You definitely have some bad juju happening there at about 3600 rpm which looks to be hurting peak torque. The tune sounds pretty half assed based on your description of how the car acts. Hopefully your new tuner can get it sorted out.

 

Hey All - just wanted to pass along an update and pose another question (or two). Picked up the car yesterday and talked to the shop for quite a while. He ended up getting an additonal 20rwhp and almost 60 TQ on the dyno, replaced both 02s. Car definitely seems to be running smoother but plan to take it out a few times this week. Not knowing what exactly to think about the trans shifting/issues I went ahead and bit the bullet on a built 4L60E he had pulled from a previous fbody (supposedly making 800hp on spray). They swapped over my stall (3600 FTI) so retained that.

After driving the car though, it still has the similar issue with regards to not downshifting into first and just overall strange feel to (wish I could explain it better). Both guys I was talking to at the shop were pretty frank in that they thought the stall was WAY too big for the car and it was essentially fighting the cam now, more or less, which was causing the strange driveability. With the built trans, he suggested manually shifting (which I've read lots of mixed opinions on) to get the most performance out of the car. The car will scream through 1st doing this but I hate that it won't downshift on a 10-20 mph role in "D". He's got a smaller stall that he has offered up and seemed to think would be a much better fit for my setup but I'm OBVIOUSLY super cautious of anything right now. He did comment that the stall was super loose and he had to force lockup on the dyno pull (which maybe explains the BIG TQ gains).

Just can't wrap my head around why the car drove absolutely fine the last yr+ with the stall and why the H/C/I install would effect that. All the research I did on the stall last year pointed me to the 3600 FTI and then seemed like the Tv2 cam would be a food fit. Wish I understood the mechanics behind it better but get completely lost in the tuning side of things. I def feels like the car revs to the stall point but just gets stuck waiting for for gear to catch up and won't downshift.

Also, I believe the TC is locking in 3rd gear...that's something that should be tuned out, correct?

Thanks everyone for all the help so far!

 

the set up I had with my Corvette was H/C/I/E/N2O 538 and 460 tq and I only had a 3200 stall and drove beautifully on the streets. So much so that when I got rid of it it had 130K miles. You're stall is way too bjg for your set up.
Oh and I had Toyos r888 when the first came out. Great on the road and good enough to cut 1.68 60ft @18lbs at the track.

 

Ok...so touched base with FTI for any trouble shooting advice and they were quick to follow-up. I passed along some of their info to my tuner, one being that my TC is single disc so NOT meant for lockup at WOT. Once I shared that with him he was pretty adimate that this was my problem based on what he experienced on the dyno and how the car won't downshift. He wasn't involved when I did the stall last year and assumed it was triple disc... probably my fault for not specifying with him and maybe the original tuner (but also who put the stall in). Sure doesn't sound like a triple disc is necessary in my case but I'm wondering if this may have caused my issues after the added power came in?? Is there potential the clutch is toast and causing my shifting issues?? Everything was totally fine prior to the H/C/I.


He suggested getting this stall out asap and replacing with a triple disc that was a little more street oriented.

 

Who ever this guy is he has no clue what he is saying. My cam specs where 235/241 615/615 112. A much healthier cam then your off the shelve cam. I had a single disk tc. You need to find someone who knows their **** and this guy doesn't. Triple disk tc are mainly for track use. When I told my tuner I was going to use one he said to go ahead and waste my money but I wouldn't need it.

 

Which jives with all my initial research on the stall last year and what FTI is saying...😕. And I suppose just more evidence of my luck with tuners.

Ok, so let's say the tuner who installed the TC did NOT tune out WOT lockup and the clutch did burn up with the added power, would that potentially cause my symptoms??

Again, car essentially will NOT downshift at any rolling speed (its done it maybe 3-4 x's in the dozen or so times I've driven since the install) and occasionally at higher speeds as well. Sometimes will hesitate then downshift from 3-2 if you punch it. Normal acceleration just feels off as well.

At this point, regardless of single vs triple disc, I'm just left with pulling the TC and sending back to FTI for evaluation (6-8wk turnaround). Unless this is still a potential trans tuning issue?? I could really care less about the extra $300-400 for a triple disc at this point!!

Thanks again everyone for sharing in my misery!

 

Jroth,

Sounds like a tuner issue mostly likely to me.

Is LPE near you? If Lingenfelter will tune it and is close that might be a good solution.

I've had Norris MotorSports in Plainfield, Indiana tune three cars for me. Two heads & cam strokers plus a bolt on car. Mike does very good quality work. While it maybe a drive from the north eastern part of the state, I think it will be worth it.

I've driven a friend's untuned 00 B4C LS1 Camaro with 3.73's & 3600 Yank SS stall and it actually drove pretty well other than random TC lock/unlock around 35 to 40 mph. That was definitely a tune issue.

FWIW - While some folks like bigger cams, that one is about 4 degrees more than my personal preference for a stock cube LS1 in a driver or daily driver. The 98 LS1 PCM is a bit less flexible and than the newer 99+ LS1 PCM's. That can make getting the tune properly sorted out a little more challenging for some tuners.

Best wishes getting car sorted.

 

If this guy burnt up your TC it will definitely affect your transmission and understand that he won't take any responsibility of he did you wrong.

