Jump to content

Recommended Posts

Posted

I have a 2015 sierra z71 5.3L

It has a k&n intake and Borla dual exhaust and a dyno tune done today. 

I ended up with 365hp/385tq. 

 

I'm looking into long tune headers next, does anyone have a recommendation on which one to go with for the best gains. 

Also anything else I can do to it reliably?

Also. I recently had a torque converter fail that trashed the transmission. Warrantee covered the transmission but is there a better torque converter I can put in that will hold the extra power a little better and help keep this from happening again?

 

 

20210530_124547.jpg

Posted

Talk to Circle D about your converter. They have an improved lock up clutch model is a tad more stall that does not require a tune. 

  • Like 2
Posted (edited)

try a double clutch converter , i like the stock 1900 stall, or even cheaper is the zl1 or boosted caddy converters 2200 stall, $350.

tune out the convrertor lock up until 4-6th gear if its 6 speed. zero out all the clutch slip parameters in the transmission, reduce torque management by 10% , disable v4 mode, delete trans thermostat, and remove the airbox restricton panel between the fender and box, install lt5 tb and 6.2 manifold.. activate Power enrichment at 60% throttle.

 

i think the factory manifolds are fine, just make  a custom exhaust minus the cats and flapper valve,

 

also the T1 truck has upgraded front rotors and calipers

 

Edited by pokismoki
  • Like 1
Posted

Certain dyno's are known to read higher too. All depends on how the shop has the thing setup and what correction factor they are using.

 

Numbers seem high to me but whatever.

  • Like 1
Posted

Maybe the op doesn't know he has a 6.2? Because those numbers are factory tune 6.2 whp territory, with a j607 correction factor. Which is also not the correction that gm uses to rate their engines. If it was the engine would likely be rated 40-50 hp higher.

 

My understanding is that its not the converter, its the tuning. Its designed and programmed to constantly slip in order to accommodate afm activation/deactivation.

 

I have a 6.2 with headers. I just took off my air intake and went back to the stock one. Its awesome! If I could do it again I'd scrap the headers and save up for a blower. Sounding quick isn't the same as being quick.. 

 

 

  • Like 1
Posted
1 hour ago, M1ck3y said:

Maybe the op doesn't know he has a 6.2? Because those numbers are factory tune 6.2 whp territory, with a j607 correction factor. Which is also not the correction that gm uses to rate their engines. If it was the engine would likely be rated 40-50 hp higher.

 

My understanding is that its not the converter, its the tuning. Its designed and programmed to constantly slip in order to accommodate afm activation/deactivation.

 

I have a 6.2 with headers. I just took off my air intake and went back to the stock one. Its awesome! If I could do it again I'd scrap the headers and save up for a blower. Sounding quick isn't the same as being quick.. 

 

 

 

Nope, it's the JBMX converter. Give this a read:

 

https://www.sonnax.com/tech_resources/845-6l80-6l90-transmission-tech-advisory-consider-an-updated-converter-in-your-next-rebuild

 

Point of fact. All converters do this now. Ever see a 6L80E torque converter behind the 4.3 grenade? Neither has anyone else and yet it has the same 20% slip programed in. Just isn't the same JBMX single plate lock up. 4.3 uses a Captive Clutch. 

 

  • Like 2
Posted
8 hours ago, Grumpy Bear said:

 

Nope, it's the JBMX converter. Give this a read:

 

https://www.sonnax.com/tech_resources/845-6l80-6l90-transmission-tech-advisory-consider-an-updated-converter-in-your-next-rebuild

 

Point of fact. All converters do this now. Ever see a 6L80E torque converter behind the 4.3 grenade? Neither has anyone else and yet it has the same 20% slip programed in. Just isn't the same JBMX single plate lock up. 4.3 uses a Captive Clutch. 

 

Thanks Grumpy, I haven't seen that one before. I'd feel a bit more confident about the situation if they listed the 8l90 specifically. That being said, I have no idea how or if the 8l90 tc differs from the 6pd one.

