Runs better at less than WOT

[Rkammer]

My MM is stock with 3.55 gears and has just the K&N cold air and SCT XCal2 with a custom tune. First gear winds up nice and tight at WOT but when it shifts into 2nd at about 46 MPH it seems to lay down. If I back off the throttle just slightly it will feel like it's accelorating harder than at WOT. This usually means a lean WOT throttle mixture in my experience but I wonder if anyone else has experienced this and how you cured it? Thanks.

[David Morton]

Mine goes to 50 or so and snaps yer neck good and hard with plenty of acceleration at WOT so no, I don't have any experience with this condition.

[Rider90]

My MM is stock with 3.55 gears and has just the K&N cold air and SCT XCal2 with a custom tune. First gear winds up nice and tight at WOT but when it shifts into 2nd at about 46 MPH it seems to lay down. If I back off the throttle just slightly it will feel like it's accelorating harder than at WOT. This usually means a lean WOT throttle mixture in my experience but I wonder if anyone else has experienced this and how you cured it? Thanks.

I have that feeling from the line. If I floor it, it seems like it takes just a tad longer to take off. If I ease into it, sometimes I can spin or chirp them and it launches great.

[Rkammer]

Mine's fine in 1st gear. It's just after it shifts into 2nd that it lays down unless I back off the throttle a little.

[Rider90]

Mine's fine in 1st gear. It's just after it shifts into 2nd that it lays down unless I back off the throttle a little.

Well good luck at getting it fixed Happy Motoring...

[DEFYANT]

My MM is stock with 3.55 gears and has just the K&N cold air and SCT XCal2 with a custom tune. First gear winds up nice and tight at WOT but when it shifts into 2nd at about 46 MPH it seems to lay down. If I back off the throttle just slightly it will feel like it's accelorating harder than at WOT. This usually means a lean WOT throttle mixture in my experience but I wonder if anyone else has experienced this and how you cured it? Thanks.

I had the same problem. i fixed it with the purchase of a Trilogy S/Cer.

One theory was at WOT the clutch in the altenator would disengage causing a low voltage condition. The low voltage would cause the electric fuel pump to run at less than peek performance.

I have not tested this theory. As far as I am concerned, consider this a "rumor".

Anyone else hear of this?

[Rkammer]

I had the same problem. i fixed it with the purchase of a Trilogy S/Cer.

One theory was at WOT the clutch in the altenator would disengage causing a low voltage condition. The low voltage would cause the electric fuel pump to run at less than peek performance.

I have not tested this theory. As far as I am concerned, consider this a "rumor".

Anyone else hear of this?

What's a Trilogy S/Cer? This theory makes sense if the fuel pump is running on the hairy edge of lean.

[DEFYANT]

What's a Trilogy S/Cer?

Trilogy Supercharger

Go to the Trilogy section under the Forums tab for more info.

[Marauderjack]

Mine does the same thing and nobody has tried to help me figure it out!!!

Dennis said all of them do it but he didn't feel it like I do driving it all the time!!

Lido said for me to buy his program and it would be fixed.....almost did it until David at SCT said not to....he was going to work on it but that was a year ago.....STILL NO ANSWERS!!!

I am like you....affraid it is a lean condition??

If you get any answers please let me know what to do....if anything??

Marauderjack

[rayjay]

After my tune I have a similiar but slightly different situation. The car screams through 1 & 2, but seems to bog down after the shift to 3. The A/F mixture graph is good through out the rpm range. To me it feels like shes running rich for some reason once she gets to 3. I'm still learning to find the "sweet spot" when hitting 3. If I hit it right, whoa, hang on triple digits come up quick. Hoping the DR Cobra exhaust I have on order will help.

[SergntMac]

One theory was at WOT the clutch in the altenator would disengage causing a low voltage condition. The low voltage would cause the electric fuel pump to run at less than peek performance. I have not tested this theory. As far as I am concerned, consider this a "rumor". Anyone else hear of this?

Yes, and it's not a rumor. It's true.

