Evo_Goodness

So as the title says i have my tune locked in have my omni 4 bar installed grimmspeed boost controller have my tune dialed in. Injen uper and lower IC pipes injen intake DW200 fuel pump stock evo injectors and now i just picked up a lightly used 3K miles set of HKS 272 cams for $50. can't Complain with that getting ready to install them, but i really am not sure where you start with tuning them obviously you can't just slap them in and make more power.

But my question is where do you start with bigger cams more fuel more timing less timing less fuel cams are new to me and there is not allot of info on tuning cams..

Yes i did search but all i find is can i install cams with no tune i know the idle will need to be bumped but what is it you start with to get power out of cams i know they are bigger and flow more so any help would be great.
Or a little write up on where to start.
I like to figure things out on my own but this is something i don't want to mess up figured out most of my own tuning by reading but not allot of info on where to start with cams

Biggiesacks

I have HKS 274/272 cams, you wont have to do much for the idle, they are pretty mild. You tune cams basically the same way you tuned the car already. Install them and do some runs, adjust your maps if they need it. You will probably be hitting higher load cells that you haven't hit before so they might need some adjusting.

Evo_Goodness

So it's pretty much getting the timing fuel maps dialed in with no knock same way I have been I have my car sitting comfy at 24 pounds tapering to 21 on stock turbo with zero knock after 100s of runs.
I have never been an an evo with bigger cams before is it a noticeable upgrade? Over stock that might sound like a dumb question lol..

Also will the stock fuel injectors be okay I am sitting at 80% injector duty cycle are they enough for these cams ?
Also thanks for getting me set in the right direction man

Raceghost

iTrader: (4)

I ran my Kelford 272's as one of my first upgrades, with similar setup to you. Biggiesacks was on the right path. Fuel and Spark is where your at. Don't forget the Idle stability and timing control table in most ROM's for a little adjustment too. Some startup fueling may need a little tweaking too, as well as ISCV steps at idle in the mid to hot temp ranges, along with possible adjusting the BISS to bring it inline. Nothing major, just a little tweaking for those things. Your Injectors are close to being maxed out, but then the question begs on boost numbers. I ran 23 PSI on your setup minus different cams. Injectors held. Just know your pushing the limits, and a next step will be size of injector upgrade depending on next mod choice.

Hope I helped.

Evo_Goodness

Ya I've been looking into injectors to just didn't know if it was worth putting the cams in with the stockers in there I can even lower the boost some to run the cams if the cams will make more power then a couple of pounds of boost

Evo_Goodness

Also i know you need to data log to find knock and all that but what's the best way to go about it with cams so is it get the idle and get the bridal driving conditions dialed in then do WOT runs to search for knock if no knock add timing fuel or vise versa to get things in check.

I guess what I am asking after you get normal driving conditions 100% set would going WOT be dangerous to find knock or is it really the only way to go about it from I know these are dumb questions but I would rather ask a dumb question then blow something up..

PS I am pretty confident in myself for tuning these just wanted to make sure I did everything the correct way thanks! for all the help

Biggiesacks

You will definitely be out of fuel with the stock injectors. I would suggest doing injectors and cams at the same time so you wont have to double retune. If you really want to get them in there though you could probably lower the boost in the mean time. Street tuning is really where the tephra roms help alot, because of the CEL flash on knock and AFR out of range you can see when thats happening in real time vs after the fact in a log. You will want to get the car nice and warmed up, I usually start with a 3/4 throttle pull to make sure AFR's aren't doing something insane. If they look ok then ill begin doing the full WOT pulls. Ill usually do 3 in a row, then pull over compare the logs, adjust the fuel and if needed timing table and go again. With pump gas you will be hitting knock before you get to MBT so its really about tuning out the knock since the stock tune is too aggressive timing wise for our ****ty gas. Just make small changes at a time and test them until you get where you want it to be and you will be fine. Because your running your MAF there will probably be zero tuning required for off boost driving. If you find you need to improve idle quality you can increase the idle rpm in the rom by a hundred rpm or so, as well as add a degree or two of timing in the ignition map. There are different methods for dealing with the BISS screw if you find you need to adjust it. If your logged ISCV steps are way different then whats in your ROM you may needs to adjust the BISS. I usually do it by adjusting it until the logged steps match whats in my ROM.

Evo_Goodness

Thanks for the reply man ya I was going to get them in there I'll bring the boost down to 20ish psi or so and taper down to 18psi is my plan o figure the bigger cams will have better power output then a few more peak psi. I am looking into converting to tephra just wanted to get my tune solid on small maps before I jump into the big maps if that makes sense..

The wife also said no to bigger injectors till Christmas because that's what she was planning on getting me since she always has a hell of a time getting me gifts lol