 

I can't find the article... But from what I've read, GM started applying controlled slippage to their tc in the early 2000's? Over time, this pulse width modulation went from short duration, limited scenario slippage to happening 100 percent of the time, thousands of times per minute. A constant rapid fire locking and unlocking of the torque converter, all done in the name of fuel efficiency. And from the way it was explained in this article, it becomes a matter of when not if it will fail in the vehicles lifespan. Obviously depending on the design..

 

Tuning does and will extend the life of the converter substantially. However that doesn't mean there isn't other design issues that will present itself.

Posted
57 minutes ago, M1ck3y said:

Thanks Grumpy, I haven't seen that one before. I'd feel a bit more confident about the situation if they listed the 8l90 specifically. That being said, I have no idea how or if the 8l90 tc differs from the 6pd one.

 

I can't find the article... But from what I've read, GM started applying controlled slippage to their tc in the early 2000's? Over time, this pulse width modulation went from short duration, limited scenario slippage to happening 100 percent of the time, thousands of times per minute. A constant rapid fire locking and unlocking of the torque converter, all done in the name of fuel efficiency. And from the way it was explained in this article, it becomes a matter of when not if it will fail in the vehicles lifespan. Obviously depending on the design..

 

Tuning does and will extend the life of the converter substantially. However that doesn't mean there isn't other design issues that will present itself.

 

Your welcome. You could find out by identifying the converter in the 8L90. JBMX is the offender. My 2009 Buick LaCrosse has a 4T65E that uses the same slip method as my 6L80E. That converter is solid. Yes a tune, the right tune, can and will extend the box/converter life. But as they say...it's a Band-Aid on a GSW. It's just a weak front cover and apply piston. 

 

I know some guys reduce or eliminate the converter slip but it is there for a reason. Harshness reduction. That also helps trans life of the internals. Shock reduction. In older boxes such as the Ford C4 (going back a way) a gear change release a band and applied a clutch and for a second they were both applied...not fully but in a controlled slip, one coming on the other off. A shift kit put a total pause between those two events. Bump on every change. Longer the pause, harder the bump. New boxes are clutch to clutch, right? If the converter remains totally locked then its like changing gears in a manual without use of the clutch. It can be done. It can be done under power nearly seamlessly. But better things can happen to a transmission that constant power shifts. Yea....I'm rambling.

 

Now all that said I have no idea if the HD version or the HP version of the JBMX falls under that issue. I think it is just the purple tag but it would be worth asking. These guys would know.

 

https://floridatorqueconverters.com/Torque-Converter-77-4543.html

 

It does not look as if the 8L90 uses the JBMX. Good news! 

 

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts
  • Member Statistics

    342,759
    Total Members
    8,960
    Most Online
    DM22
    Newest Member
    DM22
    Joined
  • Who's Online   7 Members, 0 Anonymous, 1,646 Guests (See full list)

