Cobb Stage 1 - In The Heat

Jeff@TopGearSolutions · 07-19-2011, 10:29 AM

Direction Injection can run far more leaner then typical port injections cars.

Your typical EVO/STI would normally run about 11.5 AFR.

This car has no problem running 12.5 or leaner. Although most prefer around the 12.5-13.0 for safety but it can be just as safe even leaner.

dzenno · 07-19-2011, 10:31 AM

Quote:

Originally Posted by asrautox

From my understanding DI engines experience more significant cooling from fuel than port injected motors due to a larger pressure differential between the injector and cylinder, and therefore can operate at higher AFR's, higher compression, higher temp., etc.

I would still like an answer to my altitude question. That is really the only thing keeping me from ordering an AP. If it's load based with no boost threshold, those of us at high altitude are more likely to ruin our turbos...

That's not true, no turbos will be ruined with the AP at altitude...the DME compensates for barometric pressure deviations, you'll be just fine..

dzenno · 07-19-2011, 10:32 AM

Quote:

Originally Posted by Jeff@topgearsolutions

Direction Injection can run far more leaner then typical port injections cars.

Your typical EVO/STI would normally run about 11.5 AFR.

This car has no problem running 12.5 or leaner. Although most prefer around the 12.5-13.0 for safety but it can be just as safe even leaner.

Depends where in the RPM range...stock AFR curve up top is 12.75 and I'd never try to run that much up top with high boost and/or especially upped turbos and high boost...low 12s high 11s is the way to go

Rob@Cobb · 07-19-2011, 10:36 AM

Quote:

Originally Posted by themyst

Will you implement a boost ceiling on the stage two mapping or will it follow the stage 1 logic?

There is a boost ceiling on the stage 1 maps and there will be on the stage 2 maps as well. We tuned the stage 1 maps knowing the boost would be in the 13-17psi range. It's no surprise the boost is reaching 16+ psi to us as another vendor might make it out to be. We designed the tune to handle the boost.

What we will be doing is changing the mapping to put a floor under the boost when it gets colder.

Cheers,
Rob

Jeff@TopGearSolutions · 07-19-2011, 10:40 AM

Quote:

Originally Posted by dzenno

Depends where in the RPM range...stock AFR curve up top is 12.75 and I'd never try to run that much up top with high boost and/or especially upped turbos and high boost...low 12s high 11s is the way to go

Unfortunately with any tuning platform there is no number that says 12.75 your motor is safe and at 12.8 your motor is blown. There is a large gray area in tuning.

Also fueling is not even half of the equation, exterior conditions like octane, IAT, EGT, boost, power being made, engine dynamics, ETC all factor in.

Again low 12's high 11's is still for port injection on your typical turbo platforms without DI.

Big supra guys usually dig into the low 11's for safety.

Its a moot subject and very subjective and dependent on other conditions. Mid 12's is a good rule of thumb.

mithiral67 · 07-19-2011, 10:41 AM

Quote:

Originally Posted by Rob@Cobb

What we will be doing is changing the mapping to put a floor under the boost when it gets colder.

Cheers,
Rob

Awesome

Rob@Cobb · 07-19-2011, 10:42 AM

Quote:

Originally Posted by asrautox

From my understanding DI engines experience more significant cooling from fuel than port injected motors due to a larger pressure differential between the injector and cylinder, and therefore can operate at higher AFR's, higher compression, higher temp., etc.

I would still like an answer to my altitude question. That is really the only thing keeping me from ordering an AP. If it's load based with no boost threshold, those of us at high altitude are more likely to ruin our turbos...

Your car will also run ~16psi at altitude. However, that is ok with the amount of headroom the stock turbos have. I have personally tuned a 335i in Denver at those boost levels. The car was quite happy.

Cheers,
Rob

asrautox · 07-19-2011, 10:43 AM

Quote:

Originally Posted by Rob@Cobb

Your car will also run ~16psi at altitude. However, that is ok with the amount of headroom the stock turbos have. I have personally tuned a 335i in Denver at those boost levels. The car was quite happy.

Cheers,
Rob

THANK YOU!!

vasillalov · 07-19-2011, 10:47 AM

Quote:

Originally Posted by Rob@Cobb

There is a boost ceiling on the stage 1 maps and there will be on the stage 2 maps as well. We tuned the stage 1 maps knowing the boost would be in the 13-17psi range. It's no surprise the boost is reaching 16+ psi to us as another vendor might make it out to be. We designed the tune to handle the boost.

What we will be doing is changing the mapping to put a floor under the boost when it gets colder.

Cheers,
Rob

Great post! Thanks for clarifying all this!

Litos · 07-19-2011, 10:51 AM

stupid question: if i really wanted to, could i set up my Cobb for the 91 Octane Tune and then just keep putting 93 in it ??

i got the car back from my wife last week and since then i have WOT the car 3 times leaving work.

first time against a 5th gen SS, second time with another 5th gen SS and yesterday against a Carerra 4S.

i left @ 6:30 from work and it was still in the upper 90's.

Jeff@TopGearSolutions · 07-19-2011, 10:53 AM

Quote:

Originally Posted by Litos

stupid question: if i really wanted to, could i set up my Cobb for the 91 Octane Tune and then just keep putting 93 in it ??

i got the car back from my wife last week and since then i have WOT the car 3 times leaving work.

first time against a 5th gen SS, second time with another 5th gen SS and yesterday against a Carerra 4S.

i left @ 6:30 from work and it was still in the upper 90's.

Yes of course.

Joshboody · 07-19-2011, 10:55 AM

Quote:

Originally Posted by Rob@Cobb

Your car will also run ~16psi at altitude. However, that is ok with the amount of headroom the stock turbos have. I have personally tuned a 335i in Denver at those boost levels. The car was quite happy.

