RoelSS

iTrader: (3)

Honestly, and this is just my recomendation, you should stick with the 2.99 and stock plugs. Adding a little more boost with the 2.85 creates more heat soak in the supercharger. You'll end up with inconsistent times and races. For example, 2 years ago, I was running GMPP stage 2 with the famous pulley boys 2.8 pulley. Well,I raced a co-worker with a 02 z28 auto, 3:73, Intake, Exhaust. On the 1st race he pulled me by 2 cars at about 100 or so. In the 2nd race, I got walked. I felt the car slower on the 2nd race. But I wondered why. I could only think it was the 2.8. So the next day, I put the original stage 2 pulley, and you wouldn't believe, he got me by 1 car now, and the 2nd time we raced, it was the same result. So in my own opinion, and as proven by my experiment, the 2.8 will not give you better results. But this is just my own experience.
Good Luck!

NJBLUESS

I tried my 2.8 on my STG 3 pcm and felt as if timing was being pulled back. Put the stg 3 pulley back on. When I ran on the dyno, some time back, stg 2 w/2.8 I ran alittle lean on top. Stg 2 runs af pretty rich as we know, somewhere in the 10.x:1 w/21deg. When I logged my stg 3 the other day, 11.4:1 was commanded and 23deg. timing w/stg3 pulley. You run smaller, you run risks and most likely slower, especially when running long.

MidnightNB

Whats kind of afr is stage 3 commanding in race gas mode? I am thinking about running meth, 2.9 or 3.0 and stage 3 pcm with MAYBE nitrous later on down the road and thats the biggest thign I'm concerned about now. I've been told the meth kit depending on the nozzle and which kit should richen me out by 0.5 to 1.0 from the commanded afr, is this right? If so, would I be safe on race gas mode with meth?( I'd turn meth off when I run normal mode)

sput

iTrader: (3)

Hmm.. why wouldn't you just run 100 octane gas while you're in 100 octane mode? You can't tune the stage 3 pcm so it doesn't make sense to take your chances that a certain meth mix would work safely or not.. my opinion.

MidnightNB

Well with meth you mainly lean it out and run more timing. All race-gas mode does is run more timing and maybe run leaner, the leaner part I'm not sure on. The meth kit would run allright anyway if its running a 11.7 afr, beacuse a meth kit would put it to low 11's or high 10's, even though thats not the most ideal, its still equal or better than the afr with stage 2. If race gas mode runs leaner, then I'd be all-set. The main reason for this is beacuse I wouldnt have to worry about only being able to gas-up at the track, and making sure my tank is near empty whe I get there. Meth is cheaper to run beacuse you use so little of it. Also, I can turn the car off, start it in comp mode and turn meth on anytime I feel the need. Anyways, still not sure if I wouldnt just use race gas and not bother with meth, but its interesting enough as an option that I want to know more about how it'd run with stage 3.

distillion

good info, thing is with my 2.85 is that I see no knock though, the car pulls really well. At wot there is not a trace of knock as to before with my smaller pulley and custom tune id get 4 to 6 degrees at random spots in the rpm at wot. Also a few weeks back on a hot humid day i beat the hell out of it for over 2 hours on twisty country roads and zero knock at wot.
i also have an additional front mount heatexchanger, dual pass, option b, and im spraying water.

MidnightNB

My current plan was to just run the 2.9, or maybe only 3.0, and use the race gas mode w/meth whenever I want to run hard. When I dd, the meth'd be off... I know I probably should have cooling mods other than meth if I'm not running it all the time, but when I dd if I even go wot at all, I'm shifting at 4500 or 5000, and thats maybe only a pull or 2 during my drive... I should be ok on that right?

Also, really wondering what anyone knows about running race gas mode on meth. What afr is race gas mode commanding at wot? What afr are you reading on a wideband w/ meth on, and just in general how is it working for you if your using it.

ShortStack

Well, really whast going to happen is that even with meth (high octane), the comp is still going to use the 100 octane commands, so you wont notice any performance from the meth, just the cooling effect...

Im not sure of the afr numbers, but they will be commanded the same with meth or without... unless you custom tune for it..

When i dd, and go wot, i shift outta second and when i get into third i start slowing down, shifting no higher than 6000.. and im fine.. Im sure you will be a-ok...

I guess technically, you could use premium gas, and use meth to boost up the octane to around 100, so you wont have to buy race gas...

distillion

from experience the afr wont really change with race gas unless you go to 114 octane.

RoelSS

iTrader: (3)

I tried using meth with the stage 3, it didn't doanything at all. So I sold the kit, and bought Nitrous.....It worked perfect!!

I tried that as well, the 100 octane mode shuts off.

