Should LTFT be this high with Cobb SRI?

[Lee456]

I checked the LTFT with my Cobb SRI installed today and was surprised when the numbers were much higher than with the factory airbox (with several holes cut in it and the snorkle removed) last week. With the Cobb the Dashhawk read +10.2 at idle, +15.6 when accelerating (whether mildly or wide open), and +8.6 when driving a steady 70 mph in 6th gear.

After seeing that I put the modified factory airbox back on. With it I got -3.1 at idle, 0.0 when accelerating, and -2.7 when driving at a steady speed. In each case after changing the airbox I double checked all the connections to insure they were tight, disconnected the battery and drained the charge, let the car idle for 10 minutes before driving it and then drove it about 15 or 20 miles in mixed conditions before writing down the numbers.

The performance definitely feels better with the Cobb, but aren't those number way too high? I read the other day that the Mazda standard is between -14.0 and +14.0 at idle, but the closer to zero the better and 10.2 at idle and 15.6 accelerating sounds way too high.

[scatt nasty]

that might be too high. Someone on the other forums mentioned anything above 8 or 9 is bad, so If your in the 15's and 16's thats no good. Im using the AP of course with upgraded internals and mine are always at 0

[DaleNixon]

Sounds high to me. I'll check mine out when my Cobb intake arrives on Monday.

[Moonpie.Express]

Just a question here. Did you reset the ECU each time (disconnect the battery)? I think that even then it takes awhile for it to adjust to the changes.

[LBV]

Just a question here. Did you reset the ECU each time (disconnect the battery)? I think that even then it takes awhile for it to adjust to the changes.

Quote from what he wrote: "In each case after changing the airbox I double checked all the connections to insure they were tight, disconnected the battery and drained the charge, let the car idle for 10 minutes before driving it and then drove it about 15 or 20 miles in mixed conditions before writing down the numbers.
"

[phillyb]

st00pid fucking fuel trims.
is your sri new?
when i changed my filter, my fuel trims went down

[Lee456]

Yep, it is new. One thing I forgot to mention is that I have an Amsoil filter on it. It's new, too. It is the one that was shown here a couple weeks ago that is considerable larger than the Cobb filter. I put it on right away because of a past bad experience with an oiled cloth filter. Suppose that is the problem? The car runs fine with the Cobb on it. Noticably more power and seems to respond faster. If I hadn't bought the darn Dashhawk and looked at the LTFT I won't have though anything was wrong at all.

[phillyb]

dh ftw
disconnect your negative battery terminal for 20 minutes, put the cobb filter on there, drive the car for 50-100 (maybe even more, just drive) miles, and report your ltft's

[DaleNixon]

Oh hell I don't want to hear that the Amsoil filter throws off trims. Mine hasn't even arrived in the mail yet :\

[phillyb]

d00d, i have no idea...just check the shit out

[Moonpie.Express]

Quote from what he wrote: "In each case after changing the airbox I double checked all the connections to insure they were tight, disconnected the battery and drained the charge, let the car idle for 10 minutes before driving it and then drove it about 15 or 20 miles in mixed conditions before writing down the numbers.
"

Yep, Reading comprehension = fail.

and I read it twice!!!
(hand)

[Lee456]

I'll put the Cobb back on with the Cobb filter and try it. It will probably be a couple days before I get 100 miles on it since we've got plans for this afternoon and all day tomorrow, but when I do I'll post the LTFT with the Cobb filter. If it looks different than what I got yesterday with the Amsoil filter, I'll throw the Amsoil filter on and go through the whole process again and see if that changes it and will let you know.

[Lee456]

I don't know if anyone is still watching this, but here's the result. I unhooked the battery for 30 minutes, stepped on the brake to drain the charge, and put the Cobb intake back on with the Cobb filter. The LTFT numbers were:

After 18 miles: acceleration 13.3, constant 55 mph 4.7, idle 8.6
After 50 miles: acceleration 13.3, constant 55 mph 8.6, idle 10.2

At that point I put the Amsoil filter back on, didn't reset anything and drove 30 miles in a similar manner. There was no change, so the Amsoil filter does not seem to matter and 30 more miles of driving didn't either.