Take a deep breath, accept your car will be down for a bit. Send your TC to get refurbished send your transmission to RPM and have THEM upgrade it to a stage 5 which I had and had no issues. Like stated above go to a reputable shop to get a tune and have it done right. If your transmission for some reason goes out RPM will reburbish usually for 500 dollars. That was back in my day but I'm sure thigs have gotten more expensive.

listen to the guys in here. Many of us have had shitty outcomes with tuners and shops over the years and speak from experience.

good luck
Edited the stage it's been a minute. Old chemo foggy brain 😂

 

As mentioned above, RPM Transmission is an excellent vendor in my experience too. Have an RPM Magnum in one car and if I need a 4L60e for my 02 Z28, it will be an RPM one. Plus they are here in Indiana

 

Haha...great advice on the "deep breath"!!

Thanks again everyone. Was really leaning towards pulling the stall and having it checked out at this point so may continue down that path. I just envisioning either, FTI saying it looks fine, or putting a refresh in and then having the same problems! I think additonal research for tuners is in order so appreciate the reccomendations there as well! I suppose I may be able to dial in the stall a little better for street driveabilty now since I know what my exact setup is. Silver lining, right?!!

 

Probably the MOST important thing that anyone else reading this needs to take away from your experience.... Dyno Monkeys will try and lock the T/C on a dyno pull to get you a higher #... They don't care if it smokes your trans. They don't care if it smokes your T/C.. They are paid to get you the highest # possible and even if the car can't drive off their dyno when they are done-in their eyes it's not their problem because they were paid to get you a #.

Make certain that BEFORE you run the car on a dyno again, or even any full throttle runs at the track or on the street, that you have the tune looked over. If you can post a copy of your tune, there are many qualified people here that can look it over and point out things that need changing so that you don't find yourself in this position again. If you can't post a copy, or don't know how to.. Let us know what city and state you are in and I'm sure someone close to you has HP Tuners that can pull a copy of the tune from the car and post it up for you. Do you know if these shops are using a wide band to tune your car? One would hope that they are, but you never really know especially when you pick it up after a tune and dyno session and the car is belching black smoke... How does that even happen? What shop would turn a car back over to a customer with it belching black smoke? I can't fathom how some shops can be so negligent (I'm avoiding using the word I really want to use) in their work? They had to have known that the tune was not right if they drove it on the street after the dyno session. Sorry to hear about your experiences so far. Please post an update after you get it sorted and let us know what it finally took to get it 100%.

 

It is very hard to find a good tuner that will take the time to get the tune right. They'll take your money make a few basic changes to get it to run, then make a few dyno pulls and call it good. Then your car won't hardly start when you pick it up and dies when you stop before pulling out onto the street. This is the way most tuners that I have found operates.

 

😂😂😂
New vocabulary word

with that said you're 100 spot on.

 

id start with checking the simple things first before you dive into pulling that converter out. Your stall is not too big BTW.

you should check to make sure your fluid is still red and not burnt and that the converter is locking up like it should.

if thats okay, i would check to make sure your TPS sensor is reading 100% at WOT and that the throttle body cable clip isnt broken or damaged, that may make the TPS sensor read wrong causing your transmission not to kick down at WOT.

just some simple things to check.

 

Quick update this morning...

Went and checked out the TB cable/clip and everything seemed fine. Also matted the gas pedal to check the range of the cable (did not pull the LID and look at the actual blade in the TB tho). Took it for a quick spin and my ScanGauge was showing 99 at WOT for TPS so thinking it's probably ok?? Actually don't have a volt meter at the moment to check the TPS voltage but will get that checked this week as well.

One other note, manually shifting from 1-2 seems to always get a slip at the top end right before shifting. If memory serves, I think it was doing this with the stock trans as well before we swaped to the built 4l60e. Same TC in both cases though. Wondering if this could be more evidence that the TC is slipping?? Got it to downshift into 1st at a roll once or twice in D but, in general, wouldn't budge.

 

Scan readings aside, I would do a visual on the TB to ascertain the blade is opening all the way.

 

The only thing in a torque converter that will slip will be the converter clutch and that should only be applied when cruising around with low to mid throttle input, At full throttle the converter clutch should not be applied. Other than the converter clutch if the converter is bad if will be bad in all gears all of the time, (even reverse).

To check your TPS you need a scan tool or voltmeter and slowly open the throttle looking at the scan tool or voltmeter. There should be a smooth even progression from low voltage to high with no jumping around or spots with no voltage.

I'm sure this has been said or something you already know, the trans won't change gears unless it is commanded to by the PCM/TCM.

 

No tangible updates on the car but actually talked to another local tuner last night (recommended by my wife's co-worker) who was an ABSOLUTE breath of fresh air on the phone!! Turns out he had a bad experience with my original tuner years ago which is what led him down the path of starting up himself! He's a GM/LS guy to the core and echoed basically everything that has been posted in replies thus far. Stall will absolutely work and is not way too big and the car should essentially have stock mannerisms once he's done with it...or there is something wrong mmechanically. Taking the car in tomorrow and he invited me to stay for the entire process as he pulls the tune and goes through it as a starting point.

Finally have a good feeling that we'll get to the bottom of this one way or the other! Trying not to think about how much $ I've wasted up to this point...🥴

 

Have to think of it as R&D money well spent 😀

Researching and Determining if random tuners are competent to do tuning.

Please update with the follow up.

Best wishes.

 

I too have wasted a lot of $ on bad tuners and like the guy who you have been talking, I am learning to tune my own cars. My car ran like crap after two different tuners and $1200 later. I felt that I couldn't do much worse doing it myself. So I took a course form the Tuning School and my car runs a lot better now. If one is to keep playing around with these cars invest in yourself and learn how to tune.