Considering a 2LS? Read This First! - Page 8 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Jason@JacFab · 02-03-2014, 11:20 AM

Thought I would add this as it seems to get questioned a lot... This is a typical dyno graph you will get from a 2LS:

Quote:

Here's my experience with the 2LS on a dyno. In "manual" mode, top gear set to 3rd... Got rolling up to speed, and in 3rd gear, at the start of the run it would always downshift to first, and run through 2nd, and into 3rd where it finally hit the speed limiter at ~6000 or 6500 rpms... These are 5 stock runs, that look very different. You can even see how it seems to shift quite erratically. This also threw off the rpm reading on the dyno I was on, note 17,800 rpms... To the moon!

To my knowledge, this can't be avoided unless you or someone can figure out a way to keep it in 3rd or 4th gear for the entire run... I even tried doing some runs in just 1st gear as it's the only gear it would stay in... The whole thing was very violent because of the shifting, it would loose traction, puts some major strain on the straps, broke one strap, actually tried chaining it to the dyno... Very very sketch

While yes, you certainly CAN dyno the car, HOWEVER, as you can see, because you can't keep the car in one gear the entire run, you have to deal with it shifting, which makes for a rather pointless/hard to read dyno graph if you're trying to compare products back to back etc, etc.

Angrybird 12 · 02-03-2014, 11:28 AM

Quote:

Originally Posted by RacnJsn95

Thought I would add this as it seems to get questioned a lot... This is a typical dyno graph you will get from a 2LS:

While yes, you certainly CAN dyno to the, HOWEVER, as you can see, because you can't keep the car in one gear the engine run, you have to deal with it shifting, which makes for a rather pointless/hard to read dyno graph if you're trying to compare products back to back etc, etc.

I wonder if anyone could come up with a tune that would make the 2LS transmission work like the LT's or is there some internal differences that makes it impossible.

Jason@JacFab · 02-03-2014, 11:38 AM

Quote:

Originally Posted by Angrybird 12

I wonder if anyone could come up with a tune that would make the 2LS transmission work like the LT's or is there some internal differences that makes it impossible.

From what I understand the 2LS transmission can't be tuned to work like an LT with TapShift, however it can be tuned to shift like it's in a "sport mode" all the time, but you still won't have full gear control to stop it from shifting...

I did a little bit of research, valve bodies, and transmissions between the LT and the LT had the same part numbers from what I could find... I believe the issue is probably purely in the GM software, but I've read they will not flash a calibration from an LT trim car into an LS trim car....

I thought that if I guy could come up with some kind of "black box" item that plugged into the car somewhere to allow full gear selection control, it would be a decent selling item... However, electronic transmission control, wiring, and electronics are beyond me.

Angrybird 12 · 02-03-2014, 11:43 AM

Quote:

Originally Posted by RacnJsn95

From what I understand the 2LS transmission can't be tuned to work like an LT with TapShift, however it can be tuned to shift like it's in a "sport mode" all the time, but you still won't have full gear control to stop it from shifting...

I did a little bit of research, valve bodies, and transmissions between the LT and the LT had the same part numbers from what I could find... I believe the issue is probably purely in the GM software, but I've read they will not flash a calibration from an LT trim car into an LS trim car....

I thought that if I guy could come up with some kind of "black box" item that plugged into the car somewhere to allow full gear selection control, it would be a decent selling item... However, electronic transmission control, wiring, and electronics are beyond me.

Thanks, good answer!

KILLA BEE · 02-03-2014, 11:58 AM

Quote:

Originally Posted by Angrybird 12

I wonder if anyone could come up with a tune that would make the 2LS transmission work like the LT's or is there some internal differences that makes it impossible.

Hmmm I dont believe my car shifts into fourth from third it ACTUALLY stays in gear.how fast on the dyno do they run your car up to? Jus curious so I can try it on the street. Im supposed to get dyno tuned thru hp tuners this month so it won't work ?? Sux IF NOT.

Jason@JacFab · 02-03-2014, 01:35 PM

Quote:

Originally Posted by KILLA BEE

Hmmm I dont believe my car shifts into fourth from third it ACTUALLY stays in gear.how fast on the dyno do they run your car up to? Jus curious so I can try it on the street. Im supposed to get dyno tuned thru hp tuners this month so it won't work ?? Sux IF NOT.

Try this... "shift" into 3rd gear from a stop... Drive until your car shifts up into 3rd doing appx. 40mph... Now floor it, it will down shift to first and accelerate hard... If it doesn't and seems like it accelerates slowly, you have some freak of nature...