Perhaps these numbers are normal with a Cobb. It seems like additional fuel would be required with the extra air the intake lets in and these numbers indicate that fuel is being put in. The car is running great with it.

Anyone else with a Cobb and a Dashhawk, I'd be interested in what yours says. Also, if you've got an SRI on your car or any intake that lets you see the top of your transmission, please take a look at my other recent post about the hole in the transmission and let me know if your car has anything attched to the bolt hole in that picture. I'd go over to the dealer and look at another Speed3, but you can't see that area with the factory air box installed. Thanks.

[DaleNixon]

I think it's a bit early to measure LTFT's... don't you have to let the ECU relearn? Those numbers are really high compared to mine with the stock airbox or my old HKS intake.

[Lee456]

Yes they do seem high for sure. My stock airbox with three 1 1/2" holes cut in it and the snorkle removed was -3.1 at idle and 0.0 when accelerating. As for the ECU relearning, I didn't know how long that takes. The numbers were the same after 40 miles as they were at 50. The ones at 80 were also the same, so from 40 to 80 miles it didn't change. I would think that the relearning process would be reflected by gradually changing numbers like I saw from 0 to 30 or so miles after the reset, rather than not changing for 40 miles then suddenly making a massive adjustment. If I'm wrong about this and the ECU can be expected to have a revelation at 200 miles and suddenly bring these numbers down, please let me know.

I've swapped these back and forth a couple times and there's not a lot to do wrong, so I can't see how the high number can be a result of something installed wrong. If there's something I might have missed, let me know.

[DaleNixon]

I installed my Cobb SRI last night. LTFT's are around 8.8 when idle and vary between 5.5 and 8.8 when cruising/accelerating. Sometimes they sit at 0 but it's mostly 6.8 - 8.8.

I'll keep an eye on these numbers in the next few days as my ECU learns what's up.

[Lee456]

Thanks for the update, Dale. I finally said the hell with it and sold the Cobb. Unfortunately I think the bracket is a bigger issue and will take a substantial change in the mount. There's even a post from a Cobb rep over on the other forum saying that it is happening more frequently as time passes and they need to fix it. I was all set to build something that would attach to the larger bolts on the fender well near the Cobb mount, then have a section of rubber from an exhaust hanger running over to the Cobb bracket which I would have cut off. Needless to say, cutting the Cobb bracket would have made it hard to sell if this didn't work out. Late yesterday afternoon I found myself questioning why I should be doing all this work to correct at product I paid good money for.

The LTFT's went back to -2.3 at steady speed, +2.3 when accelerating, and -3.1 at idle with the factory airbox with holes in it. The car doesn't respond to the throttle as quickly, though, and I miss the sound. Maybe I'll try a Nano when they are back in stock, or maybe I'll just leave it. Anway, good luck with your Cobb. I'll be curious if your LTFT's go up over the next day or two as mine did or if they improve.

[DaleNixon]

Thanks man. I used some rubber to buffer the vibrations from the bracket, but I'm sure that's just pissing in the wind. Oh well. I'll continue to update this thread as I do more LTFT logging.

[DaleNixon]

I haven't logged, but I'm watching and the LTFT has started rising. I get around +11.8 when getting on it, then it goes back down to around +7 when cruising... very strange.

I reset my ECU today because I had to disconnect the negative battery terminal for a turbo timer install. On the drive home I was seeing the same behavior noted above.

Can anyone chime in as to whether or not these LTFT numbers are healthy? I read that anything beyond +4 or -4 is bad. But there are so many people running Cobb intakes. Maybe I should give Cobb a call to talk about this.

[john blutarski]

I finally monitored my LTFT's last night with the Cobb SRI. I'm seeing +5 to +7 at idle and +14.8 when on throttle/WOT. I ordered a CS intake/turbo inlet and will see how that compares...

[CWPspeed3]

I'm getting in the same range as everyone reporting as well after having it on for 6 months I started monitoring LTFT's so I just thought maybe it was time I cleaned my filter.

