2700 rpm stumble on Cobb Stage 2 map?

tshrey · 07-23-2008, 05:56 AM

Anyone else experiencing this? Under moderate loads (normal acceleration with the AC on) I get a hell of a stumble at 2600-2700 rpm. First and second are most notable, probably because you go through the spot so much more slowly in higher gears. I want to see if others are having this same problem before I ask Cobb to take a look.

I know, a protune will take care of it, but I want to do a few more things to the car before a protune and the nearest tuner isn't very close.

ManInABox · 07-23-2008, 06:06 AM

mine does it as well only when the car isn't warmed up.

spongebobnopants · 07-24-2008, 12:00 PM

Quote:

Originally Posted by tshrey

Anyone else experiencing this? Under moderate loads (normal acceleration with the AC on) I get a hell of a stumble at 2600-2700 rpm. First and second are most notable, probably because you go through the spot so much more slowly. I want to see if others are having this same problem before I ask Cobb to take a look.

I know, a protune will take care of it, but I want to do a few more things to the car before a protune and the nearest tuner isn't very close.

Mine stumbled slightly in that range on the the Perrin and Cobb map. Never happened on stage 1.
BTW this only happens when your driving normal and not WOT.
I called Cobb and they said it was normal.

On my latest Perrin S2 map I have had a more pronounced stumble in that same range about 3 times. I may have had the AC on each time, but not sure.

FlashEngineer · 07-24-2008, 12:15 PM

Mine does with the cobb 1.01 stage1, and perrin 1.00 stage1, both 93octane. I'm using Perrin rev3 and it has no stumble, that's the only one I would use, I drive way more in part throttle than WOT so I want smoothness, even if the other 2 maps are bit more HP.

***Bownse*** · 07-24-2008, 12:24 PM

v1.01 of the stage 1 91 octane map does it, too. it's almost as if the turbo comes on boost then backs off. 1st and 2nd are the worst but that simply may be a function of the gearing.

i don't remember it being the case with the v1.0 stage 1 93 octane cobb or the stg 1 93 octane perrin maps i ran before.

S'poreSTI · 07-24-2008, 02:31 PM

Y'know, i thought i was just being too sensitive or something, but i do feel mine do that, part throttle, below 3k, 2nd gear usually. Good to know i'm not imagining things, that the slight stumble from time to time is for real. I swear it happens more now in the hot summer days than when i first flashed it.
I'm Stage1, Cobb 1.01, 91ACN

sleepsindirt · 07-24-2008, 02:45 PM

my car is 100% stock,i noticed it a few times the other day after i reset the ecu.its fine now.i think she is just a slow learner

yakkosmurf · 07-25-2008, 06:49 AM

I don't get a stumble, but a bit of a dip in power. You can see it on the Stage 1 dyno graph, which is where I am right now.

rgt · 08-08-2008, 03:53 PM

Edit.

Nevermind - 08's not 07 ....

HB Speed · 08-10-2008, 11:06 PM

the stumble is the cruise avcs mapping.

06AspenWhiteSTi · 08-10-2008, 11:27 PM

i really notice a dip when the ac is on, when its off, no stutter. also when the ac is on i notive lag at really low rpm's like 1000RPM, when its off, smooth as butter. maybe its that.

tshrey · 08-11-2008, 05:32 AM

Quote:

Originally Posted by HB Speed

the stumble is the cruise avcs mapping.

Uh, what? Why is cruise affecting it when I'm accelerating in second gear?

ratedz · 08-11-2008, 05:43 AM

Quote:

Originally Posted by Bownse

v1.01 of the stage 1 91 octane map does it, too. it's almost as if the turbo comes on boost then backs off. 1st and 2nd are the worst but that simply may be a function of the gearing.

i don't remember it being the case with the v1.0 stage 1 93 octane cobb or the stg 1 93 octane perrin maps i ran before.

Well, I would think others are thinking this so here goes.. I was under the impression these stage1/2 tunes were smoothing out the stock curves etc...

If thats the case what is going on here ?

***solovus*** · 08-11-2008, 08:16 AM

I have absolutely no stumble in any gear under any load with ac in any position. I have a stock 08.

CFar · 08-12-2008, 11:49 AM

I too have a slight flat spot between between 2250-2750 on my stg 1.01 91 acn. Im also using 93 oct gas.

On a side note, during full throttle, looking at boost even in this low octane map I am still going a pound a half over target.

07-23-2008, 05:56 AM	#1
tshrey STI Driver Car: 08 STI Fav Mod: Removing the window sticker Location: Underground Atom Smasher Posts: 218 Join Date: Feb 2007 Trader Rating: (0)	2700 rpm stumble on Cobb Stage 2 map? Anyone else experiencing this? Under moderate loads (normal acceleration with the AC on) I get a hell of a stumble at 2600-2700 rpm. First and second are most notable, probably because you go through the spot so much more slowly in higher gears. I want to see if others are having this same problem before I ask Cobb to take a look. I know, a protune will take care of it, but I want to do a few more things to the car before a protune and the nearest tuner isn't very close. This ad is not endorsed by this member. Please register or login to hide this ad. Last edited by tshrey : 07-25-2008 at 07:25 PM.

