throttle responce Q??

[BossBronco]

Is this normal? when I run through 2nd gear say to 6000-6100 RPM,s shift into 3rd I get a cherp from the tires and then a stumlbe in the throttle . Is this a safty for wide open shifts?

[68fastback]

My guess would be no, BossBronco. You shound not feel a stumble. Do you have any other mods? Often stumbles are a brief lean condidtion. If she's been on a dyno, can you post the pull -- might give a clue, dunno? Is this a recent occurence (in which case dyno chart won't likely help)? The 'ramp-ups' (for lack of a better word) that the OEMs bake into their tunes is to reduce impact/shock-stress on the driveline. The also build in large 'dashpot' values (delays throttle-down) for emissions reasons (just like on the old carb'd engines). The 'ramp'up' doesn't delay what your right foot did as much as control (over a very short interval) precisely how (the rate at which) it comes on. Removing that is perceived as throttle-response improvement, but it would not feel like hesitation because it's not a delay. That's my understanding.

 

One other thought... is it possible you're unknowingly kissing the rev-limiter when you clutch it to shift? It's easy to delay lifting the accelerator until a fraction of a sec after clutching has begun, such that the revs blip a bit above the intended shift point and bump the limiter. Recovery off the rev-limiter can feel like hesitation because, depending how 'hard' it was bumped, the ECU logic will have pulled timing and/or fuel (and possibly spark too), based on sensor input (throttle and clutch position, temp, rpm and rpm delta-rate, etc) using specific [proprietary] algorithms, and it takes a litttle time to put it all back together in a way that prevents a backfire or damage when you get back on it -- whereas my understanding is the 'ramp-up' is merely briefly controlling full-throttle via progressive injector pulse-width modulation to enhance smoothness and reduce driveline component stress and emissions.

 

Anyone else seeing BossBronco's hesitation?

[stump_breaker]

Is this normal? when I run through 2nd gear say to 6000-6100 RPM,s shift into 3rd I get a cherp from the tires and then a stumlbe in the throttle . Is this a safty for wide open shifts?

TC is off, correct?

[RogerS]

Reading this I was also thinking rev limiter. But due to throttle by wire it could be a glitch. I would have it checked though. I have not experienced this condition.

 

Roger

[BossBronco]

TC is off, correct?

LOL ! At me No the TC was on . I did not think it would spen enough in 3rd to kick the TC . does not fell like the RPM lem. I do not do this very often . Does these cars spen hard in 3rd???

[68fastback]

LOL ! At me No the TC was on . I did not think it would spen enough in 3rd to kick the TC . does not fell like the RPM lem. I do not do this very often . Does these cars spen hard in 3rd???

 

That'll do it.

[stump_breaker]

LOL ! At me No the TC was on . I did not think it would spen enough in 3rd to kick the TC . does not fell like the RPM lem. I do not do this very often . Does these cars spen hard in 3rd???

 

Mine will spin about 1/2 way through 3rd and the TC will make or break it. Turn it off and report back to us.

There is a pedal mod but the general consensus is it's bad even though nobody has tried it.

 

http://www.teamshelby.com/forums/index.php...c=26504&hl=

[LuLu]

Is this normal? when I run through 2nd gear say to 6000-6100 RPM,s shift into 3rd I get a cherp from the tires and then a stumlbe in the throttle . Is this a safty for wide open shifts?

The rev limiter on my SGT is set at 6250 RPMs, dyno verified. I would presume your SGT is likewise programmed. Thus, if you're shifting at 6000-6100 RPMs, and getting tire spin, most likely you're hitting the rev limiter. As (and as it has been stated) the traction control may be engaging, and this will apply brake to the spinning wheel (s).