[Lee456]

It looks like a number of people are getting LTFT's very similar to what I got. The high positive numbers seem to make sense because if you let in more air the ECU must adjust the fuel to compensate, but I was worried because I read a lot of stuff saying that anything over 4 or 5 was BAD. On the other hand, when I put an intake on my last car, a Jeep Wrangler Rubicon, it came with a module that was wired in to adjust the mixture. When I put an intake on my prior car, a BMW Z3, I got a device that hooked up to the diagnostic port and reprogramed it, sort of like a primative Cobb AP. On the Speed 3 I did nothing except let the air in and the car is compensating for it.

I posted a similar question on the other forum in a section devoted to the Cobb AP, which I was thinking of buying to correct the LTFT's, and got a number of replies that said pretty much this same thing. One said "Im presuming you are currently on the stock ECU tune. If that assumption is correct, those LTFT's are normal with your mods. So long as it is running right I wouldnt worry about it. You have increased the ability of the engine to pump air, the ECU has detected that and is compensating with the LTFT. If you WANT to correct the LTFT's, the AP with the correct tune will do it for you, but there is no NEED to."

For what it's worth, I checked the Air/Fuel ratio with the Cobb and the with the factory airbox with holes in it and they looked the same. 14's most of the time dropping to 10's at WOT. That's what really matters to the engine. I understand the ECU can only correct up to 25% and if you hit that you've got a problem. That worried me a bit when mine got up to +14.9 accelerating with the Cobb.

I had pretty much resolved myself to ignore the number's, but ended up giving up on the Cobb out of concern for the battery box breaking. Although there isn't a lot of talk about it here, quite a lot of them have broken. I have a Nano coming that should be here Wednesday. I'll see what the LTFT's are with it and post them here after I run it a couple days. I bet they will be similar to the Cobb.

[Zimmer]

Sub'n

I don't have a DH so I rely on threads like this ... correct me if I'm wrong but what I'm gathering COBB's SRI seem to be running more or less w/in mazda's spec's but higher than what's best of the engine at idle.

[CWPspeed3]

From what I've heard LTFT's between +/-10 are normal and anything between +/-20 is safe, correct me if I'm wrong. Same as Lee my A/F numbers are right around +14.7 at idle and dip as low as +10 WOT, so the car dumps in lots of fuel and runs rich, thats normal for a turbo car.

[DaleNixon]

Yep, the A/F is fine with the Cobb as it was with the stock box and my old HKS intake. The only concern here is with LTFT readings.

Lee's post makes me feel better though. It makes sense that the ECU is compensating for more air coming into the engine, and it makes sense that the Cobb is showing me higher readings than the HKS did (from a performance standpoint).

[Speed3Rookie]

My ltft are 0-0.8 at idle, 0-1.6 part throttle, 0 WOT and 7.8 on decel.

Most ppl don't monitor ltft until they get an intake or tuning solution.
I would wager you would be surprised that your ltft are not at zero with a stock vehicle.
I would also wager that you are not getting zero kr with a stock vehicle.
Anyone log these two yet while still stock?

[serialtoon]

<--- NOOB ALERT! But i also have a Cobb SRI, should i be worried? What is the bad part of running a high LTFT? I can only say that i wish i had the money to dump on a car, but alas i do not. So please, feel free to indulge me on this matter. BTW, this is my first boosted car, so treat me like a noob, please.

[LBV]

Most ppl don't monitor ltft until they get an intake or tuning solution.
I would wager you would be surprised that your ltft are not at zero with a stock vehicle.
I would also wager that you are not getting zero kr with a stock vehicle.
Anyone log these two yet while still stock?

Exactly!

[Super Unique]

LTFT on this car while completely stock was still +5 to 7 on WOT and 2 to 3 or 3 on idle etc...

Also zero KR while stock, and still no KR with cobb SRI running amsoil filter. I have watched intently, and still not a single incident of KR either while watching data live, or long drives that were logged to SD card and retrieved for later analysis.

[DaleNixon]

My Dashhawk Knock warning hasn't gone off in quite a while.

[daonly1around]

what exactly is lift? i know about knock retard... well somewhat, and of course A/F ratio... but never heard of lift... someone care to explain?

[GoFast]

LTFT

Long Term Fuel Trims

[robin2660]

From what I've heard LTFT's between +/-10 are normal and anything between +/-20 is safe, correct me if I'm wrong. Same as Lee my A/F numbers are right around +14.7 at idle and dip as low as +10 WOT, so the car dumps in lots of fuel and runs rich, thats normal for a turbo car.