The dyno graph above was actually started in third gear, upon flooring the go pedal for the dyno run, the car down shifted to first, and then shifted to 2nd, then 3rd gear and run until it finally hit the speed limiter @ ~118 IIRC, I never even hit max rpm at the end of the run. I even tried to SLOWLY roll onto the throttle to keep it from downshifting into first, but it will still do it.

911medic · 02-03-2014, 07:20 PM

Quote:

Originally Posted by KILLA BEE

as stated prior I have one of the first LFX engines built purchased it in 2011. I dont get it I can start off in 1,2,3,4,5 dont matter. Know shift denied lights no probs whatsoever. Even if its not a TRUE TAPSHIFT. It downshifts hard.every gear..pulls each gear .IT

DOES THE JOB BIGTIIIIMMEEEEEE...

As long as you are happy, that's all that matters - - TapShift or not.

911medic · 02-03-2014, 07:22 PM

Quote:

Originally Posted by RacnJsn95

Thought I would add this as it seems to get questioned a lot... This is a typical dyno graph you will get from a 2LS:

While yes, you certainly CAN dyno to the, HOWEVER, as you can see, because you can't keep the car in one gear the engine run, you have to deal with it shifting, which makes for a rather pointless/hard to read dyno graph if you're trying to compare products back to back etc, etc.

Good info as usual, Jason. I'll reference it in the 1st post when I'm not on my phone. Edit: And...done.

Jason@JacFab · 02-03-2014, 08:27 PM

Quote:

Originally Posted by 911medic

Good info as usual, Jason. I'll reference it in the 1st post when I'm not on my phone.

The word "engine" should be entire... Sometimes I just get to typing way too fast...

Quote:

Originally Posted by 911medic

As long as you are happy, that's all that matters - - TapShift or not.

That's right

911medic · 02-03-2014, 08:45 PM

Quote:

Originally Posted by RacnJsn95

The word "engine" should be entire... Sometimes I just get to typing way too fast...

LOL...didn't even notice that on the first read-through (or "you certainly CAN dyno to the"

).

Jason@JacFab · 02-03-2014, 08:55 PM

Quote:

Originally Posted by 911medic

LOL...didn't even notice that on the first read-through (or "you certainly CAN dyno to the"

).

fixed that just now...

KILLA BEE · 02-04-2014, 01:33 PM

Quote:

Originally Posted by RacnJsn95

Try this... "shift" into 3rd gear from a stop... Drive until your car shifts up into 3rd doing appx. 40mph... Now floor it, it will down shift to first and accelerate hard... If it doesn't and seems like it accelerates slowly, you have some freak of nature...

The dyno graph above was actually started in third gear, upon flooring the go pedal for the dyno run, the car down shifted to first, and then shifted to 2nd, then 3rd gear and run until it finally hit the speed limiter @ ~118 IIRC, I never even hit max rpm at the end of the run. I even tried to SLOWLY roll onto the throttle to keep it from downshifting into first, but it will still do it.

Ok I ma try exactly this after work....however.on the way to work I put it in 3rd from a stop and gunned it hard as hell well over 50 and still no downshift..but stay tuned I ma try what u said when I get off..all I can think because I got lfx early they might have let one slip by. Lmao we shall see.

Angrybird 12 · 02-04-2014, 02:15 PM

Quote:

Originally Posted by KILLA BEE

Ok I ma try exactly this after work....however.on the way to work I put it in 3rd from a stop and gunned it hard as hell well over 50 and still no downshift..but stay tuned I ma try what u said when I get off..all I can think because I got lfx early they might have let one slip by. Lmao we shall see.

If yours indicated it was in 3rd while you were stopped then yours is not the normal tap shift, you just selected the top gear it would shift to, it still started out in first. It would have been very sluggish if it had started out in 3rd.

KILLA BEE · 02-04-2014, 05:07 PM

Quote:

Originally Posted by Angrybird 12

If yours indicated it was in 3rd while you were stopped then yours is not the normal tap shift, you just selected the top gear it would shift to, it still started out in first. It would have been very sluggish if it had started out in 3rd.

Well normally yes. BUT I know how my car sounds in first. it wasnt first I can only hit 30 ,35 before i have to shif in 2nd. ......it stayed in third from stop and was still pulling hard as hell at 50 with eaeseeee..im just saying mine must not be the norm