  • Latest Articles

  • Posts

    • As a matter of amusement I’ll leave this conversation with this. Do you beat the government average fuel estimate? Statistics are a guide to me. Not a rule. Someone once said I have to have the last word. If true and possible may be. I’ll blame that on working in a family business.
    • That is a fair point, and I agree that trying to log “everything in the truck” would be the wrong direction.   There are a lot of modules and a lot of traffic. If the product became a full-truck datalogger, the amount of data would get huge very quickly, and most owners would never use it.   I think the first useful version would need to be narrow: - powertrain-side event evidence - selected high-value parameters - communication / voltage / reset events - pre/post event window - short report first, raw log only as backup   One distinction I should make is between active OBD/PID polling and passive bus capture. If you are polling PIDs through OBD, then yes: the more parameters you request, the lower the effective sample rate becomes, and you are adding diagnostic traffic to a vehicle that is already busy running itself. With passive CAN capture, the recorder is not asking all the modules for data. It is listening to traffic that is already on the bus. So it does not consume vehicle bus bandwidth in the same way that a scan tool polling hundreds of PIDs would. But your point still applies in a different way.   Even if passive capture does not add bus traffic, the recorder still has limits: - processing rate - storage rate - timestamp accuracy - decoder workload - event filtering - report size - user attention span   So the answer cannot be “log everything and let the user figure it out.” The product would need to store enough raw evidence to be useful, but only decode, graph, and present the important parts around the event.   A practical report should probably show: - what triggered the capture - how much pre/post data was preserved - which selected parameters changed - how those values compared to baseline - whether the same pattern happened before - whether any voltage, reset, bus-off, lost-message, or communication fault occurred - selected graphs around the event - raw data only as supporting evidence   So I agree with you. More data is not automatically better. The real product is the reduction from raw data into a useful event report.
    • That makes sense, and I agree with most of that.   I think the product would need both: 1. a default powertrain template, so it is useful out of the box; 2. user-selected priority parameters, so the owner or shop can choose what they want to see first.   Different users are going to care about different things. One owner may care about oil pressure and voltage. Another may care about misfire trend, AFM/DFM behavior, or U-codes. A shop may want communication events and repeatability first. Your baseline point is probably the most important one. Raw data is not very useful unless the report can show what normal looked like for that vehicle under similar conditions.   The way I would think about it is: - start with a basic known-good baseline - learn normal behavior for that specific vehicle over time - allow the event to be overlaid against baseline - show whether the event was a one-time spike or a repeatable pattern - provide a simple severity level, but with clear limits on what that severity means   For example, early severity could be something like: - Info: event captured, no obvious abnormal pattern - Watch: value moved outside baseline, but not repeated - Warning: repeatable abnormal pattern under similar conditions - Critical: communication loss, voltage drop, bus-off, reset, or severe repeated event   I would not want the first version to say “replace this part.” That would be overclaiming unless there is repair-confirmed data behind it. It would be more honest to say “this pattern deserves inspection.”   On the OBD port question, I think OBD absolutely has a role. OBD is probably the right place for: - DTCs - freeze frame - VIN - calibration information - normal scan-tool parameters - Mode 6 / enhanced diagnostic data if available The reason I am still looking at an ECM-side recorder is that the failure may happen before anyone connects a scan tool. If the owner plugs in a scanner after the event, the pre-event evidence may already be gone unless the ECU happened to save it. So I do not see this as “OBD versus ECM-side.” I see it more like: - ECM-side recorder: always armed, rolling buffer, event evidence - OBD/DLC companion: DTCs, freeze frame, VIN, calibration, normal scan data - phone/cloud: status, notes, upload, report generation, notifications   I agree that phone connection and push notifications would be useful. I just would not want the phone or cloud connection to be required for capture. The recorder should save the event locally even if the phone is not connected. The phone should help with event marking, download, notes, upload, alerts, and report viewing.   For a default GM V8 event report, would this list make sense? - RPM - calculated load / MAP - throttle position - vehicle speed - gear / torque converter state if available - coolant temperature - oil pressure - oil temperature if available - battery voltage - commanded AFM/DFM state if available - actual AFM/DFM state if available - misfire counters / roughness by cylinder if available - fuel trims - relevant U-codes / communication events - bus-off / lost periodic message / module reset / voltage drop events Which of those would you remove, and what would you add?
    • I went to the county a few years back to dispute my property taxes. To do that I hired an appraiser and a lawyer. The County Assessor wished to argue that the homes in my neighborhood the appraiser used were all 'distressed properties" and not representative of the "Market Average".    My response was," Of the 50 homes in our subdivision 43 of them were "distressed properties" under bank foreclosure and as such "Distressed IS the market". Lawyer about choked on his coffee and handed the Assessor the 'receipts'.    I won that case on the evidence provided by the Lawyer and the Appraiser.    We have the same thing going on here. My statements were based on the GOVERNMENTS NATIONAL DATA and yours on local markets in areas of your interest. They are both correct....   Thing is, this divergence was based on NATIONAL and not on LOCAL. I think you even understand that. But like you said, we are both stubborn and hardheaded.    I do not see any advantage to disengagement.  But that said we can step back to compose ourselves. 
    • Trust me I appreciate the comments and concerns. It's what I was looking for to help me evaluate the situation and what I want to do. I have decided to move forward with the BORA hubcentric slip on 3/8" (.375") with the extended lugs nuts. Fedex says they should be here Monday :). Meanwhile, the dealer got the remote start and Patriot spray in bed liner done over the last couple of days. Also, I installed an inline stop/start eliminator today. Starts back up in what whatever mode you shut it off in, so you don't have to hit the button every time you fire up.
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...