From what I've learned in a short time, anything greater than +/-10% (yes, expressed in percent) is "generally" not good.

[robin2660]

what exactly is lift? i know about knock retard... well somewhat, and of course A/F ratio... but never heard of lift... someone care to explain?

Use the FAQ!!!

[desperado-c]

LTFT

Long Term Fuel Trims

Ie., corrections to the amount of fuel that is being delivered to the injectors to compensate for increased/decreased air mass entering the intake. Without these corrections the engine would run too lean/rich. In addition to adding a less restrictive intake lots of things can affect how much air is entering the cylinders, such as warmer/colder temps and high/low humidity. All these factors can lead to corrections to LTFT. As regards an intake specifically, you want it to have LTFT readings at idle that are close to stock. That way you know that the stock ECU can make the necessary corrections to keep the air/fuel mixture within specifications.

[daonly1around]

thank you desperado

[GoFast]

see post above you. desparado was on the ball

[john blutarski]

My KR warning goes off all the time. It's enough to drive a good man insane... I think I'll check all my hose clamps since I've read some guys found this to help and that the stock IC and turbo inlet clamps are loose as heeell

[Speed3Rookie]

Also zero KR while stock, and still no KR with cobb SRI running amsoil filter. I have watched intently, and still not a single incident of KR either while watching data live, or long drives that were logged to SD card and retrieved for later analysis.

I can almost guarantee you that you are the exception...not the rule.
Anyone else that's still stock that has a dh care to share their experiences?

[DaleNixon]

I'm still not liking these LTFT readings. I get around 7.6 under moderate and 14.6 under heavier acceleration in 6th. I ran a few datalogs tonight... absolutely no KR though.

I guess I'll give this Cobb intake/Amsoil filter combo another gas tank or two before I take the logs really seriously.

[PaPaSpeed]

I was trying to watch my LTFT a little bit today, and I was mostly in the 4.7 - 8.6 range while cruising and accelerating. I have the CP-E Nano, and I'm sure its similar to the Cobb SRI. I'll keep an eye on it over the next few days, and report back. My AFR is around 14.2, I'd like to see that a little lower.
That's the trouble with a dashhawk, you know too much, maybe not knowing is more comforting. But I'm having fun with it, and that's what counts.

[DaleNixon]

14.2 is fine. You just want it to get a little richer (lower) during hard acceleration. I've never seen any problems with AFR with the stock airbox vs. HKS intake vs. Cobb intake.

And yea, the Dashhawk kicks fucking ass, but it sucks how paranoid it makes me! I used to think "no CEL, no problem!" Now I've got a damn knock warning and I constantly watch certain parameters.

It reminds me of when I was a kid and I was afraid to put my hand on my heart for the pledge because I was afraid it might stop! Haha!

[Lee456]

I know what you mean, Dale. The Dashhawk is great but when I had the Cobb on there I was completely satisified until I hooked up the Dashhawk and saw the LTFT hit 14.8 under acceleration. The Dashhawk was real helpful when I switched back to the factory airbox the other day, though. I forgot to hook up the MAF sensor plug when I changed late at night. I had an early morning appointment and when I started the car it sputtered and died after about 1 second. I remember the connector, hooked it up, and started the car but of course had a CEL. It was great to just hit a couple buttons on the Dashhawk and reset it.

My CP-E Nano should be here Wednesday afternoon. I'll give it a couple days then post the LTFT's. I expect them to be about like the Cobb SRI although PaPaSpeed is getting much better numbers than I got with my Cobb. We'll see. If the numbers are like my Cobb and I like the intake and it doesn't shriek like a jet engine as a couple people have said, I'm going to just live with the LTFT's as long as the A/F ratio is OK.

[PaPaSpeed]

Too bad you guys don't live closer. I'd swap you my Nano for a few days to try out before you buy one. I don't see a big difference between the Cobb and the Nano. I guess you you'll find out.
By the way, the outside temp here today was about 45. Looks like you may be warmer. Does that make any difference?

