports folks and see what exactly needs to be done to get the results you're looking for.

justin-overland 02-27-2013 08:26 PM

Re: big cam install help
ok thanks for all the help man

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