MidnightNB

Shouldnt it only shut-off if it detects knock? I THOUGHT, could be wrong but I heard that if set-up properly, it will work. Anyone else run this and get better results? BTW, what I meant by asking the commanded afr of comp mode, was I was figuring they might have run it a bit more agressive and lean when running comp mode. The point being that if that would be the case, meth would richen it down to an afr that still wasnt all that rich/isnt losing much power without having to tune(beacuse the ecu is locked)

Also, just wondering, how much whp gain should I expect from a 2.9 and stage 3 pcm w/ its better/leaner tune compared to stage 2's pig rich tune?
On that note, what kind of gains(from JUST going from normal mode to comp mode on race gas) are you guys seeing running race gas mode( using race gas, or if its working for you better than roelss then w/ meth)?

sput

iTrader: (3)

The PCM turns off 100 octane mode when it detects you aren't running at LEAST 100 octane.. for example, if you normally run 93 and you pull up almost empty and dump in 100, turn on 100 octane mode and go take off... chances are it'll turn off on you. (speaking from experience) you need to cruise around for awhile to let that 100 octane mix in and actually start getting used. I think it takes about a 1/4 to 1/2 tank before it will stay on for you on WOT pulls.

Also.. yes there is a definite noticeable difference between stage 2 and stage 3 with race gas. The car pulls soo nice I love it, I really do. I do have mine for sale. Not because I don't like it, but I am learning to tune myself and I need the money to buy bigger injectors and some other stuff.

Let me know if you have any other questions. I haven't ever used meth but I can tell you that stage 3 does kick ass.

MidnightNB

Could it shutting off right after you put in 100 be beacuse the 93 is still in the lines and with the advanced timing the car is knocking on 93? Its just I was sure I heard someone say they used meth and it was working fine once it was set-up properly. Its just I can only get 100 octane either at the track 1.5 hrs away, or POSSIBLY in Ottawa(also 1.5hrs away) if I can find a 100 station there if I look around... I only saw 94 octane there last time but I wasnt looking around super-hard. Right now, Ottawa is the closest town I can even get better than 91, all I can get around here is 91 when I dd,lol. If I could run meth on 100 octane mode, I would be able to have it turned on for when I go to local car club meets and go for a rip out in the backcountry,lol. I mean having it just for the track is nice, but a little more would be good.

BTW sput, I was looking at your stage 3 pcm for sale, and we'll talk price/offers as soon as my stock wheels sell, I'm not getting a load of cash for them beacuse they have curb rash, but it should be enough to work something out with you. I have 1 pretty firm sale on it, but I'm probably going to need to wait atleast 1-3 weeks till buddy gets the money.

sput

iTrader: (3)

Sounds good

MidnightNB

I got this off a faq on occ forums: " Q: What if you turn on the 100 octane mode when you do not have 100octane fuel in the tank? A: The Stage 3 PCM will default to 93 octane mode when excessive knock is detected. If this happens, the shift light will turn off to indicate that 100 octane mode is off."

If this is true, then maybe you were only getting it disable beacuse the 93 allready in your lines was making it knock? If thats the case, and the faq is right about it having nothing to do with 91 or 93 or 100 octane, but on rather or not whatever your running is knocking with their 20+ degrees of timing advance. If thats the case I'd be able to use the meth and just start the car in 100 octane mode anything I start the vehicle. If I dont need it to dd and dont want to burn meth for nothing, then I can start it without race gas mode and turn the meth off. I'm sure a small jet of meth wouldnt richen it out too much since the tune on it ismuch leaner than stage 2.

Anyone have any idea or rather everything I'm thinking of sounds right? I still am new to tuning... so I like to double-check if I understand everything allright

06 GM CobaltSS

Question for you Stage 3 guys, did you have to do a crankshaft sensor relearn when you installed the Stage 3 E.C.M.or if you switch back to Stage 2?

sput

iTrader: (3)

You do have to do a case learn for the stage 3 pcm. You do not have to do it again after that. You can switch between stage 2 and stage 3 without having to do another one. I took mine to the dealer and they did it for free!

distillion

nitrous is in and ready go, havnt sprayed yet.
gonna hit the dyno later tonite.
my question is the arm procedure, is it the same as the high octane mode/adjustable rev limit, where the car has to be in accessories?

Try2k

Meth will work with 100 octane mode, you just have to have the right mixture, nozzle and boost level where it starts to spray. ccp and I have both done this.

ShortStack

I thought it would work....

I read some threads on here saying that it actually DID work... Tested...

distillion

bump for my last question ;P

ebristol

iTrader: (4)

Would you care to share that info?

distillion

so, on the dyno.
first we coudnt get the nitrous to spray but the tune was there.
at 3500 rpm, it dumped fuel in, but no spray.
then tapped into the pcm a lil more, got the spray to work at 3500 rpm, but its like the whole tune was wipped out.
as soon as you mash the gas, the pcm shuts down and goes into safemode.
as soon as you mash the gas, it goes wicked lean, then the pcm pretty much saves my motor from there.
we managed 270 foot pounds of at 4000 rpm lol that was the highlight of the night haha
please help..

its a zex kit btw.

bump.

blownredSS

Has anyone sucessfully ran 100 Octane mode on Stage 3 using Meth? If so what nozzle and what mixture?

ebristol

iTrader: (4)

I am pretty sure that has been talked about in this thread. Did you read it?

I have heard of it being done but I don't remember who said that.