[Lee456]

Thanks for the extremely generous though. It's nice to know that someone would go to the trouble to swap parts to let me try the new one before buying it. Actually, after reading about the LTFT's, some stuff about how the ECU works, and some comments from people here and on another forum in answer to my questions, I had decided it was reasonable for the LTFT to be high to compensate for the extra air let in by the SRI. I don't expect the Nano to be significantly different. If it stays under 10 I'll be real pleased, since I understand the limit of the ECU to compensate is 25%. 14.8 was getting closer to 25 than I'd like. 8 or 9 would be better.

The main reason I'm switching is the battery box problem. Not much has been said about it here, but the other forum has a LOT of comments and even some pictures from people who have had the sheet metal piece break off. I was going to make a different attachment for the Cobb, but it would have required cutting and drilling the bracket. The rubber piece in the Nano mount should help some. If that doesn't prove sufficient it would be easy to build smething else for it to attach to that would run down to the thicker bolts a few inches further away. I'm curious what it will sound like though. The Cobb sounded good, but some people have said the Nano shrieks like a jet engine. Others have said it is not loud. I'm real curious about that. How have you found it to be?

As for the temperatures, it's no doubt warmer here than what you've got, although we've had some unpleasant weather for Phoenix. A few days while I was running the Cobb looked more like what I'd expect in Seattle. Low 50's and rain. Of course, at that time Seattle looked more like Alaska with a foot of snow. Must be global warming.

[PaPaSpeed]

The main reason I'm switching is the battery box problem. Not much has been said about it here, but the other forum has a LOT of comments and even some pictures from people who have had the sheet metal piece break off. I was going to make a different attachment for the Cobb, but it would have required cutting and drilling the bracket. The rubber piece in the Nano mount should help some. If that doesn't prove sufficient it would be easy to build smething else for it to attach to that would run down to the thicker bolts a few inches further away. I'm curious what it will sound like though. The Cobb sounded good, but some people have said the Nano shrieks like a jet engine. Others have said it is not loud. I'm real curious about that. How have you found it to be?

Well, the Nano does sound like a jet engine winding up, but its not too loud. You'll definitely hear it sucking air, but its not too bad. I kinda like it.
As far as the battery box bracket, the Nano seems to cushion the vibration with that rubber bushing on the bracket. I haven't had any problems with it. The Nano is a relatively new product, so we'll have to reserve judgement til its been tested for awhile.

Back to LTFT, have you considered the Standback from CPE? I understand you can adjust LTFT, AFR, and others if you want to tune yourself. I don't think I'm knowledgeable enough to do that, but others seem to have some fun with it.

[Lee456]

I got the Nano today and put it on. I didn't have a chance to drive it much since it was late afternoon but with about 20 miles on it the LTFT is +3.9 at idle and +4.7 when accelerating. At steady speeds it hits +7.0.

For now they are way lower than they were with my Cobb SRI at the same point. At 20 miles it was +8.6 at idle, +13.3 when accelerating, and +4.7 at constant speed. Interesting that the Cobb was lowest at steady speed and the Nano is highest at steady speed.

I'll post these again when I've got 100 miles or so on it, but if they stay under 10 I'll be happy. It certainly does sound different than the Cobb but it's not a bad sound. I actually like it.

[DaleNixon]

I'm going to shoot Cobb an email or call them today. If these LTFT's are going to be detrimental to my car, I might go back to my HKS intake. That would be some ironic shit right there.

[DaleNixon]

Chris at Cobb wants me to send him some Dashhawk data logs (AFR/STFT/LTFT/RPM/Abs Throttle). He's saying these numbers (14.1 at moderate acceleration) are higher than they should be.

I'm going to log my drive home from work today and email it to him. I'll keep this thread updated.

[CWPspeed3]

Chris at Cobb wants me to send him some Dashhawk data logs (AFR/STFT/LTFT/RPM/Abs Throttle). He's saying these numbers (14.1 at moderate acceleration) are higher than they should be.

I'm going to log my drive home from work today and email it to him. I'll keep this thread updated.

The people at cobb say it shouldnt be that high yet it seems that everyone on the forum is reporting that high? thats a good sign...

