Fresh dyno (today) but looking for more.

[TurboSmokeOG]

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?

 

 

[Grumpy Bear]

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. 

[James Dink]

world record dyno numbers you got yourself a factory freak my friend

[pokismoki]

1 hour ago, James ****** said:

world record dyno numbers you got yourself a factory freak my friend

not really , e85 on factory tune will yield this

[pokismoki]

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 June 13, 2021 by pokismoki

[CamGTP]

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.

[M1ck3y]

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.. 

 

 

[Grumpy Bear]

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. 

 

[pokismoki]

should the 5.3 trucks be using the v6 converter then?

[M1ck3y]

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.

[Grumpy Bear]

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! 

 

[Grumpy Bear]

8 hours ago, pokismoki said:

should the 5.3 trucks be using the v6 converter then?

 

I wouldn't thing so. There is a fair amount of difference between the two. Mounting bolt circle diameter to start with.  

 

Here is a HD street converter that might work: 

 

https://www.floridatorqueconverters.com/stage1-street-converters.html

[pokismoki]

entering my data this pops up, i hope this has the upgraded parts  in it

 

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

[Grumpy Bear]

51 minutes ago, pokismoki said:

entering my data this pops up, i hope this has the upgraded parts  in it

 

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

 

Ask them. 

OR

Click on the high performance tab. 

This is a much stronger converter with factory stall

1800-2000