07-23-2008, 06:06 AM	#2
ManInABox Junior STI Driver Car: 07 UGM STI Fav Mod: Cobb AP Location: Baton Rouge, La. Posts: 164 Join Date: Mar 2007 Trader Rating: (0)	Re: 2700 rpm stumble on Cobb Stage 2 map? mine does it as well only when the car isn't warmed up.

07-24-2008, 12:15 PM	#4
FlashEngineer Junior STI Driver Car: 08 STI DGM Fav Mod: Fiancé Location: Toronto, ON (GTA) Posts: 168 Join Date: Jul 2008 Trader Rating: (0)	Re: 2700 rpm stumble on Cobb Stage 2 map? Mine does with the cobb 1.01 stage1, and perrin 1.00 stage1, both 93octane. I'm using Perrin rev3 and it has no stumble, that's the only one I would use, I drive way more in part throttle than WOT so I want smoothness, even if the other 2 maps are bit more HP.

07-24-2008, 12:24 PM	#5
*Bownse* Platinum Member Car: 08 Gray STi Fav Mod: Coming Soon Location: USA Posts: 795 Join Date: Jan 2008 Trader Rating: (1)	Re: 2700 rpm stumble on Cobb Stage 2 map? v1.01 of the stage 1 91 octane map does it, too. it's almost as if the turbo comes on boost then backs off. 1st and 2nd are the worst but that simply may be a function of the gearing. i don't remember it being the case with the v1.0 stage 1 93 octane cobb or the stg 1 93 octane perrin maps i ran before.

07-24-2008, 02:31 PM	#6
S'poreSTI Senior STI Driver Car: 08 STi WRB/Gold Fav Mod: Hatchback! Location: SF Bay Area Posts: 358 Join Date: Jun 2005 Trader Rating: (0)	Re: 2700 rpm stumble on Cobb Stage 2 map? Y'know, i thought i was just being too sensitive or something, but i do feel mine do that, part throttle, below 3k, 2nd gear usually. Good to know i'm not imagining things, that the slight stumble from time to time is for real. I swear it happens more now in the hot summer days than when i first flashed it. I'm Stage1, Cobb 1.01, 91ACN

07-24-2008, 02:45 PM	#7
sleepsindirt Senior STI Driver Car: 08white sti gold bbs Fav Mod: emblem delete Posts: 392 Join Date: May 2008 Trader Rating: (0)	Re: 2700 rpm stumble on Cobb Stage 2 map? my car is 100% stock,i noticed it a few times the other day after i reset the ecu.its fine now.i think she is just a slow learner

07-25-2008, 06:49 AM	#8
yakkosmurf Junior STI Driver Car: '08 WRX STI Fav Mod: I don't know any of the mods on this forum. Location: League City, TX Posts: 94 Join Date: Jul 2008 Trader Rating: (0)	Re: 2700 rpm stumble on Cobb Stage 2 map? I don't get a stumble, but a bit of a dip in power. You can see it on the Stage 1 dyno graph, which is where I am right now.

08-08-2008, 03:53 PM	#9
rgt Professional STI Racer Car: 07 WRX STI WRB/Gold Fav Mod: COBB AP Stage 2 93 oct v1.04 Location: Dallas, TX Posts: 744 Join Date: Apr 2005 Trader Rating: (0)	Re: 2700 rpm stumble on Cobb Stage 2 map? Edit. Nevermind - 08's not 07 ....

08-10-2008, 11:06 PM	#10
HB Speed Amateur STI Driver Car: PPW 400 whp TTZ Fav Mod: Coming Soon Posts: 10 Join Date: Aug 2008 Trader Rating: (0)	Re: 2700 rpm stumble on Cobb Stage 2 map? the stumble is the cruise avcs mapping.

08-10-2008, 11:27 PM	#11
06AspenWhiteSTi Junior STI Driver Car: 06 Subaru WRX STi Fav Mod: seatbelt beep delete Location: Calgary, Alberta, Canada Posts: 158 Join Date: Feb 2006 Trader Rating: (0)	Re: 2700 rpm stumble on Cobb Stage 2 map? i really notice a dip when the ac is on, when its off, no stutter. also when the ac is on i notive lag at really low rpm's like 1000RPM, when its off, smooth as butter. maybe its that.

08-11-2008, 08:16 AM	#14
*solovus* Lurker Car: STIzzle Fav Mod: Tint Location: Toledo, OH Posts: 1,524 Join Date: Mar 2008 Trader Rating: (0)	Re: 2700 rpm stumble on Cobb Stage 2 map? I have absolutely no stumble in any gear under any load with ac in any position. I have a stock 08.

08-12-2008, 11:49 AM	#15
CFar Grassroots STI Racer Location: NOVA Posts: 546 Join Date: Jun 2006 Trader Rating: (1)	Re: 2700 rpm stumble on Cobb Stage 2 map? I too have a slight flat spot between between 2250-2750 on my stg 1.01 91 acn. Im also using 93 oct gas. On a side note, during full throttle, looking at boost even in this low octane map I am still going a pound a half over target. This ad is not endorsed by this member. Please register or login to hide this ad.