[Lee456]

I didn't record logs in the Dashhawk, but I watched mine carefully, recorded the LTFT's on a voice recorder and typed them into a document on the computer when I got home each time. I'd be willing to swear to this:

After 90 miles with the Cobb SRI (switched to Amsoil filter for the last 40 miles which made no immediate change):
10.2 idle
8.6 constant 50 in 5th changing to 10.9 on slight hill
14.8 acceleration moderate to WOT

Those were my final numbers before removing the SRI and going back to the modified factory airbox. They had not changed since 50 miles other than the acceleration number went from 13.3 to 14.8 between 80 and 90 miles after the install and ECU reset. As I've said before, the car was running great with no sign of any problem. If I didn't have the Dashhawk, I would not have seen anything wrong. I don't know if these number represent a problem of any kind, but I do know they were a fact.

With no other changes than the modified factory airbox:
-3.9 Idle
-1.6 Constant speed
0.0 moderate acceleration
-0.8 heavy acceleration

Yesterday I put on a CP-E Nano with the dry filter.
The numbers after 30 miles (the same as they were after 20 miles):
+3.9 Idle
+7.0 Constant speed
+4.7 Acceleration moderate to WOT

The only other mods on my car are a Turbosmart BOV and a Magnaflow CBE.

I apologize to all of you for posting all this again, but I thought perhaps if the Cobb people look at this thread it might be helpful to have all the information I recorded in one post.

[DaleNixon]

I linked Chris at Cobb to this thread in an email. I hope he comes and checks it out. I would like to find out how many miles it takes to stabilize fuel trims. Perhaps I need to just ride this out another few hundred?

Thanks for sharing those numbers again, Lee.

[john blutarski]

Mine now stays pegged at 14.8 under any kind of throttle

[DaleNixon]

Lee, is yours an '08 or '08.5? I'm just looking for a pattern here. I sent Cobb an email with my datalogs on the drive home from work. I just went out and started the car and listened for leaks around the intake.

When I started the car, it was idling with an LTFT of 10.2. After a few minutes, it was up to 12.8 :(

I couldn't detect any leaks with my ears.

[jengajoe]

Dale, have you recently checked the tightness of the turbo inlet clamp? I have to push the inlet tube all the way on and re-tighten mine every couple months... time for some t-clamps. The damn stock clamps have a habit of loosening up over time.

[DaleNixon]

Are you talking about the clamp between the intake and the inlet? Or the inlet and the turbo?

If it's the latter, how do I access that clamp? Thanks!

[Lee456]

Mine's a 2008, although I bought it in late July. I sure do hope Jengajoe is speaking of the clamp where the intake attaches and not something under the car needs tightening every couple months. For what it's worth I've double checked every clamp involved in each intake install, then rechecked them after an hour or so of use and again after a few days. All were tight.

I have not checked anything else for tightness, but I believe that if the source of the high readings was a loose clamp not involved in the intake install the numbers would stay high as I switched to the modified factory airbox and now the CP-E Nano. Instead, I got minus LTFT's with the factory airbox and numbers similar to those reported by PaPaSpeed who has a Nano when I installed the Nano.

[jengajoe]

I sure do hope Jengajoe is speaking of the clamp where the intake attaches and not something under the car needs tightening every couple months.

Yup, be sure to check the clamp that clamps the inlet tube to the inlet side of the turbo. It's a bitch to reach but I get at it from the top.

[DaleNixon]

My connections are fine. My LTFT's are not.

***THIS IS ALL RUMOR AND NOT CONFIRMED:
I'm starting to hear chatter that some of the Cobb SRI's from the newest batch might have improperly shaped/sized MAF housings or intake tubes. I'd love to get Cobb's take on this, but they are not answering my phone calls or emails (busy in Plano I suppose).
***END RUMOR

Does anyone know anything about this potential problem?

[john blutarski]

My connections are fine. My LTFT's are not.

***THIS IS ALL RUMOR AND NOT CONFIRMED:
I'm starting to hear chatter that some of the Cobb SRI's from the newest batch might have improperly shaped/sized MAF housings or intake tubes. I'd love to get Cobb's take on this, but they are not answering my phone calls or emails (busy in Plano I suppose).
***END RUMOR

Does anyone know anything about this potential problem?

My LTFT's are very close to yours and my SRI was from before they went on "worldwide backorder" last year.

[Sport6]

With no other changes than the modified factory airbox:
-3.9 Idle
-1.6 Constant speed
0.0 moderate acceleration
-0.8 heavy acceleration


These are pretty much spot on to my MS CAI running as a SRI - with the air straightener.

