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GSC S2 mivec settings

12K views 18 replies 11 participants last post by  BlueX702 
#1 ·
So, I'm about to tune my car with these cams with a 2.2/EF4 combo
At the moment i have the Intake set to 10 and the Exhaust set to 0 while i run it in. the idle is smooth at 950 (i could probably go lower) and off boost the car feels great.

I vaguely remember seeing a few "pro tuners" comment on how the GSC S2's mivec setup is a little different to what they had used for other cams. Whatever that means.
I'll no doubt spend many hours on the dyno trying different things...
but if anyone is willing to share their knowledge with these cams, no matter how general the tips, that would be great :)
Obviously i don't expect people to post maps that they have paid good money for, i respect a tuner's intellectual property.

I have to say I'm tempted to go to a well respected US tuner with experience in similar setups and ask/pay for advice. There's not too many setups like mine floating around down here in kangaroo land at the moment... but there's quite a few 2.0 and 2.2 FP Black cars out there now which will be using pretty similar maps so that's what i would base it on.

General ideas - these cams run a lot more overlap inherently than OEM and even stage 1s (which we go nuts with mivec on), so my thinking is that a lot less "aggressive" mivec settings will be the go, at least for spool up. midrange and top end will require some experienting.
anyways .... thoughts?? ideas?? practical experiences??
 
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#3 ·
^Yep we did/are doing our motor installs in the same shop, i see him a lot :)
TBH i haven't asked him (he's been an awesome help with a bunch of other stuff over the years though!) - i don't know if he's developed maps for these cams yet in any meaningful, dyno tested sense just yet.
If it was kelford A or Bs, or GSC S1s, or MX1, i would be all over it. I've got dyno proven maps now for those, often with thanks to initial help from others who have tuned them many times before.

I'm more asking because i remember reading that these cams behaved "differently" somehow. but hey maybe i was dreaming :)
 
#4 ·
stock works well :D haha

seriously, I doubt you can run much if any overlap on boost, so it's really just fiddling with spool...

when we have more time to invest in Daz's car (after its been run in a bit more) we can test all that stuff out...
 
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#6 ·
I agree with Tephra, pretty much any overlap on boost just leans things out like crazy with these big cams. I was able to make good power with some trial error on the intake side. 25-28 degrees during spool up had worked quite well for me.
The exhaust I leave very stockish on these cams. Bigger turbo's cars yield good results by carrying the intake cam advance out into boost. on the stock turbo any advance over 5K did virtually nothing.
 
#7 ·
Thanks guys
Tephra - guess we'll both be doing some experimenting on the dyno in the weeks/months to come
Shadowcell - much appreciated. pretty much what i have gathered from playing with other cams - the bigger the turbo the more advance you can carry through the rev range
 
#9 ·
^^ yes too much overlap during spool will cause it to surge.
and the "bigger" the cams, the less mivec you need to make it surge.

You might want to try slightly less aggressive mivec during spool
 
#11 ·
bumping this for questions for the application of these s2's with a stock turbo... my 8 LOVES my kelford 272 with the stock snail but it seems my X may need some fiddling with mivec to get these cams working great.

also, what is the idea behind tuning mivec for fuel economy? would you to retard intake and advance exhaust?
 
#13 ·
just try more and more overlap until you get compressor surge.
Then once on boost I tend to wind the EX cam back close to zero and run more IN overlap.
You really need trial and error though, you can advance these cams too far and you'll lose power. not like stock cams where you just smash out the midrange advance and hope for the best :)
 
#15 ·
Not quite
because increasing mivec overlap will mess with your boost, lean out your fuel, and change your optimal timing.

best bet when you're doing it :
lower your timing a few degrees, and add say 1.0 fuel in the rpm range you are playing with. rich is safe!!
you might start with say -15 and +20 during spool. see how it goes.
crank up the IN advance until you get some surge, and back off a bit after that. test it in 4th aswell, maybe even 5th. you don't want it surging on the highway when you go to overtake etc.

you will notice your boost sucks when you advance your mivec overlap. so make sure your fuelling is safe, then set your boost again.
Then get your fuelling sorted again (you may be surprised how much it leans out when you wind up the overlap - check after every run!)


but yeah, mivec should be the first thing you dial in. because it will affect everything else.
 
#17 ·
Instead of adding overlap 5* at a time like with the stock cams, only do it 1* at a time since the gsc's flow a good amount more air.

You will have to add a good bit of fuel, but you should be able to get that red to hit full boost well below 4k rpm.
 
#18 ·
I just installed some GSC S2 Cams and currently I am having a hard time finding what I need to adjust in ECUFLASH to get my car to Idle with out staling. Any advice?
 
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