Cheers,
Rob

The head room in the stock turbos is pretty high in the mid-range... does this ceiling decrease at the top? From the logs everyone seems to be around 12ish which is fine, but what happens if you can't reach load at say a mile high? Of course 16psi at 6000rpms would be way too high of a ceiling. Throw on some aftermarket downpipes and efficiency starts to further decrease.

MidwestGolfBum · 07-19-2011, 10:56 AM

Quote:

Originally Posted by Litos

stupid question: if i really wanted to, could i set up my Cobb for the 91 Octane Tune and then just keep putting 93 in it ??

i got the car back from my wife last week and since then i have WOT the car 3 times leaving work.

first time against a 5th gen SS, second time with another 5th gen SS and yesterday against a Carerra 4S.

i left @ 6:30 from work and it was still in the upper 90's.

I typically run the 91 map and put in 93 only because I don't feel a huge difference between the 93 and 91 and it, in my head at least, uses a little less gas.

Rob@Cobb · 07-19-2011, 10:57 AM

Quote:

Originally Posted by Joshboody

The head room in the stock turbos is pretty high in the mid-range... does this ceiling decrease at the top? From the logs everyone seems to be around 12ish which is fine, but what happens if you can't reach load at say a mile high? Of course 16psi at 6000rpms would be way too high of a ceiling. Throw on some aftermarket downpipes and efficiency starts to further decrease.

Yes Sir, there are a few different parameters that make it so boost tapers in the higher RPM range from limiters to corrections factors.

Cheers,
Rob

Litos · 07-19-2011, 12:37 PM

Quote:

Originally Posted by ecjohnston

I typically run the 91 map and put in 93 only because I don't feel a huge difference between the 93 and 91 and it, in my head at least, uses a little less gas.

sounds good.

will probably do this when i have time.

looks like i'll be on the 91 map until October when we dip back in the 80's lol.

secretsquirrel · 07-19-2011, 01:28 PM

Quote:

Originally Posted by Litos

sounds good.

will probably do this when i have time.

looks like i'll be on the 91 map until October when we dip back in the 80's lol.

That sounds like a good idea in my book. 95+ degrees and 50% humidity is a lot to ask for a turbo.

Litos · 07-19-2011, 01:44 PM

i wouldn't be so worried about it if my wife was driving it because she drives like an old woman.

but now that I'M driving it, i've pushed those turbos to 16psi on 3 different occasions over the last 4 or 5 days.

uuughgh..........scary......

dzenno · 07-19-2011, 01:47 PM

Quote:

Originally Posted by Litos

i wouldn't be so worried about it if my wife was driving it because she drives like an old woman.

but now that I'M driving it, i've pushed those turbos to 16psi on 3 different occasions over the last 4 or 5 days.

uuughgh..........scary......

I push RBs to 18psi at least 10 times a day all the way to redline

sometimes A LOT more

just have fun!!

Litos · 07-19-2011, 02:00 PM

Quote:

Originally Posted by dzenno

just have fun!!

i was HAHA !!!!

p.s.
for a basic Cobb Stage 1, ETS FMIC and DCI a Carerra 996 4S is pretty quick from 60-120 lol.

vasillalov · 07-19-2011, 02:03 PM

Quote:

Originally Posted by Litos

for a basic Cobb Stage 1, ETS FMIC and DCI a Carerra 996 4S is pretty quick from 60-120 lol.

What does that even mean?

Shellacked135i · 07-19-2011, 02:08 PM

It wasnt English, that much we can agree on.

Litos · 07-19-2011, 02:10 PM

Quote:

Originally Posted by vasillalov

What does that even mean?

sorry you don't understand basic english.

here it is Sesame Street style:

i ran a Carerra 4S from 60-120 - my car has Cobb Stage 1, ETS and DCI - Carerra 4S is pretty quick

if you couldn't understand that, then everyone that has responded to your junk posts must be on to something.......

07-19-2011, 10:29 AM	#155
Jeff@TopGearSolutions 3441 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	Direction Injection can run far more leaner then typical port injections cars. Your typical EVO/STI would normally run about 11.5 AFR. This car has no problem running 12.5 or leaner. Although most prefer around the 12.5-13.0 for safety but it can be just as safe even leaner.
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07-19-2011, 10:51 AM	#164
Litos Banned 220 Rep 2,991 Posts Drives: 2012 Challenger RT Junk Join Date: Dec 2010 Location: Houston/Pearland iTrader: (1)	stupid question: if i really wanted to, could i set up my Cobb for the 91 Octane Tune and then just keep putting 93 in it ?? i got the car back from my wife last week and since then i have WOT the car 3 times leaving work. first time against a 5th gen SS, second time with another 5th gen SS and yesterday against a Carerra 4S. i left @ 6:30 from work and it was still in the upper 90's.
	Appreciate 0 Quote

07-19-2011, 01:44 PM	#171
Litos Banned 220 Rep 2,991 Posts Drives: 2012 Challenger RT Junk Join Date: Dec 2010 Location: Houston/Pearland iTrader: (1)	i wouldn't be so worried about it if my wife was driving it because she drives like an old woman. but now that I'M driving it, i've pushed those turbos to 16psi on 3 different occasions over the last 4 or 5 days. uuughgh..........scary......
	Appreciate 0 Quote

07-19-2011, 02:08 PM	#175
Shellacked135i Banned 6 Rep 348 Posts Drives: 2010 135i, 09 335xi Join Date: Jan 2011 Location: SoFla iTrader: (1)	It wasnt English, that much we can agree on.
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