[DaleNixon]

My LTFT's are very close to yours and my SRI was from before they went on "worldwide backorder" last year.

Gotcha. The other speculation is that people only recently started watching their LTFT's and they've always been like this.

[Abilor]

I've gotta get a dashhawk to check my numbers with my nano.

[Nliiitend1]

All this talk definitely has me wanting to get a DashHawk so I can do some logging...

I replaced my BEGi Airbox with a Cobb SRI because of concern over fuel trims, and now it looks like that might've been a mistake. I still have the BEGi unit, and am thinking about buying an airflow straightener so I can do some comparisons between BEGi, Cobb, and BEGi with the airflow straightener.

Perhaps I need to bite the bullet and buy a DH before abandoning yet another intake in favor of the Nano...

[Sport6]

its a very valuable tool and with everyone's cars that were going under, I figured it would safe to monitor even a basically stock care just to be safe.

[frito]

Any updates on this thread??

[DaleNixon]

Cobb's assistance turned into nothing but silence for me. LTFT's still suck.

[dread]

me to dale, they were supposed to send me the dimensions of the intake, which I suspect are off, but Chris never got back to me.

[Nliiitend1]

This is disappointing, to say the least. :(

[PCspeed3]

cobb doesint have time to deal with dinky little turd mods like a test pipe lol

They already have enough on their hands as it is.

[serialtoon]

My LTFT's are high as well...is this bad btw? Should we even care???

[LBV]

I think everyone is getting too paranoid about LTFT`s ... it just shows that the ECU is doing it`s job to keep AFR`s at where they should be. One of the reasons fuel trim adjustment even came into being is because O2 sensors (and other sensors) age over time and are not as effective as when new ... the trims compensate for these changes so you don`t have to buy new sensors very often.

When the LTFT`s get out of hand, you`ll get a CEL - that`s when you should worry.

Having said that, never load up your car after an ecu reset (like when battery is disconnected) to give the car time to learn the new trims.

[Abilor]

My LTFT with the Nano and an oiled filter never get out of -4.0 to 4.0 country.

[Trader]

Did anybody ever figure out why this was doing it? Was the air straightener in right?

[DaleNixon]

Update. My trims are staring to move to sane levels! It's great. I recently installed an ETS 3.25" TMIC, Denso ITV22 step colder plugs, and added two shims to the blue spring on my Forge valve.

I did some WOT logs (starting in 4th gear at 3000rpm) to show someone in another forum, and I noticed my LTFT's starting looking a lot better!

At this point I'm idling no higher than +3.9, Cruise is around +3.1, Moderate gas puts it around +5.8, and hard throttle/WOT puts it around +11 to +13.

These trims aren't perfect, but they're a hell of a lot better than what I had. I'm not sure if my recent mods helped or just the warmer weather I've been driving in, but I'm one happy camper right now! My knock retard warning on the DH has been missing in action as well! (knocks on wood)

[Kurt07]

I monitored mine on the way home. At WOT my LTFT was 11.7. My mods are the BEGi cool air box and Forge BPV with the blue spring and one shim. I would have to go back and review the log to get the LTFT's at cruising speed and idle.

[DaleNixon]

Update. My trims are staring to move to sane levels! It's great. I recently installed an ETS 3.25" TMIC, Denso ITV22 step colder plugs, and added two shims to the blue spring on my Forge valve.

I did some WOT logs (starting in 4th gear at 3000rpm) to show someone in another forum, and I noticed my LTFT's starting looking a lot better!

At this point I'm idling no higher than +3.9, Cruise is around +3.1, Moderate gas puts it around +5.8, and hard throttle/WOT puts it around +11 to +13.

These trims aren't perfect, but they're a hell of a lot better than what I had. I'm not sure if my recent mods helped or just the warmer weather I've been driving in, but I'm one happy camper right now! My knock retard warning on the DH has been missing in action as well! (knocks on wood)

My LTFT's are almost at 0 when idle now :)

[john blutarski]

The other day mine went as far as -3.9% at idle. Now they're back at +6.2 at idle. I know the weather affects these things considering I haven't changed anything. I'm not going to sweat any of this anymore unless I get a CEL which won't happen unless they hit over 20%

[Silver Ecstasy]

Bringing this thread up from the dead for sure!!!