I do not agree that this is what is taking place in Rkammer's complaint, but the symptoms would be very similar. So, suspect as it is, there's an easy fix that rules this out. Return the SCT Xcal2 to the tuner and have them turn the altenator on full time. If the symptoms disappear, you'll know for sure. If not, no harm will come of it.

[Smokie]

My MM is stock with 3.55 gears and has just the K&N cold air and SCT XCal2 with a custom tune. First gear winds up nice and tight at WOT but when it shifts into 2nd at about 46 MPH it seems to lay down. If I back off the throttle just slightly it will feel like it's accelorating harder than at WOT. This usually means a lean WOT throttle mixture in my experience but I wonder if anyone else has experienced this and how you cured it? Thanks.

Ray, I have stock gears, stock tranny and T/C. When I purchased a custom tune from Dennis R. it corrected poor shifting quite well, my 1-2 shift was at 5900 rpms and it was snap your neck solid. Once it shifts your car is momenteraly out of the peak of the torque power band and this may be what you are feeling until your rpm's climb again.

Without datalogging or your car being on a dyno to measure torque curve and A/F ratio is a lot of speculation and I hate doing that, but I can provide you with the accumulated experience of 3 years on this forum and as an owner.

The K&N kit is far more likely to cause a rich condition than lean (unless you left something loose in the intake path), our cars, do not have a history of running lean, the tune you have from Dennis is very likely the same program I purchased from him and it does not run lean ever all the way to 6400 rpms.

My opinion is that your shift points may need some tweeking, at exactly what rpm's does your 1-2 shift take place? and more important what do they drop to right after the shift...the answer may lie there.

[Bluerauder]

If I back off the throttle just slightly it will feel like it's accelorating harder than at WOT.

I recall seeing a "drag strip" post about 7-8 months ago on this same subject. Can't remember who made the post ... but it indicated that 7/8's throttle seemed to pull harder and resulted in faster times and trap speeds.

Here's the link to an earlier comment 12/15/2004 by BradleyG (see post #3) !!

Better Response at 7/8 Throttle

[RoyLPita]

I wonder how much is the retrofit kit to get rid of the clutch on the alternator?

[Rkammer]

Ray, I have stock gears, stock tranny and T/C. When I purchased a custom tune from Dennis R. it corrected poor shifting quite well, my 1-2 shift was at 5900 rpms and it was snap your neck solid. Once it shifts your car is momenteraly out of the peak of the torque power band and this may be what you are feeling until your rpm's climb again.

Without datalogging or your car being on a dyno to measure torque curve and A/F ratio is a lot of speculation and I hate doing that, but I can provide you with the accumulated experience of 3 years on this forum and as an owner.

The K&N kit is far more likely to cause a rich condition than lean (unless you left something loose in the intake path), our cars, do not have a history of running lean, the tune you have from Dennis is very likely the same program I purchased from him and it does not run lean ever all the way to 6400 rpms.

My opinion is that your shift points may need some tweeking, at exactly what rpm's does your 1-2 shift take place? and more important what do they drop to right after the shift...the answer may lie there.

I will be data logging as soon as I can find some time to take her out to my favorite "tuning place". As for shift points, the DR tune has the full throttle shift points at about 46 MPH for the 1-2 (about 6200 RPM on my tach) and about 86 MPH for the 2-3. Don't remember what it drops back to after the shift. I do notice that the DR tune also has the torque converter locking up in 2nd gear at 40 MPH (in WOT only) which make it go into lock-up as soon as the car shifts into 2nd. I don't know if I like this because the engine may be to low in RPM but I asked Dennis about it and he says that's the way the tune is supposed to be set up. I may try and remove this 2nd gear WOT lock up to see what happens (using Extreme Tune). It may be better to lock it up around 60-70 MPH after the engine revs a bit higher. Anyone else want to chime in here regarding this 2nd gear WOT lock up with the SCT tune? I'll continue to report on this thread what I find as there seems to be a few members that have/had this condition.