Picked up a new Cobb SRI. LTFT's are +14 or higher. Definitely a ton higher than the MSCAI I had previously installed. Also, noticing a slight hesitation at constant rpm/throttle (ie highway). I checked clamps, but what else can I check?

[dizzin9]

i have a CAI setup before (injen). it never got below -4.7 and above 0.0, which is my LTFT at WOT also. now i'm running a nano and the first time i put it on i had around +11 to +15, then settled to +7, then +5.5 (all at idle). even after 500+ miles, my LTFT at idle stayed at around +5.5 and never get 0.0 at WOT.

recently, i changed my filter to an 8" aem dryflow filter. u have to modify it a bit to make it fit. and right now my LTFT's don't go above +3.1 but i see +0.8, 0.0 (WOT), and -0.8 more often than +3.1.

not sure if the filter has anything to do with it, the weather, or maybe the ecu has "fully" learned the trims.

[Silver Ecstasy]

Yeah, i'll be patient and see what happens. No CEL's yet lol.

What about hesitation issues? Car will be going at a constant speed and feel like as if the brakes are lightly being applied on and off. Real weird.

[whteltning]

I just put on my cobb SRI about 3 days ago...didn't reset the ECU....my LTFTs when idling are at 1.6, WOT or any kind of acceleration, 2.3, and coasting w/ the clutch in around 8...

[Silver Ecstasy]

So.. i'm reviving this thread again because my LTFT's are still through the roof. I tried fixing it by installing the Cobb TIP with the SRI, and it initially lowered them during the winter months. But noticed it's back up to 15+ at WOT. Fuel AFR and Fuel Rail Pres all seems perfect. Nothing else is out of wack.

Any ideas? I've checked all the usual suspects (clamps) and everything is fine.

[Remspeed3]

So.. i'm reviving this thread again because my LTFT's are still through the roof. I tried fixing it by installing the Cobb TIP with the SRI, and it initially lowered them during the winter months. But noticed it's back up to 15+ at WOT. Fuel AFR and Fuel Rail Pres all seems perfect. Nothing else is out of wack.

Any ideas? I've checked all the usual suspects (clamps) and everything is fine.If your that worried about it, then put the mscai on. at least it will be covered by your warranty if you still have any left...i personally think it will be fine if your not heavily modded, the short ram should show higher parameters than your stock air box or even the cai...due to the difference in volume and velocity that it creates that close to the MAF sensor.

[Silver Ecstasy]

MSCAI is gone, and i'm not going through that installation again anyhow. Anyways, the car runs just fine, it's just a number I guess.

[SallySpeed3]

So.. i'm reviving this thread again because my LTFT's are still through the roof. I tried fixing it by installing the Cobb TIP with the SRI, and it initially lowered them during the winter months. But noticed it's back up to 15+ at WOT. Fuel AFR and Fuel Rail Pres all seems perfect. Nothing else is out of wack.

Any ideas? I've checked all the usual suspects (clamps) and everything is fine.

Similar thing happened to me. Got my AP for christmas, never was able to monitor LTFT before. Installed a map, and started monitoring. LTFT's were really good. Once the warmer weather showed up they got really bad, I had to calibrate my MAF and now it seems fine.

[Neptune8]

I'm not bashing Cobb at all i think they are a great company but these OTC maps are hella lean , the best thing to combat LTFT is to make sure your BOV lines are tight and secure, as well as boost tube clamps and if you're running a FMIC ( Check welds to make sure there's no cracks in it) , as a spike in LTFT's could be a positive indicator , however making sure your MAF is Calibrated correctly is key as well, as many people have said before i believe this MAF has 5 points that it reads, Also check your MAF Voltage it should be 2.34-3.00 or there abouts, Also once you have set your MAF then you should be able to nail down the Actual AFR, i had my car tuned with a test pipe and MSCBE, MSCAI, and that's all that was done besides CAM phasing... just be aware that spending time with this unit isn't a tune on the fly like COBB says it does which it doesnt, you have to swap devices back and forth and make sure the tunning place knows that since i would take it they charge you by the hour...